built motor woes. leaky exhaust valve
 

hey ya'll.

I have a built motor with a IAG stage 1 block and some GSC valves and retainers in the heads. 2500 miles, not even done with break-in

I had an issue of oiling coming out onto the engine bay from the turbo. I thought my turbo seals were done but wanted to check further with a compression test and leakdown.

cylinder 2 has lower compression than the others, 105. (115,105,115,120). i did the leakdown on all cylinders and they were great leadown numbers 3-4% except for cylinder 2 which has leaky exhaust valves. I did the leakdown test a ton of times to confirm this, making sure i was at TDC on the compression stroke.

did the teardown of the heads and everything seemed fine but i did the water test of the valves. water leaked into the exhaust port after 5 minutes. i told IAG about this so they could teardown and inspect.

1 month later, IAG tells me theyre perfect....what?!?! and also said the engine department said its not unusual for water to leak past the valve even if theyre perfect sealed. i always thought valves are suppose to be airtight seals, especially when new. or am i completely wrong?

they say potential issue might be in the short block or cam timing. not sure if that is true but would like any insight into this if anyone has anything helpful.

air escaping leakdown here

So did you have this installed by a certified IAG installer ?

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No. i bought the short block and got the heads machined by them and installed everything myself.

Ok wow impressive!! So I was just gonna say if you happen to be close to one, maybe consider getting checked by one ?

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Well the heads are with IAG now and they say theyre perfect so i rather have them just fix or do whatever neeeds to be done under warrantt hopefully but they say nothing is wrong which i think is bs. I have to get them back to me first. Iag is in maryland and im located in CA. Distance was always an issue.

"Leaky valves seats are normal." LOL
Get those heads back from those butchers and send them to someone who knows what they're doing, or learn how to lap them yourself.

Yeah, that is not okay. They probably eff'd up the valve seat grind or are not lapped properly. I would try to lap them first. If they don't seal I would say the seat needs reworked.

I kept rereading the email like maybe i'm misunderstanding something here. but they plainly state

"The head inspection came back perfect. Our valve seal test registered at the top of the scale. We physically cannot make it seal any better than it currently is. For your water test, they clarified that it is not unusual to have some water leak even with valves that seal perfectly."


yes that's what im guessing as well. I replied asking if lapping the seats can be done for the seal.

not sure what this means, i did ask for clarification, but sounds like theyre not going to do anything because it won't be in spec?

"At this point we have determined there is nothing wrong in the heads themselves and no way for us to improve sealing since it is already well past specification."

It's within spec... and their spec is trash.

Couldn't find any leakdown spec for the valves/head only. It's just general leakdown test for the assembly. There is a way to check valve to seat contact in the manual with prussian blue. It is linked in Ultra's sig.

My dad taught me how to test with prussian blue when I was a kid. Dry erase marker works well in a pinch.

Would it be worthwhile to look at the valve springs? It seems that IAG say they ruled out problems with the seats.

I'm a little confused.
Did IAG just machine the head or did they also assemble it.

I'm assuming that they also assembled it.

I've had water seep albeit slowly from good valve jobs. During operation the valves are closed for such a short period of time and are slapping the seats pretty hard. Did you check valve clearance During disassembly?