formula 69

Hello can anyone give me any advice, I have a 1989 formula 242ls which is currently powered by a 454 mag 7.4 335hp which i have stripped to the block and will completely rebuild with bravo 1. I would like more hp but not sure which parts to upgrade. Does anyone know if its possible to re-bore to 502 ci.
Any advise would be much appreciated thanks.

88242LS

Hello welcome to OSO, if you have a mag it will be a 365hp, the 330hp is not a mag, anywayz not sure on the bore thing, some guys will chime in I'm sure, are you a member of SW? if so Aquaforce is repowering his 242 also he may have some good tips for ya, where do you boat? and does yours have bolsters?

formula 69

Hello thanks for the reply, no am not a member of sw, sorry got the horse power incorrect it is 365 hp. I run my boat in the channel islands its a group of islands in the english channel between france and england.

I dont have bolster seats but have been looking out for some i have just the captains chair type ones at the moment.

mopower

Can't bore a 454 to 502. But you can replace the crank with a 4.25 stroke and get 496 cu in.

formula 69

Hi thanks mopower do you know if you have to change the cam pistons and con-rods to if you upgrade the crank to a 4.250

mopower

To get 496 , I believe that is a +.030 on the bore also so new pistons would be required. Both Scat and Eagle make stroker kits with H beam rods and forged cranks at reasonable prices.
Why not change the cam for more performance while your at it. It sounds like that is what you're looking for anyway