I know its been said 234908234 times. The compression is too high. The pistons are ****.

But how long did yours last? How hard do you drive your car?

I put on about 1000-1500 miles a year in mine. I do floor it, but its not raced regularly or anything crazy like that. I dont pound it, but I dont baby her either. So I figure, its not THAT unreasonable to be able to go 8PSI intercooled on the stock bottom end for about 5-6000 miles until I am out of college and have the budget for a top notch rebuild. Currently has about 17,500 miles on it.



I was planning on doing Heads and Cam this winter. Going large on the heads (In anticipation of going Forced Induction and stroked, later on ... ) But my boss keeps trying to push me towards a super charger or N20. And I cant argue with my man with the stickers can I .

So I thought about it and I know a few things right off the bat: I dont want to go any more than 8 PSI. I WILL NOT do it until I can afford a intercooled set up.

I was leaning towards a ProCharger, but I am open to options as long as it would be intercooled. Also, I plan to later on, make a 383 ( Or stock bore possibly? ) I will be building a low compression motor that would likely see 12-14 PSI ... I am plannin on eventually building a real monster of a street car. But I dont want to buy a supercharger now and have it not be able to make the boost I want later on. Would a P1SC support that kind of boost on a 383? I would be shooting for at least 600 at the wheels long term. I thought a D1SC would be better, but I am new to the whole forced induction scene. Never built a blower motor so ...

What would you guys say would work for now, and be able to keep up later with a different pulley?

 

Honestly..its all a chance game..seriously...I know people who have blown up new engines on say a 50 shot of nitrous..and I had my first trans am with 133k(harrrd driven miles) and i sprayed a 150 shot..with 93 octane..no tune and a set of shorty headers..for a whole summer without a problem...your car might* take 8psi fine..it might* 10psi fine...but then again..it might* not. Also..if your planning on doing a 383 stroker later..then no the P1 wont be what your looking for..youll want a D-1..I dont think you can pulley a P-1 past 12psi anyways(correct me if im wrong). But like I said earlier..its a chance game..theres a chance..that your fully forged 383 might blow up on 8psi..theres too many factors to consider to be able to properly "forsee" any damage. I think your car would be fine for 5k on a p1..but I dunno about a D-1 ..maybe if you can pulley it down alot lower. But your better off getting a D-1 now...(even though it will increase the risk..but then you wont have to go back later and upgrade.

 

Thats kinda what I was thinking as far as the D1 vs P1 thing ...

Theres gotta be a pulley to get a D1 down to the boost levels I want.

I keep thinking my car will take it, but I dont want to blow it up now, and have to do my whole rebuild on credit lol. I want to do it, as I have the CASH for things.

Hopefully some more people will post up how long theirs lasted to give me a idea of how well 10.4:1 and 8PSI mix lol ... Thanks.

 

Honestly...you cant go by what other people run...they might be the lucky ones..like i said..who knows..your car might be a car that can hold 8psi on a D-1 for 3 years before blowing..or it might last 20 min. Get it..pully it down as far as it goes..get meth injection..and have it tuned right....meth injection is a huge deal..esp on a stock motor..its extremely safe..and helps prevent(but not stop) detonation. Its the best 3-400$ you can spend on any FI car.

 

Mine lasted over 2 years driven daily with only a popped head gasket (fixed with ported heads and cam). It's in a friend's car right now getting ready to be started again.

 

8k miles on 6-7psi non-intercooled with a safe tune before I pulled the engine. Compression test shows everything is still good.

 

I've put on about 15k so far and no problems with 7 psi tuned but not intercooled. Actually I ran half the miles at 5 psi and the rest at 7.

 

Thanks everyone ... I knew it was kinda a hit n miss deal, but really, if I can get 5,000 - 6,000 miles out of it, I'd be content. It has 17 almost 18K origional miles on it now. It is in perfect shape. I understand each car was different, but I was just wondering how long it seemed to last most people.

I put on about 1500 miles a year. Its strictly my "fun" car ... And I wouldnt be totally brutal on it so heres hoping ...

