One More Volvo Prop Query..

[Magicallbill]

Len;Matt,MOP;Mr.Grizz;

Any and all old Volvo guys;

My mechanic has both Jason's and my Sporters together..
Time to prop test..
As per your all's instructions I told him about the Solas line..
He looked into them, finding out that they, nor anyone else that he could find makes Stainless Props for the 250's..
Apparently, the 250 Volvo's require a "Short Hub" prop that is not available..
He can get Stainless props for 270/280/290 Volvos in a longer hub configuration,but not for the 250's,as they need the short hub,which is not available in stainless.
He is gonna get an aluminum 23" from Michigan Wheel to try out.(The 19"wheel Jerry Eisele had on there let the thing rev to 6 Grand on the inital test, so we need a 23 to slow the spin down,as Lenny said we would.)

Are we missing something? Can you get a Stainless 23"Wheel in a short-hub package? What do you guys think about the performance of the aluminum wheel as opposed to the stainless?
This boats been under construction for 2 years now..We are sooo close, and I'd like to get both of them dialed in and home.
MB

[mrfixxall]

mb you can use a long hub prop on a short shaft volvo....you need to get a short spacer and a extended prop nut..

[whalerman]

I'm Bill's mechanic working on his old 16, It has an volvo 250 with out a drilled prop shaft. Only short hubs fit as I need to use the tab washer and cone to hold on. If there is one that will work please let know. Randy

[BillG]

Why not drill the shaft and use a long hub prop? I did it on my 250 and so have many others on the forum. You can do it right on the drive.

BillG

[penbroke]

Get one of these. I just pulled the photo from a current ebay ad.

Drill and tap the end of the prop shaft (5/16-18 as I recall). You can use the hole in the cone as a guide and drill it in place. It is not hard or complicated. I did my 200 with a cordless drill.

Use the upper left piece in the photo and the bolt to retain the prop. Throw the rest in the tool box. The rest of the pieces allow you to use a short hub prop as well.

Check clearance between the prop and exhaust outlet/trim fin before running. You may have to alter the spacer between the prop and the gear housing depending on the prop.

Go play.


Frank

[Tony]

I drilled my shaft as well, it is not difficult and results in a more secure prop as well as offering more prop options. One thing, though, have several thrust washers made up of differing thicknesses. This is the washer that goes on first, keeping the prop from rubbing the zinc ring. Be sure you have enough clearance, one time I had clearance at the dock but while underway the prop apparently pushed closer to the zinc ring under load and scored the screw heads holding the zinc in place. This resulted in an exciting "at the dock" repair at AOTH 2!

For what it's worth, I found that a basic 14 x 23 aluminum worked best for a combination of low and mid range thrust, with decent top end. My boat has an AQ200 and about 300 hp coming from a worked 302.


:beer:

[BigGrizzly]

I have thoes props in stock and used them on my 1966 16. Pembroke is correct. Since I am the one who got Solas to make the props in the first place and my Corsican was the first boat they were used on i feel I have the heads up on this product. The long hub refers to the prop nut not the shaft. The nut countersinks into the prop hence Long hub. Dont get the Michican aluminum prop it is a poor prop. With Jerry's you turn 6000 the 21 and 23 has so little slip that the 23 will bring you down to about 1000rpms. example My Corsican with a 351 Ford cleavland and CMI hedders pulls 4800 with the 23 Solas prop. I also have 23 Hill prop which pulls 5500 rpms. same boat and same day. The hole in the shaft is easy. the shaft isn't hardened on the end. any deasent tech can drill and tap it with a 5/16 and use a allen bolt in stainless avalable at Lows and Home Depo. I have done this about 15 times. The bolt is safer than the tabs. Becausr the hub and bolt have different threads it would have a difficult time backing off. Of corse if you don't tighten it well, we can fix anything but stupid. The solas prop uses all the stock shaft bushings from the 200 threw the 290 drives. The only issue is the trim tab on the lower unit. the big fat exhaust one has to go and the small 1968 up one without exhaust must be used. BTW do not modify the volvo spacer. if you do the prop may hit the zink around the outdrive between the prop and gearcase. I did neglect to say that prop is a big diameter prop 25+inches. I can bring both a 21 and a 23 to cumberland I have a right and left 23 to let people try

[Lenny]

I can attest to ALL of Grizz's numbers.
I had mny shaft taken out and drilled and tapped in a lathe just because I am ANAL. :rolleyes:

The prop I did spin saw 5400 at best, and it was a 24" Ultra. Grizz's 21 SOLAS took my same motor RPM's on the same day to 4400. At best !!!

The slip is all buy imeasurable on the SOLAS. The ULTRA is 19%.

Prop down 4-5" if you ask me as compared to high slip Ultras.

Lovely prop. :yes:

[Moody Blu']

definately drill and tap the shaft, it is easy to do might want to use loctite on the bolt just to be safe though.

I have a right hand 26p volvo ultra long hub and i have a 24 1/2" left hand short hub that has a brand new heavy duty hub that i see 4800 rpm's with after being reworked, i use to hit 5100 with the same prop but it was repitched balanced and cupped a bit its much faster then before and handles the water amazing.there practicaly no slip on this prop either

i never tried the ultra yet it needs to be cleaned up a bit

both of them are for sale if your interested.

[Magicallbill]

Thanks all, for the replies..
I have called "Whalerman"(my tech) and alerted him to check the thread here to get your answers.
I've posted this before, but the specs on the engine are as follows;

347 CID Ford(Formerly a 302)
At 5000RPM/383.5 FT/LBS of Torque.
365HP
At 5900RPM/353.9 FT/LBS of Torque.
397HP
These numbers are off the spec printout that I got when the engine was tested. Whalerman said that when he tested the boat with Jerry's 19 on there it wouldn't stay in the water and the tach was bouncing off 6 Grand..Hence our prop search.
Moody, thanks for the info on your props..We'll get with you if we decide we'd like to buy one..

MB

[whalerman]

What is the part number for the smaller trim tab. My books only show the thru exhaust style #VP0854061. Randy

[Lenny]

Magicall Bill. Sounds "to me" like you need a 23" SOLAS from Grizz and it should spin in the right RPM with those Ponies. Get the small torque tab or remove it altogether. It will be toooooo close otherwise. These are BIG props.

[Magicallbill]

Thanks Len;
Whalerman had already figured on a 23' also..Hopefully we can drill/equip the drive to handle the stainless wheels so we have lots more options
Anyone know the part number for the smaller trim tab that he asked about above?

MB.

[Forrest]

All good advice on this thread . . . and the Grizz has spoken.

You're set now.

[penbroke]

Anyone know the part number for the smaller trim tab that he asked about above?
MB.

I never found one so I made my own. (http://www.donzi.net/forums/showthread.php?t=2356)


Frank

[MOP]

Nice to dig up a good thread! Frank since you have time to play did you end up setting it at an angle or leaving it straigt?

MOP

[penbroke]

For normal everyday running around I use the center trim pin hole and have the tab pretty much straight. The boat steers easily anywhere up to about 45 MPH. Above that it pulls a bit but is not hard to handle. If I trim the drive up to the top hole or somewhere in between I have to play with the tab to get neutral steering. The range of speed where the steering is neutral is much narrower for any tab setting with the drive trimmed higher and it doesn't take much adjustment to make a big difference. It's easy enough to do as I can reach it from inside the boat standing beside the engine. I don't think I have had the tab more than 10* from straight ahead at any speed/trim combination to get neutral steering.


Frank
I wish that whole power trim thing had worked out...

[Magicallbill]

Thanks all;
Appreciate the replys;
The shaft has been drilled&tapped;We can now fit the stainless props we need on the boat to "play the field" so-to-speak,and test several.
Whalerman will make an aluminum fin,or tab, to replace the one that had to come off to get the props on..The torque adjustment won't be critical,as we have hydraulic steering on both the boats.(Thanks,Pembroke.)
Mr. Grizz, thank you too, and I'll flag you if we need a prop.
Sure wish I could help you all like you help me...

