Mercruiser 5.0 Performance Boost

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: Mercruiser 5.0 Performance Boost

Although I have never used one, I have heard quite a few negative comments about the shifting props.

Go to your local Merc dealer. He should have a prop program where you can 'buy' a prop and take it out and test it for the weekend. If you're not happy with it, you take it back and get another one, until you find the one you want.

If you're currently running a 21" 3 blade ali, and you're getting into the recommended RPM (4200-4600), then go for a 21" HighFive as a starting point. (select a prop that takes you towards the top end of the max revs, 4600)

You can use Merc's prop selector website.. http://appcenter.mercurymarine.com/propSelector/home.do

Chris.......
 

The Joker

Cadet
Joined
Jul 8, 2006
Messages
8
Re: Mercruiser 5.0 Performance Boost

What about some 1.6 rockers? Those are cheap and wont change duration just lift. I just went from a 2 barrel to a 4 barrel on my boat and I love it.
 

Philster

Captain
Joined
Sep 15, 2009
Messages
3,344
Re: Mercruiser 5.0 Performance Boost

Thanks everyone for the feedback. Right now I think im going to just upgrade the stock prop after reading alot of posts on the prop boards. Currently running a 21 pitch 3 blade aluminum so there should be ample room for improvement. Now the next question is do I drop to a 19 high five to preserve my RPM? Or should I get a shifting prop?

Holy smokes... Get a modern, SS prop with proper cupping and rake and maybe four blades instead of three and you will feel the 'snap', also called 'bite'.

It's all relative... and relative to basic 3-blade alum, the SS prop will feel hooked up.
 

bral77

Recruit
Joined
Jul 20, 2010
Messages
1
Re: Mercruiser 5.0 Performance Boost

I have a 94 19' crownline with a 5.0 (305) in it. I could not pull a skier with my prop which was 14.5x19 3 blade aluminum. I switched to a 14x18 4 blade aluminum and now i can pull skiers up with 1 ski. You do lose some top end. I went from 51 to 47, but unless you look at the gauge, you cant tell. The boat pops out of the water awesome and also does much better with tight corners. I wont buy an ss prop because there is no give if you hit something and you will ruin your outdrive. Also my 4 blade only cost about $160.
 
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