ISX CM871 New Head Or Rebuild Old Head

[Rawze]

(04-09-2016 )same101us Wrote:  Hi everyone
I am working on a cm871 that was loosing coolant fast. I removed head and found a blown headgasket. One of my camshaft is junk because 3 lobes show extreme wear and the 3 rocker arms show same wear. The cam bearings are showing copper. Engine has over 700000 miles on it. What would you guys recommend I do with the head. Buy a new or reman head or rebuild my old head. I think I can get it rebuilt at a local machine shop for around 1500 to 1000 dallars.

I am out here to make money, and not waste it -- So I do not say this lightly ---

The rule of thumb is that if for ANY REASON! -- You have to remove the head and you have more then 450k miles on it,... replace it with a new one!.

I cannot tell you how many people I have come across that claim they had their head refurbished by a shop,.. only to tell me that they are having problems again in short order. -- Those heads are throw-away and cost about the same as a turbocharger.

The number one reason you do not re-man it is because the valve guides wear out, and the valves sit high in their seats as they age,.. and eventually it snaps a valve tip. Re-manning the head and re-doing the valve guides makes them ALL ride high,.. and then you have trouble later with engine brake clearances etc.

The second reason that you do not re-use a head is that 4 out of 5 will come back bad after a magnaflux and pressure test. this is an expensive process to have done,.. and then you add on top of that, the cost of having it re-manned,.. New bearings, new injector cups, new valves, new springs, all valve guide seals etc. replaced, and all the other work that has to be put in it to actually do the job right,.. GUESS WHAT!--- you have just as much in the head as buying a new one!. -- I can just about guarantee that anyone who is re-manning them for only $1000 bucks or so,.. IS NOT DOING A THOROUGH JOB!. -PERIOD! -- it costs about that just to have it magnaflux and pressure tested etc. alone, and if your not doing this,.. your wasting your time completely considering the fail rate as they age.


The difference in costs is not worth bing in the middle of Montana or northern Canada and it -20 outside, you relying on that truck to run and get you down the road,.. and it fail because you tried to save a few dollars!,-- Just not worth it.