Compression Test + Leak Down Process?
 

Hello Pelicans,
I want to do a compression test and leak-down test.
The proposed sequence:
1 - warm up engine
2 - remove AC compressor/etc.
3 - remove all plugs
4 - compression test cyl. 1 then leak-down test cyl. 1
5 - do #4 until all 6 are done
6 - install new plugs
7 - install other stuff

The question is should I do all the cyls. compression test and then go back and do the leak-down tests? The means I would have to thread in the Stomski extender again on all cylinders.

The leak-down test might take a while because I will have to adjust the pressure on the incoming gauge if the regulator doesn't keep it right on. I plan to test with 80psi on the incoming gauge. I'll calculate the % after to compensate for not using 100psi.

Thanks.
-Henry

Following….

okay - I'll post results here.
It seems the people on BaT want both and having a record of results might help others.

If you want to follow along.... I started a thread here.
http://forums.pelicanparts.com/911-engine-rebuilding-forum/1102537-need-advice-leak-down-great-compression-test-not-so-much.html#post11461512

The engine says hot for a long time so rushing is not really needed. Getting the plugs out and having a setup to make the leak-down and compression tests get connected to gauges that work is needed.

I was told that you do a leak down test stone cold.

I don't do either hot.
for one its a pain working on a hot motor.
two what about temp differences from start to finish.
not worth it in my opinion.
people also say to hold the throttle wide open. I never see any difference.
as long as you do them all the same way is what matters.

I would check head bolts and do a valve adjustment first.
just check to see if any are broken.

pull the fuel pump relay