Trouble is, I don't know anything....

Unless you need to know about drums..I'm OK with them.....

MB

[Magicallbill]

The Latest...

WhalermanRandy ran the boat after drilling&tapping the propshaft,enabling him to outfit it with a 24 Stainless(Not sure of the brand.)
Result? He called me saying "why did you put this big of a motor in a 16ft. boat?"
Following it up with "It still hit 6 Grand with a 24'wheel." He said it's in the 70MPH range,and if you do the math, it probably is.
Jason's 350 MAG 300HP 18 ran 67-68 with his Alpha at 5000.
My Scorpion 377 runs low 70's with a 25'Mirage on a BravoXZ..
So..my 347CID putting out 397HP at 6000 is probably right in there.
Question;
Can an AQ200,Eaton Interceptor,250 Volvo, or whatever it is take short bursts to 6000 safely?
If not, what is the highest revs that it should go to without pressing the "Blowing apart envelope?"
Randy says I'll be scared to death anyway, and it won't be an issue..He's always right about boating issues, but I'd like to know anyway,in case I want to return briefly to my teenage years.(I own one of the fastest production 18's (my Scorpion) so I've been in that register before.
To summerize, I don't want to slow the thing down if I don't have to..

MB

[Moody Blu']

5-5500 rpm's 6k is pushing it

[penbroke]

I was told 5k max. but have been beyond for short bursts...


Frank

[Magicallbill]

Thanks Moody&Penbroke..
Talked to Whalerman today; he's gonna put a computer-chip-rev-limiter on the thing to stop it at 5000,for the longevity of, well, everything,including me, probably.
He says the 24 wheel is perfect,and doesn't want to put a bigger one on, as the drive would have trouble with it. Since the torque/HP is so great on the engine that the 24 won't slow it down, the limiter is the answer, I guess.
Part of(most of) me wants to turn the thing up to full smack,but the boats been under construction for two years;I guess it would be stupid to blow the Volvo up and put it down for half the summer.

MB

[Lenny]

Bill, I don;t think you could spin one of Grizz's 23-25 SOLAS anywheres near 6K. Those props of his (SOLAS) are your rev limiter. Bolt on a 23 and see what happens :D

[Moody Blu']

ea honestly, i would say prop it till it wont tap out higher then 5500 rpm's, then chip the over rev for 6000

no need to look for a 1.3 ratio just go up in pitch

[whalerman]

This is Bill's mechanic, the motor pulls the 24 to 6,000 if you give it the gas to fast it will slip the cone in the drive so I don't want more prop. I want to put an 5,000 chip to save the drive, the boat is well over the hull speed.

[Moody Blu']

Moody the hole point would be if he has the HP there why try to find a 27 or 28 pitch stainless volvo prop???? the 1.3 will give him a wider selection in props
Lenny has the right idea the solas props are massive and with probably perform the best on Bill's setup


well, i figured switchin to a 1.3 is much more time consuming then just swappin a prop:boat:

[mrfixxall]

I would go for the gear ratio,,,if you keep throwing bigger wheels on it,,,, it will over heat the drive and cause other problems...

[penbroke]

I would go for the gear ratio,,,if you keep throwing bigger wheels on it,,,, it will over heat the drive and cause other problems...

I agree with using the taller gears if ya got the ponies to pull 'em cause the props just aren't there. But, how is spinning the internals of the drive FASTER (lower reduction) going to cause the drive to run cooler??

I suspect the Solas props (with their better slip numbers) on the current drive are the right answer.


Frank

[Lenny]

I agree with using the taller gears if ya got the ponies to pull 'em cause the props just aren't there. But, how is spinning the internals of the drive FASTER (lower reduction) going to cause the drive to run cooler??
I suspect the Solas props (with their better slip numbers) on the current drive are the right answer.
Frank

Like me spinning a 24" Ultra to 5400 TRUE RPMS and then bolting on one of Grizzs' 21" SOLAS props and spinning 4400 RPMS in the same afternoon, and swapping back to the 24" Ultra and again, back to 5400... Basically 17-19% slip compared to about 2-4%. :eek:

I like to think of the ULTRA as a centrifugal clutch :D

It does sound meaner mind you ;)

[Magicallbill]

Thanks soo much for all the replies..
Boat has to stay in Michigan for another couple weeks waiting for the engine hatch to be painted..
In that time, is it possible to get a 23 Grizz-Solas prop?
How do I go about it?
If it isn't what we need, can it be returned for a refund?
Where is he located? Is it possible to meet, maybe somewhere&try one out?
Lenny, if he isn't reading this, maybe you know how to touch base with him.
I wouldn't mind talking about it..

MB

[Lenny]

Bill, I will email you his number. A 23 would probably slow your motor down a TON. If not, a 25 would. They bite sooo hard, you NEED Ponies to spin 'em. NOTHING like an ULTRA, not even close. Email a coming. :)

[Lenny]

Spent a half hour on the phone with Grizz.

He is waiting for your call Bill.

:) He has a 23" a waiting.

[BigGrizzly]

Bill and Walerman, My 18 has a modified HHolman & moody 351 Ford Clevland engine with GMI sport tube hedders. I to can wing a 24 ultra at the high 5000 rpms on the Volvo drive I turn a 23 Hill at better than 5600. I chased doe the Solas people and put a thread on this site we got over 40 replies. I convinced The CEO of Solas Propd Doctor Solas Ling that there were props to sold to old Volvo drive people. First They made a one off for my boat. ( they like me because I work for American Honda and we buy many props a year from them and I use to test for them). Anyway two years ago they flew two engineers out and we tested and designed the props around my Corsican and the clasic rocker hull which is on all 16 and 18 donzis. These props work on the Magnums too. I started my own company to sell these props and Turbo props. Untill this time the only prop you could buy in stainless was a Hill or an Ultra(which is no longer in production). The Hill use to cost $600+. Both the Hill and ultra are old prop technology and doesn't work with big power. Funny now we have the props and it has been posted many times no one calls for a prop. The only sizes available are 19, 21 or 23. Michican wheel props are alunimun and I have to have them pitched to 25+ and overrev with them. BTW if you have the V8 Volvo 1,63:1 you cannot regear that drive with any success so that is not an option. Whalerman, you asked why do we put such big power in little boats? The answer is simple WE CAN!! With money you can do anything. I have a 300+ hp 1966 16 a 1971 Corsican with a 351 Ford CLeavland(not Winsor) WITH WELL OVER 300 hp AND A Criterion with 690 HP with Dyno sheets to back it up. Why you ask-- because I want to do it. One other minor detail These props handle better than any other props I have tried, and I have tried every prop made for a Volvo drive. That is the whole story there isn't any more to tell.

[Magicallbill]

Lenny&Grizz;
Got your E-Mail Len..Appreciate your time and effort..Thank you, and have a great trip to Powell..Tell us about it..
Mr Grizz..Will call you in the next couple days..I am not mechanically versed,therefore I am having this work done, but I will tell you as much as I know about the rig..I'm certainly interested in the '23..Thanks for your input..Looking foreward to the chat..

MB

[Magicallbill]

Lenny;
Just had a good talk with Grizz..
Looks like this '23 is my baby. I'm putting Whalerman(my tech)and him together on the phone Tues eve. I am an inefficent middleman,and mechanical info should not run thru me,as I could spout the wrong thing to the wrong party.
Apparently it has to be determined that the 23' Solas can fit behind the aluminum fin-plate,or something.
If that can be orchestrated, the last chapter will have been written,and I'll let you all know the results and throw in some shots as well.
Your help is greatly appreciated..Let's meet at a gathering sometime,and I'll buy you a beer and a couple tanks of gas..

