After modifying rocker arm oil pipe drilling a 1/16" hole over each roller rocker when first starting the engine it smokes quite bad and every once in a while running it will puff. Has anyone ever tried using valve seals on these engines?
Valve seals on two cylinder engines
- Thread starter mdross1
- Start date
- Views: 4748
CCWKen
Veteran Member
- Joined
- Mar 22, 2005
- Messages
- 1,173
- Location
- South Texas, USA
- Tractor
- Ford-3910, JD-420C, Kenbota-Custom, IH-2606
I'm into a valve job on my 420C now. It blew a head gasket and figured while I have it down that far, might as well do a valve grind. Good thing I checked. They were pretty bad. As I was saying... 
Valve stem seals were not originally used but many are using what's called an Umbrella Cup. It basically keeps excessive oil from running down the stem. (Not my claim) They just float on the valve stem so they really don't seal anything. Mine has those but they're not included with any gasket set I've seen. And I can't find a supplier for them. I guess I'll just reuse the old ones. Mine doesn't smoke a bit but the valve guides aren't sloppy either.
To use a true seal, you'd have to remove the valve guides and machine a lip to let the seal grab something to stay in place.
The name and number molded into one that I have is "FoMo Co. 2D70 FF".
Added:
I just found these but they're too small of an ID for my valves.
Sealed Power MV1921B - Valve Stem Oil Seal | O'Reilly Auto Parts
Valve stem seals were not originally used but many are using what's called an Umbrella Cup. It basically keeps excessive oil from running down the stem. (Not my claim) They just float on the valve stem so they really don't seal anything. Mine has those but they're not included with any gasket set I've seen. And I can't find a supplier for them. I guess I'll just reuse the old ones. Mine doesn't smoke a bit but the valve guides aren't sloppy either.To use a true seal, you'd have to remove the valve guides and machine a lip to let the seal grab something to stay in place.
The name and number molded into one that I have is "FoMo Co. 2D70 FF".
Added:
I just found these but they're too small of an ID for my valves.
Sealed Power MV1921B - Valve Stem Oil Seal | O'Reilly Auto Parts
Last edited:
Thanks for the info. A few weeks ago attended a plow days was out in the fields over 5 hrs. plowing by the time I loaded the tractor to leave could tell it was running much different. The engine is all new inside all it needed was to get to operating temp and run the rings have seated now and what little smoke now is normal even with the oil pipe squirting oil over the intake valves. Next spring will make up a new oil pipe with 1/32" holes and see how it goes.
CCWKen
Veteran Member
- Joined
- Mar 22, 2005
- Messages
- 1,173
- Location
- South Texas, USA
- Tractor
- Ford-3910, JD-420C, Kenbota-Custom, IH-2606
Sorry for getting back late but thought I'd add something for others in the future. On the 420 the rocker shaft (tube) had the holes covered by the rockers. The holes are 180 degrees apart and parallel to the head. The ends of the shaft originally had cork plugs. Mine were deteriorated so I made new ones out of wood (Ash) and pressed them into the shaft ends. The rockers on the 420 are made of folded and pressed metal with inserts for wear on contact ends. The way they're made allows the oil holes to lube the rockers at the shaft as well as oil the ends as the rocker moves back and forth over the holes. I noticed my oil pressure is a lot higher afterwards so the plugs must have really been leaking. The only thing holding them in was the cotter pins. When I pulled those, the corks just fell out.
Added: Oh yeah, and be sure to use he correct stud in the back location. Oil pressure is fed up next to the stud and through the rocker stand to the rocker shaft.
Added: Oh yeah, and be sure to use he correct stud in the back location. Oil pressure is fed up next to the stud and through the rocker stand to the rocker shaft.
Thanks CCW all is well with the 70 now that the engine has worn in a little. At startup there seems to be less than normal smoke at startup and none while engine is working. So the rocker arm oil pipe will stay the way it is I like knowing it is getting so much more oil especially over all the rockers. I'm hooking to a dyno in the spring and see what the difference is between a straight pipe and a muffler.
