install valve guides
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I had someone wreck a head for me replacing the inlet guides. I don't know if it was when he took them out, put the new ones in, or got the interference fit wrong. What I did find out is that the design, especially around the intakes makes them pretty fragile and it necessary to be very careful with these particular heads. It's simple to make up your own extractor with 1/4" threaded rod.
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nortonspeed
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Hi RichJ, what exactly went wrong on the liner job??
You may hate me for this, but I would never use bronze guides for road use. I have seen a few cylinder heads that have been using bronze guides, & they have been really clapped out, & I mean really bad. Also seen bronze seats worn down into the head. Cast iron for my road bikes. I know a lot of you would disagree, but from what I have seen, I will stick to what I feel safe with.
As for removing & replacing guides, use a proper puller. In the past I used to turn good fitting drifts up & use them for hammering the guides out & back in. Problem is, it can crack the guides when removing them & swell the bores in or crack them when hammering them in.
As for removing & replacing guides, use a proper puller. In the past I used to turn good fitting drifts up & use them for hammering the guides out & back in. Problem is, it can crack the guides when removing them & swell the bores in or crack them when hammering them in.
I tend to agree with you, the various bronses are the most suitable for performance use but don't really seem to last long on the road. That said a guide liner is bronse of a type, it's made out of a sheet and rolled, some have dimples in them to hold lubricant,the guide is reamed to a set size the liner pushed in,they are resonably tight, and then they are sized using carbide balls which is pushed through the liner and it basicly swages the liner to size, the limitations is that in thin walled guides the parent guides flex or split when sizedFlo said:
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Hi , I remember some new guides fitted with more play inside than the old one , yes they were iron and from a well known dealer...........the problem with iron guides , apart of the previous quote, is that when not fitted correctly they could lead to oil passing between them and the head, though the bronze tend to have a better "grip"and grow in size with temp.........
One of the best bronze guides is made from Calsibro, a high quality bronze. My problem with them is that they are a rolled bronze, which has no oil retention properties. I find this useless for prolonged high speed movement. Cast iron has good oil retention. Ever seen a cylinder barrel made from bronze?
Some old cylinder heads, such as Rudge used bronze heads, but they were cast.
A lot of modern bikes do not use guides, to keep the cost down, but they are cast heads.
End of waffle.
Some old cylinder heads, such as Rudge used bronze heads, but they were cast.
A lot of modern bikes do not use guides, to keep the cost down, but they are cast heads.
End of waffle.
Hi Jack,nortons3 said:
You can remove and install new guides yourself by heating and using care, but you will have to be able to measure the head for ovality and the need for an oversize guide and then ream the head to fit it, with interference. Then ream the inside diameter to fit the valves you are using. IMHO, send it to someone you trust and let them take it through all the steps. Oh yeah, then cut new seats too. It may be best on this to find someone you trust and say, "Here."
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