Magicallbill....

[Lenny]

Let's meet at a gathering sometime,and I'll buy you a beer and a couple tanks of gas..
Magicallbill....

...forgo the GAS, substitute BEER :D

Hope it works for you. :) I am SURE it will.

Get rid of the torque tab if it is in the way. I jettisoned mine. These are HUGE props. One look at one and you will see the blade surface area is very large. Run her in the second, and then the third, hole on the drive. You will probably prefer the third. :D

[Moody Blu']

id like to see a picture of a solas so i can compare it to my prop. i believe griz told me on the phone once that they are similar to the elephant ear props but made more efficient. correct me if im wrong.

I know my prop sure grips the water alot more then the other props i have used and theres practically no slip. I sure would like to try one on mine so maybe some day ill be at a meet and hope griz is there so i can try em out. but for right now, i have to install my new kevko 9 quart 4 gate with a windage tray oil pan and change my tank :cool:

http://i35.photobucket.com/albums/d194/beerock69/me%20pics/boat/DSCF0116.jpg

[boldts]

Your help is greatly appreciated..Let's meet at a gathering sometime,and I'll buy you a beer and a couple tanks of gas..
Magicallbill....

Bill, sounds like a great reason to start holding 2 gatherings at Lake Cumberland a year. The Awakening of the Horses and then around August or September, The Retiring of the Horses. Been tossing the idea around. Maybe it's time to expand the Midwest Donzi Club a bit. I'll just want to check other club gathering dates before deciding any dates. Glad to read the boats are almost finished. I know I like others would love to see some pictures.

[Magicallbill]

Thank you Scott:
I've always maintained that the late-summer-fall period is Cumberland's finest.
Your spring fling is so big, though,that if it doesn't catch on for the fall, I totally understand.
In any case,we'll make a bunch of pics,and when I meet Jerry at Brookville or wherever,you are invited if you can get away to take a spin

MB

[Patrik Sweden]

Here in Sweden you can by a kind of converter for Volvo Drives, then it is posible to buy and run Mecruiser Props..

Edit: www.propellertrim.se // 350 USD + shipping.

[EricG]

Here in Sweden you can by a kind of converter for Volvo Drives, then it is posible to buy and run Mecruiser Props..

Edit: www.propellertrim.se // 350 USD + shipping.

Patrik,

I was just thinking about this yesterday...instead of fighting to find props for the volvo's, why not make the volvo work with the props that are already out there....can you tell us more about this product? Have you tried it on your boat? I'm looking through the site - but it doesn't mean much to me :eek!: :biggrin:

EG

[Patrik Sweden]

Patrik,
I was just thinking about this yesterday...instead of fighting to find props for the volvo's, why not make the volvo work with the props that are already out there....can you tell us more about this product? Have you tried it on your boat? I'm looking through the site - but it doesn't mean much to me :eek!: :biggrin:
EG

:biggrin: so you don't read Swedish..

I only had a DuoProp on my old Bertram, since then I always had Mercruiser, don't trust Swedish stuff:p ;) But I have friends who tried it, and it works very well!

I will give Propellertrim a call tomorrow and ask them for picture/manuals.. I will post everything here hopfully tomorrow!

[BigGrizzly]

The old Volvo prop shaft os a bigger spline then the merc. People have even installed modified Volvo hubs in other props. We have been over this before.They had even made a prop shaft to fit the merc but it didn't work well. We designed this prop for world wide sales. In your case you spend 350 for the converter than another 400 for the prop which may or may not work well with the hydrodynamics of the lower unit. These lower units like big diameter props. My props are 15.25 diameter and designed for the drive. Your Idea is good but has already been done with less than good results. Very few props are this big. Hydromotive, powertech, and several others have Refused to work with us because low volume. I did this for all of us. It took over 2 years to do with out any help. I origionally got 40 plus responces. When the props finally arived I got 4 takers only. This was probably a waist of my time. I already had my props. I have been trying since late 1970 to have something besides the Ultra available. There are old Magnums and Novas that have changed drives because of the prop issue. Our own Forrest is one of them. The props came after his swap. This prop thing has been kicked around the board since 1999 that I know of. Now we have props and your trying to reinvent the wheel.

[EricG]

Grizzly,

I absolutely value your opinions, and very much respect and appreciate what you have managed to do with the Solas props...but I believe the lack of sales is due to the information (or lack thereof) that is availible on this board. The general consensus is that the Solas props are increadibly efficient, but require LOTS of HP to spin.

For folks like you, David, and now Bill, that outgrew the Ultra's, it's a no brainer. But my guess is there are a lot more folks like me on the board that have a more modest amount of HP that haven't contacted you to buy a prop because any information they have seen says they they can't spin it.

I want my boat to go faster - and I believe we all do, but as I don't have the resources to build a motor, I'm forced to look for things that might give a small performance increase, such as a prop. On my 18, I currently spin a 24 LH ultra on a 280 to 56 @ 5200, which is around 22% slip, any info I have seen says I'll lose somewhere around 1k with a 21 solas - which even at around 4% slip would only give me 50. So if I can inneficiently spin my Ultra at 56 (22% slip), vs spinning a 21 Solas at around 50, I don't think it's the option for me, which is why I've never called you to order one. If you have any testing results from the 19, or different data, please share it.

I have a very controlled testing environment availible to me, and I'd love to try one or two of your props vs the ultra and post the honest results for all to see on a "stock" powered 18 if you'd be willing to let me do it. I'd be happy to pay the shipping, and I would be willing to put up the $$$ against any damage, with the understanding that if I wasn't happy with them I could return them. I would be more than happy to post all of the data I collected for all to see. I believe the reason you haven't had more takers is that we have yet to see any speed numbers from those of us that don't have heavily modified boats.

Once again, I value your opinions very much, and if I've gotten any of my assumptions wrong, please correct me and I'll be happy to help spread the word and get some of your props sold.

EG

[Patrik Sweden]

I just spoked to Propellertrim here in Sthlm, and the converter is still under production, but they will finish it within 2 weeks.

The price I mention, is for their costumers who also buy a prop from them, as a service they get the converter for production cost. If you only buy the converter it will cost $610... :eek!: I will post more info as soon as I get it!

It will work on: 280-290 and SX

[EricG]

I just spoked to Propellertrim here in Sthlm, and the converter is still under production, but they will finish it within 2 weeks.

The price I mention, is for their costumers who also buy a prop from them, as a service they get the converter for production cost. If you only buy the converter it will cost $610... :eek!: I will post more info as soon as I get it!

It will work on: 280-290 and SX

WOW...I guess if something seems too good to be true...it probably is:rolleyes:

[Magicallbill]

Grizz;
Got your Private message;sent you one back..
In case you go here 1st..Whalerman had a Doc's appt. last nite&got in late..
He told me today he'd call you tonite..
Thanks for checkin' in..

MB

[BigGrizzly]

Erric I have a faiirly warm Corsican that had various 23 inch props. Ionlyrun the 23 for a high speed cruise. The 21 turns aabout 53 but at 67mph. Did you think of a 19 inch pitch? Less slip can usually net bigger gains and handling. The more a prop slipps the more ineffirnt it is. you have a big lower unit with water intake holes right in the noise so a bigger diameter prop runs in clean water which is one reason for the bite. The otheris blade design. The ultra is over 30 years old in design My boat is nothing special. It has a Ford Cleavland which weighs almost as much as a 460 block at over 700lbs.The corsican is also heavier than a normal classic. One reason for no sale is the short long hub discussion. the other is everyone is waiting foe someone else to buy it first. To bad because I think that another design probably won't happen. I stuck my neck and it may be chopped off. The reason my boats go well is because I try new stuff not just because of the motor. a prop is what makes Criterion what it is not just the motor. I propped another almost 10mph into the boat. The Corsican could go about 56->58 with stock volvo props. new props get me to mis 60's.
lets address the adapter. First it is a resplined Merc square drive so now we can run a Marage plus or a Bravo neither work well on that drive. we did this about 5->8 years ago with not good results. dianeter is too small for the lower unit. I will take my stock to a Donzi event like i have done before.

