Hopp'in up my 330's -inexpensive route
 

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 -

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:D

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.

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.

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

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.:p

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

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.

Crazyhorse, Your PM box is full

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

Ran-Dom32,

Depending on how far you want to go will obvisously depend on how much money you want to spend. Sounds like you're looking for a 5mph increase and that you want to work with most of what major parts you have there now.

With your 330's you probably have the stock "peanut port" GM oval port heads with the stock 2.06" intake valves and 1.72" exhaust valves in them. You can take those heads and have the larger 2.19" stainless intake valves and larger 1.84" stainless exhaust valves installed in them. This will be good for about 15hp. Or you can keep the stock size valves, but replace them with stainless steel valves. WHATEVER size valve you decide to go with, make sure you have the heads "pocket/bowl" ported. Install bronze wall valve guide liners---these will usually don't wear as fast and are more forgiving than the stock steel valve guides. The guide heigth may have to be machined to clearance the lift of the new cams otherwise the retainers may hit them during engine operation. Have a 3-angle valve job done. Replace the heavy, stock cast iron piece of junk intake manifold with an aluminum dual plane intake manifold (Edlebrock or Wieand). Install a new hydraulic cam/lifters with something like a 222* intake duration and a 230* exhaust duration on a 112* lobe seperation angle. For the new cams you'll need new valve springs to match. I would add a some moly 10* retainers and machine hardend locks. Do the engine a big favor and replace the stock stamped steel piece of junk rocker arms with a set of aluminum roller rocker arms. The stock GM stamped steel rocker arms won't allow for the bigger lift and duration anyway. "Scorpian" brand makes a decent rocker arm (blue colored) for what you're doing that are reasonably priced. Add new true double roller timing chains sets. Replace the stock pistons with new forged or hyperutectic pistons. The stock cast cranks will be fine as well as the stock 3/8" connecting rods. Just have the stock rod bolts replaced with an ARP "wave lock" 180-190psi bolts. If the block needs boring have the shop use a torque plate when they finish hone the cylinders. Make sure they check/measure the main saddles and have them align honed if needed.

Just make sure you have EVERYTHING checked and MEASURED with a MIC by a reputable, competent performance machine shop that knows how important the difference of .0001" of an inch can make. Have the entire rotating assembly balanced.

As far as aftermarket aluminum exhaust maniflolds go, it is probably the most important thing you can do to help the performance of an engine---they help the engine breath better and are usually cast aluminum which makes them MUCH lighter. The stock Merc cast iron exhaust manifolds are very CRUDE breathing and are extremely HEAVY! Stainless marine or even Gil marine makes a decent manifold. Stay away from aftermarket manifolds that have only a 2.5" collector and/or have a riser that has 90* bends and a poor primary design within the manifold. Buy a manifold that has at least a 3.5" collector and elbow shaped risers/tailpipes. Adding the cams, intakes and head mods will help your engine(s) and you still might even be disappointed, therefore until you add performance exhaust manifolds to those mods I have given, you're probably not going to see the KICK IN THE PANTS performance that I think you're really looking for. My .02 of course. I hope it goes well for you.

Ran Dom- Is your boat all yellow???

the 330 on steroids route is a good combo... go with what Crazyhorse listed and keep the at 5500 or under for RPm's and use a good machine shop!!!!

Crazyhorse, Dyno and I are all on the same team actually----Team Chaos that is. We've all put our heads together for these souped up Merc 330 combinations that work.

Thanks for all the suggestion's guys - roughly how much $$$ are we talking? Correct me if i'm wrong but would'nt it be cheaper to buy a used pair of 502/415's such as the ones in OSO classified's for $15,000/for the pair. I'm not sure I have the mechanical ability to do a rebuild. If I have to pay someone to perform the surgery on my 330's - I may be better off pulling out what I have?
I have to way to cost. My main concern is reliability - are these 330's going to hold together @ 450 - 500hp 5500 RPM or are they wicked? I'm located on Lake St. Calir bordering MI -how reasonable is Tyler Crocket??

I had about 6K in mine 2 years ago....I had one set of Merlin heads, but I bought EMI exhaust also.....thats for two motors !most engine guys around here get 800-1000 to assemble them.
I had one MSD ignition and bought one more....You can pick up some parts off the board or if you get lucky some one might sell a set of 502's but they arent cheap....

OH and one more thing we are getting about 250-300 hrs before rebuildimg them......very few problems....

I got 10MPH with twins......

