Prop for 22' Bayliner with MerCruiser 350

[LiquidC]

I need a new prop for my 22 foot Bayliner deep v hull cuddy cabin. I hit a rock with the stainless steel prop, and I'm not able to get the numbers off of it. I have MerCruiser 350 engine, and a 55 gallon fuel tank. I'm not sure of the weight. Any suggestions?

 

[Robert Palmer]

They generally take around a 15 1/4 inch prop. I have seen up to a 17 inch on that engine, though that is general when some one is trying to use it a a ski boat for adults. A good supplier will give as good advise as anyone. Generally bigger props more torque less power. The power give top end speed the torque pull the boat out of the water onto the plane. I have always used aluminium props as we are on a shallow river and stainless will only last longer if you don't hit the bottom.

 

[steelespike]

Did you look on the hub under the nut for numbers.
Do you have any lightly loaded performance numbers for us?Year of the boat/motor?
Lightly loaded wot rpm and gps speed.

 

[jestor68]

Well, the Merc prop selector comes up with a 17 pitch prop based on a dry weight of 3900 plus 500 lbs of stuff and 40 gal of gas yielding an operating weight of 4628, assuming a 1.47 gear ratio(normal with a 5.7L).

But since you repowered from a V-6 which usually has a 1.81 gear ratio, the recommendation using that ratio is a 21 pitch.

 

[jestor68]

They generally take around a 15 1/4 inch prop. I have seen up to a 17 inch on that engine..

What are you talking about? Props come in sizes expressed in diameter, followed by pitch; example 15-1/2 X 18.

 

[LiquidC]

Thanks for the info so far guys. It's a 1994 Bayliner 2252 Classic. The original motor was pulled (a V6) and I installed a Mercruiser 350. Last season, I ran it with the same prop from the V6, and it seemed to work out ok. I was getting around 4500 RPM at WOT, peaking around 35MPH. I'm more interested in saving fuel rather than performance if that makes a difference. Thanks again!

 

[LiquidC]

Update ... Guess I was looking in the wrong spot. The prop I want to replace says 14.25R17 Thanks

 

[jestor68]

I'm not understanding why the new 5.7L V-8 can't turn more prop than the V-6 did.

Did you change the gear ratio, or is it the same as with the V-6?

 

[LiquidC]

Yes, the gear ratio was changed to match the new engine. It was changed to 1.47 I had to change the old outdrive anyway, the upper case was cracked.

 

[jestor68]

Yes, the gear ratio was changed to match the new engine. It was changed to 1.47 I had to change the old outdrive anyway, the upper case was cracked.

OK;great. In that case, the recommended pitch (from the prop selector) would be 17. But it says that it should do about 4600 rpm @ about 41 mph based on the weight data. So it seems that you're a bit shy of that. But these projections are not locked in concrete and will vary from one to another.