D6 9U Engine swap?

You have to consider three options, sell outright, rebuild what you got, or swap out some other power source. A D6-9U series is a pretty good machine, but you are not going to get rich selling it, in fact, you would be better to sell it as is, take your lumps, and get out from under it. If you're going to keep it to use, then you have to weigh the two available options - rebuild the Cat (if you have to), or swap out the engine.

If the machine has sat for ten+ years, the chances of the engine corpse working is slim. Just through normal condensation there is probably a good buildup of "mung" in the diesel and cylinders, unless it was properly laid up and kept out of the weather. And unless by some miracle the Cat engine rebuild isn't going to be a lot of dough (mutually exclusive with Cat rebuilds unless a relative is the local distributer), you have to consider skimping on costs, which is also not a good way to go with Cat rebuilds.

The best solution, if you don't want to sell it and you want to use it for yourself, is to repower it, and the best way to repower it is to use something cheap and easy to fix or replace in the end, buy some ear plugs and stick in a Detroit (whoa, can hear the cries from the pure Cat folks now). I just bought a D6 that has a nice 6-71 installed in it, just for that reason. It coupled up directly to the Cat housing and clutch! The D6 has a lousy track record with the hydraulic pumps on the front of the engine - the Detroit can have a rear pump on an output shaft and makes a nice couple to the Cat hydraulic system. Plus, it's cheap, and adds a lot of power to the unit. You have to turn down the horsepower of the 6-71, maybe you might opt for a 4-71, or?

Bottom line - if you're wanting to sell it, dump it now and don't mess with the engine, leave it as a mechanic's special. If you need to use it, either fix the Cat engine if it's cheap, or dump it for a cheap generic swap-out.

Thanks a bunch,
Matthew

O ya, Could you define "mung"? Just kidding, I think I will find out what you mean when I take it apart!

I wonder how hard it would be to put a direct injected engine in it? Something like a D436 International or something on that order. I am afraid the cost of overhauling the CAT engine will be tremendios.

Cost will be the determining factor in what I do with it.

Any thoughts?

I will try to pull start it when it warms up. First I'll have to get the vavles free and there is a brake stuck as well. Any thoughts as to the best way to get them loose?

Haven't got the valve covers off yet. Would you know what the valve lash specs. are for it. I have a manual but the first two pages are gone.

Even the pony motor parts aren't too bad. $70 for a piston, can even get oversized yet, Wow I thought. That gives me new hope on the old CAT!!

Heck, it cost $90 for a piston for my Arctic Cat! If I could trouble you some more, I need the rod bolt torque and head bolt torque for both motors.

Is there a special engine manual for these? The book I have mainly covers the trans and engine removal and also maintence.

Thanks again
Matthew

Yup the wind, she sure can blow out here!`

The engine in it is low on power. It will probably need an overhaul, so I've been debating on whether I should fix what I have, or just put a direct injected engine in it. I can get an old IH combine engine for $1500. I imagine the worst part would be getting the coupler and engine flywheel lined up straight.

Any thoughts?

If I repower it with something else I'll post back here and let you know.

As for the clutch thing, I'll have to jerryrig something or at least try to figure something out that would work. I would'nt put a CAT motor back in it. They just cost too much for what I would be using it for. I know Oliver used a chain coupler on their tractors to hook up the engine to the transmission. I think a good machine shop could fix up something that would work. Would'nt they?

Thanks,
Doug D.

Thanks again
Matthew