The Ford Barn

swedishsteel · 06-05-2022, 01:39 PM

What do the experts do to when an exhaust valve guide is loose in the block???. Situation: bought an 8n Ford tractor (same valve guides as flathead). Sat over winter and front three exhaust valves stuck open. #3 guide loose in the block so it was able to drop down and ride the lifter with the spring compressed. No damage done. Got everything apart and rust cleaned away on valve stems and inside guides. There is a lot of oily carbon in the valve pockets on that cylinder, but the top of the piston has no carbon at all on it--indicates oil coming up that valve guide to me. My first choice would be an intake guide rubber seal, but I don't have one. Ideas and suggestions welcome. Rod

alanwoodieman · 06-05-2022, 02:34 PM

the old fashioned "knurl" would work

Bored&Stroked · 06-05-2022, 07:14 PM

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Another method is to have the guide copper plated, then use a reamer on the inside to bring it back to spec. The nice thing about copper is that it transfers heat well - away from the valve. But, since this is a tractor, probably not a big deal . . . I'd knurl it.

06-05-2022, 01:39 PM	#1
swedishsteel Senior Member Join Date: Jan 2011 Posts: 357	Loose valve guide in block What do the experts do to when an exhaust valve guide is loose in the block???. Situation: bought an 8n Ford tractor (same valve guides as flathead). Sat over winter and front three exhaust valves stuck open. #3 guide loose in the block so it was able to drop down and ride the lifter with the spring compressed. No damage done. Got everything apart and rust cleaned away on valve stems and inside guides. There is a lot of oily carbon in the valve pockets on that cylinder, but the top of the piston has no carbon at all on it--indicates oil coming up that valve guide to me. My first choice would be an intake guide rubber seal, but I don't have one. Ideas and suggestions welcome. Rod

06-05-2022, 02:34 PM	#2
alanwoodieman Senior Member Join Date: May 2010 Location: upstate SC Posts: 3,006	Re: Loose valve guide in block the old fashioned "knurl" would work

06-05-2022, 07:14 PM	#3
Bored&Stroked Senior Member Join Date: Jan 2011 Location: Central Ohio Posts: 5,906	Re: Loose valve guide in block Sponsored Links (Register now to hide all advertisements) Another method is to have the guide copper plated, then use a reamer on the inside to bring it back to spec. The nice thing about copper is that it transfers heat well - away from the valve. But, since this is a tractor, probably not a big deal . . . I'd knurl it.