I want to make a significant bit more horsepower than I am now. I wanted to do a LE3 head ( For more flow later down the road ) LE1 HL cam, but my boss is making it sound like he doesnt want to inspect it for me like that ...

 

right....but he wants to inspect a blower car..heh...

do what you want to with it...not what someone tells you to..

I say screw the blower and get a turbo....

 

Yeah...I second the "do what you want, not what others tell you to do".

Far as boost on stock internals, it's a crapshoot. The most important thing that I will stress to you is GOOD TUNING, GOOD TUNING, GOOD TUNING. I ran 7psi unintercooled boost on stock internals, I broke 2 shortblocks, and 7pistons within 3 months. Each time, the motor lasted about 1000 miles of extremely hard driving. I'm building up the 3rd motor currently. My strongest recomendation to you is to have a safe dyno tune done. It's something I don't think is stressed enough when people ask "is it safe to run XXXpsi on stock internals?". If you have a healthy motor, yes you can, but it's all in the tuning. The last shortblock I blew up had cylinder leakage of only 3% across the board (avg.) and ran extremely strong, until detonation occured. Knock and detonation is most likely what'll kill you.

This is why tuning is my most important recommendation. I did a mail order tune from a very reputable company. The person who did the tuning is prolly one of the most knowledgable in his field. But because it was mail order, he had to merely work off previous tunes, and guess what would be safe for my setup. The tune ended up not being safe enough (too much timing) leading to detonation that absolutely destroyed my ringlands. EVERY car is different, and when you add FI I'm a strong believer there are too many factors to take into consideration, without having the car in question at you're fingertips or data from the vehicle, tuning should not be done. So, absolute minimum do you're FI and take it to a dyno, and stress a safe tune. Second, get yourself some stuff to monitor what you're car is doing, most importantly knock. (i.e. scanmaster)...this way if you've been driving in 90* weather for 3hrs and you're car is horribly heat-soked, you'll be able to see the knock and get out of the throttle before you toast you're motor.

Just my $.02.

 

In my opinion the main deficency using blowers on stock shortblocks is ring end gap. My factory shortblock had top ring end gaps of .010" to .012" when I took it apart and checked it. No piston material available will keep the ring lands on the pistons with a gap like that under boost. That is what fails the stock pistons IMO. Intercooled systems can buy you a little room in this regard, but it's really just a crapshoot. If your motor has tight gaps on the rings, it will break the pistons, if not, it will probably work. In this regard, lower miles on the engine is probably a negative. I took mine apart at six thousand miles mind you.

I actually consider myself fortunate to have not broken mine. I failed an iron valve guide on my TFS heads which put metal debris in the motor. It was because of that, that I decided to freshen the engine just to clean it properly. That's how I found out about the end gaps. Had I not done that, and subsequently installed the blower, I am certain I would be on the list of guys complaining about stock shortblocks.

FWIW, I have been running a set of hypereutectic pistons for the last six years albeit with .028" end gaps, and have had zero issues.

Roger

 

blew my pistons in about 300 miles.

 

from what i have read you are the man too talk too about making the best of a powerdyne..what pistons are you running? stock? what CR? head specs? cam? just curious thats some very too times and espcailly MPH, what did it dyno?

 

I am running KB-197 pistons on Manley 5.850" rods, stock crank. The CR is 9.9:1 with the 12cc dish and the 62 cc head. The heads are TFS twisted wedges which are quite rare for good reason. They flow well (251@.400, 279@.500), but they took a lot of work to get right. GTP ported them twice, and I had a lot of issues with geometry, and the aforementioned guide issues among other things. The cam is an XE224/230/112LDA/107ILC I have not dyno'd the car. I am putting a TH350 in right now in hopes of getting an ET commensurate with the MPH.

Thanks for the complement. Jeff (of pinks fame) has me covered with a PD slightly.... for now... ;^)

Rog

 

yea i knew of jeffs set up as well his sounds very impressive what kind of set up does he have.. anyone ever have good powerdyne results on a 383?