[Lenny]

Eric, if you can spin the 19, (which is what I SHOULD have with my stock-ish motor, you will see 57.5 with no slip measured in at 5200. You should be able to spin it to 5200. Slip is in the 2% area. So, suffice to say, you will bite harder, handle better and have similar MPH numbers. To spin the SOLAS to the same RPM numbers you are seeing with the Ultra, and given the same pitch, (mind you one is odd, the other even) you will need about another 100 ponies. With that said, you will be going FAAAARRRR faster spinning these wheels at 2% slip and similar RPMS.

I am just waiting for the extra 100 ponies part. :D right after I make it so Deneen can steer it.

[Kirbyvv]

Grizz,
Sent you an e-mail. Interested in a prop.

[Magicallbill]

Lenny;
Just getting ready to mail a check to Grizz for a 23 Solas,as per yours and his recommandation.
Will keep you posted on the results..Both he and Randy(my tech) says we put too much engine in the rig, but..I want to relive my "golden years" one more time..
Since you hooked me up with Grizz,you should get a commission, or something.

But that's between you two.......

Magicallbill.

[BigGrizzly]

Lenny and his lovely lady better better get there butts down to an event where I will be at. We still have some unfinished driving lessons in the Criterion that he needs to attend. BTW I still have the picture. Erric, David O did the tests with his stock 350 about 240 HP but his gear ratios were of the lower variety. so he bough both a 21 and a 23 so when he builds a bigger motor and gets the right gear set he is ready to go. as for you testing props -- show up at an event that I am at like David did and with test equipment we can get it done. I travel in my boats with at least 2 GPS on board and sometimes more. I then take the slowest speed as a refference. If you cant do it most ofl the time then you didn't go that fast. You told us everthing except the most important things. How much power do you have what speed do you go now at what RPMs. Remember in 1966 the smallest V8 in a 16 was a 185HP 260CID interseptor that went 46->48 mph with a 14 3/8X21 Volvo prop. Now the average top speed of these boats is mid 50 with top speeds in the 70+ mph range. I can tell you this that this speed increase came with alot of expermentation and money, but in every case the prop made the final speeds possible.

[Moody Blu']

randy, any chance you can post a pic of the props? or email me ? beerock69@gmail.com

[BigGrizzly]

I will try. I am 90% shure I will be up in NJ with my visiting my brother. If I do I will being some props to play with. so get the boat fixed. There is nothing to it but to do it!

[Lenny]

Thanks Matty. Pretty much says it all.

My 21" SOLAS on left, my 24" ULTRA on right. :eek:

As you can see, their is no comparison in the two wheels. A 23" SOLAS will definately slow down Bill's RPM numbers :D

http://www.donzi.net/forums/attachment.php?attachmentid=12480&d=1118894452

[BigGrizzly]

Matty that can only be a 15 1/2X 23 We Solas dosent make anything bigger and won't unless there is a big need. As you know it has less slip than anu prop I have ever used. therefor it is more like a 25 or 27. I must have missed the last part of th at old post. I don't use any plastic thinggy(washer between hub and prop).I didn't do anything to my trim fin. I use only the recomended spacer and bolted it on stock completely. the 280/290(same foot) has a short and long edg long twards the stern. After Lenny had his mishaps I looked at mine and double checked everthing I had no clearence problem. I than looked at the 270 and no problem there either.
Matty if I go up to N.J. I think it would be great to compare notes. BtW my best speed was with the 21 prop of 67 mph at about 5300/5400rpms and 60with the 24 ultra at 5800rpns and I didn't like the handling. I also used the 24 ultra 4 blade that Poodle has, the prop Volvo says they never made. I wasn't any better. They do make a 17, 19, 21, and a 23 in left and right. I asked them to do this for ths for the Magnums and other Twin applications. . Should have called me. I would have told you that a 23 prop was too much for your power. One little correction to Lenney's statment It should read it will deffinatly lower the Rpms! not slow them down. I will look like after the $ of July befor I get up there. a lot happening here. I am retiring from Honda and will concentrate on my propeller business, both sales and testing on sport and high Horse Power boats.

[Magicallbill]

Len;
Thanks for the look at a Solas.
Obviously a different animal than the ultra.
Grizz and Randy seem to think it'll stablize the boat at high speed with the extra blade area going on.
They both seem to be a little worried about the boat being unsafe due to the extra power&torque of my engine.
I own and operate one of the fastest production 18's out there in my Scorpion. While certainly no expert as some of the guys are on here, I'm sure, I have handled that boat in the low 70's on a regular basis, and have figured out how to steer thru the instability of the hull in that high speed register.
The way I see it, there will be less weight aft in my 16,due to the aluminum characteristics of the engine,single battery, etc. My Scorp is stern-heavy(Bravo Drive, dual batts, 377 engine, etc.)
The math I'm doing in my head says that the 16 will handle better than the 18 due to balance and less stern weight..
Is the 16 going to be squirrly at high speed,just 'cause it's smaller&shorter?
My 18's already a handful..Will the 16 be worse? It doesn't seem like it to me..

[Magicallbill]

Thank you Matty;
The only time I've ever run an old 16;well, ANY 16 was the short test run we made with the rig in question when we first test-drove it. That lasted all of five minutes as it overheated quickly,and we went back to the dock to pull out.
The 23 Grizz-Solas is being shipped according to Grizz,and Randy(my tech) should have it in a day or two.
Obviously, I have more questions than answers with all of this,and am excited that after two years, it's within reach.
At 25 years old, I would've put me, the Solas,and the Donzi in Davy Jones Locker, but at 51(almost 52) I'll start gradually and work up,being careful.
When we first bought the boat, Jerry Eisele's old 302 was in there(that was the engine that overheated.)
Pics and results coming..

MB

[Moody Blu']

randy, i will try to get the boat finished before you come to nj. If there is a big improvement over my reworked hwlae prop then id definately buy one. I am really impressed with my bronze prop though.

matty, maybe you can haul that 16 of yours down to LBI and we can have a small donzi meet and FINALLY all go to dutchmans!!!!!!

[Magicallbill]

RESULTS IN.....
Grizz'z Solas 23' was tested by Randy today..
Slowed the rig down to 5500 at WOT..
Randy say's it handles better than the 24' he had on there in the upper register.(4500-5000.)
His MPH comment was..."Well, it didn't slow it down any!"
So, if it was over 70 at 6 grand,which Randy was sure it was,I'm guessing mid-60's at 5000 to 5500.
Lenny, you were correct about the 23 Solas..
No rev limiter needed.
Boat comes home next week.
Jerry Eisele,watch for pics to be posted when we get it back.
Grizz,please call me, or message me to let me know you got the check,OK?

[Moody Blu']

70 in your 16... though you have the power to get there is in my mind unlikely due to your drive setup and your lack of ability to trim and your propeller selection limitations... as well as the deep drive.... 5100ish rpm, 1.65 ratio requires a 25P prop to see 70...


rootsy do you remember bzmarine?
he has a 18 with a volvo 250 408 stroker windsor and a 29 or 30p prop and said he was pushing gps 80 mph at 3/4 throttle 5krpm but he said he couldnt hold on to the steering wheel and had to back off

[Moody Blu']

are we talking 16's here or 18's???? somebody shifted gears on me when i wasn't looking??

there talking about 16's i shifted gears and said something about an 18, but it was because of what rootsy said about the drive not being capable to attain high speed without an e drive. bzmarines drive has a nose cone thats it.


matty you never responded, will you get your ass down to lbi for dutchmans if grizzly makes plans to test props? im hoping randy agrees to meet down in lbi cuz im sure hed like to stop at good ole dutchmans....

