My (reputable) machine shop says he typically sees this type of valve guide wear in over 5,000 hours and it has to be an oiling issue. Rocker shaft and tappets check out okay. Oil passage on rear of block which feeds the rocker appears to be fine. Oil passage to rear cam bushing appears to be lined up with oiling slot in cam bushing. Oil pressure is/was very good.
thanks for any help, but go easy, just a farmer trying to turn wrenches ?
This engine is after my time BUT is the wear general? Or just one or two valves? If it's just a couple. The problem is the rocker or rocker shaft. I suspect oil holes in shaft have little to no camfer.  Enlarging chamfer increases surface area. Allowing oil pressure to push rocker away from shaft. The rockers they used to use didn't bother lube but if they have changed. You'll have to watch them work to make sure oil reaches valve.
Well, he said all of the exhaust guides were badly worn, with #2 being the worst, obviously, and the intake guides had substantial wear also which he said he rarely sees.
Looking at the top deck of the block, it appears the correct gasket was in place.... wouldn't the rocker shaft have a lot of wear if it had no oil?
a lot of the new guides tend to be made of a softer material than the old ones. have run into this twice in the last few years. both of them where tw ford engines no IH though. also had one that was running high egt for prolonged period of time that wiped out guides.
Is there a brand or source of known better quality guides?
What is the application of the engine? In truck applications if they had an exhaust brake installed you could see guide wear. The claim was excessive back pressure was causing it. Do not know if that was really true or not. Just a thought.
It's in a 5488 mfwd which gets used pretty hard.
Sounds like the perfect time to toss this grenade= are you using IH No.1 30wt.?
I am curious if this is a cnh reman motor since you said there are 1000 hrs on the engine or if you rebuilt it locally?
Well... it's a long story that I thought might take the thread off into the weeds so I kept it short in my OP. It was rebuilt locally.. but there's more to the story, as there always is.
Summer of 2016 I had leaky exhaust manifold gaskets, got them replaced and broke a bolt tightening the thermostat housing. (uGHH) By the time I got that bolt extracted, the threads in the head were ruined, I stuck in a stud and welded it in place to get it running for fall season. Next winter, (Jan 2017) removed the head and the aforementioned machine shop sent this head off to another shop to fix the threads, the second shop sent it back, said it can't be fixed. Sooo... I bought a used head from LKQ truck parts and took it to my (reputable) machine shop to have it gone through and surface ground.
In framed the engine, went back together just fine, ran and pulled very well...except..the (Reliance) head gasket was leaking externally in like 3 places. Feb of 2020 I stuck in a new gasket which sealed up the leaks perfectly. As of now, I can't be sure that the Reliance gasket was the correct one for a C series.
So, I'm doing a complete out of frame overhaul, but can't find anything that would've caused the problem.
like I said, go easy on me lol ?
I have seen excessive guide wear on tractor where they put aftermarket guide seals on , as "they came with the kit".
I think you are on to something here . With seals the guides are running too dry . I dont use the valve seals on my overhauls on turbocharged engines . The cylinders have air pressure in them on both the intake and exhaust strokes controlling excessive oil going past the guides . Never had an oil consumption problem by not putting in the seals . Just my 2 cents worth .
Just out of curiosity, how did the valve get in there? Head break off? Strip the keys? Stem break below the retainer? While the the valve striking the seat crooked when nearly closed is less than ideal, it is possible that you have unrelated coincidences here. After all , valves do fail when everything is running straight and true. Like the one pictured. There comes a point in time that the valves and springs and keys should be thrown away in high- time engines, or, in your case, a head of unknown origin, to minimize the possibility of a fatigue failure.
Do you think its possible that this gasket could have started your problem? Maybe something wasnt right with it causing the upper end of engine being starved oil?
Well, a little over half way through planting season this spring, it started blowing by out the breather and steadily got a little worse. With no fall back option, I decided to keep running it as long as possible. It almost made it, only 40 acres of field cultivating left. The valve ended up embedded in the piston in two pieces, I think it broke. The guide was so far gone that there was a worn spot on the top of the liner where the valve was rubbing!
That is a possibility, yes. I just don't know either way though. It was in there for close to 600 hours.... wouldn't there be some serious wear on the rockers if they weren't getting oiled?
I'm very much a proponent of using OEM parts.
But in the case of IH engines, what brand is OEM quality? I've been told by the best CaseIH parts guy I know that the parts they sell are Reliance. I'm certain that CNHi is not manufacturing parts for IH 400 series engines.
So in this case, which brand of valve guides are good quality and which ones are not?