cloudmaster_321

I pulled my port exhuast manifold and valve cover to investigate a small oil leak. I then shone the light into the exhuast ports and found #4 port wet and had baked on oil. Upon further investigation I could see the bronze valve guide half way or better up the exhuast valve stem and the seal up under the valve retainer. Turning the motor over and watching verified the guide is moving with the valve. I did compression checks to see if a valve was bent, I had 165 to 170 on the whole bank.

What happened to the guide? Motor has less than 20 hrs since total rebuild. SS iconel valves/ bronze guides......

MER Performance

Is it an aluminum head?
Was it a shouldered guide?
What was the clearance between the guide and valve?
What type of stem seal?
What was the O.D of the guide and the I.D. of the guide boss?

cloudmaster_321

can't answer many of your questions, as i didn't do the build. It was done by Goodwin Competition. They are the stock cast iron heads. I can also say the seals were not the umbrella type, they are p.c. valve seals

MER Performance

I know of Todd, I know Steve M, owner of Comp. Products & Howards. Todd, is Steve's guy. I would take that back to Todd, and let him look at it, before you start getting on here looking for answers. Is he willing to look at it?

cloudmaster_321

Plan on it. Been working with Todd now for a year. I just came upon this problem today. I think i've been running it like this for awhile from the appearance of the exhuast port and valve stem. Don't know what would have happened if i didn't catch it. I'll be talkin to Todd tomorrow, but just wanted an idea of why this guide would have come out like that.

MER Performance

I have seen valves stick in the guides, usually they bend the valve. The bore could have been to loose for the guide, high exhaust temp would expand the valve and cause it to stick or low lubrication to the valve, someone else posted about the samething, but an alum. head. They said; something about the engine leaning out, they had more than one guide pull out.

cloudmaster_321

It was the only one that I found that was like that. I did the compression check and figured with the good numbers the valve was not bent. But i could be wrong.
What would have happened if i didn't catch it and I kept running it?

cloudmaster_321

I'm being told that due to the previous exhuast, and burning a bit of water due to reversion, it is causing the guides to loose press.....................

BenPerfected

Assuming the previous water reversion caused the issue, shouldn't a relatively inexpensive guide been replaced when the head was reworked? Not sure what water reversion would have to do with a pressed fit guide. At this point, it will likely be hard to determine who shot who. It seems to me it would be worth asking for some consideration from your engine builder.

cloudmaster_321

The head was reworked last year when the engine was overhauled. Bronze guides were installed at that point. But, the silent choice exhuast was reinstalled after the engine was done. Which if you were following my previous posts, was removed and longer risers and mufflers installed. But it was put on 3 hours too late. Engine builder is saying that the water heated and cooled the guide which made it loose it's press and/or the valve was rubbing the guide too much. He wants to look at both heads to make sure they are good. Also wants to look at the rest of the engine to see if there is any other reversion damage.............. He does plan on "helping" me out, but full warranty, he is not doing.