Compression Ratio, Will I be able to tell the difference? Options

[sdoolin]

Rebuilding(ish) my 2056. On my first build I was able to achieve a compression ratio of very nearly 9.0:1. With this build, I am having to add .020 spacers below the jugs to get any measurable deck height in the jugs. I am calculating a compression ratio of 8.6:1.

Will I notice the loss in compression ratio?

[Jack Standz]

Bolted things up on one side of the engine today and clayed the heads. I am measuring more than 0.1" between piston and valves. From my last build, this seems safe? I am double and triple checking as I have lost some trust in my own capabilities to do this stuff. Older than I used to be.

This is with a .020" spacer below the jugs. No "gaskets" in the heads.

A lot of this stuff requires carefully designing, measuring and implementing it into your engine build. We can't know what's up with your motor by typing on our keyboards. (IMG:style_emoticons/default/smile.gif) Heck, we don't know what cam you're running and whether it's lift exceeds coil bind in your heads. This is an important, but different issue than either piston to valve clearance or deck height.

We also don't know anything about your last build and how it went (or didn't).

Yes, double and triple check your measurements. Make sure you rotate the motor through at least 720 degrees (two+ full revolutions). It takes 2 revolutions of the crankshaft to complete one combustion cycle. Depending on your cam, you can have valves hit a piston at a point other than Top Dead Center(TDC). And, of course, clearance between the piston and valve is critical as well as deck height. One, so they don't hit each other. And, also so you have good quench and don't kill power.

If you don't trust your own capabilities, finding someone you do trust might be the best way forward. There are good competent engine builders out there. Something to consider.

Those heads cost more than $5,000 (with tax & shipping), it'd be a shame to not have them reach their full potential (IMG:style_emoticons/default/driving-girl.gif).