cp5899

iTrader: (1)

I bought a 90 baja 235 force and I'm having the motor rebuilt right now. The build is pretty mild. Reconditioned stock crank and rods, flat top pistons, cam motion custom cam, edelbrock intake with rebuilt quadrajet carb, stock manifolds and peanut port heads.

I haven't run the boat so I don't know how fast it will be in stock form. While the motor is at the machine shop getting built I'm thinking about adding a set of edelbrock rpm heads to the build instead of the peanut heads. This is my first power boat and what I'm trying to find out is what will all of this add in real life boating situation (aka speed/mph). Will the cam and intake help any when it comes to speed or was it a waste of money? If I add the heads to the build what will they bring to the table?

The boat will be used in fresh water.


Thanks for the help!!!

SHAWN DAVIS

the peanut head is probably done at 4000 rpms, the rpm head is better, think they list flow at 300 @.600 lift.
the cam motion cam is a good choice they are pretty sharp over there.

cp5899

iTrader: (1)

Yeah, they have done a few cams for my turbo ford small block cars.

What does it take to gain mph on a boat? In my business (drag bikes) 10-15hp equates to 1 mph gain in the quarter. I understand boats have a ton of varibles due to hull design, length, weight, etc etc. Anyone have any rough ideas what I can gain from the cam and intake swap and possibly the head swap? If all of it is only going to be worth 1-2 mph then I won't bother with the heads, but if theres decent gains to be had then I may just add the heads to the build. The short block was built today so I have a day or so to make up my mind.

Thanks for the reply.

jeffswav

Peanut port heads on a 454 run out about 4600-4800 RPM. If you have a custom cam they already set it up for those heads. You need to set it up specifically for the heads you are going to use. Did you use Bob Madeara for your cam?

gsxr1216

if your running the stock exhaust i dont think the heads will be worth the $$ since your ex will be limiting your HP potential, plus it limits your cam choices also.

what do you run for a drag bike??? I've got a Topgas Suzuki that runs 8.17@167mph

rssteiny

You will gain more than 1-2 mph with the heads the peanut port heads suck, 15 hp = 1 mph till you start making 600plus then it takes more to pick up. Id also get rid of the qj and put on a good holley with a 1" super sucker spacer. some better exhaust will help the heads and cam. And dont forget you will need to most likely prop change unless you were low on rpms with the old set up.

cp5899

iTrader: (1)

I'm not sure who at cam motion did the cam.

If going with a set of $1800 heads is going to make the boat 1-2 mph faster then its not worth it to me. LOL I was figuring heads, intake and custom cam would make at least 450hp and if thats only worth 1-2 mph over a 330hp stock motor then its not worth the money. I would have thought it would gain 10 mph from a 100hp boost, but like I said I'm new to power boats and have no idea.


As for bikes we run the 1/8 mile mostly. Inline 4's to twin cylinder two stroke motors. Times are from 6.0's to 4.9's depends on the customers budget as with anything. We do alot of forced induction/nitrous builds.


thanks for the replys

cp5899

iTrader: (1)

This would make me feel like I was getting something for my money if 15hp=1mph. I just looked up the edolbrock rpm kit and they claim 540hp with this kit. Ok, so I'm running manifolds and a small carb. That being said 450hp seems like a realistic number. If 15:1 was some what accurate then that would be close to 8 mph gain and would spark my interest...LOL If I changed to headers and bigger carb (which I would do as I got the boat running) then I would start to see the full potential out of the edelbrock kit.


I understand this is all bench racing, but I'm trying to weight out $ to mph. If a 120=8 mph I'm interested. 120=1-2 mph I'm not interested and just saved money for a couple months worth of fuel

pqjack

had edelbrock heads in my previous baja 240,on top of a mild 454,comp cam 226/234,roller rockers,holley 750,gil exh. edelbrock intake...got me right at 70mph,spinning a 23 mirage at 5200

MDGperformance

My guess in your boat extra 100hp 5-7mph,extra 150 6-8mph,extra 200 8-10mph ,boat will need right prop for the extra hp and a good performance exhaust will be needed for any decent hp gains