Follow-up Deere d lapping valves

Patsdeere

Well-known Member
A while back I had asked for ideas on how to lap some valves in a d as no local machine shop could. Someone mentioned making an adapted out of some hose and going at it. I did and it worked peachy. However, they aren't cleaning up like I thought they should. Am I going to far or not far enough, or am I over thinking this and am fine?
a223305.jpg
 
Looks like they are beyond lapping between the pitting and too high of a seating area. I'd have to check though as the late B and A are to seat high like that. Nothing a good grinding and seat narrowing from the top won't cure.
 
id say the same , better get that head rebuilt @ a shop , i rebuild heads in machine shop for years , looks like valve is pitted , seat is off edge which means it wont seat , there is 1 deg. interferance on seat & valve angle , so in other words makes a sharp edge about 1/3 way down form margin (top)- also pic. hard to tell but margin of valve looks thin ( thickness from top to edge of face surface) in my exsperiance most old engine need at least exhaust valves replaced . With out a pic. cant say for sure, but id bet the seats are sunk into the head too , there again if never replaced they should be because the original cast seats dont hold up to todays gas , you will fix to problems at once by replacing , no more sunk valve & hardened seats for todays gas . i know most guys dont like the thought of spending money on a show / play tractor if thats whats the case here but from what i see you will need to , either now or later when you tear it down the second time
 
that valve is garbage.lapping is an obsolete procedure. there is an interferance angle that is used when grinding valves. thats why i dont buy old tractors from tractor jockey's as they are just "patched up" to run. the seats have to be a specific width, not just lapping a worn out valve into a pounded out seat.
and another thing with that rusted out valve there is the possibility of the head breaking off then smashing the piston. that valve is for the garbage can, as there is no margin left and the seat face has pits in it. when grinding it the valve will become sharp so maybe u can use it to shave with.
 

Depends...As that one is, it will probably serve you well the rest of your life...BUT..
Since the head is off, why not have the Valves/Seats ground..?? At most, you may need a couple exhaust valves..
A GOOD 3-Angle Job should be Expected..
 
I was hoping lapping would clean them up and get the rust and carbon off to make it at least run. The guy that owns it is just going to kick it down the road, so I don't think he really cares.
 
OK so now the brain trust has me second guessing myself. Given the above pictures, would the best plan of action be to totally revamp the head (seats, valves and guides)? Only reason it came off was due to rust and valves not moving freely. You will see a little gray stuff on the left seat, a bit of residual lapping compound.
a223371.jpg

a223372.jpg
 
I think it might be time to look for a new head. It will take some serious shims under springs because the valves are so deep in the head. That baby has had a few valve jobs in its day.
a223403.jpg

a223404.jpg
 
looks like new seats and valves are required from the pic.#4 valve looks like it is the only one that has the seat positioned on the valve in the proper spot. the others are to high especially the second one is bad and will just burn the valve like that. that valve job on there was never done properly, as it looks like the head surface was ground also putting the valve ressesion way to low. not good.
 

Lapping valves is a hang over from the bad old days when people were trying to make do with nothing.
Have a knowledgable engine shop do a three angle valve job and be done with it.
 
That valve is too sharp too grind.
The only thing lapping is good for is to
check where seat is contacting valve.
Take the head to a shop where they have the
knowledge and equipment to it properly.
 
I am curious if you are actually going to fix it right , or patch it up and sell it to some unsuspecting soul.
 
I received a "Waukesha-Climax K75 6 cylinder with a failed exhaust valve:

During the autopsy, it was noticed that several of the Valves were as bad as this one:
a223607.jpg
 
I feel bad for you Pat as it sounds like you are in a tough spot as this belongs to someone else who is just wanting rid of it anyhow.
All of those wanting you to "fix it right" I'm betting would not put the money in to do it either. To fix it right I also will bet requires more than just a cyl. head repair as I'd bet the rest of the engine won't measure up either. So now we are throwing thousands of dollars into it that will surly exceed what anyone will pay for it !
Maybe the only thing left one can do to be honest is to stick it back together and see if it will run and if it does sell it as a running tractor and disclose it could use a valve job. You are telling the truth so nothing to hide.
 
You are right Mike. Most every old tractor if fixed right
will cost more than it's worth. If one wants to keep a tractor
having more than it's worth is more bearable.
As far as this D goes if it wasn't running before there's no
reason to think it will by just putting it back together.
Just put it together and forget it. It will bring what it will
bring.
I have several in all condition and was lied to on most all.
What do you do after driving 400-500 miles?
 

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