Compression ratio

[NorCalDime]

Im trying to find out what my compression ration might be. Im pretty sure its gonna be too high for turboing to be an option, but i dont know.. Is there a way to easily figure it out?

 

I have a L20b with a stock 510 head i think has number 210 on it. Was told it had bigger intake valves and was shaved. Some of the lettering is about 1/4th grinded off.

[datzenmike]

cc the head and I'll tell you.

 

For stock L20B with a 38cc L16 head the compression works out to 9.31 This is not too high for use with pump gas and 7lbs of boost I would think.

 

Why the L16 head? It has crappy port size, shrouded valves and was designed for the L13 motor. Larger valves on a small port isn't the way to go. Grab a U-76, everything is bigger and much better cam for the larger displacement L20B. 8.5 compression too. That much shaved off is going to retard the cam because of more slack in the chain.

[NorCalDime]

i really have no clue why it was used. i bought it with it on there.

was told that the Intake ports were ported. bigger valves and heavy duty springs were added. head was shaved to boost up compression.

 

Whats a U-76 run?

[hang_510]

Grab a U-76, everything is bigger

 

 

U67 :lol:

 

you should be able to locate for under $50 in clean & stock cond.

then buy Z valves and get it ported (for the new cam & rockers)