just got off the phone w/ the machine shop, doing a 383 stroker,
i'm not the most knowladgeable bout this stuff. he said my heads have a 52 cc chamber. ? (le2 heads) he was going to use srp flat top pistons, and said that would put me at around 11:1 compression, that would need a mixture of pump/race gas. this IS NOT a daily driven car, but i don't want to HAVE to put race gas in it, want to be able to run pump gas.
he said j & e has a new piston, its a 28 cc reverse dome piston (?) that will put my engine around 10 or 10 1/4 compression, which would be best and make the most power. i am going up there later today to look at and order some pistons, what are my options?
thanks alot for any help
-Jason

 

Generally, you'll make more power with a higher compression ratio. Whether you need to use "a mixture of pump/race gas" would depend on the dynamic compression ratio, and you need to know the cam specs to figure that out. I seriously doubt you would need anything other than premium pump gas with 11:1 on an aluminum head LT1. It would make no sense at all to drop below the stock 10.4:1.

You need to get all the specifics of the engine, and check the guy's calculations. Go to one of the online CR calculators, and you will find a list of all the dimensions you need.

Given the information you provided, I would get a "second opinion" on virtually anything the "machine shop" guy tells you.

 

On a .039 gasket, that 52 cc head will put you 13:1 with a -5 flat top.
I could be wrong, but I don't think most people categorize that as a daily driver.


That -28cc dome piston he's talking about would put you at 9.9:1 on the same heads and gasket.
You can get over 10:1 if you run the Impala gasket, but I wouldn't run that gasket if you plan on spraying it decent.
Price: $659.97 For the pistons, $99.97 for a JE moly ring set.

 

say i ended up with 10:1 or 10 1/4 compression , how would that run?
so to get the most out of it, i need to strive for 11:1 compression. what piston would i need w/ a 52 cc chamber?
thanks for the help, i really appreciate it.

 

you could run the 13:1 if you figure your dynamic compression ratio is around or less than 9:1 post the cam specs to one of the guys here and I am sure one of the guys with a calculator will figure you ration for you

 

i was wanting to get a custom grind..somewhere around this

236/242 .608 110 lsa

 

Why haven't you looked at the -14 and -16cc dished pistons? They will put you in the low to mid 11's for compression and that's about a perfect blend for HP and durabilty.

BTW I would really wonder if a guy told me a compression ratio that's OFF 2 points of compression.

Remember the quote in my sig...... also works when buying parts too fast. Where is the money for them going to go? Your GF or old lady going to spend it for you. BUY THE RIGHT PARTS THE FIRST TIME

BreT

 

This really seems like it should be discussed in an Engine Tech Forum...

Also a search would turn up a lot of answer to questions you have had.

Transferring, thanks.

 

That's the point I was trying to make in my response... but I guess he missed it. He needs to question everything the shop is telling him, because most of it makes no sense at all. Learning how to calculate compression ratio might have been a good start.... and leave him less vulnerable to the BS he is getting. Sounds like he'd rather just "settle" for 10:1, as long as it "runs".

Ken - I'm glad you moved this off of "Advanced Tech".... I should have done it.

 

flat top pistons with those heads will give you a really high compression...im using -16cc pistons with 55cc heads ..and im right around 11:1