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bootdaddy
08-29-2011, 12:46 PM
Hey gang - I am curious about performance with an upgrade to a duo prop with a Volvo 270. It's for my 69 Corsican with 351 Cleveland all upgraded. Currently running a 19 Solas at about 5700 rpm at 55 mph. (Was getting 52 mph at 4400 rpm with 21 Soals.)

Will my performance be substantially better with duo setup and are there any other issues to consider?

thx

-Patrick

BUIZILLA
08-29-2011, 12:50 PM
Hey gang - I am curious about performance with an upgrade to a duo prop with a Volvo 270. It's for my 69 Corsican with 351 Cleveland all upgraded. Currently running a 19 Solas at about 5700 rpm at 55 mph. (Was getting 52 mph at 4400 rpm with 21 Soals.)

Will my performance be substantially better with duo setup and are there any other issues to consider?

thx

-Patrick i'm trying to understand the 1300 rpm difference for only a 2" pitch change?

bootdaddy
08-29-2011, 01:12 PM
I thought it was the 23 Solas (it may be in fact) but the local prop guy says old prop 21 and new prop is 19...

Not really sure why the big difference in rpm other than it seemed to load the motor and looking at it sure seemed like a big prop for the size boat...

given power in boat, seem to be missing some speed...or not?! engine buillder said it can run in low 6000s and be ok...

Kirbyvv
08-29-2011, 01:18 PM
something doesn't match up. I'm running a 21 Solas turning it to 4800 rpm, with a stock 260 hp sbc. I tested the solas 19 and it turned about 5200 rpm. I did here something about the early batch of solas 21 props having more pitch than marked though. Griz would have had the answer, Man I miss Griz.

Morgan's Cloud
08-29-2011, 02:26 PM
Prop questions aside ,I'm not sure I got your question right ..

You said you are curious with an uprgade to a duoprop with a Volvo 270 ...

There is no 270 duoprop outdrive.
Do you mean you are considering chucking everything out and going with a new duoprop package ..engine , drive etc ?

As far as performance benefits go , are you reasonably happy with how your boat runs/handles now and have you tried a d/p setup before ?

I know that it's very hard to find smaller boats like ours that we can easily compare to that have D/P units .

biggiefl
08-29-2011, 02:44 PM
I have seen a 16' w/DP and man is that a heavy outdrive on a small boat. I can't rmrmber if it had a 4.3 or a 5.0. When my bud removes a DP or a B3 from a boat he has to do it in 2 sections because of weight. I thought they were for big underpowered boats but I guess they have some benefit. Props are not readily available like regular props, you buy them in sets which makes it REALLY hard to dial them in not to mention REALLY expensive.

bootdaddy
08-29-2011, 02:51 PM
I'm curious on what difference a duo would make or if its even possible. I have the 270 and its in very good shape. My bud just redid his Hiliner w new volvo engine and new duo and mentioned that Wilbert (owner) of French Creek marina has 2 duo prop units for my drive...

When I spoke to Wilbert today, he considered my question and said he couldn't think of any reason why it couldn't be setup on the 270...

In one sense the 21 solas was decent but just couldn't get rpm's to hit power band with max rpm 4400 w trim. The 19 is seems right but thought I would have better top end than 3-4 mphs, its better around docks and gets 5700 w trim and the engine sure sounds happier...

I guess I'm just wondering if I am missing something (as ususal!)? Ha!

The boat at speed is definitely very fun...lanyard clipped in!

There are no trim tabs as I wanted to keep it looking as original as possible.

The other issue is heat...with trim at speed it gets a little over 180 degrees until I pull in trim or reduce throttle...

Finding the balance of performance with originality...not always easy.

thx

mattyboy
08-29-2011, 03:14 PM
The 290 DP lower should( i have not tried it but alot of the AQ stuff can be interchanged)bolt right up to a 270 upper. Is this a 270 T ???

finding a matched set of props will be hard to find in the right pitch to let your motor run in it's power band. not sure a DP is gonna like living at 5grand or higher.

a duo will eliminate hunting when off plane and torque steer while on plane.

the numbers you posted( if it is a 1.6) on the 19 solas are around 14% slip that is very high slip for a solas . the solas I have run have been at or under 10% slip

have you GPS'd your numbers? have you confirmed the drive ratio? confirmed the tach? 5700 rpm on a 1.6 with a solas 19 should be 58-59 ish

once you have reached top end have you tried to lower the trim a tad??

