4 Blade Prop
 

Hello all, I am a former owner of a 1988 Formula 206 and hopefully future owner of a 1989 242 SS (barring a successful marine survey). The prop on there is a Mirage 21P but it could use a reshaping,,, I am curious if I should just invest that money into buying a 4 blade prop?? Are there more advantages such as planing up, speed, etc?

The setup is a 1995 7.4L Mercruiser and a Bravo 1 outdrive.

Thanks in advance

A 4 blade - like a Revolution 19P - would give you a better hole shot, lower minimum planing speed, but a slightly lower top end speed.

Depends on a few things like how deep is the x dimension and are you looking for Max speed, max cruising speed, or? Typically you will see 3 blade props on those.

On my 242LS I run a Bravo 1 22pitch labbed a little runs very nice, but mine is on a alpha 1.47 ratio, you would be very close with your bravo.

Thanks for the responses guys... I am more concerned about a quick and painless hole shot rather than top end speed (since I like what money that is left in the checking account). I would assume lower planing speeds is more efficient for mid-range cruising?

I have not bought the boat yet (although if its not this one it WILL be a 242ss) but I want to get a head of the game. After the marine survey, I will sea trial it before the cash transaction. At that point, I should monitor top end rpms to see if I can down pitch to 19p, or are you saying its pretty safe to do so with this boat in general on a 4 blade prop?

Where should my RPM range be on the 454?

Your max rpm should be 4600 on these boats you will need to trim it up to get that.

I have a 242sf with 8.1 MAG/375 hp. I run a 22" 4 blade with Smart Gauges. cruise at 32 and almost 5mpg (my 350/260 got 1 mpg, 38mph at 4200 running 3 blade 16"x16") wide open I gotten her up to 58mpg at around 4700 rpm. Takes 4 big guys, 133 gallons of gas and tackle right up and out. Of course lower top end but who cares, I'm going fishing. Nicer ride at cruise speed.