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Donzi Vol
12-31-2010, 05:45 PM
I'm running a 351 paired with a Volvo 270. As far as I can tell it's all original equipment. Either way, the motor runs strong, and the outdrive is solid. However, top speed is 48.5mph (gps) at 4800 rpm. It will rev to 5500 rpm, but no gain in speed. I'd like to see 60mph. Any thoughts with this outdrive? Not looking to make the switch to Merc power currently.

thescooter
12-31-2010, 07:46 PM
try different props, i think you will find part of your answer. nick the scooter

penbroke
12-31-2010, 08:58 PM
Props.

I've seen 56 gps with my 289 Ford / Volvo with an Ultra 24p.

I may have a 270 with a nose cone available in the spring but I don't know that the nose cone will help all that much at these speeds.


Frank

zelatore
12-31-2010, 09:20 PM
I'm running a 351 paired with a Volvo 270. As far as I can tell it's all original equipment. Either way, the motor runs strong, and the outdrive is solid. However, top speed is 48.5mph (gps) at 4800 rpm. It will rev to 5500 rpm, but no gain in speed. I'd like to see 60mph. Any thoughts with this outdrive? Not looking to make the switch to Merc power currently.

Now more than ever we miss Randy...

48 sounds very low for that combination. I would guess mid 50's anyway.

Are you saying you hit 48 at 4800 rpm and then continue to pick up rpm to 5500 but with no increase in speed? That sounds like a TON of slip.

I know jack-all about these Volvo drives - does this have power trim? If so, I'd start there guessing you needed to trim it out quite a bit from where you are. If it's a fixed drive, as I think it is, maybe try moving the trim to a higher hole (?).

And of course the question everybody will be asking is what prop you're running now. And while we're at it, what ratio. But I'll let the prop scientist ask those questions...:wink:

Hope you're New Year's celebrations are going well!

Just Say N20
01-01-2011, 01:08 AM
Vol, I ran my boat (16' 310 hp SBC, Volvo 290 w/power trim) with the big old aluminum prop. 5000 rpms = 47.8 GPS mph.

People who have seen this boat run by the previous owner swear it ran 62 GPS mph using a 19 pitch Grizz Solas prop. I have not run the boat since I bought the same prop 2 years ago, but even Grizz said it ran 62.

I would start with props.

jl1962
01-01-2011, 07:59 AM
People who have seen this boat run by the previous owner swear it ran 62 GPS mph using a 19 pitch Grizz Solas prop. I have not run the boat since I bought the same prop 2 years ago, but even Grizz said it ran 62.



Nah - mid 50's w/ a 19" Solas - maybe a little over 60 w/ a 21".

I think Maddad has the fastest Volvo set up in his 18. He has big power, good steering and a 23" Solas.

Happy 2011!

Donzi Vol
01-01-2011, 11:19 AM
Thanks for the replies, guys. Lots of good stuff to think about here.

Don, the first thing I thought when I started this thread was how much I miss Grizz right now. This was certaily his specialty. In fact I mentioned it briefly at our Chatt event back in August and he said something to the effect of "David, don't worry...we'll figure it out."

So the details are:
No power trim, unfortunately. I've thought about looking for a 280T, but would like to stay away from the investment if there's anyeasier way to get the speed. I do need to try it in the third hole, though. I keep forgetting to do move it up. It's in the middle hole now. I imagine that might give me a few more mph.

I don't know exactly what the prop is, as it came on the boat and I haven't switched it out. It's S/S and has 27 stamped on it. I'm assuming that's a 27 pitch. There is also a LOT of cup in it. I've thought about getting it labbed a little.

I also don't know the gear ratio. Again, came on the boat and haven't done much further with it.

Donzi Vol
01-01-2011, 11:23 AM
Are you saying you hit 48 at 4800 rpm and then continue to pick up rpm to 5500 but with no increase in speed? That sounds like a TON of slip.

Hope you're New Year's celebrations are going well!

Yep, that's the situation. That's why I'm figuring it's something to do with the drive. I've been told in the past that these drives can reach a certain speed and then stop accelerating the boat due to aquadynamics (if that's a word).

As for the New Year's celebration...it was good.:) Pretty tame, but a fun time with friends. Hope yours was good as well!

David

mphatc
01-01-2011, 11:38 AM
David,

Try to figure out your drive ratio and what precisely you have for a prop now, and then try a different prop. With a 351 H&M you should be around a 23p LH on that boat, but someone could have changed it to a RH rotation???

. . .there are several boats here running Volvo's that go over 70 MPH w/o trim . . . and I'll be running twin Volvos on my Magnum 27 and will be over 70 mph as well, thanks to Grizzly for getting me two Solas props.

Madad has a SBC in an 18 that easily runs over 70 MPH ! :yes:


Mario L.

Donzi Vol
01-01-2011, 01:39 PM
David,

Try to figure out your drive ratio and what precisely you have for a prop now, and then try a different prop. With a 351 H&M you should be around a 23p LH on that boat, but someone could have changed it to a RH rotation???

. . .there are several boats here running Volvo's that go over 70 MPH w/o trim . . . and I'll be running twin Volvos on my Magnum 27 and will be over 70 mph as well, thanks to Grizzly for getting me two Solas props.

Madad has a SBC in an 18 that easily runs over 70 MPH ! :yes:


Mario L.

This is good news! Well now the obsession of gaining speed has begun. I will take some pictures of the prop and post them. I'm pretty sure it's a left hand rotation. As for the drive ratio, I've never crossed that bridge before, so how do I figure that out?

Thanks

MOP
01-01-2011, 02:04 PM
You can try!!! May work if the cone stays engaged!!!! Put it in forward then put a chalk mark on the balancer pulley then put a line on the prop shaft with magic marker, bump the engine over two revolutions with the coil wire out. Now look at the prop shaft from the prop end so you get an idea of how much short of turning the two revolutions of the engine. Say you marked the shaft at the top which I do, if it is a 1:61 It will be short about 3/4 short of making it to the bottom of the shaft. A 1:5 will be at the bottom as it will turn 1/2 turn less than that of the engines two turns, 2:1 would make it to the bottom. The RPM's you stated with the possible 27" pitch has me thinking someone slapped a 4 cylinder drive on and propped it up.

Donzi Vol
01-02-2011, 02:37 AM
You can try!!! May work if the cone stays engaged!!!! Put it in forward then put a chalk mark on the balancer pulley then put a line on the prop shaft with magic marker, bump the engine over two revolutions with the coil wire out. Now look at the prop shaft from the prop end so you get an idea of how much short of turning the two revolutions of the engine. Say you marked the shaft at the top which I do, if it is a 1:61 It will be short about 3/4" of making it to the bottom of the shaft. A 1:5 will be at the bottom as it will turn 1/2 turn less than that of the engines two turns, 2:1 would make it to the bottom. The RPM's you stated with the possible 27" pitch has me thinking someone slapped a 4 cylinder drive on and propped it up.

Thanks for the input here MOP. I knew you'd have some light to shed on the matter. I have a few questions, though.
As far as determining the gear ratio, is this something I can do with the motor winterized?
Second, if a 4cyl drive is on there, what do I need to be looking for in the way of new equipment? Will just a lower unit do it, or do I need to replace the whole deal?
Lastly, if replacing the whole outdrive, does it have to be an exact match to fit the hole already in the transom or is this an opportunity to upgrade...maybe to a duo prop?
I really appreciate the help. Still a bit of a novice on the drives.

MOP
01-02-2011, 08:14 AM
Bumping the engine over won't hurt anything, as far as the drive if in fact it is a 4 cyl it would be easier to swap the whole drive. Your gimble housing will accept all the older style including the early duo's. Let us know what you find.

