Newly Rebuilt Tractor Overheating

[Coyote machine]

The Yanmar being repaired isn't a V-8 Chevy or other specialty car application with moly lube needed to fasten the head to the block- it's just a basic tractor, no frills. Oil and go.

 

[Car Doc]

We are having a friendly conversation is that ok with you?

 

[careyo63]

I "always " run a head bolt through the block holes and check the threads before I even Think about installing the Gasket/Head esp. if you can see it. Hit them with a orbital brush and clean up the threads. Blow them out after finishing the resurface Clean or New Bolt and you won't have any problem.

 

[Car Doc]

The OP has already installed the bolts with anti-sieze its already a done deal so hopefully he will learn from our posts for the next time. That's my intentions as always try help someone for the next time if I cant this time.

 

[kenmac]

He's had a rough time with this tractor. Let's hope he's got her repaired / fixed this time

 

[RickB]

You can feel when a bolt or nut is tight its not rocket science. Torque to yield is the exception but we dont have them on tractors thank goodness.

Torque-to-yield fasteners have been used in (some) ag engines since at least 1987.

 

[dirtdonkey]

I appreciate everyone's input. We all have opinions. I used to work for A W Chesterton. We supplied the Navy with Nickel Anti-seize and they spec'd it on their valve assemblies and used it in their assemblies on motor and engine rebuilds. I was schooled by Chesterton's engineers and told to use anti-seize on anything that had a chance of rusting together and just watch tightening since you could reduce the required torque by 15-18% depending upon the application and if the assembly was listed with oiled bolts or dry on initial installation. When I removed the head bolts the first time I had to use a 4' breaker bar on 2 of the bolts and heard the perverbial snap when they finally let loose. Upon inspection I could see that the bolts had dry rust residue on the threads. I was determined not to ever have to deal with that situation again. For those that didn't see my previous post when I rebuilt the tractor I had to use Hoye's injector puller and it took 40-50 whacks on the slide hammer to get the injectors to pull out. Needless to say I cleaned and coated both the head and the injector with nickel anti-seize, even though they don't touch, they won't get the particles in between and rust in place like they were going forward. Car Doc's question about the sleeve liners sticking up slightly got me thinking and I don't remember if they were slightly higher or not. The motor wasn't overheating prior to the valve seat letting go and damaging everything so I just assumed redoing the head would solve the problem along with the new piston and new rings in each cylinder. I included a pic of the damaged piston on #1 cylinder, when I first tore it apart. Again thanks to everyone for their comments and suggestions.

 

[clemsonfor]

Those liners look a few thousanths higher to me at least from the pics at least which is not the best angle to notice such a thing?

 

[Car Doc]

Torque-to-yield fasteners have been used in (some) ag engines since at least 1987.

Interesting wonder why are they using aluminum heads on ag engines now and who is doing it? They are a complete joke in the automotive industry fwtw. I could have said and will say in the future we dont have to deal with them on OLD tractor engines! :laughing:

 

[Car Doc]

Ok I remember this engine now after seeing the valve seat disintegrated pic I talked to you then also.

I am slow sometimes yes it does appear there is some protrusion on the liners and there doesn't appear to be any gasket sealing issues either pre-disaster so that is probably ok. I may have mentioned the actual spec at the time you tore it down and what to look for?

I sure done remember now but that's water under the bridge I just hope she is sealed up now so you can get back to work. :thumbsup: