8070 motor fail

Tim NH wrote: Add in the cost of having a adapter plate made, or being able to buy one, to mate the Cummins up.    Tim

KJCHRIS wrote: Pictures look like it didn't burn a piston but dropped a valve, which beat hell out of piston and head, you'll also want to have that rod checked for damage.  I'd do an out of frame complete rebuild or replace on that engine.

Anyone have a rebuilt Motor for this tractor here on this form??

All exhaust valves from an engine that has had the timing advance fail need to be scrapped.

Looking at the first head pic, the injector seems to be the cause of your issue, can see where it was spraying back on the head and valve, and continued use with it running poorly, will make it $h!t the bed. Not in any way the engine's fault. Fix what you have and get it back in the field. Too bad I'm no longer living in Colo lol! That head will need replaced, plenty of good used heads around to be acquired. Leaving an old copper washer in there, and adding a new one with the injector can cause it to not spray in the piston bowl, but on the head surface. Overhaul it, and get another head core to have rebuilt. 

Bhuffaker1, welcome. Hear what you’re saying about being tired of spending money & then it’s not reliable. You’ve also stated in your previous posts that your 8070 has already received a new radiator, new turbo, 8500hr, & otherwise decent shape. From pictures I see it is a Fwd - right? Is it PS or PD transmission?

Lots of great advise on this AC forum. So with that support/direction, rebuilding its current AC 670I engine might be best money spent going forward? Then you should know exact condition of the engine. 7050’s engine might do ok too? It’d compliment your 7080’s likeness. Always a chance for 7050 engine to have issues later though. Cummins 5.9 would be a good engine, but it’s conversion will be expensive. You say you have little to no local AC support. So if you can locate a good local Cummins support, that may be another good direction for you & any future issues?
Good luck whatever you decide!

Edited by AC7060IL - 06 Jun 2021 at 2:58pm

Lars(wi) wrote: I don’t want to sound out of line here, but, what does this tractor run/pull when it’s working? Is it possible that you are expecting too much from this tractor? You may have too much of a load on it? Just curious what you use this tractor for?

injpumpEd wrote: Looking at the first head pic, the injector seems to be the cause of your issue, can see where it was spraying back on the head and valve, and continued use with it running poorly, will make it $h!t the bed. Not in any way the engine's fault. Fix what you have and get it back in the field. Too bad I'm no longer living in Colo lol! That head will need replaced, plenty of good used heads around to be acquired. Leaving an old copper washer in there, and adding a new one with the injector can cause it to not spray in the piston bowl, but on the head surface. Overhaul it, and get another head core to have rebuilt.

I don’t know anything on this topic. Unless these motors that your thinking of buying came out of an 8070, you might end up half to three quarters of an engine swap to find hard to find puzzle pieces and regret the decision.

You should rebuild your motor. At least you know what you have. The other 426 may last a long time or quit tomorrow. When doing a overhaul have the pump and injectors tested. Could replace pumps and even put a A pump on. A cummins swap will require a motor adapter plate and flywheel modification. I think the frame rail gets cut to make room. How can injectors be put in wrong when they have lines to match up to?

Calvin Schmidt wrote: About a month ago, I looked at a brown belly 7580 that was supposed to have a rebuilt engine. There were other issues so he was willing to sell at a part out price. I didn't pull the trigger, but if it has not sold and I bought it , the engine would be available. Also has 32" wheels. I'm a long way from you in Ontario.

Correct, return line towards valve cover on engines with American Bosch injectors. Sometimes guys put them the other way thinking the returns are easier to get to, not realizing the holes in the tip are at an angle to compensate for the injector sitting in the head at an angle. Allis Chalmers built injectors are foolproof, inlet on side, return on top. 

If it's got an Ambac pump...it has Ambac injectors...fuel line on top,return on side.

Edited by SteveM C/IL - 06 Jun 2021 at 9:58pm

injpumpEd wrote: Correct, return line towards valve cover on engines with American Bosch injectors. Sometimes guys put them the other way thinking the returns are easier to get to, not realizing the holes in the tip are at an angle to compensate for the injector sitting in the head at an angle. Allis Chalmers built injectors are foolproof, inlet on side, return on top.