[Lenny]

Magicall Bill, ... :D

Get a GPS and get some third hole numbers at WOT... :)

[Magicallbill]

Rootsy;
I needed your input..
I heed what you say and will be EXTREMELY careful with the boat. I wasn't aware that with the same "V" 2 feet would cause that much more instability.
When Randy(my tech) said he was past 70, remember that was with the drive turning a crazy 6000 with the engine pushing 400HP. I don't know what propshaft HP would be, or how much HP is lost thru the Volvo drive.
Lenny, I have a bud with a GPS and we'll get positive numbers instead of guessing, which we probably shouldn't be doing anyway.

MB

[Lenny]

keep stickin up for your lil white artifact...

...nicely,... nicely,... play nice Jamie :) I got me one of those too. ;)

[BigGrizzly]

I think 80 in a 16 is insane, but so is 80 in a 18 for that matter regardless of the drive. Yes Geoo's was different, take the T-fin off than drive it! Any way as for capableity. With enough Hp you can push a brick at 100 mph. as for hydrodynamics go that volvo is better than the Bravo drive. There is more to that Solas than the blade size, I known because I was there remember. When a prop is designed around the drive this is what happens, providing the designer knowes what is going on. these props were designed in a test tank used for testing hulls torpedos etc. not some guy on the back of a truck with a hammer. As for handling the days of the old clever prop are long gone in the outdrive market. Look at the SST racing outboards The old clrvers have been modified and don't look the same anymore. Bill I am glad it worked for you and I was sure it would. The 16 works really good up to aboutt 58 then you need be on it all the time. As for speed and prop size Jamie, whell it all depends on slip. Beleive me I didn't think the 21 on my boat was going to net 67 mph at 5500-5600 rpms either with that ratio drive either but it did more than once. I also didn't expect the 23 to cruise at 50 at 3500rpms either, but it does. the slip on these props on this out drive is well under that of any prop I have tried on Volvos or any other lower unit for that matter.

[Moody Blu']

jamie i agree with ya the 16's are def the most limited in terms of speed/stability, ill always stick up for the volvo drive, being that they were made long before the "bravo" and just as strong it says something about em.

matty, supposedly bz marine had shaved his lower unit a bit he ruined one lower unit just to see how much he could get away with, so it was not as large as a regular volvo 250. Hopefully if all goes well i should have the new tank or bladder in by mid july maybe sooner, i have physical therapy 3 times a week so getting down the shore is a bit tricky.

[Magicallbill]

We are gonna keep Grizz'z 23 on there..As he said, it's the best choice. With the rig spinning about 5000 or maybe a little over we figure mid-60's or so. With what Rootsy says about the squirrliness of the 16 and the chance of the drive blasting apart at 5500-to-6000,70 is probably optimistic, at best and dangerous at worst.
I am gonna go get it early next week. When I get it home, pics-a-comin'.

Thank you all for the help.

Magic.

[BigGrizzly]

Jami its good to have discussions with you. after meeting you and giving you a not as fast as I wanted to give you, both of us have a good respect for each others opinion. As for the SS Merc really quit as you said because of big dollars and the stock power was getting larger and Imco came out wither drive which is much more slippery thab the SS. With their own racing drives and the Outboard racing lowers Corperate didn't want to fix it. Also at this Corperate politics is still rapped up in the outboard stuff and the IO takes backseat. This comes from some engineers I know at Merc. They spent well over 100,000,000 dollars ( i did not put too many 0's onit) on the Varado. AS for doing a new drive, you would do better with the Imco. Its faster stronger and you can counter rotate it easier, just reverse the shifting. As for handling my persomal experience was with a 24 Python not a Donzi. It was done same day with only one hour down time between runs. The other thing the stainless marine race boat had ajustable X dimention while underway. They would lock it down for the race. If I had another 22 I would think about a shortie, However the Criterion will stay as close to stock as possible. I now go as fast as I want to go now. You have been in it and the torque and acceration is great. There are limitations to boats and drivers, and that boat and is just where I want it. Besides my wife drives it and likes it just where it is, easy to handle and faster than the average bear.

[Lenny]

We are gonna keep Grizz'z 23 on there..As he said, it's the best choice. With the rig spinning about 5000 or maybe a little over we figure mid-60's or so. With what Rootsy says about the squirrliness of the 16 and the chance of the drive blasting apart at 5500-to-6000,70 is probably optimistic, at best and dangerous at worst.
I am gonna go get it early next week. When I get it home, pics-a-comin'.
Thank you all for the help.
Magic.

Bill, can you post REAL GPS numbers with this prop please. At WOT. And, if you are feeling generous, change it back to the Ultra or whatever, and post those RPMs and WOT GPS speed please?

The SOLAS, as I have found in the 21" , has 2% slip. I know that is a nutzo equation, but yes, 2%. So, if you are seeing 5500 RPMS Bill (truly) you will see 74.4 GPS with NO slip, and about 72-ish with 2% slip.

I am VERY curious.

What a GREAT THREAD :)

I will also bet $20, payable to the Registry, that your 24" prop, spinning 6000+ rpms was actually getting you about 68-69 and a lot of revolutions and 18% slip.

You in Bill ? The result goes to the Registry either way. :)

[Magicallbill]

Len;
I'd be happy to..
Consider me in,if you don't mind waiting while'st I scare up a GPS(I do not own one)
I am picking the boat up next week, as I've said, if nothing else goes wrong. I'll try to get a GPS thru Randy(my tech)or borrow/buy one.
I would like to perform the tests up in Michigan with Randy, as he is keeping the 24 to put on Jason's(my sons')red 66'. That way,both props are handy.
I need to do this anyway with the prop-swapping we've been doing,and with this engine/Solas 23 combo,it'd be a shame not to know how fast it is.
I keep thinking about what Rootsy said about the hi-speed handling quirks of the 16..
If your math is correct, my stomach'll be doin' the Macarena..
I will keep you updated..

Magicallbill

[TXDONZI]

Whats the latest notes on these props.?

[Lenny]

Whats the latest notes on these props.?


They WORK, they have all but NO slip (2-5%) and they BITE HARD, very...

Bill was VERY pleased with his and will not go back to the Ultra...

Ultra's run about 18-20% slip, like a centrifugal clutch so to speak. These do NOT. They cost my motor about 1000 rpm's over my 24" ULTRA when I went DOWN in pitch to 21" and the SOLAS. If you have about 250-300 ponies in an 18 you will want the 19". 300-350 the 21, 350-400+ the 23"

They are GREAT !!!

[BigGrizzly]

Pretty good sumation Lenny add trim and they are the best there is. They really handle the rough stuff well. Bill put one on Jasons boat too. My wife and I were out in the Corsican yesterday. With the powerassist Teleflex steering and the prop my wife was thrilled. She dissapeared for an hour and came back to say we are keeping this boat too!! Then somthing about a bass boat oh well! Ask Scott Bolts how he likes the boat and steering.

[TXDONZI]

I have a 21' Kona Daycruiser with a AQ290A/280PT 1.61:1 elephant eared outdrive. When the motor threw a rod I built a 383 10.5:1 compression, World Products Sportsman II heads, Scat crank, 375hp/350 factory spec. cam, edelbrock Performer RPM,750 Holley vac./sec. Running an (Ultra 14x24LH)??? Volvo Penta PN 853791-2 long hub prop. I get 52mph on a pitto speedo @5200rpm. I have the gorilla torque steer like everyone else. I bought a (Ultra 14x24RH)??? Volvo Penta PN 853790-4 long hub prop. to see if it would help but have not tried it since I am rebuilding the motor and interior at this time.

