Does anyone have this correct info? I am having custom pistons made an did not measure this before I disassembled the motor. I thought I saw this info in the shop manual but I was wrong.

Thanks!

I measured mine at around 80cc

Thanks for the reply. What did you use to get that measurement?

A better question is what volume do you want for your custom pistons? The stock 430's I've measured yielded below advertised compression.

If you haven't gotten pistons you could mock up your old stuff and get the numbers. Standard methodes with a cc plate and burette. The heads need a known volume cylinder to determine valve, plug and small chamber (later heads) contributions

I am trying to drop the compression ratio from 10:1 to 7:1. So i am going to need the exact combustion chamber size at 10:1 so i know how much i need to dish out of the piston to acheive 7:1.

With the commonly available flat top pistons your compression will drop anyway appx. down to 8 or 9,0 :1 Ratio. I wouldn't go lower anyway.

You'll need 137cc's total with standard bore and a .040" head gasket. 83cc's is about 10.5. with a steel shim

Lincoln Mercury offered an export kit that sandwiched a 3/16" (or so) plate between two steel shim head gaskets to drop compression to 7.

Sorry I did not mention this earlier...I'm buliding a blower motor so compression needs to be low and the pistons need to be forged. Also I am boaring the cylinders .060 over so that needs to be taken into account.

I appreciate the all of your replys but all I am looking for is the total stock combustion chamber size of the head and cylinder. I messed up and did not measure these before I disassembled the motor. I was just checking if anyone has ever measured these. When I get my crank back from the machine shop I can use a burrett to do the measurement if needed.

Thanks for all of your help!

I kinda figured it was for forced induction. Roots or centrifical?

Seems like a '65 engine I checked had 98 or so, I can look later in the week for any notes.

When I did my '58 engine I used an extra 383 piston which stuck out of the bore on a 430 crank. Then machined it to what I wanted including valve reliefs. Sent it to the manufacturor and said make this. 'Course I wasn't lowering compression.

Brian Nutter who was / is at Wiseco speaks MEL and could design a 7.0 piston for you.

I have an old Weiand intake for a 671. If you could check your notes that would be awesome. Then I would have something to compare my measurements to. Also, I am in contact with Wiseco about making my pistons but I'm afraid Brian Nutter does not work there any longer. I have been speaking with Sue Nash. She can't find the info that I need even though Wiseco has made 430 pistons before