Best Way To Deck Height

[Guest SBZ]

I would like to know the best way to check my Deck Height in a SBC 350.

I am just workin on the best way to dial in my compression ratio and when I built this motor 2 years ago I was not very aware of valve timings affect on DCR or what it was.

[jt1]

If you're dealing with a bare block, it's probably best to get a machine shop to check it. The tools to check a bare block are pretty expensive, probably 3-400 $.

 

If the motor is assembled, you can use a bridge mic. With heads off and a clean deck, bring piston to TDC with a dial indicator, then check piston depth with the bridge mic. This doesn't really tell the deck height, just the depth of the piston below the deck, which is what you want for compression calculations.

 

You can also use a good quality straight edge and feeler gauges. Clean the deck and piston tops, find TDC with a dial indicator, lay the straight edge across the deck and use the feeler gauges to find the distance between the straight edge and piston. This takes a little practice, so play around to get the "feel" of the feelers sliding under the straight edge. This is not as precise, but is generally within a few thou, which is usable for compression purposes.

 

Always check directly over the wrist pin so piston rock in the bore doesn't affect your measurements, and don't be surprised to see the measurements vary some. A lot of tolerances can come into play and affect the results.

 

John