Phil

Sweet little 16
01-02-2011, 08:42 AM
the lower determines the ratio. 200 thru 270 are pretty much interchangeable
if you could find someone with one of Grizzly's 23 props to try the 2. ratio might just work out for you
all volvo props are high in slip except for Grizz's some even get higher in slip the faster you turn them.
you numbers don't add up or that prop is a real POS if you can turn a 27 pitch to 5500
A) if your tach is right a 2 ratio drive your prop has over 30% slip you want to be around 10% or under
B) your tach is off 1000 rpm and the prop is a 21 not a 27 then you have a normal or common V8 ratio of 1.6 and the prop has a normal 15% slip like most volvo props
high pitch volvo props above 26 are very hard to come by and usually were merc type props that had volvo hubs pressed in them .
besides the method above you can remove the drive 2 side pins then the top bolt might be a good time to check the u joints and the boot that cover them . mark the input shaft and the prop shaft turn the input shaft til the prop shaft makes a complete turn then see how many turns the input shaft makes 1 and a 3rd its a 1.3 1 and a tad more then half it's a 1.6 , one a a tad more than 1 and 3/4 it's a 1.8 and 2 it's a 2
Randy will be missed and the work he did in this area (the old volvos) was a labor of love and is appreciated dearly by old volvo owners. there is alot of documentation here and on donzi.org about his prop testing
the 351 came in a few hp versions the most common was the 290 HM package but later versions were rated at 260 and 250 all of which were a little overstated. but with the right prop mid to high 50's day in and out can be easy.
if you can spin a solas 19 to 5200 rpm it will have you knocking on 60's door.

mrfixxall
01-02-2011, 07:16 PM
mine boogies ,it likes the 3rd hole,should be good for 5-6 mph with the rite prop..try to find a ultra propp and send it to my prop guy..mine will go in to the 70's with the rite conditions..post a pic of your prop so we can determine what it is..

look where the shift cable goes into the front side of the drive,their should be a letter at the beginning or end of the serial number... B = a 1.61 ratio,C = a 1.89 ratio and D = a 2.15 ratio..

Donzi Vol
01-02-2011, 07:44 PM
mine boogies ,it likes the 3rd hole,should be good for 5-6 mph with the rite prop..try to find a ultra propp and send it to my prop guy..mine will go in to the 70's with the rite conditions..post a pic of your prop so we can determine what it is..

look where the shift cable goes into the front side of the drive,their should be a letter at the beginning or end of the serial number... B = a 1.61 ratio,C = a 1.89 ratio and D = a 2.15 ratio..

Hey fixx,

I was getting ready to drop you a line because I knew that you had yours dialed in nicely. I took some pictures this afternoon of the prop and will post them when I get home from the office. I will also check for the ratio...nice to know it's as easy as reading the serial #! When you say that it's where the shift cable goes into the front side, do you mean that I just need to take off the cover with the 270 stamp on it?

Thanks

mphatc
01-02-2011, 07:45 PM
I have a pair of 23P Solas props set aside for my Magnum . . I am willing to lend one of these to you to experiment with

1 LH and 1 RH . . .

Madad's set up is a stock drive and stock steering, his engine is a big bore small block making around 435 HP . . he and I ran side by side he was running his 23P Solas and I was running a 21P cleaver, I ran to 6150 RPM with no GPS , ideal water and about a mile run . . he lost a right side helmet screw during this run!!

I think the 18 needs 400 HP to get over 70 MPH you should see low to mid 60s with a good running 351.

Mario

Sweet little 16
01-02-2011, 07:52 PM
the serial number will tell you what the ratio is if the drive has never been touched, someone could have replaced the lower at some point over it's liftime . the number can also been found on the top cap by the dipstick

Donzi Vol
01-02-2011, 09:41 PM
Well...I went back to the boat to get the serial #, but couldn't find it. Maybe it's non-existent after all the years. Pictures coming soon...

Donzi Vol
01-02-2011, 10:13 PM
I have a pair of 23P Solas props set aside for my Magnum . . I am willing to lend one of these to you to experiment with

1 LH and 1 RH . . .

Madad's set up is a stock drive and stock steering, his engine is a big bore small block making around 435 HP . . he and I ran side by side he was running his 23P Solas and I was running a 21P cleaver, I ran to 6150 RPM with no GPS , ideal water and about a mile run . . he lost a right side helmet screw during this run!!

I think the 18 needs 400 HP to get over 70 MPH you should see low to mid 60s with a good running 351.

