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View Full Version : Repower complete-what prop for my Sweet 16?



John C in PA
04-28-2017, 03:44 PM
So the Repowering is done. I'm suspecting +\-300 hp. The cam is rated idle to 5 Grand, which I think is a good redline for me.

Using a tweaked 3 blade SST 14.25x21 the acceleration to 3000 is very good-then the cam and carb really come on and the revs jump like afterburners are lit. At 5200 rpm I throttled back. GPS MPH was about 62.

Figuring I can pull a 23" pitch, a custom shop let me try an OMC Cyclone 4 blade 14x23 tweaked. Wow, awful. I lost 700 rpm, lost a few mph top end, and got chine walk at 58-59 mph as a "bonus".

At at his point I have 2 options: keep the SST and mind the tach, or buy a new more recent design prop and try to pick up some mph.

We're headed to the River soon so I could use some input.

Thanks folks, John C

tmdog
04-28-2017, 04:48 PM
John, choose a prop that will get you to the established red line. Say you want to limit rpm to 5200, select a prop pitch to attain that goal. I suggest a 14- 14 1/4" dia. and a 23 p. There is a lot of misconception on limiting rpm and choice of pitch. The question is, how long and how often are you really going to pour the coal to the engine. Best to choose a pitch you are comfortable with. Obviously you don't want to lug the eng or over rev. Stay away from 4 blades. Hard on the outdrive.:yes:

John C in PA
04-28-2017, 05:16 PM
John, choose a prop that will get you to the established red line. Say you want to limit rpm to 5200, select a prop pitch to attain that goal. I suggest a 14- 14 1/4" dia. and a 23 p. There is a lot of misconception on limiting rpm and choice of pitch. The question is, how long and how often are you really going to pour the coal to the engine. Best to choose a pitch you are comfortable with. Obviously you don't want to lug the eng or over rev. Stay away from 4 blades. Hard on the outdrive.:yes:

This ain't my first prop rodeo 🎲🎲 and I agree with all your points.Those were my guidelines, however I may have let my guard down with the custom shop selection. Especially trying a 4 blade prop.

John C

John C in PA
04-30-2017, 03:22 PM
Hmmmmm, not much in the way of replies. How about this guys: due to my drive (Cobra) and usage my choice of make/model is down to two, maybe 3.

Does anyone have experience with a Turbo1 and/or a Turning Point Mach3 Express?

The wild card is a BRP Raker, possibly an older model.

John C

Morgan's Cloud
04-30-2017, 04:20 PM
due to my drive (Cobra) and usage my choice of make/model is down to two, maybe 3.



John C

Isn't there available now the splined insert for that drive that you can then fit any Merc prop onto ?
That would open up a whole lot of possibilities .

John C in PA
04-30-2017, 07:01 PM
Isn't there available now the splined insert for that drive that you can then fit any Merc prop onto ?
That would open up a whole lot of possibilities .

Been there, tried the prop finder.......and failed. I tried fish/ski, performance sterndrive, and runabout. I tried top speed, handling, and overall performance. I couldn't get past the engine make-no OMC or Ford. And selecting Evinrude/Johnson (aka BRP/OMC) only brought up eggbeater power.

The best prop for my rig has been a tweaked 21" OMC SST2, but I can't locate one in 23".

John C

tmdog
04-30-2017, 07:10 PM
Turbo1 would be my choice. They perform very well on our type boat.

John C in PA
04-30-2017, 07:55 PM
Turbo1 would be my choice. They perform very well on our type boat.

Thanks buddy. That's the type of input that really helps.

John C

Pat McPherson
05-01-2017, 09:50 AM
I liked the 25P Turbo 1 on my 22. It ran vary similar to my 25p Mirage none plus, 100 or so more RPM, little better acceleration, and same speeds. I love the Merc Rev 4 but you'd need some sort of adapter I guess.

John C in PA
05-01-2017, 05:56 PM
I may have found the solution I was looking for. My current prop is a 21" SST tweaked by DAH Pro-pellers. Runs great and no chine walk. With the new engine I'm a bit underpropped. DAH said they can't add any more cup to that prop but they have a difficult to find a 23" SST, the same as my current prop except +2" pitch and untweaked.

I guess (hope) the Turbo or Turning Point discussion is unnecessary.

John C

tmdog
05-02-2017, 08:13 AM
Precision prop makers of Turbo prop. They are now owned by Yamaha. The nicest and most helpful people I have dealt with. The owner of Turbo used to attend most of the Donzi events and loan out props to be tested. Had a member that had passed that lived near me on the lake and happen to be a Turbo distributor. Tried most of what he had and chose the Turbo 1.

This is the link for Precision Prop. Call them. Hopefully, you may be surprised.
http://www.turbo-props.com/index.php

smokediver
05-03-2017, 03:27 PM
A good OMC prop to try is a Raker . Lots of bow lift . you might want to hit up DAH propellers and see what he's got laying around . That SST prop is NOT a performance propeller by any stretch .. Like others said , Turbo1 is an excellent choice as well and at 300 hp you should be able to spin a 23.. I believe the OMC has numerically smaller gear ratio like 1.43 vs. the 1.5 and 1.47 found in most alpha drives mated to small block V8s

John C in PA
05-03-2017, 07:39 PM
A good OMC prop to try is a Raker . Lots of bow lift . you might want to hit up DAH propellers and see what he's got laying around . That SST prop is NOT a performance propeller by any stretch .. Like others said , Turbo1 is an excellent choice as well and at 300 hp you should be able to spin a 23.. I believe the OMC has numerically smaller gear ratio like 1.43 vs. the 1.5 and 1.47 found in most alpha drives mated to small block V8s

Actually, DAH has a raker on the wall as well as an SST. I forgot the pitch on the Raker but I know the SST is 23". I'm shipping the 4 blade back tomorrow and, when I call DAH to let him know, I'll cover this.

The reason I'm leaning toward the SST is my current SST has no chine walk, unlike the OMC Viper and Cyclone.

John C