I Just pick up a 24ls. 454/330 slightly modified probably around 350hp. I just wondering what prop I should be using and what kind of top end I should expect. anyone with a similar setup have any input. would like to squeeze the most out of the top end.
thanks
Dennis

I had a 88 242ls with the 454/365hp mag, turned a 21p mirage plus at 59.8 mph really light on fuel bye myself

The difference between 330 hp and 350 hp in a 242 would most likey be the same or maybe 1-2 mph increase. The real GPS speed should be around 53 mph. Speedo speed could be way different. The Mag boats are around 56 MPH GPS. A 21 pitch is most likely the right prop. I have around 530 hp and I see flat water speeds of around 61-62 and around 64 with some chop. My speeds however are with a mirage prop that is in bad shape.. I'm now going to be using a new Mirage plus so speeds should increase a bit.

Either way 242 are great boats, that ride very well, but they are not speed demons and need a lot of power.

Thanks, gives me a good basis to start from. I'd like to get close to 60 so i guess I'll have to up the hp. thanks again.

We have a 232 bowrider with the 454 mag that just spent the winter being redone. Block is .030 over with little different cam , pistons and light port work, removed silent thunder for thru hull, spinning a 21 mirage in no particularly special shape and did 64.7 in choppy lake water on GPS. Cant wait to see what she does on a glassy morning.......70 would be crazy in our little BR but am stoked to see what it does now !!

You will need around 425 hp to hit 60.....

I did 59.8 with a 365

I got a Mirage + 23 and the difference is astounding!
I gained 10 MPH, the boat now handled well, carves turns with stability and without falling off plane and planes at a lower speed, around 22 mph. No more cavitation.

Now to find a new, hotter motor........

Nice, I put on a new Mirage Plus 21 on my boat and I'm now at 69 mph. What a difference between the plus and non-plus!

Just tested my 242LS with twin 350s after upgrading the intake manifolds and carburetors from 2 to 4 barrels - previous top speed was 56.0 GPS (on 1 ft chop, ocean) @ 4700 RPM. Tonight, I hit 58.4 GPS @ 5100 RPM on a fresh water lake. I'm hoping that translates to 60 in the ocean. Will find out next weekend.

The RPM sounds high for these engines, so I think I may increase the prop size a little. I currently have 13 7/8th, 21P 3 blade Quicksilver Lasers. What prop size/pitch do you guys recommend? My wife will love it if I need to order a couple of new props!