I am working on my build, and have successfully replaced my EVO9 springs with Cosworth singles, (kelford CAMS, etc). In the process I am pushing air into the cylinder via an adapter to force the valves up so they don't fall in when I remove the retainers. Blah blah, a good write up with pictures coming when complete.

What I noticed is that in cylinder #1 the intake port is leaking more air than any of the others. Its consistent and audible. Both cams are off, so no pressure on the valves at all. They should be fully closed. This had me worry that there could be damage to the valve or valve seat, but I don't know enough about HEAD, , to determine.

Can folks let me know if there are tests I can complete to confirm or deny valve damage, or sealing issues. The air is not leaking out the pistons (I have the oil pan removed and the motor on a stand). Its specifically coming out the intake port on Cylinder #1. It was not so much that my air compressor couldn't fight it, so I could still change the springs, but I worry if there is damage that requires removing the head and getting it worked on/fixed/ported, etc.

Thank

 

This is the EcuFlash forum, this thread belongs in the engine/turbo/drivetrain section.

 

There is always going to be *some* leakage, obviously less is more better. Unfortunately listening to the amount/volume/sound of the hissing isn't very quantitative.

Use a leakdown tester to get real numbers.

 

whoops. fat fingered the forum. I always have the engine and the ecuflash forums open. I must have mixed up. Can a moderator move it, to clean it up for me? Sorry.

 

what do you have your headstuds torqued to?

 

I don't know. Its stock head. So, I have never taken it off. It never exhibited any poor performance or dirty colored exhaust. Essentially a very strong self tuned stock turbo 9.
I am doing the cams and spring now, and just noticed the #1 different than the rest.

I suppose I will have to do a leak down test as QH15 suggested. I need to research what I need for that.

 

You need an air compressor (which you have) and a leakdown tester with the appropriate adapter for your engine's spark plug thread size and pitch.

 

Might be crud built up. Increase to 100psi to see if that seals it (don't have car run over you) . With everything back together, what does cyl 1 compare for compression.

 

I restarted this thread in the correct forum.

https://www.evolutionm.net/forums/ev...ml#post9925197

I have been using 100psi. I guess I need to take the head off and look. Was trying to avoid buying another head gasket.