My question is will the Solas 15x23LH work in my situation. From what you say I will see 4200rpm and it will act like a 25 or 26 inch prop. What will it do to my speed? Will it have the bow lift like the Ultra? Will I pick up speed?

I was going to have Ron Hill build me a 4 or 5 blade 25 or 26 inch prop. to gain more holeshot and increase speed. From what I read here it sounds like a waste of time and money.

Are the Volvo Penta 853791-2 LH and 853790-4 RH a match pair of LH and RH props. per say?

Thanks, Tt

[Lenny]

I have a 21' Kona Daycruiser with a AQ290A/280PT 1.61:1 elephant eared outdrive. When the motor threw a rod I built a 383 10.5:1 compression, World Products Sportsman II heads, Scat crank, 375hp/350 factory spec. cam, edelbrock Performer RPM,750 Holley vac./sec. Running an (Ultra 14x24LH)??? Volvo Penta PN 853791-2 long hub prop. I get 52mph on a pitto speedo @5200rpm. I have the gorilla torque steer like everyone else. I bought a (Ultra 14x24RH)??? Volvo Penta PN 853790-4 long hub prop. to see if it would help but have not tried it since I am rebuilding the motor and interior at this time.
My question is will the Solas 15x23LH work in my situation. From what you say I will see 4200rpm and it will act like a 25 or 26 inch prop. What will it do to my speed? Will it have the bow lift like the Ultra? Will I pick up speed?
I was going to have Ron Hill build me a 4 or 5 blade 25 or 26 inch prop. to gain more holeshot and increase speed. From what I read here it sounds like a waste of time and money.
Are the Volvo Penta 853791-2 LH and 853790-4 RH a match pair of LH and RH props. per say?
Thanks, Tt

If you can't see 5000-5400 then bail on this. You NEED more Ponies...ULTRA'S are like slipping clutches...15-20% slip, brutal props, but fun for instant RPMS.

You could NOT spin the SOLAS 23 to redline in ten thousand years...the 23" needs to see at LEAST 350 HP after the drive coefficient.

Build 400 HP, square the torque, tighten that up, then you will be fly'in....

[Magicallbill]

TXDONZI;

Numbers for me,for your quick reference..

347CID Ford Engine
397HP at 5950 RPM (Tested at Shop- Not on the Donzi.)

Radar-Gunned offically 62 MPH at 4800 RPM.

My concern for the longevity of the Volvo keeps me from flooring the thing, but comments from members here, Lenny, Big Grizz and most recently Randy(my tech) says that I might be being overly cautious,and maybe I can air it out a little more come spring.
Grizz says that doing the math would put me at 70-or-so at 5500 with this setup. It is capable of those RPM's with one person aboard.
I highly reccommend Grizz's props..It did everything he said it would..I'm gonna get a spare so Jason and I have one "on-the-shelf" in case we ding one of ours..They are the real deal, and so is Grizz.

MB...

[TXDONZI]

BigGrizzley I sent you a PM I would like more info. PM me back with a phone number please....

Tt

[kjly63]

They WORK, they have all but NO slip (2-5%) and they BITE HARD, very...
Bill was VERY pleased with his and will not go back to the Ultra...
Ultra's run about 18-20% slip, like a centrifugal clutch so to speak. These do NOT. They cost my motor about 1000 rpm's over my 24" ULTRA when I went DOWN in pitch to 21" and the SOLAS. If you have about 250-300 ponies in an 18 you will want the 19". 300-350 the 21, 350-400+ the 23"
They are GREAT !!!

Lenny,

Are you saying you went up 1000 rpm's when going from 24 Ultra to 21 Solas? I am running 320 HP ? with a 270 B drive and 24" LH Ultra @ 5400 RPM. I cannot push more rpms; what size would you think???

ken

[BigGrizzly]

No! When he put on the Solas his boat would only turn 4500 rpms instead of 5500 rpms. the Ultra is so ineffience it has approx 18 to 20% slip. the solas has approx 2% slip this is closer to the theory pitch of props.

[BigGrizzly]

TXdonzi, got your mail. will get back to you later but if you have questions that want real detail info call me tommorw night after 7:00pm EST. 706-216-8194

[boatnut]

This is an amazing thread (esp since we plan to rebuild our H&M 18 soon). I have run a lot of volvo drives over the years (esp in the 70's) and some with over 300hp sbc engines, twins in Magnums etc. We used to accept that we couldn't get over 58 to 60 mph or so out of a Volvo (250,270,280) due to the lower unit design and the prop basically blowing out of water (like a governor) at a speed close to 60 (regardless of hp). However we were running various props that were I believe all 19" diameter. It seems you guys are getting much more speed (70 - 80) if I scanned this thread accurately. Is this because of the larger diameter props that extend farther out past the hub assembly? Or were the lower units modified with nose cones? Or ? I have never seen a volvo (without a speedmaster lower unit) able to get much beyond 60. Thanks, Ed

[kjly63]

Looking back at a prior post of an Ultra next to the Solas..........seems the Solas has much bigger ears? My concern is bow steering I experienced with a big ear aluminum prop at above the 45 mph range. Has anyone experienced this while testing the Solas?

Ken

[BigGrizzly]

No, there is NOYany bow steer. I suppose you could get some if you put drive in the first hole. What I have seen is people confusing steering problems with loose cables and loose helmit bushings. The boat dives when throttle is pulled back. My hydralic steering has no such chariterists. Boat nut the old problem was the fact the old props were poor excuse for propellers, untill Ron Hill came on the sean. Now even they are outdated. I even pitched a prop to 27 inches and revamprd yhe pitch progresswion to go faster. it worked untill cavitation are the blade. I did put on a nosecone but no speed increase just a handling advantage at slow speeds. It doesn't wag as much. I was just Lucky that they listened. There is absolutly nothing wrong with the old Volvo drives except prop style availability. It is no worse than the Bravo just stronger

[boatnut]

[QUOTE= Boat nut the old problem was the fact the old props were poor excuse for propellers, untill Ron Hill came on the sean. Now even they are outdated. I even pitched a prop to 27 inches and revamprd yhe pitch progresswion to go faster. it worked untill cavitation are the blade. I did put on a nosecone but no speed increase just a handling advantage at slow speeds. It doesn't wag as much. I was just Lucky that they listened. There is absolutly nothing wrong with the old Volvo drives except prop style availability. It is no worse than the Bravo just stronger[/QUOTE]

Wow, that is great news Randy. Makes me want to get the 18 project going. What diameters are these new props? Are they still available as new props or do you have to find a used one? I am not sure what we will do with the motor yet, probably some variation of a 302/351 as we want to keep the H&M pkg as original as possible. Ed

[kjly63]

Randy, I think you hit the nail on the head. I am not sure how I feel about my existing steering and is why I would like to change to the hydraulic in line type you were talking about. Also, in addition to the bow steer; I also get it if I pull back too much on the throttle? When I check the helmet & cable..........there does seem to be a little play, but can't really tell where the play is.

Also, I do want one of these Solas props to try. Between me, Matty and my neighbor we have 3 Volvo boats to test on.

I have a 20 Cig with 270 Volvo/ 350 sbc-320 hp. I am pushing a 24 LH Ultra @ 5400 rpm. What do you recommend??????? 21"

Ken

[Magicallbill]

I definetly recommend hydraulic steering for any high-HP application.
When my 16 is in the high-speed register,the steering is perfect. The only problem is hanging onto the thing while it chine-walks.
We also noticed that after bolting on the 23' Solas,the 16 was more stable at hi-speed than with the 24 on there.

[kjly63]

You think I have enough ponies for the 23".............or is the 21 what I should replace the 24 Ultra with?

