Engine rebuild question

[Anonymous]

Everyone.

As some of you might now, I have finished rebuilding my 200 which had been suffering from low cylinder compression. I was re-reading the sticky on head swaps my CZ and I was thinking I may have unknowingly overlooked maintaining a good compression ratio with my rebuild.

This has been the first complete rebuild to the engine but a head swap was performed sometime in the past (I guess to compensate for unleaded fuel - it's a 77 now). So I would like to of course rebuild it right!

I used a Felpro no re-torque head gasket (looked pretty thick). I'm assuming it's probably around .050" in thickness. I also used 9.2:1 CR pistons (that's what they were labeled on the boxes) and the dish is slightly smaller than the originals. No oversizing was necessary.

So with that little information, can anyone guess at my CR with my current rebuild? I would like to achieve somewhere around 9.5:1.

If I deck my head, say .050", would that be okay?

Thanks.

 

[CobraSix]

Try this:

http://falconperformance.sundog.net/compcalculator.asp

using the calculator, and just playing with some numbers that sound like they might be right:

anywere from 9:1 to 9.5:1

Slade

 

[CZLN6]

Howdy Stang200:

Yes, you can safely mill a stock '77 head .090". .050" will get the chambers back to the '66 volume of 52 ccs. You must mill another .025" to compensate for your FelPro head gasket.

Also know that your new pistons have a 6.5cc dish and that the stock deck height on a typical '66 200 is about .025". Also know that most replacement pistons are made with an additional .005" of deck height by lowering the crown of the piston.

Click onto the compression calculator that slade posted and run your numbers. Be sure to measure carefully and often, and write them down for future reference.

Adios, David

 

[Anonymous]

Thanks guys!