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BruceDP

Valve Guides

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dentwizz
The way I usually check for ballpark is to release the springs and wiggle the head of the valve with it lifted about 1/8 inch. It should have a little movement but not a lot. That was actually how the machine shop told me to check it. Not as precise as one would think, but so far it has proven right.

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BruceDP
That's what I did and there is a little but wasn't sure if that was good or bad. I think there may be a little more play than there should be. I'm rebuilding the engine, found the piston skirt was broke and the pieces layed in the pan. The engine was still running good before I tore it down and I haven't found any other damage. It was using oil and smoking a little. Don't know how it broke the skirt?? Thanks!

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dentwizz
The skirt can have micro cracks from age fatigue since it is aluminum. I just had a piston separate and trash a new valve job, so don't let it go if you want to use the thing sizably(it took 2 years to go bad for me). The other cause of skirt damage is if there was ever a connecting rod failure that somebody repaired. Either way, a new generic piston is a lot cheaper than a hone and valve job.

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BruceDP
Yes, I wont let it go. I'm going to order new parts today, piston, rings, seals and gaskets so that's why I was wondering about valve guides. If I needed to this is the time to replace those as well.

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stevenj
If you have the specs for the valve stem OD and the valve guide bore ID and wear limit, subtract the two to get the diametrical clearance. Then measure the stem of your valve and use a dial indicator on the valve stem to measure the diametrical clearance when moving the valve stem back and forth radially and compare to calculated limits.

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dentwizz
One interesting note for the horizontal iron engines that I found out when I went to get valve guides put in: The machine shop looked at the bronze sleeve inserts that Briggs sent me according to the part number and shook his head. The type he said was the right kind(exactly what came out) was actually older Kohler type valve guides which are iron cylinders. The entire tower that the valve rides in is the guide. At the time it was only $12 per and a drop in fit.

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BruceDP
I held a starrett rule at edge of valve and while lifting valve out about 1/8 inch I wiggled valve back and forth in a couple different directions while reading the amount of movement. My rule only reads as small as 1/64. I re-measured and the exhaust valve moves about 1/64 and the intake moves less than 1/64. Then I converted it to decimal so I think (if my conversions are correct) the exhaust moves .015625 and I would say the intake valve moves about half of that.

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