CHI heads---valve guides

This is the first failure I have heard of, did you contact CHI to get their input?

Julian

CHI reply--------


Hi Mike,

That’s not something we see, we do see on occasions 1 or 2 guides with some extra wear but never have we seen what you are describing.
Early on the previous owner of CHI had some guides made locally which were probably softer in material than what we would have liked but they still did not wear in just 3k miles.

We have since moved to a CHE type guide, but I think the same thing would happen. You may need to have a look at your rocker geometry, or the lube the heads are assembled with. These are just suggestions I not trying to tell you what to do, or that you have done something wrong. Let me know if I can be of further assistance.

Many Thanks
Scott March

Mike, Can you show us a pic of the assembled upper valve train? Profile? What components are you using? One member had to cut releif in the back of his rocker, It solved his problem, but I'm not sure that was the right solution. I always think twice before I start modifing some body elses' parts' unless they come from Tiawan!

Its all apart now and I dont have any close up pics. I will do some good pics when it goes back together. At this point I dont believe anything was out of alignment or rubbing etc.

Mike

quote:

Originally posted by midenginemike:
I have CHI 4V heads. About 3K miles on them.
The valve guides are completely shot !!!
Anyone else had this problem with CHI ?
Im disappointed, to say the least.....

Mike

I had about 7K miles with no detectable problems on my CHI 2V heads that MPG of Colorado assembled for my last engine. The only complaint that I have ever heard about CHI heads is that they are more expensive than some of the other aluminum heads that are on the market today. Sorry to hear that you did have a problem with the CHI heads.

Visited the machine shop today. He wasnt kidding about the valve guides being SHOT. Looked at the valve stems. I can just see where the roller rocker was running on them. Its right thru the middle. Couldnt be any better. While its down its getting some oil restrictions and he also has the fixtures to index the lifter bores and then bush them. To be continued............

Its back together and running !!
Here are a couple pics of rockers.
Assembled with the same parts as it was before.

another