oil running from exhaust

[crawlspace2112]

just thought of something, i believe the guide is the seat for the inner valve spring so the inner valve spring would sit higher in the seat than the outer spring if the guide had slipped. just another way to make sure this is the problem. i'm not sure if it slipped enough to visibly see a difference, check it out.

[DEmily]

Crawlspace,

Well.... I see you are a night owl too!

The valve guide in the cylinder in question is not sticking out as much as the rest in the valve camber. I don't know for sure that it has moved but it is the only thing that is making any sense. If oil were to run in to the exhaust valve chamber, most of it would be spit out the exhaust from the combustion right? I mean, I really can figure no other explaination. How else could oil get to the exhaust without burning? I have built many auto engines and am lost with this beast. I think you guys are on the money. At least I hope you guys are on the money.

[crawlspace2112]

it makes sense that it wouldn't be a full burn because the exhaust gasses are pushing the oil away from the quench area. if it was intake it would be sucked in, and of corse let it sit and the oil would drain into the open valve and huff when you start it. this would explain why the quench area is not drenched in oil and your plug's not fouled badly. it could be that when the original valve was bent it pushed the guide up enough so the o-ring lost it's squish, now add heat and the oil runs by the guide and o-ring. you didn't say if the oil level was down, by how much and how fast if you did check?

[Geezer]

Originally posted by DEmily
The valve guide in the cylinder in question is not sticking out as much as the rest in the valve camber. I don't know for sure that it has moved but it is the only thing that is making any sense. If oil were to run in to the exhaust valve chamber, most of it would be spit out the exhaust from the combustion right? I mean, I really can figure no other explaination. How else could oil get to the exhaust without burning? I have built many auto engines and am lost with this beast. I think you guys are on the money. At least I hope you guys are on the money.

Since you have strip the head anyway, take out the other exhaust valves and see if that one is sitting higher on the inside. If you do remove the guide, it's likely that you will have to do this in 2 stages. I've found that I can seat valve guide that isn't all the way down by heating the head but to install new guides, the guides need to spend the night in a deep freeze (a couple hours won't do it.

Just to be sure we're on the same page on the head, preheat the oven to 400 and put the head in for at least 1.5 hours and have it in combustion chambers down wouldn't be a bad Idea.

If you're sure the guide is otherwise good, then reseat it. If there is any question about the condition of the guide, replace it.

[DEmily]

Greezer and Crawlspace,

After smoking up the house and stinking up the kitchen, I got the exhaust valve guides out. They drove right out just like you said.
After looking at the oring that was on the valve guide, it is obvious to me where the leak was. The orings that came with my gasket set looked to be three times a thick as the ones I took out. They were almost as thin as dental floss. With the guide being pushed up as far as it was and the seal being as thin as it was, I can't see how it could not have leaked.

Now what is the best way to put them back in? Deep freeze for the guides and 400 degrees for the head. How should I drive them in? What part of the guide is strong enough to take the smacking from the hammer? What should I use to drive them in with?

[CMA1]

Well I am glad you found that DEmily, instead of the feared crack!!!! The other guys know a lot more than I do about installing the guides, but I wanted to post the congrats
I know how you feel about investing "too much" money in the bike. I thought I was being 'smart' buying mine because it was cheap ~ 800.00..... then the sh*t hit the fan and I found out how much I didn't know!!!! But I sure have learned alot... about the bike and people too. Plus I got to make some new friends here!!!
What a great forum!
Good luck with the reassembly
-CMA1

[DEmily]

I'll keep you posted CMA

[crawlspace2112]

get a brass drift thats small enough to fit on the spring seat but has a hole to fit the guide opening so you are not misshapping the valve opening on the guide. like a socket that just fits over the opening. try to find something brass because it's soft enough it won't hurt the bronze guide. yes heat the head and cool the guide it will lessen the chance of damaging the guide especially if you don't have a good brass drift. you said you got them out easy, then they should go back relatively easy the same way. what did you use to hammer them out? the old socket trick would probably work, just don't use a good one the end that you hit will mushroom. impact sockets are softer than chrome ones, try that if you have to.

[DEmily]

Crawlspace,

I used a small socket that fit the exact diameter of the guide and drove a small rod into the socket and used it to guide the socket to the exact position by slipping the other end of the small rod into the valve guide. So I should use something brass large enough the fit around the guide but that will rest on the spring seat . Use the spring seat as the point of impact. to drive them in.

[Geezer]

Originally posted by DEmily
Greezer and Crawlspace,

After smoking up the house and stinking up the kitchen, I got the exhaust valve guides out. They drove right out just like you said.
After looking at the oring that was on the valve guide, it is obvious to me where the leak was. The orings that came with my gasket set looked to be three times a thick as the ones I took out. They were almost as thin as dental floss. With the guide being pushed up as far as it was and the seal being as thin as it was, I can't see how it could not have leaked.

Now what is the best way to put them back in? Deep freeze for the guides and 400 degrees for the head. How should I drive them in? What part of the guide is strong enough to take the smacking from the hammer? What should I use to drive them in with?

If you put the guides in the deep freezer over night and then heat the head back up to 400, the guides will slip back in easy as pie. Try to get them back in the same holes they came out of.

Geezer

[DEmily]

Greezer,

Thanks for the tips. I should have her back together in a week or two and will keep you all updated on the progress. I hope to sign on in a week or so screeming SHES ALIVE!!! Thanks again to everyone who has help me through this 12 month, shall we say, adventure. You guys are the best!!


Dan

[DEmily]

Has anyone ever used dry ice to chill valve guides for installation? I was wondering if the o-ring could be damaged by the deep freezing effect of the dry ice.

[Geezer]

Originally posted by DEmily
Has anyone ever used dry ice to chill valve guides for installation? I was wondering if the o-ring could be damaged by the deep freezing effect of the dry ice.

I don't see why it wouldn't work but first you have to track down some dry ice and keep it in a cooler. On the other hand, I already have a freezer and I can keep the guides in there until I'm ready to go. ;o)

Geezer

[DEmily]

I can get it locally for not much money. I may look at that option only because I want to assemble on Friday and I have ordered a new guide for the one that was giving me trouble, just to be safe. I will not get it until Friday and the dry ice option will freeze the guide down to temp in a very short time. I am hoping to have it completely back together and running by Saturday night. Well, either way, I should have her back together this weekend.

[cbird]

You can get dry ice at Baskin Robbins. Don't eat it!