1966 Mustang Sprint 200 package - Several years ago I zero decked the block and installed a Clay Smith 264 108 center lobe cam, but re-install the original C6 small log cylinder head with 52cc chambers. I was measuring 200psi for each cylinder with the mod. Fast forward to this year, I came across an E0 large log cylinder head, with the 1.75" intake valves and 62cc chambers, from an 80s Granada. My instructions to my local machine shop was to bring the chambers of my new head from 62cc down to 52cc by shaving off .050" and an additional .025" for the composite head gasket. He claimed they brought the chamber down to 52cc and verified. However, with the new E0 large log installed, I'm only seeing 130psi per cyclinder instead of 200psi as before. I believe I need to find another machine shop. Thoughts?
All Small Six Head swap yielded lower compression
This relates to all small sixes
Your suspicions are right on its always that same story! I would bet that if you CC'ed head you would find that it only had a light surface cut no matter what you told them to do or they said they did. The standard machine shops are few and far between that will ever listen to you and mill cut a head that much they do it the same for everybody and their likely not going to CC the head to check it. You always need to do your own CC'ing to know we're you are starting from and then when you get it back to know what you really have. After you done this stuff enough times you can look at the chamber and see that is not at 52 CC's. Best of luck
Thanks for the feedback @bubba22349 , just wanted to validate with the community.
Your shop may not of got the cc s you wanted, but 130 seams lower than I would think it would be even at 62...There may be other contributing factors making it that low.
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