Ran-Dom 32

Over the winter I would like to put together a cost effective package to increase HP of these motors. Currently runn'in completely stock '96 7.4L carb motors in a 32 Sunsation - top speed 67-68 GPS 4600rpm 25" mirage props - hoping to pick up 5 mph - does anyone have a proven recipie/combo for these motors? please be as detailed as possible - is exhaust upgrade necessary? head work? intake? cam selection? on a budget -keep that in mind. -any help is apreciated -

Rambunctious

Dennis Moore will have the cook book proven answer. he should be around any minute.......

he has recently joined the oso ranks. if you don't get a reply, you can buy his book on bigblocks and learn everything and them some

formula31

There are quite a few of us running engines that used to be 330's. You really have to decide how much you want out of them and are you ever going to want more (most of us are never happy). The easiest way to is to put whipples or prochargers on them, keep the boost below 5Lbs and you will get your 5 mph, no problem until they blow up. probably $5-6000 for a pair if you shop, I think. If you decide to tear into them, there is a right way and a cheap way, you cant do both. I have done the cheap way many years ago and they will eventually blow up and you end up loosing half the summer. I have about $3000 in each of mine and thats all machine work and parts (most of those I hunted for). I did all the assembly myself. They make around 450 hp and will run wot all day. But if, i ever decide to make more power, I can, because the bottom ends are built to take more. My primary concern is reliability of the power plant so I wanted to know the insides very well.

Theres a lot to be said for buying stronger engines and selling what you have to defray the costs. Unless you like to tinker and want the pride of doing it yourself.

Its your call.

26 CHECKMATE

I had this same question about a year agoand this is what I did. I added a wieand 177 blower changed the cam and did a valve job. I was told that even with the lower end of a 7.4l motor being cast it would hold. I rode it for about 12 hours before the I detonated two pistons spun three main bearings and a rod bearing. I ended up pulling the motor and rebuilding it top to bottom and put it back in and within 10 hours I burned up two pistons again. I finally figured out that my oil temp was getting way to hot. Now its back in and running fine I had to get a much larger oil cooler. I have spent somewhere around $13000 in order to get where I am now and originally all I wanted was about 100 more horsepower and about 5 mph, where I ended up is about 580 hp and about a 15 mph increase. I guess the moral to the story is if you want more hp and speed dont do it on a budget because you will be dissapointed in the end when you spend half a summer with out your boat. just my 2 cents.

traviss

Crazyhorse has built a few higher hp 330's for a few west side michigan boys.. If I remember superV's dynoed a hair more then 500 hp.. and he built a few for dyno's sonic..


crazy will chime in on this post any time I would think..

Good luck bro..


Travis

formula31

And yes, clearances, balance and runout have to watched religiously in a rebbuild along with oil temp, fuel pressure and water pressure while your running. Or BOOM.

Bo Knows

Have twin 330's that ran 67 mph on GPS. Ported and gasket matched the cylinder heads, up graded the cam, lifters, & valve springs, changed the intakes, rejetted the Q-jets, added carb spacers, installed a double roller timing chain, installed thinner head gaskets to increase compression, and now it runs 71 mph. It sure sounds a lot healthier with the new cams in it !! Let me know if you have any questions .

Bo

Crazyhorse

Dyno and SuperV's engines started out as 330 Mercs. SuperV's dyno run was performed by Tom Earhart and the one Tom dyno'd made 505 chp at 5500 rpm. I would expect Dyno's engines to be about the same as the two sets of engines are virtually identical except Dyno has Federal Mogul H693CP hypereutectic pistons (9.5:1 c/r) while SuperV is running Federal Mogul L2465F forged pistons (9.65:1 c/r). Both sets of engines are running the same cams (all parts are off-the-shelf Federal Mogul), and both sets have Merlin oval-port heads. I can provide you with a complete parts list if you'd like. By the way, Dyno picked up 10 mph over the stock 330 engines in his 31 Sonic and did not need to make a prop change.
Waterfoul and BGIII are also running Federal Mogul parts in their engines, but I think BGIII opted for an Ultradyne cam/lifter setup while Waterfoul has Federal Mogul cam/lifters. I think we put H426CP pistons (8.6:1 c/r) in those engines. They both have GM rectangle-port heads. Let any one of us in Team Chaos know if we can be of any assistance.

Playn

Crazyhorse, Your PM box is full

Crazyhorse

Jeez, I didn't know I was that popular. I'll empty it out.
There, that feels better.