951c track loader with bad motor

there is a 951c here local that i would like to go check out.
pics look nice and clean

from the seller,
1980 caterpillar 951 trackloader. This machine has 2700 original hours. Has water in the oil, which caused either a crank or rod bearing to fail. Will start and run, but has heavy knock. This is a well maintained, one owner machine owned by a power company. Undercarriage is in excellent shape. Trans shifts smooth and brakes work good. This dozer is not junk, engine is only issue

any idea what it would cost to rebuild motor,
probly need new crank or possible turn down, pistons, rings,
bearings, and seals.
i can do most of the work myself.
not sure on the water in oil, head gasket, or head cracked?

asking 6500, whitch i think is too high.

Yes that U/C looks very good,it's got sealed and lubricated tracks on,the most likely place water enters the engine is through the water pump as it is gear driven,it also can get in at the liner seals,loose liner,precombustion chamber or cracked head,the oil cooler too can be suspect if you get oil in the coolant,with it knocking that probably means it knocked a rod bearing out and it is likely the shaft will be damaged and may need to be ground,the engine will need to be removed,I have no idea of the cost but a call to your local dealer for an exchange unit will point you in the right direction.
AJ

I've built quite a few CAT engines, but it's hard for me to give a price for someone to do it themselves. Usually for me to do one it winds up being $2000 to $2500 per cylinder. That includes me pulling it and putting it back in, all parts, and all machine shop charges. The variation on price gives the customer pretty much a best case, and worst case scenario to account for things like a bad head, or another major part that needs to be replaced.

To get a better idea, call your local engine machine shop and ask them what their part of the job will cost. They ought to be able to get you in the ballpark on that end. Parts wise, those shops often buy enough to get discounts from the various aftermarket mfgs, so they might be able to save you some money that way.

If they can't do anything, give Offroad Equipment Parts a call. I've done a few of major jobs on the older CAT equipment, between engines and steering clutches, since finding them. So far they have saved my customers thousands in parts costs. Their inventory is constantly changing, but you can often get OEM CAT parts at aftermarket prices, and really good prices on the aftermarket items as well.
Offroad Equipment Parts