Mario

Thanks so much for your generous offer. I really appreciate it. I would like to take you up on it, the only problem is that I wouldn't be able to do any testing until mid-April, as it's gonna be too cold to get her out until then. I imagine that the props might already be spoken for on your Magnum at that point. Mine is a LH rotation, so that would be the direction I would need to go.

Donzi Vol
01-02-2011, 10:16 PM
Ok, here are some pictures of the outdrive and prop. Again, I'm referring to it as a 27 pitch only because 27 is stamped between each blade of the prop. Please let me know what you think. Thanks

Donzi Vol
01-02-2011, 10:18 PM
one more...

mrfixxall
01-02-2011, 11:36 PM
the serial # is here(starboard side of the cable),you will have to turn the drive to see it..it looks almost like a hill ptop but shaped like a ultra blade,the hub area is to small and is interfering with loading the prop with water so that where the cavitation is probably comeing from,griz is not here may he rest in piece,you can find the solas props on ebay..

Donzi Vol
01-03-2011, 12:18 AM
the serial # is here(starboard side of the cable),you will have to turn the drive to see it..it looks almost like a hill ptop but shaped like a ultra blade,the hub area is to small and is interfering with loading the prop with water so that where the cavitation is probably comeing from,griz is not here may he rest in piece,you can find the solas props on ebay..

That makes sense. In fact, when I was examining the prop today I thought to myself that the hub area is awfully small compared to the plate. It seems to me that that's why I'm not picking up any speed between 4800 and 5500 rpm, as only so much water is hitting the surface area of the prop. I'll start looking for props to test...Solas first. Any suggestions on pitch?

I'll try to get back over to the boat this week to look for the serial # again. Maybe I'll be able to find it in the daylight :crossfing:

Thanks again for the help...looking forward to more speed come April :yes:

Sweet little 16
01-03-2011, 08:50 AM
hard to tell from the pictures but it looks like the water pickups have been glassed over???? if the boat is a 1970 it should have a 250 on it not a 270 . so someone could have done some tinkering. you'll need to find the numbers

IF the water pickups have been glassed over and they are are not perfect they could be disrupting the flow to the prop as well at speed.

look for a 22 ultra or a 21 solas you are probably going to need a few different thrust washer when you try props to get them to fit right

Inferno
01-03-2011, 09:42 AM
David,Sounds like your boat needs the same as your VOLS....a good tune-up !!! How can your VOLS do this to the SEC image ??? What a heart breaker !!!! Don't worry as my Auburn Tigers will make the SEC proud against the Quacks.I know what you mean when you say"wish Randy was here"...I tore my 22 apart and he was going to help me with the project and now I'm scratching my head,as I look at all the parts scattered all over my garage floor !!!! WAR EAGLE Stan

maddad
01-03-2011, 10:29 AM
Hey donzi vol, I don't know about the 270's, but on a 280 there is a small tag riveted on the upper housing that has the drive info on it. Like it was already said, that is how the drive was built and may have been changed. You can see the tag between the boot and top cap in the pic. The right prop should get you to the 50's easily, it's after that that the vodoo etc. is needed.
http://www.donzi.net/forums/attachment.php?attachmentid=60660&stc=1&d=1294068298

Donzi Vol
01-03-2011, 11:05 AM
hard to tell from the pictures but it looks like the water pickups have been glassed over???? if the boat is a 1970 it should have a 250 on it not a 270 . so someone could have done some tinkering. you'll need to find the numbers

IF the water pickups have been glassed over and they are are not perfect they could be disrupting the flow to the prop as well at speed.

look for a 22 ultra or a 21 solas you are probably going to need a few different thrust washer when you try props to get them to fit right

You're right about the water pickups. The water pickup is on the bottom of the boat, so the ones on the outdrive have been covered up. I've often wondered if this is a problem in consideration of keeping the drive cool. Obviously, I need to clean the whole thing up quite a bit.

