Powerboat Forums at SpeedWake banner
1 - 12 of 12 Posts

·
Registered
Joined
·
128 Posts
Discussion Starter · #1 ·
Prop question on a 242 ss 454 330 hp


I have a 242 SS 1988 with a standard 454 330 HP 1997
GenV. The prop is a Mirage Pluss 17, I know the prop
is to "small"
Ex.:
3200 rpm my speed is 28 miles
My rpm is much higer then it is supposed to be, but I have
never taken it higer then 4500 then I get aprox 42-43 miles.

I have a lot more throttle to give but, I havent let the engine
gone over the 4500 rpm.

I am going to buy a new propp, but I am not sure what kind of
prop either mirage P19, mirage P21 or bravo1 4 blade 20

My normal boating is 2-4 people some gear, I am not to stressed by top speed, but of course everybody want his boat
to go as fast as possible.

I would like it not to be to slow to plane, and have a good midrange preformance.

So what should I go for??
 

Attachments

·
Registered
Joined
·
1,282 Posts
I have a 242 LS with stock 454 (330hp) with a bravo drive. I am running a mirage P21. works well nice hole shot and good top end :)
 

·
Registered
Joined
·
128 Posts
Discussion Starter · #3 ·
242 formula said:
I have a 242 LS with stock 454 (330hp) with a bravo drive. I am running a mirage P21. works well nice hole shot and good top end :)
Thanks for qiuck reply *S*

What is the speed at 3200 rpm?

Top speed?
 

·
Stokers Rule
Joined
·
4,387 Posts
The bravo1 four blade is worth a try. Can you get a 20 pitch bravo?

Others like the revolution which is a 4 blade also.

With this 24 degree hull more blade surface area helps to push it better and why the four blade does wonders for mid-range which is where the boat is most of the time anyway.
 

·
Platinum Member
Joined
·
1,495 Posts
242 formula said:
3200 is about 40 mph
That seems pretty optimistic, only a 9% slip... Whats your WFO RPM with that prop?

If I remember correctly my 22" Bravo1 gets my 242 to 36MPH at 3200.
 

·
Platinum Member
Joined
·
1,495 Posts
aquaforce said:
The bravo1 four blade is worth a try. Can you get a 20 pitch bravo?
As far as I know the 22" is the smallest B1 prop made, just for reference It just turns a hair over 4900 with a 502 in my 242. 60-62MPH depending on the water.
 

·
Stokers Rule
Joined
·
4,387 Posts
SweetEmotion said:
My Libby hull is pretty similar to Formulas. When I had a stock 454 i ran a 21p Mirage 3blade top end 54 at 4800rpm


A three blade prop will usually get the better top end because there is less blade drag in the water which lets the pitch really go to work.

On the other hand the four blade has more blade surface area which normally drags top down just barely but increases launch, plane and mid-range a great amount.
Typically the four blade is more efficient because it works in the rpm range that the boat is in most of the time.
 

·
Registered
Joined
·
1,606 Posts
I believe the bravo 1 Prop will be too much for your set up. I think the diameter is larger than the revolution, and I had a 21P revolution on my old boat and before the motor mod's it was about all the engine wanted. But I loved the prop only lost a mph at top end.
 

·
Registered
Joined
·
128 Posts
Discussion Starter · #12 ·
3wood said:
I believe the bravo 1 Prop will be too much for your set up. I think the diameter is larger than the revolution, and I had a 21P revolution on my old boat and before the motor mod's it was about all the engine wanted. But I loved the prop only lost a mph at top end.
Hi

Ordered a Mirage Pluss 21, did not test it yet.
I hope it will be ok
I would like to try a 20-21 P revolution as well

What was your Speed with the revolution?

Easy out of the hole?

Midrange?

Top end?

regards
Rune
 
1 - 12 of 12 Posts
Top