Topic: Replace guide or use liner?

[754]

 Took my head to the machine shop today. One bad exhaust guide. The guy said he could bore it and put in a bronze liner......he said easier than re and re a guide. I can't get a guide fast enough unless we pull it from another head.
 I assume it is done on the Serdei .
 Sounds ok to me, anyone done it?

[Haybus]

Bore the cast iron guide and install a thin bronze liner? Assume you would still need to ream/hone the liner. That's easier than throwing in a new nickel-bronze guide? You have to ream twice for the former versus once for the latter. I'd be worried that liner would move around. The aluminum head is retaining the cast iron guide, but the liner is doing the work to retain itself. Better be pretty thick to maintain the press fit, and have a decent press fit that isn't ruined with the ream, huh.

I did all the guides on my race head. Was sooo easy. Heat up the head and draw out the old, draw in the new. A guy like you with a lathe can re and re all guides in less than an hour after making the drawing tools. One is a cup with a bolt and washer to draw them out, one looks like the head of a valve to draw the new ones back in.

My 2 pennies,

Alan

[scottly]

 I've heard of thin-wall bronze guide inserts used on V-8 cast iron heads with integral valve guides. After seeing Frank's question, I called a friend who used to work in a high-end automotive machine shop and asked him. He said that he had indeed installed them, and had never had a customer return with a complaint, but he didn't really trust them.
I have a couple of NOS early bronze exhaust guides with no provision for stem seals, but even if they would work it would take a while to get one to Canada..

[Big Jay]

Just knock all the guides out and replace with a set of bronze guides.

[754]

My biggest problem, they can have it done by Friday, then they are closed a week.
I told him I cant get a guide fast enough, he said some he got from Honda still need reaming.
We could pull one out of a another head, I left him, but I just want it done, if it last 3 months I am happy. I pulled the exhaust springs this morning, looks likeconly one guide
So when he suggested sleeve, I said do it.. Not a minty head.
I want to be in Colorado by Aug 15 and plan to get there.

Too make doubly sure I got a motor coming, looks fresh , clean in the ex port.
 Plus I may get another 836.. So I think I can get there.

[scottly]

I want to be in Colorado by Aug 15 and plan to get there.

This reminds me of where I was with my bike 3-4 weeks before my first ride from CA to CO.

[PeWe]

I have heard about guide liners too. One old CB750 restore guy I know had got a head done that way.  He heard that the method is used in heads were they have problems to find new guides. Old cars.

[turboguzzi]

their called k-line liners...

cant see anything wrong with them actually

[cbr954]

From what I have seen in the automotive industry the liners seem to wear pretty fast.  Have seen two v8 engines wear them out in about 10,000 miles.  A lot of different things can contribute to fast wearing though.

[754]

It's done, they took a guide out of the other head I brought with it. They tried liner first, guide broke.
 Now to sort some springs so I can unleash my long sleeping RC 315.. WHOO hoooo.!