MitsuStyle - View Single Post - Am I overlooking something? Low compression

s1ngletracker · 01-12-2011

so i did a leakdown test with the engine in the car, but I did it more thoroughly on an engine stand after I pulled it.

Here is a picture that most easily details my results:

The thing that disturbs me is the intake noise in 3 & 4... this is a rebuilt head. The engine is obviously stone cold and outside the car, but should I be concerned about that? I tried rotating the engine back and forth to make sure the valves were closed fully, no real change in the noise.

1 & 2 seem expected, little to no noise in the intake and exhaust, i think the noise and compression loss is due to the rings.

I think either way this head is going to headwerks for a thorough inspection before I dare put it in the car. I might have them look at my original un-rebuilt head as well. They didn't do the rebuild.

I'd like to hear opinions on this. Is there anything I should test with the head still on the motor? I might wait a bit in case there is something else valuable to test.

Thanks for the help and sorry about the book!

01-12-2011	#5
s1ngletracker Join Date: Oct 2005 Location: The land of the next-gen HMMWV Drives: A BMW Posts: 1,875	Re: Am I overlooking something? Low compression so i did a leakdown test with the engine in the car, but I did it more thoroughly on an engine stand after I pulled it. Here is a picture that most easily details my results: The thing that disturbs me is the intake noise in 3 & 4... this is a rebuilt head. The engine is obviously stone cold and outside the car, but should I be concerned about that? I tried rotating the engine back and forth to make sure the valves were closed fully, no real change in the noise. 1 & 2 seem expected, little to no noise in the intake and exhaust, i think the noise and compression loss is due to the rings. I think either way this head is going to headwerks for a thorough inspection before I dare put it in the car. I might have them look at my original un-rebuilt head as well. They didn't do the rebuild. I'd like to hear opinions on this. Is there anything I should test with the head still on the motor? I might wait a bit in case there is something else valuable to test. Thanks for the help and sorry about the book! __________________ Style's automotive engineer Sponsored by DB Performance (dbptuning.com) A dsm, a bimmer, a DORGE CUMMINZ, and a non running DSM race car... for now. Last edited by s1ngletracker; 01-12-2011 at 11:28 PM..