All Small Six Overbore and deck height question

[clochard68]

Two questions that arose while calculating and measuring for static compression on my 200:

All my pistons have „30“ stamped in their dish, does that mean that my block is bored .030 over?



And I measured my piston to deck height with a deck bridge and a dial gauge. I measured between 0.87mm and 0.92mm, which equals to a piston to deck height of .034“ to .036“. I found this thread where also .031 is mentioned: Negative Deck Height for 200 | FordSix Performance Forum

Has anyone else a similar deck height?

 

[bubba22349]

Yes those are the aftermarket .030 over Dished Piston's. The Ford Standard Piston was a 1.511 Piston Compression Height (CH) and were typically a Neg .019 Deck Height, the Aftermarket Pistons are typically a 1.5 CH. So yes that is about right on the Deck Height and will cause you a little lower Compression Ratio. Looks like they are smaller Dish 6.5 CC's. Yes .019 plus the .011 is a the .030 deck height for most, also your Block Deck Height maybe a little more than the averages.

 

[clochard68]

Thanks bubba, lot's of good information as always!

.030 overbore means in diameter, right? So the overall diameter of my 200 would be 3.71"?

 

[drag-200stang]

Yes, it should be.