I too have taken a 330HP 454 and done significant upgrades. The best advice, is good quality machine work and attention at assembly. I had my block align bored, new ARP rod bolts, .030 over with hypernuetechtic pistons, new 3/8 push rods, cam, lifters, and roller rockers. I have tried two different cams and two different sets of heads and two different intake manifolds, and I'm still not happy. The dyno figures look pretty good, but the actual performance in the boat has been disappointing.
Before you do this, I would suggest that you figure out how fast you want to go, then figure out the power you are going to need to get there. Then, see if it is feasible to do all this work on the 330's or get a couple crate motors. I'll be happy to share any info with you.
Good Luck

Hey Whiteknuckle what are you running for exhaust? you should be around 500 hp depending on your heads and exhaust.....3--5 mph I jumped up 150 hp in a single engine application and gained about 5

Dyno,
Good to hear from you. I am running EMI exhaust. I am still running a Q-jet, and everybody except a few are telling me thats why I lack top end. I have power getting on plane, good midrange, but I hit a brick wall at about 4600 RPM. So I am going to give in a buy a 800 CFM Holley this winter and try that in the spring. I'm all ears!:confused:

Whiteknuckle it sounds like we are very simular in our set ups I'm at 9.5 to 1 and am using a 850 holley with an rpm intake......I've tried a single plane but did'nt like it the power band was too high I wanted to stay under 5200...the 800 holley works better than my 850 we dynoed SuperV's and it made 505 hp at 5500

Very similar here too, Except Im using 780's with a single plane torker 2 intake and Gils. The 850's didnt run any better WOT, idled and started bad and used a ton more fuel. I dont know how to work with Quads but I had the same result as Whiteknuckle did with the stock ones. The Quad maxed at 4700, the Holley ran 5400, everything else the same.

I've mentioned this before, but when we dyno'd the engine the first time, (with big valve peanuts) and the q-jet, the engine acted like it needed more cam or fuel. We then put a 830CFM Holley that was tricked out for a Busch Grand National engine, and bingo, it jumped 41 HP. Of course this carb would be impractical on a boat that requires decent low end and idle situations, but the I figured in my own dumb ass way that I just was not getting the full benefit of the Q-Jet. Now after two seasons of fooling with it, new 049 heads with big valves, new Ultradyne cam, that maybe its the Q-jet that not getting the job done. Actually it ran just as strong with the peanuts, with sharper midrange.

I know Dennis Moore is a strong supporter of the Quad and hates Holleys and I am sure there are people who know how to trick out Quads but Im not one of them. I know how Holleys work and how to set them up and I never had any luck with Quads.

Formula31, you are correct.
Dennis Moore is one of the reasons I have persisted in trying to make this q-jet work. The carb has been worked over by people that are in business and specialize in modifing Q-jets.
I'm not blaming my lack of top end performance on anyone but myself, as I make the decisions, however I fell for the carb sizing routine, that actually figures mathmatically that this 750 CFM Q-Jet is oversized for my 461 cu in engine.
For $500.00 or so bucks, I'm going to try the 800 Holley.

Since I am using vacuum secondarys and single acceperator pump, it took a few years before I found the right combination of jets, pump size, cam size, squirter size, power valves, springs etc. but now it starts and runs like its injected. Without a choke. You wont be dissapointed with the holley I hope. They dont make them like they did in the 60's any more.

I bought a couple 850's on ebay for cheep!!!

Whiteknuckle, long time no talk. I also like the Q-jets but I think the Holley 800 or 850 is a good carb in your application. Dyno's, as well as SuperV's, engines perform very well with the Holleys. Both of those guys have their jet and powervalve info written down.

Crazyhorse, How ya doing?
Hey, I'm humble, I'll accept all information on tuning I can get. Any suggestions on setting up the new Holley are welcome. It is sold as "standard marine calibration" so I guess that is a good starting point.

I'm not sure on the power valves but SuperV and I are jetted at 75 front and 89 rear...

I really like running the Holleys with the rear power valve plugged. Your carbs may come with the rear metering blocks blocked where the power valve screws in. And I think the general consensus is that you'll need to be around 8 to 10 jet sizes bigger on the rear when not using a rear power valve.

Dyno, Crazyhorse,
Thanks, I'll probably be picked your brains this coming spring when I attempt to dial it in. I'll see what happens.

ttt

Ran-Dom 32
 

Did you decide what to do yet? Time's a'wastin', bub. Spring is almost here, at least as far as your machinist is concerned. One thing no one mentioned to you, now is a great time to learn how to read a micrometer. You can save some time (read "money") by doing some measuring yourself. Things like main bearing bores, big end of the rods, crankshaft rod and main journals, stuff like that. Keep us informed as to your decisions and progress. Of course, you could always bring the engines (in pieces is ok) to west Michigan and let Team Chaos put 'em on steroids.:D

Oval port intake manifolds
 

Ran-Dom,
I about to hop up my 330's when I found a deal on some small blocks with more hp. I bought new Eldlebrok Performer Intake manifolds they are oval port and still in the box. I will give you a deal on them send me a private message and we'll talk.
Max