426 Hemi piston...?

[Gunnar]

Hello.

I just took my Hemi apart and trying to decide what cam to use in it...

It came with a 312 deg "Cam Dynamics" cam, CHR 312 s, but I want a more "streetable" car...
I put a original -70 & -71 cam in it and let it run for 20 min, but I think it have to much comp for that cam.

Now I have looked at the pistons but I can't id them...

They go 20.7mm above deck and the only marking I can find (without taking them out) is C & A (Child & Albert?)...
No number or anything...

They look like this:







The questions are:

*What are my cr? (Piston id)
*What kind of cam is to use?
*Do I have to change pistons to have a streetable car?

[Cooter]

Looks a little high Compression to me for the street, but do wedges, not Hemis...

[Ghoste]

Impossible to say what the cr is without a proper measurement but Cooter is right, those are higher domes than the standard Street Hemi.  As for cam, also impossible to ay without knowing more about the rest of the build and your goals for the car.  Whether those pistons are okay to use, well, the Hemi head does lend itself to higher compression ratios but again without knowing more about the rest of the car and your fuel availability and goals for the car it's impossible to say.

[tan top]

Looks a little high Compression to me for the street, but do wedges, not Hemis...

Impossible to say what the cr is without a proper measurement but Cooter is right, those are higher domes than the standard Street Hemi.  As for cam, also impossible to ay without knowing more about the rest of the build and your goals for the car.  Whether those pistons are okay to use, well, the Hemi head does lend itself to higher compression ratios but again without knowing more about the rest of the car and your fuel availability and goals for the car it's impossible to say.

yes looks higher than a stock piston !  grooves in the block also , suggest the block has been o ringed at some point , = serious compression

  see the insides have been painted glyptol also so its been built up with some carefull  attention 

[Rolling_Thunder]

those are some healthy compression pistons...    my boss bought a hemi back a couple years back and the pistons looked similar - was something like 13:1 compression ---  but no way of actually telling...     would definitely say its over stock compression though

by contrast the pistons pictured were in a 10.5:1 compression engine

[hemi68charger]

those are some healthy compression pistons...    my boss bought a hemi back a couple years back and the pistons looked similar - was something like 13:1 compression ---  but no way of actually telling...     would definitely say its over stock compression though

by contrast the pistons pictured were in a 10.5:1 compression engine

I agree,,
Those are some hefty pistons.. Here is mine with OEM factory replacement pistons. Hate to say it, but if you want something that's rather streetable, keep the '70/'71 hydraulic and ditch those high compression pistons....