I have the fastburn heads with the zz430 package. The CR is currently 9.6 I would like to drop it down to at least 8.5
Does any body know were to find a good set of pistons to do this? The problem is the heads have 62 cc chambers.

I also have another question, how does the altitude affect how much boost can added? I found a formula last night for effective compression ratio and the numbers show I can go to 8 psi and still be at a 12-1 compression ratio. How is this affected by the altitude. Im at 6000 feet

 

Dished pistons are everywhere, you must not be looking hard enough. TRW makes a turbo-blower piston that is -21cc and I think SRP makes one that is -28cc.

 

 

Thanks for the reply,

How can you find the compression ratio with the head and piston cc?

 

http://www.sdpc2000.com/catalog/298/...num-Piston.htm

http://camaroz28.com/services/calcs/

Go to the compression ratio calculator and put in your specs.

 

JE also has some options, they're a little pricier than the above two tho. Most off the shelf pistons will have an advertised CR for the stroke they're designed for with a few various different chamber volumes.

 

Anyone know how fastburns perform in boosted applications?

I hadn't really considered them or e-tecs, but I wonder if their chamber design would still work right with dished pistons and boost.

 

Thats a good point thanks for bringing it up

 

TRW part # l2441f
this piston is for a 4" bore, and with a 58cc head gives an 8.71:1 comp ratio. You can look on Federal Moguls' site and look up the part number there. Its a forged d-cup piston with a -21.1 cc dish.

Also, www.smokemup.com has some great auto math calculators. There is a good calculator on here to calculate exact compression ratio.

 

Great Thanks for the part number and the link

 

Does anybody know how the dish piston will do with the fastburn heads?

 

Well, if you’re just looking for a dish, they’re fine. If you’re looking for a reverse dome to match the fastburn head chambers and retain some quench, then they’re an awful match.

I’ve built a fixture to cut reverse domes that match the vortech chambers (should be similar if not identical to the fastburn chambers), but it’s not something that I think that the average person can do themselves.

 

Be wary of stating that as fact. More is involved in determining compression than just head CC's and piston dish, as you can see from the calculators. I have these same pistons with 62cc chambers and my compression is about 9.0:1.
I just don't want anyone getting the wrong idea.

 

That's why I posted the link to smokemup.com, so he could go there and calculate for himself. I was mearly stating what the advertised CR would be.

 

I figured you were, it's just safer to say 'advertised', that's all. A lot of people take statements like that as solid fact and spread their misinformation, I always try to help prevent this. It's really not that big of a deal though.

At any rate, I'm happy with the pistons so far, but my engine isn't fully broken in yet so I can't say much, heh. I'd recommend getting them balanced though, as mine were not terribly weight matched out of the box.

The SRP's are supposed to be good for the price also.

 

How big of a problem will this be?

I wouldn't have bought the zz430 if I would have known I was going to add a turbo later. Seems like I am replacing amost every part.
My goal is to put 500 Hp on the ground what will this take at the crank (t56 with 4.10 zexel torson differential)

I know the internals of the zz4 block are suppose to be good to 500 hp, What would 500 at the crank do at the ground?

Is there any way to reach my goal with my 9.6 pistons and Pm rods?


Sorry for the extensive questions, Im new to the turbo game
Thanks everyone for the help

 

That depends on how optimized you really want the setup to be…



With properly matched/well designed parts it should take very little boost to get 500hp out of that combination. With an IC and/or water injection, proper tuning… you should easily be able to push more then 9psi through it, which should be plenty to reach that hp goal

I’d suggest that you do a lot of reading and learning before doing it though since it would be even easier to just bolt whatever people tell you to bolt on and blowing up the engine.