There is pretty significant cylinder head pitting on my 3T1 D7. The service manual doesn't say anything about this.

How does pitting like shown in the attached pictures affect engine operation? Is there anything that can/should be done about this?

Not sure about the after affects but I have a head off my 933 that looks like yours and am going to do a valve job and run it. My master mechanic friend says it was caused by water and should still run fine. we will be the first to know. Good luck, Scotty

Yes coolant leakage into the combustion chamber is the main cause usually is caused by a bad head gasket or a chamber leaking letting the coolant into the comb. chamber. That was quite common to see at the Cat dealer where I worked and most times you had to have the head resurfaced or even would be cracked and sent out to be reconditioned or put a remanufactured one on.

When I pulled the heads off this unit it had water standing in several of the cylinders which ran in from a rusted out exhaust manifold. The cylinders were so pitted that I am re-sleeving the engine. No telling how many years this dozer sat around with water in the cylinders.

I replaced one of the heads with one from a salvage unit, but I have about reached my threshold of pain on spending before I see this engine run, so I am going to grind the valves and re-use this second head.

Like Scotty, I am going to find out how well it runs with this much pitting.

Thanks

hello KansasD7 ,i would say that it may cause the head to run a bit hotter in that spot were the pits are ,if you are not using it for work i would reuse it ,the pitted surface has more area making it hotter in that spot compered to other areas,just my ideas ,bruce oz

That makes sense, bruce oz. Those peaks are going to want to heat up.

I thought about using my TIG to fill in the pits and grind it level, but I am worried that I might induce stress and cause more problems than I fix.

SJ - any idea what technique was used to add metal fill and resurface the head?

I do plan to use it to do work, so I don't want to put it together like this if it can't be used.

I would bet money that more of these 1951 cable D7s are running with pitted heads than not! I pulled the heads off two of them at a salvage and both had pretty bad pitting on the heads and valves.

KansasD7

I wouldn't worry about the pitting, I've seen worse running with no problems. If the head isn't cracked or the precup seals aren't leaking, run the heck out of it and don't worry about it running hot because of the pitting. just don't grind the old rusty valves to thin.

As Old 3T said some pitting won,t hurt I,m sure but what you have to worry about is if the pitting is out reaching where the head gasket has to seal and the valve seats and many times a resurface job will clean that up but at the dealer if they were too bad we either put a rebuilt one on or sent them out to this rebuilder we used from Brooklyn NY to recondition them.He could fix cracked heads no matter how bad and they came back like new. In my later years at the dealer Cat had an exchange program of their own for cracked and bad heads on an exchange program.

SJ- From the pic's, you can see where the headgasket once was and there is no sign of rust pits in that area. Also, looks to me like that even tho he has an early serial#, he has later model heads (Wider valve spacing) and that's good.

On second look....I take back what I said about those being later model wide spaced heads. Those are the older, narrow valve heads.....sorry. Still, nothing to worry about.