Ford 9N valve job

Panther 65 · Feb 2, 2020

Good Morning, I have a 9N that was built in 1940 that is burning oil and have no power. I decided to do rings and valves on it this winter but when I actually got into it I discovered that I simply couldn't handle pulling the front end off the tractor by myself. I'm 72 years old and have no family nearby to help. Since it was apart I thought I'd at least do a valve job and bought parts from Yesterdays's Tractors. Unfortunately, I discovered how many questions the Shop and owner's manuals leave unanswered. Neither says anything about lapping the new valves in but I went ahead and did that. Upon reassembly, I discovered that the valve guides I removed only had rubber seals on the intake valves so I ordered four seals from Yesterday's Tractors and even in the catalog it states "Sold Separately uses four per tractor." As I was assembling the valves I watched a video by Stiner Tractors and they look to have used the seals on all the valves. Now I'm confused. Is Yesterday's tractor right and Steiners just trying to sell more parts? or is there a benefit to using the seals on all the valves?

metalbender · Feb 2, 2020

In simple terms. Intake valves would have seals, preventing oil being drawn into the combustion chamber on the intake stroke.

Panther 65 · Feb 2, 2020

metalbender said:
In simple terms. Intake valves would have seals, preventing oil being drawn into the combustion chamber on the intake stroke.

Thank you for the reply, I assume that means that as long as the exhaust valves seal properly when closed the rubber seals on them would be like a belt and suspenders situation, in other words only be necessary if something else is wrong.

metalbender · Feb 2, 2020

If your engine is burning lots of oil, prob need rings done. Big thing to check is for ring ridge at the top of the cyl. If the cyl is worn, rings won't help. Easiest way is to get a new ring, put it into the cyl about 3/4 inch below the top and measure the gap. Done with the piston at bottom of stroke, gently turn the crank with a wrench to let the piston square the ring in the bore on the up stroke. Bsaic test, no fancy tools needed, feeler gauge is already marked.