compression test

[Malahki]

So after attempting to do a compresion test on my slow cranking engine (addressed in another thread http://real4x4forums.com/PinzgauerBBS/v ... =12&t=6288), my results were all in the 80-90 range. This was also after doing a valve set. So I'm wondering:
1) is my slow cranking speed bringing down my results?
2) What is the minimum acceptable operating range?
3) What is the compression when new?
4) also what is the compressor ratio? 8:1, 10:1??

Thanks

[edzz]

1:7.5

http://real4x4forums.com/PinzgauerBBS/v ... ompression

[edzz]

The slow cranking could affect compression test. I also believe that the cold temperature could affect testing. I’d most concerned (initially) about consistency from one cylinder to the next in trouble shooting your current issues. A leak down test would provide a better indication of condition than a compression test also leak down test is independent of cranking speed. Once more I haven’t a clue if either test is affected by your spring temperatures.

[Malahki]

Fortunately the Pinz is in a heated garage, so temperature is not an issue. Good suggestion with the leak down test

[Malahki]

So with good batteries the slow cranking problem was corrected and the compression test results were much better. All cylinders were in the 115-120 range.