Valve guide interferance
 

I had to weld up one of my exhaust ports since I was a bit over zealous with the porting tool. Now I need to install a new valve guide. The hole in the head measues 0.505" the valve guide is 0.515" . I think 0.010" of interferance is too much, just a gut feel. Anyone have an idea on what kind of interferance should be used?

Thanks,

neilca

Sounds a bit big to me too.
Maybe .005" is closer....you can spin the guide using a drill and sand the OD with paper to reduce it.
Bob

I was thinking of using a 13mm reamer (0.5115") and clean up the hole. That would give me 0.0035" interferance. I have a cylinder head jig and a large mill so I can maintain the vector of the hole. What do you think Bob?

2 to 3 thou is good. You can get oversize guides and turn them down to the correct interference. Use lube to avoid gulling.

As Craig suggests...you are in the ball park for the sizes.
And by all means...heat the head (wife's oven?....LOL) before pushing in guide.
Bob

Craig,
Good call on the lube, what kind would you suggest, old oil, anti seize etc

Bob,

I usually freeze the guide with dry ice. My Mother's oven had been used inthe past to fit bearings into motorcycle cases. I am not sure I would chance that with my Wife's oven. LOL..then again if she were off shopping.....

dont for get to check your head for sq and flat after the welding.....
Yes to the dry ice Listen to them scream !
yes to oven heat cycle a couple times B4 doing valve job after the guide install
(incase they move after heating up)

Just a good penetration oil in the bore and the guide works well.