bootdaddy
08-29-2011, 03:26 PM
The 290 DP lower should( i have not tried it but alot of the AQ stuff can be interchanged)bolt right up to a 270 upper. Is this a 270 T ???

finding a matched set of props will be hard to find in the right pitch to let your motor run in it's power band. not sure a DP is gonna like living at 5grand or higher.

a duo will eliminate hunting when off plane and torque steer while on plane.

the numbers you posted( if it is a 1.6) on the 19 solas are around 14% slip that is very high slip for a solas . the solas I have run have been at or under 10% slip

have you GPS'd your numbers? have you confirmed the drive ratio? confirmed the tach? 5700 rpm on a 1.6 with a solas 19 should be 58-59 ish

once you have reached top end have you tried to lower the trim a tad??

Actually, I just downloaded the INavX app on Ipad and going to do that this afternoon to verify speeds...it was initially done pacing new jetski Ha! There is a noce little chop on St Lawrence today to run test.

Yes 270 T

Not sure on ratio but have been told that tweaking and labbing prop easiest way to gain a few mph and have to agree when I consider Wilbert wants $4500 for lower and $800 for set of props...he did mention best with a little lower rpm...but then again, not in powerband and lots of $!

bootdaddy
08-29-2011, 03:32 PM
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mattyboy
08-29-2011, 03:38 PM
umm it might be a 270 drive leg but that is a 290 transom housing a 290DP will hook right up and I believe the transom cutout will work for a newer volvo drive/transom assembly as well.

another thought would be someone hung a 270 lower on 290 setup. with that setup I would really want to confirm the drive ratio before I did anything.

bootdaddy
08-29-2011, 03:51 PM
umm it might be a 270 drive leg but that is a 290 transom housing a 290DP will hook right up and I believe the transom cutout will work for a newer volvo drive/transom assembly as well.

another thought would be someone hung a 270 lower on 290 setup. with that setup I would really want to confirm the drive ratio before I did anything.

thanks Matty - will confirm ratio

Forrest
08-29-2011, 03:51 PM
The DuoProp will really work wonders in terms of handling in all sorts of water conditions, and with single-digit slip numbers it will be more efficient as well, but don't be disappointed when you find that your Corsican is not going any faster than with your single prop AQ270/Solas setup. You are going to need more power to go faster.


Also, though very similar to the 270, to do a DP conversion I personally would want to first find a good AQ290 type upper and transom. The 290 has integrated trim and tilt, and generally less slop in the gimbal than the earlier Aquamatics. Though the 270t is good, but the 290 upper is just better suited when spending good money on a DP conversion.

Just Say N20
08-29-2011, 04:44 PM
Beautiful set up. Very tight engine compartment.

I'm curious. . . . was your engine builder primarily a CAR engine builder?

Marine engines are different with respect to torque/hp/rpms. I'm asking because if your rpm numbers are correct, and you can only spin a Solas 21 to 4400, but you can spin a Solas 19 to 5700, it sounds like the engine has to really get spinning to develop it's horsepower, and at 4400 rpms it is still down on power big time. Works for a car, not so much for a boat.

I have a Donzi Ski-Sporter 16, Volvo A290 with trim, a 1.61:1 ratio, and a 350 Chevy. I can spin a Solas 21 to just about 4700, and I can spin a Solas 19 to around 5000. That is more what I would expect from a marine engine. They have a pretty flat torque curve, and don't have to rev to almost 6000 to develop peak hp.

Generally, each inch of pitch change will change rpms between 100 - 200. On my boat changing 2" of pitch (19" => 21") changed my rpms by 300.

Morgan's Cloud
08-29-2011, 07:59 PM
Is this morphing back into a question of 'will a 290DP unit bolt onto an existing 270 transom ?'

Because I've seen these questions a dozen times before here and I cannot recall anyone saying definitively 'yes' or I tried it ..no .

It's been a while since I've seen a 290 up close , but from what I recall it looks a lot different than any similarities an Alpha might have with a Bravo , and we know that's not a direct changeover.

Elsewhere , I've posted on my great results when I switched my single prop SX/A unit for a DPS/A on the same boat .
Literally took an undriveable monster and turned it into a dream . And maybe even faster !

bootdaddy
08-29-2011, 09:02 PM
Ok so it topped out at 42 knots on GPS = 48.33 mph at 5700 rpm on Solas 19.

It's actually slower (if we put any credence in a brand new jet ski mph instrument) which had me clock at 52 mph with Solas at 4400.

It sounds better but is not as fast...so that's what I'm dealing with.

