HarrisonTX Posted November 23, 2005 Share Posted November 23, 2005 Alright, so heres the deal I have 2cars, my '79 malibu, and my z. The Malibu is a pretty deticated street/strip car, with no a/c, heater, power steering, and high idle, due to a rough cam. My going to try and keep the datsun somewhat of a daily driver. I just got my 302 pistons, which have a 11.8:1 comp. ratio. I was going to get it milled down, so i can run some 93 gas. I got to thinking, why not mill it way down and install a Pro Charger. I Dont know much at all about boost, i would run something mild like 6-8psi, to try to get some life out of the motor. Im not gonna lie about it, i will drive the car, and drive it hard every now and then... 1.Whats the difference in intercooled systems, and non intercooled systems, yes i know one has an intercooler, and makes more power, is that just because the air is cooler? 2.If i only want 6-8psi, i can get a small procharger correct? 3.Can i still keep the A/c With the procharger, is there enough room in a z engine bay? I HATE clutter, (thats the reason the malibu has an almost empty engine bay) 4. True or false, the lower the comp. the more effective the procharger 5. Is 10:1 too high for a procharger Any random info will be gooood Thanks guys Quote Link to comment Share on other sites More sharing options...
Guest mofaster Posted November 23, 2005 Share Posted November 23, 2005 1- An intercooled system will allow you to fit a larger amount of air into the combustion chamber because the cooler air is denser; more air means you can burn more fuel in a single charge resulting in more power 2- ? 3- Maybe, but if you go with the intercooler probably not 4- ? 5- no. if you want the high compression with the supercharger I would look into a Rotrex Supercharger. They wind up almost as high as a turbo and work very well on the low end Quote Link to comment Share on other sites More sharing options...
HarrisonTX Posted November 23, 2005 Author Share Posted November 23, 2005 Cool, i was your first post. I found this nifty little chart on the procharger site Looks like with 10:1 or so comp, i could get 6psi... Hmm Quote Link to comment Share on other sites More sharing options...
HarrisonTX Posted November 24, 2005 Author Share Posted November 24, 2005 anyone else? Quote Link to comment Share on other sites More sharing options...
BringIt Posted November 24, 2005 Share Posted November 24, 2005 What are you going to mill down the piston tops? I would think of just using some different pistons - Forged would be nice. Most the time when you go with boost the piston has a dish not physically shorter. 9:1 / 10:1 - is fine as long as the tune is on and you dont get too radical with the boost - 6-8 lbs of intercooled boost is about right on 10:1 Lower compression doesnt not equal more effiecent forced induction - Its all relative to a dynamic compression ratio. Boost + Compression = Max Compression Ratio using a certain octane of gas. Is this going to be a blow-through carb or a EFI ? Quote Link to comment Share on other sites More sharing options...
Mikelly Posted November 24, 2005 Share Posted November 24, 2005 YUp, I'd sell those pistons and buy dedicated forged pistons that are the target compression. I'd also shoot for lower compression. Also, I'd not put a blower on anything without an Hbeam rod and 180K capscrews. Mike Quote Link to comment Share on other sites More sharing options...
dsommer Posted November 24, 2005 Share Posted November 24, 2005 I'd shoot for the 8:1 CR with the intercooler. Make sure you run a good rod (standard Eagle SIR rod are good to 500HP). Reason being for the lower compression is that you can up the boost later on. How many times have we wished for more power? Go see the post Grumpy made the other day on what your tying to build. If you haven't started building the engine yet then I would build for the supercharger applacation if you truly want to go that route. Plan on installing an intercooler I feel it is a must on a boosted engine, them more you can cool the intake charge the better. There was a good write up in on of the hot rod mags somebody posted earlier can't find it now. Read this from procharger it basically tells you how to set up your engine: http://www.procharger.com/bebs.shtml (Mike you beat me to the rod issue;) Quote Link to comment Share on other sites More sharing options...
iaconsultants Posted November 24, 2005 Share Posted November 24, 2005 Just some information that you may want to know. 6 to 8 psi is not a lot of forced induction to run on an engine. In general you can run that much boost on a stock motor without it comming apart on you. The general rule has been keep the boost 10 or below on a stock type of engine with stock compression. When you run 12 pounds of boost and upwards you will need to start doing more things to your engine and the higher the boost goes the exponentially it goes up (intercoolers, water and/or meth injection, grooving the head and/or block, pistons, valves, rods, polishing chambers and the list goes on) I have done many different set-ups and if you are just hoping to put together a motor and placing a supercharger on it then sorry to say you are going to have a big learning event. You are lucky in a lot of ways because there are people in your area that have a great amount of knowledge on forced induction. The best guy to locate in the Dallas area would be a guy named Corky Bell, he has written a few books on the subject and you was the owner or Cartech Turbo Industries some years ago (I don't think it exists any more) Back when I talked to him a lot and created a straight six monster that had up to 30 psi of boost on it, which was in a 77 280Z. My suggestion is first read up on turbo charging and supercharging. Get a really good understanding on what it does and what the weak points are on your engine. I have just seen to many bad things with people trying this and not knowing what they are doing, like I said I have worked on and designed these systems for cars and am currently designing one now. Running higher compressions will not be a good idea, especially if you do not go all the way through the engine. I will see if I can find some pictures of some destroyed engines and cars that might let you understand better. I am in Dallas frequent so if you would like you can bounce some ideas off me and I will let you know some things you will need to do to make it more a daily driver. Quote Link to comment Share on other sites More sharing options...
