I now realize...

...that I didn't do something both several of you and the book said to do. When I bought the tractor, it was a fresh rebuild-less than 5hrs on it. I didn't know at the time, and it didn't register til today, that I should re-torque the head bolts after 50hrs. I did not do this, and wonder if this may be the cause of coolant getting into the combustion chamber.

Anyway, now that the head is off, I'll take it in and get it checked out.

Also, as was cleaning gunk off of everything, I noticed that on one of the piston heads there was a perfect picture of the valves. Only this one had it. Is this somewhat normal/expected? What may be causing this?
 
(quoted from post at 03:25:57 09/14/13) ...that I didn't do something both several of you and the book said to do. When I bought the tractor, it was a fresh rebuild-less than 5hrs on it. I didn't know at the time, and it didn't register til today, that I should re-torque the head bolts after 50hrs. I did not do this, and wonder if this may be the cause of coolant getting into the combustion chamber.

Anyway, now that the head is off, I'll take it in and get it checked out.

Also, as was cleaning gunk off of everything, I noticed that on one of the piston heads there was a perfect picture of the valves. Only this one had it. Is this somewhat normal/expected? What may be causing this?
Re-torque is absolutely necessary in my opinion. I had a ton of direction from the pro's on here when I did my head gasket awhile back. I ran mine until it was up to temp and then re-torqued. I got between an 1/8 and a 1/4 turn more on every head bolt before the torque wrench let me know I was at spec..
 
I never retorque them, ever. I usually go a little over spec right from the beginning... and take 1/2" head bolts up to 110 ft-lb. Clean bolt holes is the key.
Sometimes you do everything by the book and things still go sideways...

I'd be a little concerned about the valves... are those valves tight in their bores?

Rod
 
I'm with Rod. I really doubt a missed re-torque is causing your problem. It might account for some oil leaking down the side of the block a year from now, but not a compression leak.

I would be far more worried about the valve imprint in your piston. Assuming the pistons were replaced at the last rebuild (in other words, you're not looking at prior damage), you HAVE to figure out what's causing the contact.

What's the bore size on this engine? 4.2 or 4.4"? Have the machine shop check valve recession while they are looking at it. I don't have an exact spec in front of me, but if memory serves, the valves should be around .050 to .060" recessed.

If that checks out, piston protrusion would be the next thing I am looking into. This will also determine which head gasket you use. More on that next week after I do some research.
 

Yep! I'm with Rod and Bern. I've never retorqued a head bolt in my life. Do the three step torque in proper sequence from the get go.
 
i look at it like this.

it's too east to NOT retorque them after warming.

I even use the fel pro head gaskets that say you don't have to.. and I still do.

havn't lost one yet..
 
I guess it depends on how much time you want to spend on it. Lots of those straddle tractors with loaders are NOT easy to work on so it's not exactly easy to go back and re-torque... In fact it's a pure poison misery job. So you torque them once and move on. I've never lost one yet from not re-torqueing... so our records are about equal. lol

Rod
 
Luckily I've never had to do a head gasket or worse on a tractor. I've done it on cars and motorcycles, and I've always followed the manufacturer's service manual and I've never had a problem. Motorcycle engines always seem to call for a re-torque of the head, but that may be due to the nature of the air cooled engines on most motorcycles. Cars have called for it less and less as the years have progressed.
 
I know the felpro gaskes recetly i got from napa said no need to retorque.... ( but didn't say you couldn't if it gave you warm fuzzy's or helped ya sleep better... :) )
 

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