Re-Engine Early HD6 G Shovel Part II

Ok Guys:  The saga continues on trying to re-engine the HD6G.  I am had very little luck in finding either engine parts or a good running 344 block near me.  So I was thinking about using a 2-71 out of an HD 5 to run in the HD6?  

Mactractor- I was thinking the 2-71 would be an easier fit due to the fact that the 2-71 originally came in the HD5 and would slip right in.  

I am not quite understanding the process here. You have an HD6 and the engine is bad, I guess I missed whats wrong with it, but unless the block imploded I cant see why it cant be repaired, but anyways you want to take out an engine that AC put in that worked beter than a Detroit, and find a detroit of unknown condition, go threw abunch of work to make it fit so you can go backwards in the design? I dont find the logic or economic sence it that. We have a truck here with a 8v71 detroit in it, its a good engine makes good power etc, but the noise is almost more than I can stand, and the torque is compensated by a million gears, this winter its coming OUT to be replaced by a Mack, which I know is going to be alot of work but at least the truck is being upgraded to something better, not to mention the value is increased. Your HD6 with a detroit is going to go backwards in value, not to mention all the work your going to do, and have less motor.

Is the engine a 13,323 or higher? which I am going to assume the lower number is probably a precup motor. If its 13323 or higher the kits are available. I dont remember the guys name in WA but I do remember calling him for parts for a guys HD16 he was alot of talk but no action, if its the same guy. Just remember a running Detroit doesnt make it a good one, if you go the detroit route, and find out the engine is need of an overhaul etc, the detroit will run into as much money to reapir as your 344 plus its getting harder and harder to find qualified detroit guys that actually know how to set them up to run properly.

I should have some good used 344 pistons and linners let me have your pistons parts#

Actually the deep cup shallow cup has no exact meaning. We went round and round about this on a 745, and an HD11B. There seems to have been no rhyme or reason as to which engine had which piston. You can have a older direct injection with a shallow cup, and than you can find a newer engine that has the same cup. Some guys said its a newer version but that does not ring true, on the 516 we have worked on there is no telling whats inside untill you open it up. But the injectors are different, and if you have a shallow cup mixed with a deep cup injector they dont run worth a damm, and you cant assume the injectors in these old motors are correct to the bowl, becasue we have found that not to be the case.The only way to tell is lifting the head or sending a scope in to see what bowl you have.

There are 2 Allis Chalmers 7000 engines on eBay. You can tell which pistons by the cylinder head and the engine tag. If the injectors are on the top of the head it is a direct injection engine with cupped pistons. The engine tag should say Allis Chalmers 6000 engine. If the injectors are on the side of the head with the pre combustion chambers on the other side of the head the engine tag should say HD344. The HD344 has flat top pistons. New sleeves and rings are available. Bearings are harder to find.

Orange, if the engine is just stuck but you know it ran before,if I was you Id pull the head clean up the corrosion, make sure it didnt crack anything if your in a part of the world that freezes. These engines can be stuck but that doesnt mean shot, if you get the head off use a hone, or even just emery cloth by hand and get the cylinders freed up and cleaned up, have your head gone though, valve job, maybe check your injectors, and Id be willing to bet for less than $1500 you would be back in business. The fact of the matter is this tractor isnt going out on a job site to be pounded 10hrs a day 300 days a year chances are its going to be a toy to play with, so who cares if it does burn a little oil, or has some blow by, its never going to log enough hrs to make a bit of differnce. Thats my opinon, and from my expierence it doesnt take alot to hold an engine tight, and after it runs for 10 minutes on its own it will have the walls just as nice as can be. You could just try to unstick it with the head on, but if it were mine Id like to see whats inside, if you still have alot of cross hatches that cylinder wall is good.

KCGrain, Trevman and Dozer:  Will work on the engine using your recommendations.  Was not able to get to the machine today, as I had yard chores, (getting lawn furniture in for the wife and started getting my wood supply in for the winter.  

I'm new on here but just ran across this post and thought i would throw my 2 cents in. I had the exact same issue you've got. I know the dozer was driven to the exact spot it is at right now but over the past 6 years it leaked water through the exhaust and stuck the engine. I pulled the head 2 days ago and found a mess! I was able to use emery cloth (and a good deal of time) and clean them up. As i got each cylinder cleaned up i poured a mixed of marvels mystery oil/diesel and moved on the the next. when i got done with the last i used a wooden handled 2 pound hammer and let the end of the handle drop around the edges of the pistons (not to hard but enough to give them a little shock) this kind of broke up any crud in the rings a little before trying to turn it. Then i put a socket on the crank pulley nut with a breaker bar and just wiggled it back and forth until it was loose (didn't take much at all) Then run the pistons down in the bore and use emery cloth and clean up for the final time because there will be some more rust/corrosion that you couldn't get to before. mine spins over like a new one now. I realize this was what the guys above were telling you but i figure since i had done it in the last couple days i would share. I'm waiting on my head gasket to come in (hopefully today) 

I thought of an alternate r3epair. Since the engine has taken on water thru the exhaust, Odds are that there is only one cylinder effected. Take the cylinder head and oil pan off. If the effected cylinder is close to the top of the stroke manually turn the engine backwards to re hone the bore. If the piston is near the bottom of the stroke, remove the rod cap and rotate the engine manually to pop the sleeve. Remove the sleeve, rod and piston as an assembly. The in frame rebuild will be much easier than removing the engine

Using a 2-71 will drop HP about 1/4 of what the origonal engine had and you might find your way underpowered for what you want to use .

I am probably asking a dumb newbie question here but, is that gauge the same as the one for the HD-3? 

Guys: You have mentioned using a 50/50 mix of acetone and ATF to use as a lubricant to free a stuck engine.   I have both products in the shop.

I have some used sleeves that could be honed and re used. The sleeves for the HD344, 6000 & 7000 motor are the same. Ask gemdozer he might have some good pistons and sleeves. If you can't find flat top pistons you could convert your HD344 to a 6000 motor. This requires the 6000 cylinder head, pistons and connecting rods and dished pistons. If the pistons are stuck in the sleeve, turn the crankshaft to pop the sleeve out of the block with the piston.

Best wishes