Some of the 4th gen guys are starting to scare me. They are saying w/an ati procharger and 3 core intercooler, the most boost I should run on my motor is 6psi. I was planning on running 9 since ATI swears up and down the motor will be fine with 12 psi provided great tuning and lots of guys here have said 9 at the most. I wanna hear from the folks who have been there and blown up their motors. What went wrong?

And...how much does it typically cost to swap pistons?

 

LT1's have 10.5:1 compression and Hypereutectic (sp?) pistons... 6 PSI is the practical limit on the stock engine and fuel system. Now I know of a few folks who run 9 PSI, but they have upgraded their fuel systems and some have had their ECM's reprogrammed. At those boost levels with a BONE STOCK LT1, youre asking for trouble.

Unless you have an LT1 in your car, those limits dont apply to you. I also just noticed that you have a ZZ4. I dont know what the compression ratio is on a ZZ4 but if I was you, I'd call ATI and ask them for your boost level recommendation. MAKE SURE that you tell them EXATLY whats on the car.

 

The 4th gen guys say that because they are on the whole ignorant of thirdgens.

Our cars have nearly a full point LESS of compression then their motors.

Any cast piston is asking for life on borrowed time since any hint of detonation can weaken it.

And if it goes, it depends on what it takes with it. Sometimes it will blow a ringland off and it will go right uot the exhaust. Other times could damage the cylinder wall.

a set of TRW/Speed pro forged slugs is usually approz $300. Then get them pressed on and off the rods. New rings, bearings, and hone or bore on the block if it needs it. Turn crank if it needs it.

I wouldnt wory much about it at this point.

Well... wait. I just looked at your compression. 10:1... Id still stay around 9psi. You will be fine there as long as you follow what we told you in the other thread.

 

Thanks again Guido. I think I will be calling around shortly to see how much a piston swap would be. If you guys have an idea, let me know so I know what price i should be looking for. Thanks!

 

Not to be a dick or anything, but you said in the other post you were running 12 pounds and 150 shot of juice??? And turning 11's

 

Read the other post more carefully and you'll see that I was talking about Jim Secrest, and his setup on his old IROC, not mine.

 

if you're gonna go to the trouble to swap pistons, make absolutely sure to ditch the hypercrap and go forged :lala:

 

That was the plan...

but I have a feeling it is just going to be way to expensive for the install.

 

Too expencive for the install?

You should prolly buy a nice 350 block for like 200 bucks with rods and stuff, and buy a manual and just start building it on the stand. THen swap it in YOURSELF.

Everyones gotta learn somewhere.

Then when you pull your old motor, you put it in the want add for
$250.00, and let someone offer you 200.00.

-- Joe

 

not to beat a dead horse but i gotta know-dont zz4's come with hypereutectic pistons in the holes too-i uderstand the pistons are going to be changed-but even if the c.r. was acceptable-the construction still wouldnt be, correct?

 

yes they are hypereutectic.

 

hey anesthes-your approach to building our cars is THE best approach to this little addiction ive had for 20 years or so. right down to the wheelin and dealin that makes the next step in whatever project that your involved with either possible or gettin closer to it. man, dudeman, wowsers-doing it yourself and LEARNING farfu*kinout- thats half or more of the fun.(sometimes not fun) but thats the part of the game too. :hail: hats off to you seemingly "old schooler" what i was gonna post was maybe the desired result here would be achieved more effectively if the question was "guys who have NOT blown up their motors...." methinks anyhow, average retail value is about 2 cents. :rockon:

 

If you swap out the ZZ4 short block Id be sure and sell it for more than 250 bucks...SHEESH! My old man ran a 142 wieand on his ZZ4 at 6psi with no intercooling (obviously) and as long as he pulled timing out of it never had a problem. The car ran very strong in fact. For what its worth my opinion is that in a ZZ4 with the right fuel system can take nine pounds intercooled with the stock short block. Sure seems like a lot of work to pull a fresh motor out and change slugs. Maybe you should look into a water/alcohol injection system or something that will add insurance with a lot less work and money. Just a thought

 

i think the point is being missed here