Budget partial refresh on a 60 series Detroit.

Lets say you purchase a older Pre emission 12 liter Detroit that is in the truck you want at a reasonable price and the engine runs and dynos fine. But it currently has 900 thousand plus on it and you just bought with the hopes of going out on your own and having a reliable truck but you are also very mechanical.

So you decide to do a partial rebuild on the major moving parts that could have a catastrophic failure and crush your hopes and dreams and also address a few smaller parts that could lead to engine failures.

So the 1st thing you do is pull the oil pan and main and rod caps and see what they look like .From what I have gathered on here 90% of the time the crank is fine and everyone just replaces the bearings with fresh ones.

While you are in there you replace the oil pump because this is the Heart of the life blood that enables your motor to live, without it you are dead in seconds.

I don't know if the rear seal is replaceable without pulling the transmission but if it is tackle that at the same time.


The next set of critical moving parts that could cause a catastrophic failure is the valves in the head.
So go ahead and replace the head with a complete rebuilt one.

Next thing I would replace is all the belts and hoses and clamps and than pressure test the system and the radiator for leaks.

Next install a new water circulating pump so your cooling worries are addressed as I believe overheating kills more engines in the long run.

So the argument now would be is you did not address the cylinders and pistons. If you ran it on the dyno and it performed up to snuff with no real data showing ring blow by or loss of cylinder pressure why mess with whats not broken yet?
Get out on the road and save some more money for injectors and a new turbo for your next upgrade.

if either of these fail on the road they are not a huge amount of hours to replace.

If a alternator or starter fails once again something that a mechanically inclined person can address in a parking lot if it fails on the road.

If you had a few extra bucks while you had the truck down for doing the head and such go and pull the tranny and do the flywheel ,clutch,pressure plate and throw out bearing and whatever other parts are associated with a clutch job.

Than run until you van save for pistons and sleeves and a bully gear.

Is this good thinking or am I being unrealistic?

 

I am a firm believer in preventive maintenance. Bad hoses,broken belts and bad water pumps lead to an overheating situation that can lead to running an engine overly hot that now leads to a blown head gasket or warped head.

Who knows when a engine is ready for crank and rod bearings and a oil pump or one of the valve keepers or springs is ready to fail and drop a valve into the cylinder?

You have already gotten 90% percent of the life out of the motor why play with fire with the last 10%
out on the road? The service needs to be done eventually so why not tackle it before it fails?

 

Let it build for what. Expensive breakdowns and repairs on the road?