Ken

[BigGrizzly]

Sorry for comming in late but I have been a little busy lately and my wife left today on business. Any way. Holding onto the wheel is no problem with the Telifles Power Assist unit. I wish I had it 10 years ago. My wife is in love with the Corsican again. Yeppie I get to keep it longer again. She actually wanted to take it for a ride instead og the Criterion. Hell must have frosen over. Yes the props are available as new. Heck there only a year and a half old in design. As for if you can turn a 23 instead of a 24 ultra no. Unless your twisting that thing at 6000 rpms. Lenny's post is pretty close. TheDianeter is about 15 1/2 inches. The surface area on the Solas is aoput 30% more than the ultra. The efficiency id what makes it work so well. Boat engines are torque engines but the old props didn't cope with it because designers were not infrormed hydrodynamically like airplane people- another story. Right now I'm waiting for Ryan 23 to get back to me on his prop order ande ship my testers back. not not a problem yet because boating is over for most.BTW I may be headding to the dust off with some stock

[Kirbyvv]

Randy, great to hear you're going to make the Dust-Off. Will it be the critter or the Corsican? I'd love to try one of your props then. Should have the 280T installed by then. I already did a bunch of prop testing, but figured I'd wait till the trim is in before finalizing an order with you. Great thread.

[bmc69]

What a great thread..I'm a new guy on this forum and just read it from beginning to end. I'm not new to Donzis - I've had my '73 16 for about 16 years now. But, I recently completed a restoration of the boat over 5 years, and I too got 'silly' with the engine I put it in it. I didn't have it built for the boat; rather, I had it in a TT (stadium) racing Bronco and 'retired' from that so I simply stuck the engine in the Donzi since it was none the worse for wear after 5 seasons of racing..internals got a good check and it was like new.

But..I'm sure it was not the best choice of motors and I'm hoping to leverage off this thread a bit and get my own prop situation sorted out. I hope this does not qualify as a hijack..if so, tell me and I'll movoe it to a new thread pronto.

The motor: Mexican-block 302, solid lifter, with heavily modified '69 351W heads running 1.94/1.60 valves and a lot of porting and other work. 780 CFM Holley. The engine was dynoed when it was built and reached the following peak numbers:
405 ft-lbs @ 5500, 492 HP @ 7000. Stepping back to 'rational' numbers for the 270 Volvo drive and long-term motor survival., at 5500 its still at 424 HP and 405 ft-lbs. But..it's got no low end at all, as you would expect. At 3000 RPM, it is only putting out 156 HP and 273 ft-lbs of torque.

The boat handles like crap with the 'dunno what it is but I think its an old Michigan' stainless wheel that is on it. It runs too flat at speeds aproaching 60 mph, even with tabs all the way up and the drive on the second peg up, and is more than a handfull in terms of both stability and a very powerfull amount of torque steer. It is very slow out of the hole..a consequence of the motor being so gutless off idle. (it sure does sound good idling though:wink: ).

Anyway, since this forum is obviously populated with some real prop gurus that know my boat..and there are prop options I never knew existed, where do I start to find something that suits my setup better than what I have? I'll take some pics of the prop that I have on it now..but the thing has zero markings on it of any kind..:confused: I realize that one answer would simply be - first, put a motor in the boat that makes more sense for the boat its in. But its in there...

[BigGrizzly]

I'm not going to tell you to pull the dam motor. after all I have a 351 Ford Clevlend with the big ports and 2.19 intakes and my cam has 108 lobw centers. So on we go. the handling is part due to the prop. the other thing is see how much play in the lower unit if someone holds the wheel still if real loose check the helmit bushing then splinds in the yoke. My guess is the cable is the old cable screw from old teleflex. I first changed to a rack steering and helped alot. now I have an internal hydraulic teleflrx Seastar unit with power assist from Teleflrx, and it is great, as for torque that is the nature of the boat. the better the prop hooks up the more pronounced it becomes except for one minor detale. That is that the new props help over the sh** inducing instability that they call chine walking. The better the prop the worse the hole shot. Cruising at 3200->3500 is normal for me, and you have enough torque for that. As for the engine, I know you have plenty of experience and know your engine but let me make a small suggestion.Unless your messing with the origional cam and have done this advance the cam 3 deg and put on a 600 CFM carb this will give more low end besides at 5500 rpms that motor can't use 700 cfm let alone 780cfm. I guess you couls use a restrictor plate but the whole carb always worked better for me, If you don't to do this you can cruise at 4000 the volvo will take it. Anyway welcome to the board. We are here to help each other.

[bmc69]

Thanks very much for picking this up. I'm new here but have read through a ton of the threads to 'get up to speed' somewhat and that's how I came to the conclusion that there is some real technical know-how on this board that I wanted to tap in to

I need to throw in a couple more pieces of info to clarify where I am at, now that you've got some good suggestions going:

1. The 270 was rebuilt completely just before the 'last' motor blew up on me. This included new steering cable, new shift cable and new helm box and the steering is real tight all around.

2. The torque steer is one problem..and I guess its something I could(or will have to) live with. The chine walking and snaky steering behavior that kicks in just below 60 mph..that is another matter altogether and is so bad that I dare not push it farther. (I have had other go-fast small boats in the past whre I could and did 'hammer through' such instability barriers..but this thing scares even me at that point). I overpowered an old Chris Craft Special Sportsman some years ago and about killed myself and a pasenger when it violently swaped ends without warning due to the combination of excess power and too much prop lift. I know that is not remotely the same animal as the Donzi 16 with respect to hull and propulsion geometry..but it 'feels' the same and I'm a bit timid to push it and see if I can wipe out another boat.

3. The dyno numbers were with the 780 cfm Holley, as I indicated earlier. However, I neglected to mention that I have already gone and stuck a 650 Demon vac secondary carb on the motor. I can't say it really helped with take-off noticeably..at least not 'yet' with the prop I have on there now.

Of the props you were talking about earlier..do you have a feel for what flavor and size I should be looking at?

Bill

[Lenny]

You want mechanical secondaries I believe. Also, my little boat (x-18) was horrible, ABSOLUTELY HORRIBLE, to drive until I switched props. It was night and day. Not even the same boat anymore. The prop is what is causing you to scream I bet. Also, trim, (or trim hole) is the other. I am in hole three on my 280 and I wish there was a hole #4 :D. It is an absolute joy to run, and is all but impossible to stuff given a bit of throttle. Prop change time. Try Grizz's Solas, you will not be disappointed.

[kjly63]

:propeller that's it ............I nees a Solas. I have almost the same set-up as Lenny. A 21" I beleive:yes:

Griz, PM me with the cost. I know its winter for most of us, but when I find something I think will work on the old Volvo-------grab it:wink:

Ken

[Magicallbill]

BMC69;
Can't believe this thread would go this far when I started it.
When I first tested my 16, the torque was bad on it..Pulled real hard to Starboard, I think.
With the power we put in there,(see my last post for specs,) Randy(Not Grizz)my tech-guy said hydraulic steering was a necessity.
He was absolutely right. Boat steers PERFECTLY,no torque,and the boat was radar-gunned at 62MPH.(4800,or so.)
You have big power in yours..Get Hydraulic steering,and you'll get rid of the pull. That torque-pull is preventing you, or should I say "hindering" you from steering out of the chine-walking your getting.
When you put these rigs into the 60-plus register,you need all the factors on your side so you WON'T flip it.
Mine is rockin' from side-to-side a bit at 62, but it is driveable.
My tech Randy said that Grizz's 23 helped immensly with the handling of mine also, although I didn't personally ride in the boat when he 1st tested it with a 24-pitch.
In closing, it's easier for me to spend your money than you, I'll admit.
However, I consider hydraulic steering a necessary necessity. As does my mechanic Randy, and this is not his 1st time at the rodeo with boats.