Maddad,
Thanks for the info. I will check there as well.

boatnut
01-06-2011, 08:50 PM
This is very likely a useless dumb response but I will throw it out there anyway. I had a 270 drive once with a volvo prop -- the boat used to go in the mid 50's and suddenly it was going in the low 40's with about the same engine rpm as the previous mid 50's. To shorten the story, the rubber hub in the prop was slipping and acting like a governor -- I guess the torque reqd to get beyond the low 40's was enough to break the friction and the prop would turn no faster. Had the hub changed at a prop shop, problem solved. Ed

mphatc
01-06-2011, 09:16 PM
not at all a useless dumb response . . first time I launched the Corsican 10 years ago this happened to me, but it went from full speed to zero speed . . never knew they could do as you describe . ..

///M

Sweet little 16
01-07-2011, 09:10 AM
no not dumb or crazy the thought did cross my mind and I guess anything is possible . what swayed me was when hubs have spun on my volvo props it was like Mario said I could only maintain idle speeds and couldn't plane off.
If it is a volvo rubber hub which were notoriously weak there will a tar like sunstance oozing from the hub if it's spun . this would be the first spun hub I have seen to achieve 48 mph. I would also imagine if it was spun when it broke loose it would loose speed not maintain it . also wouldn't a spun hub continue to get worse??

boatnut
01-07-2011, 11:42 AM
no not dumb or crazy the thought did cross my mind and I guess anything is possible . what swayed me was when hubs have spun on my volvo props it was like Mario said I could only maintain idle speeds and couldn't plane off.
If it is a volvo rubber hub which were notoriously weak there will a tar like sunstance oozing from the hub if it's spun . this would be the first spun hub I have seen to achieve 48 mph. I would also imagine if it was spun when it broke loose it would loose speed not maintain it . also wouldn't a spun hub continue to get worse??

This happened to me about 35 yrs ago. The prop may have been an OJ (Made by Johnson propleller in Oakland, CA) rather than a Volvo -- they looked similar. You could see where there was very minute oozing between the hub and prop. I had spun a hub before which did completely break loose and limit speed to an idle. This prop must have been slipping at speed rather than completely spun loose. I only tried it twice for probably 30 seconds total time. I also think it would have continued to get worse.

David O
01-31-2011, 08:36 PM
Good reading from way back on Solas props with volvo drives.
only prop to consider is the solas that Randy worked up for the volvo's
what a GREAT person
http://www.donzi.net/forums/showthread.php?t=38664

Donzi Vol
02-03-2011, 11:37 PM
Good reading from way back on Solas props with volvo drives.
only prop to consider is the solas that Randy worked up for the volvo's
what a GREAT person
http://www.donzi.net/forums/showthread.php?t=38664

Great thread...thanks for posting. It will definitely be helpful.

Still missin the Grizz...

JimG
02-04-2011, 09:34 AM
I'd like to try a Solas one day...

My Ultra does pretty good. It started as a 24 lh, and I had an inch taken out to get the rpm up. Middle hole I get 56 mph at 5100. I can get to 58 in the last hole, but the boat does not like it. Squirrely... That's really as fast as I want to go in that old girl with original steering!

dsparis
02-04-2011, 09:38 AM
iboats has Solas props cheap

BUIZILLA
02-04-2011, 09:50 AM
might want to check with Lady Grizz FIRST to see what Randy had leftover

Donzi Vol
02-04-2011, 09:51 AM
might want to check with Lady Grizz FIRST to see what Randy had leftover

Good call, Jim. I'll check with her.

Thanks

champ
02-06-2011, 11:49 AM
....so this is one for me to watch. I got the same issues and the same set up. I got a 14x22 lh ss prop (not sure what kind) and get to 5100 rpm's max, although 4800 is the sweet spot but then the slipping starts.
I think I will try the prop swap first, Where to get a 23or 24 solas?

Sweet little 16
02-08-2011, 07:27 PM
solas Titan is the model, Randy's props were slightly different from the new ones being offered from solas directly which cause some dialing in with different size thrust washers. I would check with Lady Griz first.

23 pitch is as high as they go and your motor will have to eat it's wheaties to turn one, if your turning a 22 to 5100 now the big grizzly version 23 solas will drop you down 600-800 rpm depending on what dia. the 22 you have now is.