Engine builder is car guy with specific Cleveland experience, special oiling system as oil tends to lay on one side of motor, but also has marine experience...says 6100 is ok with setup, but again motor runs hot at high rpm w trim...

I don't have ratio yet and am wondering about labbing the 21 to find the sweet spot vs huge duo prop expense...

Will get ratio nailed down soon.

Just Say N20
08-29-2011, 11:30 PM
Bootdaddy, something isn't adding up.

When I'm running 4800 rpm, with a 1.61:1 Volvo A290, my GPS reads 50.8. When I plug that into this prop calculator ( http://www.rbbi.com/folders/prop/propcalc.htm ) it works out to be 5.3% slip. This is on a Classic 16, but they tend to be slower than some of the larger boats with the same engine/drive. This low slip is consistent with what many see using the Solas props.

I ran the Solas 21 to 4750 and GPS said 54.4, or 7.3% slip, which is still very low.

I have a Volvo Ultra "racing" prop that is a 24 pitch. At 4900 rpms, the GPS reads 55.7 mph. This equates to 19.5% slip. This is pretty normal for this prop.

If your numbers are correct, you can plug in speed, rpms, prop pitch, and slip and it will tell you your ratio. This isn't the best way to do it, but using your rpms and speed, and assuming around 7.5% slip for the Solas, it shows your ratio to be almost 2.2:1. That would be gearing for a Briggs & Straton 18 hp engine!

Also, while your engine might be happy running 6000 rpms, outdrives don't like to live that high. The A290 on my boat came with a 310 hp SBC that had a max operating range of 4800 to 5200. I know MrFixx runs his engine/drive way up there, but most would recommend against anything above 5,500.

mattyboy
08-30-2011, 09:13 AM
I wouldn't spend a dime on anything until the ratio is verified.

it's been stated by several here something is a rye . your numbers are not adding up. finding a v8 ratio outdrive is becoming harder finding a 4 cyl ratio 2:1 is easy. It happened to us found a replacement 270 for the cig project seller said it came off a v8 boat which it did but it was still a 4 cyl lower.

the 290 DP will most certainly bolt up to a 270 lower and a 270 upper will bolt up to a 290 transom housing. there is a 275 duoprop on ebay now that the seller said he modified to a duo prop.

I do agree with forrest the trim setup and steering are improvements over the 200-280.

there are several here that are running higher HP thru a volvo with a solas or ultra. It's not impossible to reach low 60's with 350 ish hp and a solas 21 on a 1.6 drive

Forrest
08-31-2011, 03:29 PM
Is this morphing back into a question of 'will a 290DP unit bolt onto an existing 270 transom ?'

If you are asking if cutout in the transom for a 290 is the same as a 270, the answer is that it's close, but not exactly a fit. Small amounts of cutting is some spots will be necessary. To go from a 280T to a 290 you'll need to fill holes left by the 280T external power trim "ears".

Now if you are asking if a 290 will bolt on to an existing 270 transom assembly, the answer is, I haven't tried it, but I'm sure that you could make it work; however, you really would't want to go that route since much of the 290's upgrades over earlier models are in the transom assembly. The 290's major improvments are integrated power trim and a tighter stromger gimble tha you won't have with a 270 or even a 280 or 280T transom assembly.

If you do this upgrade, you will want a 290 transom assembly with a complete 290DP drive. Better yet, fill the Volvo style cutout and pony up for a complete Volvo DP-S outdrive package. You may even find one used or salvaged. The old stype DP-S is just fine. The new style would be over-the-top. The DP-S is hydrodynamically better than the Aquamatic style duoprop and every bit a strong as a Bravo drive . . . but all of this stuff could get pricey!

Just remember, once you go with a duoprop, it hard to go back to anything else. The 280T to DPX conversion I did in my Magnum was literally a difference of night and day in terms of effficency, handling, rough water capability, and smoothness. Since slip was killing me at 30-ish% with my 280Ts no matter what props I tried, I ended up picking up 12- to 15-MPH by recovering power that was previously going to waste though excessive slip just by going with the DPXs over the 280Ts .

BTW, that Corcican is nice, BG would be proud!

blackboat
09-01-2011, 06:26 PM
Something does not sound right,I ran my 69 Donzi Corsican with a modified 351 ci
Ford Windsor 10:1 comp 280 comp cam,and 292 comp cam turning 5100-5200
RPM with Spinelli Chopper props 24 pitch and 26 pitch wheels.
Had a 270 Volvo drive with nose cone and external steering.
Ran 68 to 71 mph range.
Seems to me with a bone stock 351 Cleveland,you should be somewhere around 58 to 60 mph.