HarrisonTX Posted November 24, 2005 Author Share Posted November 24, 2005 Alright, good info, im learning alot. The reason im using those pistons, is because those are the only 302 pistons avalible. 302's came from the factory with 12:1, so they are just stock replacments, and yes, they are forged, so is the crank, and teh rods i plan to buy. a 302 has a 4inch bore, but i cant just stick in 350 pistons, because (i forget the tech. term for it) the distance from the wrist pin, to the top of the piston is differnt. I could maybe get away with running a 13:1 (or about that) 327 piston, which in a 302 would equal to about 9:1, perfect. I know 6-8psi is low. Im not trying to get crazy. I like to build the motors, for more power than i have. For example, i built my malibu motor, and its got forged probe pistons, forged rods, forged crank, and is a 4bolt main, and only making about 350 Horsepower. I planned to sprey it, so i built it right the first time. I want this z to be my daily driver, so i want to keep it tame at 6-8psi. Im not trying to squeeze every little bit of horse power i can out of this procharger. iaconsultants: i plan on making this a tough motor. dsommer: i dont have the option of 8:1 Quote Link to comment Share on other sites More sharing options...
BirdmanZ Posted November 24, 2005 Share Posted November 24, 2005 you should try looking through a summit racing or jegs catalog. sealed power forged pistons in a 8.78 to 1 compression ratio are only $263. i wouldn't even consider having pistons milled. they only have so much material on top and weak pistons + boost = bang! Quote Link to comment Share on other sites More sharing options...
getZ Posted November 24, 2005 Share Posted November 24, 2005 Last time I read prochargers website, they recommended at least forged pistons of 9:1 but said you could get away with stock rods up to around 500 horse, the reason being supercharged engines are easier on the bottom end. Personaly, I would run at least a 5148 rod at that horsepower level. As far as compression, are you planning on running a carb? EFI gives you more room for error flirting with the edges of detonation, but it is a very expensive upgrade. Intercooling is another option, but why not spend the money on lowering the compression with pistons now and have the option of upgrading to an intercooler later, besides prochargers intercooler isn't any cheaper. Quote Link to comment Share on other sites More sharing options...
HarrisonTX Posted November 24, 2005 Author Share Posted November 24, 2005 Last time I read prochargers website' date=' they recommended at least forged pistons of 9:1 but said you could get away with stock rods up to around 500 horse, the reason being supercharged engines are easier on the bottom end. Personaly, I would run at least a 5148 rod at that horsepower level. As far as compression, are you planning on running a carb? EFI gives you more room for error flirting with the edges of detonation, but it is a very expensive upgrade. Intercooling is another option, but why not spend the money on lowering the compression with pistons now and have the option of upgrading to an intercooler later, besides prochargers intercooler isn't any cheaper.[/quote'] Carb... Bird, they dont have those pistons for a 302 chevy, as i said before Quote Link to comment Share on other sites More sharing options...
getZ Posted November 25, 2005 Share Posted November 25, 2005 I didn't realize forged 302 pistons were so hard to find off the shelf. You can always custom order them, but that is not necessarily a cheap option. You'd have to call JE or some other manufacturer and get a quote. What kind of head volume are you running? I found a set of SRP's that will yield about 9.5:1 with a 76cc cylinder head. Another option may be to stroke it to a 327. I believe it's just a crank and piston swap. I assume all 302s were all small journals, so you'd need a small journal 327 crank. Quote Link to comment Share on other sites More sharing options...
HarrisonTX Posted November 25, 2005 Author Share Posted November 25, 2005 I didn't realize forged 302 pistons were so hard to find off the shelf. You can always custom order them' date=' but that is not necessarily a cheap option. You'd have to call JE or some other manufacturer and get a quote. What kind of head volume are you running? I found a set of SRP's that will yield about 9.5:1 with a 76cc cylinder head. Another option may be to stroke it to a 327. I believe it's just a crank and piston swap. I assume all 302s were all small journals, so you'd need a small journal 327 crank.[/quote'] 302s are large journal. Im using a forged 283 crank, and a small journal 327 block. I dont want to stroke it to a 327, i have a 327 crank if i wanted to do that. I am facinated with 3inch stroke Quote Link to comment Share on other sites More sharing options...
Guest Phil1934 Posted November 25, 2005 Share Posted November 25, 2005 Ford 300 6 shares compression heights and valve reliefs with 302. Just juggle pin sizes. Quote Link to comment Share on other sites More sharing options...
Collectindust240Z Posted December 1, 2005 Share Posted December 1, 2005 Another thing to consider when using a ProCharger is the camshaft. Lobe separation plays a big role in cylinder pressures and controlling detonation. With forced induction, you're gonna be way more likely to grenade you're motor with just the slightest hint of detonation. My boss is running a 383 stoker w/ AFR 210cc heads, SRP dished piston, Eagle H beam rods, Eagle forged crank, Edelbrock Vitor JR intake, Holley 650 (prepped by ProCharger), No intercooler, I can't remember the cam specs though. It is a custom grind Comp billet roller. It made 604HP on the ground through a 2004R tranny and Ford 9 inch. At 9 puonds of boost. It's set up to run 14 pounds, no intercooled. The fuel through the carb acts to cool the intake charge somewhat. He fragged the last motor because the cam grind wasn't blower friendly. Had to do with lobe separation. Quote Link to comment Share on other sites More sharing options...
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