350 Mag mods?
 

I just picked up a Formula 242 with a 350 Magnum w/roller cam. From what I've read this engine is underpowered for this boat. I don't what to replace the engine with a big block but instead want to build this engine up to 400 hp. I'm planning on leaving the bottom end alone. The boat only has 300 hours on it! I am going to replace the heads, cam intake and whatever else I need to to hit the 400 hp goal. What suggestions do you have?

Have you thought about going with a supercharger?? There are some systems available with low boost, that would give you a real performance gain.

BTW does the boat have a Bravo drive?


Darrell.

I agree with DMOORE. I have done both a Whipple and Procharger on that engine and they both work great. They have all made at or over 500 hp effortlessly. I really think that will be the best bang for the buck in your case. There are really no modifications that need to be done to the engine other some some programming to the ecm. I would be glad to help if needed.
Eddie

This is the carbed 350 magnum (1987). Is that kind of power possible with the stock non-vortec heads?

After looking into the supercharger it looks like that is going to be a bit out of my budget. I was thinking, about a bigger comp cams xtreme marine cam, world sportsman II heads and
stealth intake(which I already have) and put a set of Imco risers on my factory manifolds. Anyone think this combo would be good for an extra 130 hp? I should be able to do all this for under $2000.00 vs $4500 for the whipple.

Alpha drive.

For now, yes I have an Alpha. Over the winter I'm going to do a bravo conversion. Until then the Alpha will last through the summer with 400 hp.

Coming from a guy that has been messing around with heavy single's (boats not women) for a while, I would say save the money and go with boost. You can wake it up a little with heads, cam etc, but if you really want to feel it then boost is the way to go.

If you have an alpha drive, I would do neither. The alpha will hold up to 400hp on some of the lighter boats (ie 18 foot Donzi's) but on a heavy boat you are pushing your luck.

Well Iguess a supercharger it is then.... Is there a reason nobody uses Weiand blowers? There half the price of a whipple. Is the whipple than much better?

All I can say is most of the time you get what you pay for. I have had nothing but good ecperience with Whipples, just do your research before choosing an ECM. I hope your alpha lives untill winter. Good Luck.

On a small block, that isn't going to put out a ton of boost, the weiand will work great for you. Check out the classifieds, and spam section. If you do get a used one( off a 525SC maybe?) you simply need to get a manifold for the small block. The reason I say 525SC, is that a lot of guys upgrade the blowers to whipple, and sell of the stock setups. The 525SC set ups would work *****en on a small block. Plenty of boost, without spinning the blower too fast.


Darrell.

Darrell,

The more I've looked into this the more I agree with all of you that supercharging is the way to go. What kind of difference would I see with using say a Whipple over a used 525sc blower? I'd really like to get up to the 470+ hp area if possible and still have the motor be reliable. The boat does a have an Alpha now but that is going to get pulled and replaced with a bravo. If I'm correct all I need for the conversion is a drive, drive coupler and the outer assembly, right? Right now my formula 242 is going about 48mph with a 19 pitch Mirage my goal is mid to high 60's with the supercharger and bravo. If I can find one I'd like to put on a shorty. Opinions on any of this?

any other opinions on this?

Well thanks for all the opinions on the 350. I decided that a BBC would really get me where I want to be. So I picked up a 396 that I will be putting in my 242 this winter. I'm trying to get the specs on the HP3 525 hp engine and see what I need to do to get that power.