Morgan's Cloud
09-01-2011, 09:08 PM
So , essentially (@forrest) the long and short of it is a 290 wont just bolt onto where a 270 once fitted . And more than likely the transom will have to be either modified or re-cut ? (because the 290 transom plate is completely different)

And when it comes to the D/P drive .. you're preaching to the choir ! ! :smash:

Tony
09-01-2011, 09:29 PM
Call Wilbur at
French Creek Marina
Clayton, New York
315-686-3621

Used 290DPT, used transom assembly, new/used DP-S, new/used DPX...whatever you need they will have.

mrfixxall
09-01-2011, 09:32 PM
you can use your upper and just bolt on the dp lower..

on my x i run a few props depending what im doing,most of the time i run my 26p ultra that has a heavy cup,knife edged and ballanced..i can turn this prop to 5600 rpm's and sometimes more depending on the water temps and conditions..with 1/4 tank and 2' chop i see between 68-72 mph but never under 68 mph @ wot...when i run my 24 ultra that is labbed by DAH propeller i can really wind up the rpm's,the boat will almost leave the water on the hole shot (boat copletely out of the water but the prop still in).. max speede is 68 mph usually around 5800 rpm creeping up to 6200 rpm's and the boat is a hand full with this prop but i like the snappyness and the acceleration of the 24 ultra..

bootdaddy
09-10-2011, 11:52 AM
Not sure on the ratio, but certainly not the right mix.

My guy is lokking for the upper at 1.61:1 with single screw helmet...should have back in water later with 21 solas to test

Just Say N20
09-10-2011, 12:45 PM
Bootdaddy,

Please post pictures of your e-drive. I wouldn't think the Solas prop would even fit on it.

The E-drive is usually worth 5 - 7 mph over a standard 270/280/290 just by bolting it on.

bootdaddy
09-10-2011, 12:56 PM
[ QUOTE=$originalposter]{$pagetext}[/QUOTE]

the upper gear box is an E drive; lower standard 270

guy said it has roughly 12 teeth vs. 24...developing

bootdaddy
06-12-2012, 09:35 AM
OK - it turns out my numbers were with a 21 and 17 solar...not a 19.

I had the upper gear box replaced with rebuilt last year so that should be square.

I spoke to Hans at French Creek and he has new and rebuilt duo-prop bolt on lowers.
$3500 for rebuilt + props. $500 trade against the old upper.

Trying to decide if I go with a 19 solas (or another recommended single prop) OR bite the bullet and go duo prop with Volvo stainless...

mattyboy
06-12-2012, 10:26 AM
Boot
I hate to say this but something is not right here think you have been given some incorrect info. The ratio is made in the lower as far as I know all the uppers are the same on the 200-280
If it is an e drive lower it will use merc racing props not Volvo props

Again a marine 351 making approx 300 HP should have no problem turning a solas 19 to 4800 or higher rpms on a 1.6 drive

bootdaddy
06-12-2012, 12:17 PM
[ QUOTE=$originalposter]{$pagetext}[/QUOTE]

yes - I was incorrect (again) in props and the upper gear case was not standard.

Going to give the 19 a try. What I thought was a 19 was in fact a 17...

The 21 got me to 4400 so thinking the 19 will be right and wait on duo prop for now.

Will post numbers late in week or early next week.

Anybody interested in 17 solas with 3 hours and/or 21 solas with 25 hours?

bootdaddy
08-17-2012, 03:20 PM
Apologies for previous bad info.
Previously told I was running 19 when it was 17, plugs were toast and wrong drive ratio...

I ran the 19 Solas (yes the 19 this time!) and hit 55mph on gps at 5400rpm.
may try and post vid later - motor sounds great and boat feels happy.

Do I need to be concerned about the telefax internal power steering with assist running this setup? Duo safer maybe?

Have a line on new Kiek tabs w internal plumbing.
Do other corsican guys use tabs or duo prop?
Wonder if it's worth the expense of duo prop or if top end is close to same...
kinda hate to add tabs because stern looks so clean but better cruise and idle so may have to.

I have left hand 17 and 21 Solas available to board members for $100 plus ship each.

bootdaddy
08-17-2012, 10:37 PM
19 left available

c freund
08-18-2012, 05:22 PM
I am interested in the 19" l/h solas. Pls reply to c.freund1@frontier.com
thanks, Carl