[bmc69]

[QUOTE=Lenny;394728]You want mechanical secondaries I believe. Also, my little boat (x-18) was horrible, ABSOLUTELY HORRIBLE, to drive until I switched props. It was night and day. Not even the same boat anymore. The prop is what is causing you to scream I bet. QUOTE]

LOL. That's what I want to hear..I'm in the 'horrible' zone at the moment and want to experience the 'joy' that a well-chosen prop will make. :wink: To be perfectly frank, I didn't even know there were any decent perfromance prop options for the old 250/270-series drives untill I joinedthis forum and saw this thread...the local marina that does Volvo work had no clue about other than props for 'big' boats going slow.

I'm not a big fan of mech-secondary carbs over a properly set up vac-secondary model. Allthough, it is also true that I have not set up the Demon..its stock out of the box, just to get a feel for how it differed from the 780 Holley, which had been extensively worked wrt jets, power valve, vaccum actuator spring, and accel pump cam, pump volume upgrade and squirters to work well with the motor it was set up for.

I don't like the Demon (that's another whole subject) ..so another carb is in the boat's future as part of all this. What's the general concensus here as far as mech v vac seondary carbs on these litle boats? (Hate to change the subject from prop to carb..but I guess its all related at the end of the day...)

[BigGrizzly]

OK I have vacume secondaries and with that setup I would keep them. Sorry you don't like the Demond. It should be good. however I have a holley on mine and depending how lasy I am it is a 600cfm or a 750 cfm. I like the 600cfm better, but took it off to put on my 71 Mach I, got the car straightened out but am too lazy to swap it back. Do what you need, we will be here for you. The reasion the dealers don't know of the props is because they have blindfolds on when not selling brand new boats.
Beleive me or not I could not get any prop company to make me one except for Ron Hill. When I got that $650 dollar wonder in 1993, I said we are in deep do,do if this is the best. well I didn't quit I just kept at it and a door opened and I stuck my foot in it.

[Marlin275]

Randy,
I got a Volvo Ultra prop
14X26
short 2 5/8 spline LH
270 with a 161 ratio
350SBC 265hp
hydraulic steering
What prop would be best for me and what kind
of performance numbers could I get?
Getting about 53-58 mph, 42-4400RPMs now, depending on hole placement.
Thanks for your help.
http://www.donzi.net/forums/attachment.php?attachmentid=8060&d=1102007640

[Lenny]

Marlin, the Ultras, (yes I have two) are nice, but they slip like Hell. To the number of 18-19%. Grizz's SOLAS are in the range of 2-4% :eek: Expect to lose about 1000 RPMS when changing over. I could NOT spin the 21" pitch prop with my Chev 350 with some "stuff" in it. I went from 5400 with the 24" ULTRA to about 4400-4600 or so with the 21" SOLAS. With your rpms I would think you should look at the 19" pitch SOLAS. You will not be able to spin the 21 either with those low RPM numbers and an Ultra (which is like a centrifugal clutch in reality) :)

[bmc69]

I think I'm seeing the choice come down to either a 21" or 23" Solas for my setup. I'm going to go take a pic of the prop I have and make some more attempts to ascertain the pitch too..but I'm leaning toward the 21 Solas since I also pull a skier with it from time to time. The motor has rediculaous amounts of 'margin' as far as RPM limit goes. Slap me if I've got that totally wrong.

Correction: I USED to pull a skier with the old 315 HP motor and aluminum 19" Volvo prop..the current prop/motor setup is not getting it done in the take-off region, as I explained earlier, and no 'fun' to pull out skiers with.

Love the help..this sure beats heck out of scratching my head and/or total resignation to my fate.:)

[Marlin275]

Lenny, Randy,
What kind of performance would I get with the 19 SOLAS?
Faster top end? How much?
The boat handles great, no issues there.

[Lenny]

Calculate your slip at about 4% and see where that takes you with a 19"P. Like I said, I CAN NOT spin the 21" SOLAS to more than 4400RPMS, and I can spin the 24" ULTRA to 5400 all day long. :eek: If your 350 is relatively stock, you will not be able to spin the 21" SOLAS either. I know it seems wrong, but they bite, on the VOLVO, all but 100%. At 5000rpms and the 19" SOLAS, you would see about 54mph. More than 5000, you do the math :)

I'd be seeing about 63MPH with the slip factored in with my (now blown up) 350 IF I could spin the 21" SOLAS to 5400. I see about 58 with the ULTRA at 24" and the ton of slip. (inherent to these props)

Magicall Bill is a good example of the bite these things have and he has 400 FT LBS pushing his and went DOWN in prop pitch from his previous propeller.

[Marlin275]

Lenny - At 5000rpms and the 19" SOLAS, you would see about 54mph. More than 5000, you do the math :)
Lenny, I did all the math and it didn't seem like I would gain anything, may be 2 mph?
What am I missing?

Thanks for your help !
Happy Thanksgiving !

We got to be thankful we got these great boats!

[BigGrizzly]

Marlin, I don't think you want to turn less than 4800->5000 with that engine. I have a little mor power and almoat the same setup and a 23 will give me only 4800RPMs at best. and 62mph+. the 21 will give mw more top speed and more rpms. Point is when you lug the motor you loose power. I have enough torque to do almost both. I use the 23 just to raise my cruise and get better economy. I always carry the 21 in case I get rammy and want to pi** off some other guys with this old boat. I think the 21 may be what you want. Personally I am not aq fan of the ultra because of rhe slip. It is a copy of the old chopper prop. It works well in racing conditions where you need power comming out of turns especially on outboards where keeping the RPMS up are a high priority. One thing I can say this is going to be a fun spring with all the diversity amoung us and a great gathering of data for others. What we need are good GPS numbers and honest testing not just that one time super hid speed you can't ever duplicate again. I have been there but can't do it again, so I don't use them. I am looking foward to this and all the intrest finally.

[Magicallbill]

Grizz;
More news for you..This thread's really turned into something..

Anyway;Results for Jason's red 16 are in.Randy ran the thing day-before-yesterday in the bay at low-40-temps.

Specs..Similar to mine;347 Ford V-8
343HP at 5700 RPM
Water-tested at 4800-4900 WOT developing 318-320 HP. with the 23 Solas.
No speedo,or GPS..Randy estimates 60-or-so at top speed. My guess is that's accurate,as mine was Radar-Gunned at 62 at 4800 or so,same engine, sister boat,same prop.
All's well;another plus for you and the Solas;Randy says Jason's boat is the way it should be.
Stay in touch;Hope your holiday was good..

MB.....

[BigGrizzly]

Bill, thanks for the reply. I am pleased for Jason he really seems nice on the phone, hopefull we will meet soon. Tell Randy that his love for testing in 40 degree weather far exceeds mine. I wish him well he too is a real gentalman. He must be made of steel. Again your lucky to have found such a guy. He still puts his customers before the God almighty dollar.

[kjly63]

this post died.................you can tell winter is here for alot of us:boat: .

Big Griz, still looking for a 21" Solas for my setup. 350 chvy/270 volvo drive.

thanks,
Ken

[scibby]

I have a 1974 Donzi GT 21. Power is the original 350 cu. in. ChrisCraft rated @300 hp@5200 RPM with a Volvo 280 drive with full power trim. Lenny suggested going to a solas 19 in. stainless prop and that I should post this as there are other members with GT 21"s with small block power that may have some good input .Your help would be appreciated.

[BigGrizzly]

Lenny is correct. I don't think you can pull a 21 Solas. Ken I havn't forgotten just its cold and i figured you'ed call soon anyway

[Magicallbill]

Grizz;
Best to you as the holidays approach.
Give me a ring at some point..Need to chat with you about a couple things.

MB.

[BigGrizzly]

I sell them, and will get back to you soon