valve guide clearance

[pishta]

14 valves seem perfect in their guides, no movement whatsoever. 2 have just a hint of movement without the seals, cant see it but you can barely feel it. Is it safe for a weekend cruiser? 3/8 Miloden stainless street valves in X heads. Thanks.

 

[Brian Hafliger]

14 valves seem perfect in their guides, no movement whatsoever. 2 have just a hint of movement without the seals, cant see it but you can barely feel it. Is it safe for a weekend cruiser? 3/8 Miloden stainless street valves in X heads. Thanks.

If the guide is cast iron (or the originals bored into the cast head) you'll want .002-.0025. If you have a liner or bronze guide, then you'll want .0015-.002.
Any less and you need to have appropriate seal and oil flow or you will stick a valve in most cases with a 3/8 stem.
Brian

 

[pishta]

would .002 (cast) be discernable as "lateral movement" or does it have to be seen on a mic bore guage ( I dont have one anyway). Thanks again.

 

[moper]

I doubt you'll feel .002". If you can feel it I'd guess it's at least twice that.

 

[Brian Hafliger]

would .002 (cast) be discernable as "lateral movement" or does it have to be seen on a mic bore guage ( I dont have one anyway). Thanks again.

Best way to guage clearance is with a guide bore guage. But you can also use a pilot for seat cutting to get close...