Head and Valve by hand

A week and half ago, I decided to put a snake camera into the spark plug holes on my 1940 A. I found a puddle of antifreeze sitting on top of #3 piston and could see that the head was leaking at the gasket. I immediately tore off the head and found that the gasket was in terrible shape. After more inspection I found that two exhaust valve seats were completely gone! I can't understand how the old girl even ran!. After a lot of hard work without power tools I reground the seats and lapped the new valves (purchased kit) and installed them, springs included. Guides were within in tolerance using go/no go gauge. I checked the head for flatness and found it to be .002/.003, I figured I had it opened so I used progressive sanding and got it super smooth and down to .0015/.002 I had compression of 80-85-60-85 going into the job and now after heating it up and re torque the head and setting the valves hot, I am now at 95-98 on all 4. Cylinders were all smooth and looked good. Checked all piston journals and bearings last year.
I used the tractor today for a parade and drove it 6 miles each way up a bunch of hills. I drove in 4th gear up all these hills where before the whole job I could only do in 3rd.
I am very glad I did the work it was tough and slow going but worth it.

Have no idea why there are doubles and triples of the pictures, I only uploaded each once

NICE work!

How's the governor working now?

that rough seat in the picture has had water sitting in it to corrode it like that. that's what happens to these engines that people get running that have been seized up. there is nothing in them, but yes they will run. should have had a new seat installed. plus those valve seats are waay to wide on the valve. that is the problem with lapping, it is no longer used. it is 1920's technology. the seat should be about 1/2 that width and in the centre of the valve face. with that wide of a seat good chance of carbon getting stuck in between. not running down your work as good job with what you did with what you had to work with. just that there is no such thing as lapping valves anymore. the seats are ground to 45 degrees and the valves to 44 degrees this gives a fast valve seating and if carbon should get caught inbetween it will work out.dont know how you can check valve guides with a feeler guage. about .003 is good.

from your picture that puddle of coolant is on #2 not #3

I take no issue with your approach. In fact it is fine and dandy. It will run for a long time. Jim

Looks good. On valve in head engines we have used an electric drill to lap valves like that.Just tighten the chuck on the end of the stem. Never did one with the seat in that bad of shape though. We use a pencil mark for a fit gage if it wipes a pencil mark out when turned by hand it is good.

Fine job sald, lots of time and work involved in lapping those valves and seats, for your use it should run a long time.

For a daily use working tractor as some have said the valve seats are a little wide but for your app it'll be ok.
On higher compression engines like my diesels sanding the head smooth and flat is a no no, the small groves the cutter wheel leaves when a head is milled flat helps hold the gasket in place and keeps it from being pushed out, again not a issue in this case.

Years ago a friend was selling off the machine shop side of his truck repair business.
I purchased his old Sioux valve grinding outfit, it's been real handy over the years.

Thanks, you said the same thing my father did (Mechanic of yester year) He said it was low compression designed to replace the horse LOL. Yes the shoulders are at .090 and the spec is .078. I needed to keep going until I had a full seal (Tested it). If I have a problem down the road it is not like I am using it for an income. I will tend to it again. My father told me he had a valve grinder like that.

I didn't want to chuck to valve stem due to not being able to control lateral movement. I did slip and air hose on the stem and hand spin in because the suction cup kept popping off LOL.

Thanks Jim, as others I am sure, I think your blessing is something to strive for. It was hard work but the pay off was more than I expected so I guess it was. You were the one that said it should make hills in 4th gear which is what sent me off on the hunt for why it didn't. Well it had no issue now. I have fixed the linkage issue and have it topping out at 1800 no load and 550 idle. With the 11.2 tires it was going 16 mph.

You are correct. I tried to go back and edit but could not. Good catch

You run precision balls through the hole. Go or No Go. I used them for gear bores when I was working in a gear house after college.
All your other points are well taken. I am not using this tractor everyday but for leisure, tooling around the roads and parades. If it ran with no seats, it will take a long time to get back that way. I was told the tractor laid around for 2 years and when they went to start it there was water in it but never seized. You cans see evidence of the water on the vale caps.Thanks

Governor is fine. When I rebuilt the carb I put a rubber seal on the throttle shaft and it didn't belong there. Derrrr. It was enough resistance to keep the governor from pulling it back to idle.
It runs up the hills now. These are fun and I always loved engines and would help my father after my mother told me to. He used to yell at me and get and put back his tools but I now realize I learned a lot. I mentioned that to him yesterday and he said that never happened LOL.

Thanks. The effort you put in now makes all later work take less time because of knowledge gained and skills built. Jim

Very nice work! Thanks for sharing your work and photos. I just pulled the head on a 1968 IH 140, but I sent it to the machine shop for all the surfacing and valve work. The nine 1/2" head bolts on my C123 were only threaded on the bottom with 3/4" bolt heads (and washers) on top. I used (a lot) of copper spray-a-gasket on the head gasket and head surfaces. I re-surfaced the manifold and water return nozzle also. I haven't seen water in the oil since (knock on wood). These cylinder heads are heavy duty!