I got a set of 10:1-10.8:1 pistons for a street car! But i think i may turbo it. I don't want to sell or buy another set of pistons. So whoever has a Compression ratio in that area with boost please let me know what you are running and problems occured, etc.!!!
Thanx,
Stan

P.s. I have read about 5-6 different threads that were brought up under the SEARCH BUTTON (the only threads) but they just argued about which cr is better and 3% loss to 1:1 cr drop but about 3.1ish% increase per 1psi boost! SOOO?!?!?!

P.s.s. It is a 347 stroker(MEXICAN BLOCK)! Heads and cam haven't been purchased but they will be after i see about this cr/piston stuff!

FEED BACK IS GREATLY APPRECIATED!!!!!!!

 

C16,ic,and keep the boost down.
Alky,no ic and leave it as is.

 

Hang a turbo off the side, run good gas, listen for detonation. If the pistons can't take it, they'll let you know. Maybe then you'll want to buy another set.
issuez

 

10.75 to 1 28 degrees of timing 7 pounds of boost , rear mount turbos, slight air to air effect in tubing and snow meth kit, 94 octane and no problems. The higher compression makes it more fun on the street, and I had it at 17 psi with half 94 and half 116 and it hauled ass!

 

c16 only and give her hell! nothing less, 10 to 1 is what i'm shooting for.

 

What cc head are those pistons designed 4? If that cr is rated for a 60-62 cc chamber and you havent bought heads yet you could get some 70cc chambered heads and get a more friendly cr that way.

 

You can also use a thicker head gasket, like .080" or even thicker. I also like the idea of using a larger chamber head, or doing some chamber work to remove some material while getting better flow at the same time.

 

Pistons equal

10.8/58cc 10.41/61cc 10.05/64cc 9.61/68cc

I really want AFR heads but I don't think they make a 205 or 225 with a 70cc or even a 68cc(but i haven't researched this fact YET!!)

What heads are that big and make great power with great flow for a turbo setup with a 70ish cc chamber(but a gasket can make up some of that volume.) Would you go aftermarket or get a set of 351 heads and port/polish/enlarge them???

If anyone has done this please chime in!!!

Thanx,
Stan

 

You can take material out of the chambers and change it a few tenths of a point. When I'm done porting my e7's and gt40p heads they both have 64cc chambers, from 61.5 stock. I also did a set of e5 351 truck heads and they are now 70cc, and flow fairly well. unshrouding the valves also helps flow along with lowering the compression which is great for boosted apps.

 

Well Trick flow makes a 70cc head HIGH PORT TFS-5170T013-C01 part number. They are 2500 though !!!!! I guess i'll have to roll with these?!?!? Anyone who can give an alternative instead of 2500 dollars I'll consider the pros and cons!!! Flow kinda like that TF and have a 70cc chamber is what i need i guess!?!?!?!

Thanx,
Stan

 

You can get Victor Jr.'s in 70cc but they're unassembled.

Brodix has Track 1's that are 68cc and would work awesome.

 

I bought a set of 70cc vic jrs for 1300 assembled from keith craft racing

 

Really? :hmm:

I've seen them for $1200 or so unassembled (no port work, parts, etc). Were they used when you bought them? When did you buy them?

 

Who makes a thick head gasket? I would like to go from 10:1 to 9.5:1 or 9:1

 

lubbock gasket in texas will make you any thickness copper gasket up to .250

 

I think they only make these in 58cc .

 

I see your are running 28 degrees total time. What is your base time?

 

What he said!! Shit if you haven't bought heads yet get some of the Victor Jr. 70cc's. Get the chambers polished and unshroud the valves and you could have about 73-74cc by the time your done with them. Then run a .053 or .063 Cometic head gasket. Don't go to much bigger with the gasket as it negatively affects the quench of the chamber.

 

i've been thinking of asking this same question. i have 11.2:1 with my heads now(out ofbox cnc bmf 268's) . i am about to mill them to get 14.5 ish to 1 since it was built with nitrous in mind. but been thinkin forced induction would be more fun. don't really want to get new pistons, since these were pricey since custom made. am i dreaming when i think i can put a procharger or something on this and make it live? if its too nuts i'll just stick with the plan and spray the way

 

I you're looking at buy heads but don't want to buy pistons????

Heads $1000.00 plus
Pistons $400.00 or less

Simple math not even new math or anything like that..........