53 sa engine

I had a small water leak between the head and block so I pulled the head to replace the gasket. Initially the engine looks good. This tractor will probably never do real work again. It was my grand dad's and I am restoring for the hell of it. The engine runs pretty good with just an infrequent miss with no load. Should I go for a head rebuild while I have it off? What else should I look at while I have it down? The new head gasket says sealer required. What is recommended?

Richard

Rich, you'll no doubt get a variety of opinions/responses. Mine is this: If I were just going to keep the SA around as a keep-sake and maybe parade tractor I wouldn't spend a load on it. What I would do is take the valves out of the head while keeping them in order, to return them to the seat they came from. I would clean them and all ports on the head as well as I could by hand. I would then lap the valves by hand to their respective "homes." If they appear to be seating I'd clean them up good and replace them in the head, lubing the mating surface with a light oil at this time.

This wouldn't be a bad time to place the head, level and face up on the bench and pour some diesel fuel into each compression chamber on the head as a test. I consider that if no or very little fuel seeps out in 15 minutes it would suit the purpose of putting around without being concerned about valve failure.

When I replace heads on old tractors I use Copper Coat in the spray can, per directions on the can.

I've never been sure head gaskets needed any help in sealing but for some reason an inner voice made me use something. I have used aluminum spray paint when I didn't have anything else.

I hope that helps or at least gives you something to think about. gm

the correct way is you should have done a compression check before removing head. now you need a machine shop to remove the valves and have a look at them and the guides. if you don't know what you are looking for then its like staring into the dark. you also need to have it checked for warpage, as that's a good cause for the leak.it would have to be planed then. you cant get a definite answer here cause we cant see the valves. if it was mine I would just get the head done cause its already off. I use permatex high tack sealer on head gaskets, and all gaskets. oil and gas resistant and easily removable.
now its a good time to have a look at the sleeves for wear also. once you get an engine apart the repair keeps going.

Thanks Gary.I have an MD that I am working on.That is the answer I was looking for too.

Clean the head and block well then give the new gasket a coat or two of hi-temp aluminium paint. Tighten head to 80ft lbs and then redo after getting warm and you should be ready to go. Had one that did same thing about 5yrs ago same thing as yours replaced as i said and it hasnt leaked yet

Thanks gentlemen, I do want it to run "right" but a full head job for this tractor is overkill. I will clean, check for leakage, and lap if necessary. One thing I would like to add is a temperature gauge. I notice that the lower water intake that bolts to the block has what appears to be a boss on the side. Is trying to drill and tap this a bad idea? I have not seen new ones for sale.

You wont get any readings with the sender placed there unless you can run shutters. You can get good readings with the sending unit located in the upper radiator some housings for SA and SC had such a housing.

You claimed to be restoring it, but are really only repairing it.

With that said, if it ran good before, and you do not want to spend money on it, then I would just replace the gasket and re-torque. It you start, it is hard to stop.

To get good readings the engine apparently needs a water pump. For my 53 Super A I put a sender in a SC upper outlet and the temp reads on the edge of the red with a load in just a few minutes. With no load it drops almost immediately. Looks like the temp varies a lot with themosiphon engines.

sure don't see how a valve job is overkill. that tiny little engine's head is a piece of cake. without valves seating you have nothing. takes compression to run and start good. lapping is obsolete. seat width and position on valves is critical. all lapping does is make the seat wider in an already wore out seat. if the seat is as wide as the valve face you definitely need valves resurfaced along with the seats. and if seats are pounded out they have to be replaced also. you may get them to seal being stationary but when running the valve will walk around and not seal properly anyhow. the biggest culprit is the valve guides. you want it to run right but neglecting valves makes no sense to me. just pull the valves and post a pic of the valve faces and seats and I am pretty sure it will require valve grinding..

We finally got a bit of agreeable weather this week end. I pull a couple of the valves. The guides are elliptical and the valve stems are worn. Before I do more damage than good how about a little advice on changing the guides. Also what to do about bad seats. And what are the small clips inside the spring for?

Thanks
Richard