Valve Guides Question

[Guest]

My 1100ez is under going a crank up re-build. Builder inspected head before it was sent off to Star Racing and told me that two valve guides were broken.

I originally thought he meant that they were worn and needed replacement and didn't question it. When I asked him about it in a subsequent conversation he said that two of the guides on the #2 cylinder were chipped. He wasn't sure why but said there were also two broken springs. Bike had 107K miles, approx 35K since last top end rebuild. The bike seemed to be running fine and the three reasons I sent it off to be rebuilt were cam wear, and timing chain seemed to be at end of suggested tolerance and engine was out for a frame replacement.

Question is: can the bike seem to run well, no external noises, smoke, or oil use and have those conditions?

I'm not questioning the builder and I was expecting to replace just about everything in the head including the valves, but I'm still curious. I suppose you could have a chip that doesn't disrupt the inner seal, but if the springs were broken........

 

[hampshirehog]

I've not seen chipped guides but I've seen broken springs on both bikes that seem to run well and those that don't. I presume the chipped guides were on the same valves as the busted springs?

 

[Guest]

Builder wasn't certain broken springs and guides were on the same valves. He thought it was likely but wasn't sure.

 

[posplayr]

Builder wasn't certain broken springs and guides were on the same valves. He thought it was likely but wasn't sure.

Which side of the guide was broken (seal side or valve side)?

If there was carbon build on the seal side, and the spring was broken then the valve could float more when going over the top of the cam and the (tarnish) guide build up might stress the guide and chip out the top.

For the other side, I would have to invent some other theory

 

[blowerbike]

ive bent valves and chipped the bottom of the guides before(factory cast iron).
i lapped in a couple used valves and went on.
no smoke or problems on my 1150 and it was raced every friday at the track and rode through out the week.
when a head is ported the over hang of the guide is removed anyways.
i had .340 cam with large lobe centers and the rev limited unhooked.
i twisted it in low one day and over revved it.. it sounded like the rev limited was still hooked up.
later that night at the track it spaghettied 2 exhaust valves and chipped the guides all the way to the head casting.

 

[Guest]

Which side of the guide was broken (seal side or valve side)?

If there was carbon build on the seal side, and the spring was broken then the valve could float more when going over the top of the cam and the (tarnish) guide build up might stress the guide and chip out the top.

For the other side, I would have to invent some other theory

Jim,

Don't know for sure. Probably won't be able to ask any more questions till I pick it up in three weeks. There wasn't any mention of bent valves so you may be right, I was getting new ones anyway. I never really ever abused it and do use the Dyna Rev limiter. Oh well time to start fresh.