Oil on my Plugs, but WHERE is it From?

[braol]

On my '46 H I frequently (frequently enough to be annoying, but not every time I run the tractor) have to pull the same two spark plugs due to oil fouling. I get a nice gunky build-up on the ends of the plugs, effectively filling the gap. The odd thing is, I don't have the common trail of blue smoke that often accompanies the burning of oil. I also regularly am (of course) adding oil (I joke that the H has 'self-changing' oil due the frequency that I have to top it up. The problem persists even after I removed and cleaned the oil breather and replaced the oil breather "filter" inside the tube assembly (and checked to make sure I got good airflow in there after changing the goofy filter material).
So I am wondering if others have had the same symptoms and what was the cause? Valve guides or piston rings?
Has anyone had luck in adding stem seals in an H? I see seals advertised but I have a distillate head H and the notes (on the Steiner site anyways) say the seals fit: "'some' of the following models using gas cylinder head casting #'s 8043D, 8043DB, 8043DC." Are distillate valve stems too short to fit the seals? Or do distillate valves have thinner stem diameter? Anyone add modern o-ring type seals? Do seals even matter?!
I am of course going to do a leak-down test, but I'm at work the next 3 days and figured I'd pop into the Forum because my overactive-brain is impatient to get out there and get some info. The last time I did a leak-down test it turned out that one of my exhaust valves lost it's keeper clip and the valve had dropped down...rendering that cylinder in-op (no damage done, fixed and working again)...and once I discovered that I then got sidetracked with the repair and moved on to other things. But the oiled plugs and oil consumption remain a problem to be solved. These days the oil consumption bothers me more because oil is getting noticeably more expensive.

 

[old]

If it where me I'd do a compression check. I might also change to a hotter plug and use an NGK brand to boot

 

[the tractor vet]

Well when they foul plugs and your dumping oil it is past rebuild time . They don't last forever . Plus with the oil burning come extra oil to coke up the rings making them stick more in the ring groves . Will a rering help ????? all depends on how much ware and out of round along with taper of the sleeve , If ya had a step at the top of the sleeve Nothing is going to help but a rebuild . Yea ya can install anti fouler s hotter plug but it will keep getting worse .

 

[rustred]

thats a yes as the vet said. u can check the guides by removing the valve cover and get each cylinder at tdc on compression and do the
wiggle test on each valve. if you can see the stem wobble in the guide it is worn out. and putting valve seals on old worn out guides is
useless. none of them tractors had valve seals from factory. so if the head is rebuilt properly with the correct stem clearance they do
need the oil for lube. guides dont wear out that fast in them. but with seals they sure will. they are a slow turning engine and the oil
lubes them stems. plus the top of guides are on a taper just for that reason. the excess runs off. just like them old stationary engines...
u had to manually oil the valve stems. the lb engines had a felt that u oiled and it dripped on the stems. same as the old 1920's and 1930's
tractors. u oiled the felt and then it was good for the day.

 

[RedRamGT]

I've been using NGK 2910 (AB-6) spark plugs, with good results. They take a 13/16 spark plug wrench, too...

 

[BarnyardEngineering]

How much oil over how many hours are we talking about? What oil are you using?

Sounds like a typical run of the mill tired engine. You might be able to get more time out of the plugs if you get a couple of anti-foul adaptors from your local NAPA store. Take a plug with you to make sure you get the right ones. I think you need the 18mm ones.

 

[caterpillar guy]

I'm with Old and TV compression test for rings and cylinder health then the wiggle test for the valves. IF either fsail it is major time. Sleeves pistons and head work. While there might just as well check the crank and bearings. Though if you put sleeves in just do the crank work while you are there. Yup you will have to split it to get the crank out. Not a big deal just a bit more work. Dig deep into that piggy bank cause it will cost for this work.

 

[braol]

I'll get back before Wed (I hope) with a report on compression and leakdown...in the meantime:

Are guides for the distillate valves the same as for the gas? I assume the valves are the same stem thickness? The Steiner site (for example) only lists valves, guides, etc for tractors with gasoline heads.

If everything measures within tolerance and nothing is obviously scored or damaged, has anyone had success with a re-hone plus new rings without sleeves? I assume that the most common problem is that the sleeves probably wear out into a slight oval shape, but it is at least worth asking the question. Now, if I could just invent oval rings I might be onto something!

The good news is that I have decent oil pressure, even when all warmed-up, so I am confident that my engine bearings at least are in relatively decent shape...generally speaking. My engine with it's relatively brand new magneto and carb runs like a top so it's too bad about the oil situation. I'm still surprised I don't really get any blue smoke out the pipe...and I do a lot of work with the tractor.

This post was edited by braol on 11/11/2023 at 03:41 pm.

 

[used red MN]

Not sure what doing a compression test is going to tell
you? Seems like just a routine to follow that is going to
tell you pistons are going up and down in the cylinders
and the valves are moving up and down properly and
sealing reasonably. He says it jokingly self-changes
the oil. Let us be realistic, I am certain everyone that
has answered here knows what he is going to find
when he tears it apart. Worn out cylinder sleeves with
a big drop off ring ridge that will require the sleeves to
be replaced, so automatically new pistons and rings
are part of the deal. Also a good valve job with the
guides replaced and new valves as needed. No Farmall
H is going to pump that much oil down the guides,
so trying to fix this with seals is fruitless. I am almost
sure if he works a couple acre patch on a calm day and
stops at the end of the field and looks back across it
he will find where his oil is going by seeing the blue
haze whether he wants to admit it or not.

 

[rustred]

Its this easy. Your plugs are fouling and smoking blue so
that means u are burning oil. Its your tractor so u should
know how much oil u are going through. U asked u got
the recommended thing to do. And no sleeves dont wear
in an oval! They wear in a taper , wider from the top of
the sleeve ring travel to no wear at the bottom. So until
you tear it down and do your inspection u are just
speculating. And yes u can just do a re ring job if things
are in spec. Such as pistons and sleeves. Sounds to me
like u have never had an engine apart from your
comments , so be a good idea to have someone either
experience beside you. You have no reason to worry
about the head. That goes to a machine shop and they
rebuild it. What good is guides to u ??? Nothing.

 

[BarnyardEngineering]

I believe he said it is NOT smoking blue.

Regardless, if it starts good runs good, you can dump a LOT of oil into it for what an overhaul will cost. Even if you do it yourself and just pay for the parts.

Farmall H's are not rare, or valuable. Odds are you can find one with a less-tired engine for about what it will cost to overhaul this one. Then you have TWO tractors, and how can that be a bad thing?

This post was edited by BarnyardEngineering on 11/12/2023 at 06:03 am.

 

[used red MN]

..I believe he said it is NOT smoking blue..
if he has to clean 2 spark plugs often enough that it is
become annoying.. then he is burning oil and smoking
whether he sees it or acknowledges it. A low
compression gas engine just will not burn clean when
higher flash point hydrocarbons like oil or diesel are in
the cylinders. Yes the gas is there to help the
combustion along but is still does not burn clean. Just
my thoughts or opinions he can do whatever he wants
to with his engine. You have a good point about just
purchasing another H. The problem is honest farmer
sellers a getting less and less, so the question is will
the next one be any better. They can show you
receipts for overhaul parts but they might be installed
in their keeper tractor in the shed.