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Posted: 3/7/2006 8:06:16 PM EDT
[Last Edit: 3/8/2006 4:41:13 AM EDT by BullDogger]
Ok folks i been out of state working the last couple weeks. Just a reminder Im working on a blown 383 stroker motor to stuff in a 85 short wide truck. My cam finally came in along with my retrofit hydrualic roller lifters, and my roller rockers, etc. Now i need the crank,rods,pistons for this thing. I have found all kinds of forged fully balanced kits i like but they the wrong pistons. I need something like JE blower pistons thats made to give 7.5-1 or so compression ratio. Everything i have found is designed for naturally aspirated motors with ratios like 10 to 1 or so. So if any of you could help me find a already balanced ALL forged rotating assembley using low compression pistons for a 383 stroker motor i would be very thankful
Link Posted: 3/8/2006 4:42:27 AM EDT
btt come on folks im only going to be in for 5 days and i need to get this stuff ordered....anybody know what it would cost to have a shop balance everything for you?
Link Posted: 3/8/2006 5:01:23 AM EDT
balancing should be around $500. make sure you include the flywheel if it's a shift car.
Link Posted: 3/8/2006 5:09:13 AM EDT
Buy/borrow a digital scale and do it yourself.

Weigh each piston, rod, ringset, clips/buttons and bearings. Then mix and match till everything is as close as possible in weight as a set. With high qualitly parts you should only be off a couple grams from heaviest to lightest. As long as they arent slipper skirts, you should be able to take a couple grams off the skirt of the pistons on a belt sander to match the heaviest to lightest.

Go slowly when removing material. You can take it off, but you cant put it on.

The crank should come balanced.

I've been out of the game for a while, but I'd bet that today with high quality name brand parts it won't take much to balance.
Link Posted: 3/8/2006 5:11:28 AM EDT
i have called 3 machine shops this morning and everytime i ask them if they balance rotating assemblys you hear a uniform "huh?" lol do they sell already balanced cranks, already balanced rods, and already balanced pistons seperate?
Link Posted: 3/8/2006 5:23:37 AM EDT
thanks for the help captain....if they are only off buy a couple grams probably do you think it is that crucial that it gets balanced beforehand?
Link Posted: 3/8/2006 5:28:34 AM EDT
Like I said, the crank (a name brand performance crank) should come balanced. Then it's just a matter of balancing the pistons etc...by weight. It's isn't rocket surgery.

Link Posted: 3/8/2006 5:37:42 AM EDT

Originally Posted By BullDogger:
thanks for the help captain....if they are only off buy a couple grams probably do you think it is that crucial that it gets balanced beforehand?




Just take some material off the skirt of the heavy pistons on a belt sander. Be careful, go slow, and weigh, weigh, weigh. If one piston is way off, send it back and get another one.

A couple grams is nothing in the real world but if you're building a a motor for HP go for perfect.

At the speeds pistons travel and stop a gram here and there adds up but like I said, I'd bet that today's name brand performance pistons would be pretty close out of the box, both in size and weight.

Oh, and just so we don't have a "Flight of the Phoenix" moment. I was a motorcycle mechanic and I've been out of the trade for a while.
Link Posted: 3/8/2006 12:31:31 PM EDT
ok well i ordered a eagle 4340 non twist forged crank rated for over 1,000+ hp and some eagle h beam rods rated to over 1,200 hp....that and the bearings was $1,243.95. I will probably order pistons and rings and maybe cylinder heads next time i come in from work. Anybody have a suggestion for a centrifugal supercharger? Im wanting to run around 10 pounds of boost
Link Posted: 3/8/2006 2:22:36 PM EDT
I'm no FI expert but I like the ATI Procharger. Self contained, easy install, reliable from what I hear, the Vette guys seem to like them a lot. Make sure you get the 8 rib belt, some guys with really high HP motors are shredding the 6 rib.

If I had the money I'd buy one.

www.procharger.com/TRUCK_SUV/truck_suv.shtml
Link Posted: 3/9/2006 1:05:33 AM EDT
If 10lbs is all you are running, you probably don't need low compression pistons
Link Posted: 3/9/2006 7:50:49 AM EDT
The way it was explained too me was the lower your compression ratio the better....and I might not be satisfied with just 10 pounds...lol....i want to leave myself some room for improvement if i choose to go that way
Link Posted: 3/9/2006 5:04:12 PM EDT
[Last Edit: 3/9/2006 5:06:34 PM EDT by jstang]

Originally Posted By 2ridgebacks:
If 10lbs is all you are running, you probably don't need low compression pistons

I concur, it will be a complete pig while not under boost.



this is a 383 stroker built to take 20psi. It was done by Billy the kid performance engines in Torrington CT, give him a call for a piston source. I'm a Ford guy so I can't help ya.
One thing to consider is keyways on the crank for the balancer, if you are going to turn up the wick you'll need bigger and maybe more than one because of side loading on the blower drive pulley.
Link Posted: 3/9/2006 5:39:21 PM EDT
I dont recall seeing what supercharger you are going to run. I have an intercooled ATI procharger on my mustang and it can give you more leeway in terms of compression ratios, fuel and timing. Ive read in the past that roots blowers and turbos especially needed lower compression motors.

As far as balancing your rotating assembly, its hard to believe you cant find someone to do it in a big state like Texas. Mine cost around $125 if I remember correctly.
Link Posted: 3/10/2006 5:29:31 AM EDT
I have about made up my mind that a ATI procharger is what im going to get. Whats a package cost with intercooler?
Link Posted: 3/10/2006 5:40:17 AM EDT

Originally Posted By BullDogger:
I have about made up my mind that a ATI procharger is what im going to get. Whats a package cost with intercooler?



I believe you're looking at 5-6k for the full kit with plumbing and intercoolers. I'd hunt around, I've seen them used on the Corvette forum for 3k and even less.

Sometimes they sell in halves, just the head unit and just the plumbing, that's where you'll find the best deals. I saw a head unit sell for 800 and the same day the complete intercooler kit got bought by the same guy for 800. He ended up with the full kit for 1,600!
Link Posted: 4/3/2006 11:33:14 PM EDT
BDS- Blower Drive Service can and will answer your questions on building a blower motor. Parts including pistons for your application are available through them as well ,,and the knowledge base there is fat. Look them up on the web its should be a toll free number
Rotating assemblies need to be balanced in a shop on a balancing machine to get it right Period!!
forget the woodshop tools and spend a few dimes to talk live to a pro and browse your internet on engine balancing for longivity plus performance gains.
A good balance job will free up many horses and also NOT cost over a couple hundred dollars. Balancing includes wristpins, spiro-locks, piston- rings, bearings plus the crank with flywheel and harmonic balancer attached and balancing both the big and little ends of the rods, ya can't do that with the old high school wood shop tools. There are special tools and holders for engine rotating assy work, I can provide you with a top builder and engine balancer shop owner to speak to if ya want to talk a bit. It isn't that exspensive to do it right the first time.
Have your ignition system set up correctly either by using the correct electronic pieces from MSD or send the distributor to BDS for curve work and talk to them for timing needs. Your timing and curve work in the ignition will make or break you for keeping the engine cool and living at most any PSI-boost you will run on the street.
Exhaust side of your heads is the power side with a blower, again talk to a blower shop and learn all you can,Eagle rods are very good for your application and use only FORGED pistons, hyperkinetics will not live long and plain old cast types won't go more than a few stop lights.
Good luck
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