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07-19-2006, 06:31 AM #1
Here's a nice OT to get Wednesday rolling
I friend brings up an older JOY 600 CFM air compressor that has Detroit power... 6V71 with 3800 hours on the meter.
It was given to him to move, his customer parked it in running condition but the exhaust caps have long since rotted away. Direct shot for rain, etc.
The engine is locked up and I told him we could at least pull the injectors and fill the cylinders up with PB Blaster or whatever?
So what sort of secret formulas do you folk suggest?
I friend just did 2 Ford 429 wind machine power units that had sat for 4 seasons and they unstuck them with a long pull bar.
Thanks and sorry for the lengthy story!
07-19-2006, 06:49 AM #2
Their is no way of knowing how bad this is stuck,i would be inclined to think it is pretty solid in this case.Every one has their own "favorite" brand of HORSE P--- that "works best".Be careful with the crow bars,it is easy to break the ring lands out of the pistons.I might be inclined to fill
the jugs with ATF,but still think it is "IFFY".
07-19-2006, 07:21 AM #3
It sounds like the innards of the engine have been exposed to water for a long time. Chances are, along with pistons being stuck, the valves are probably rusted in place and there is water in the crankcase. If you do get it freed up, you will probably have poor compression due to pitting of the cylinder sleeves. Also if the crankshaft has been sitting in water, the bearings won't last very long.
Your best bet, if you want to save the engine, is to tear it apart and rebuild the engine ($$$$). You should be able to remove the pistons and sleeves as one piece and then press the pistons out.
07-19-2006, 09:38 AM #4
I concur with George. There's never been a magic potion work when water and the oily parts of engines are coincident in time and space.
Rust is an abrasive. Barring it over may irrepairably damage the engine. If you somehow get the engine started without removing the rust first means you'll lap 5000 to 10,000 hours off its longevity with the first thousand revolutions.
There is no simple fix for a rust locked engine. Only a few anecdotes where the ignorant and foolish were lucky. The many thousands who tried and failed are seldom mentioned.
Get out your wrenches and take that engine apart, remove the rust, replace the parts that are damaged, send out the injectors, and the other things responsible diesel mechanics do. If your friend is not willing to do the right this by that fairly low time engine at least pass it on to someone who will make the labor investment.
07-19-2006, 10:29 AM #5
At minimum I'd pull the oil pan and the heads to see how awful it looks. That everything is one solid block of iron oxide is a likely as 2 sets of rings rusted to the bores. No information equals speculation.
I've had good luck unsticking locked up motorcycle engines with a spray can solvent sold by Mopar for the purpose of unsticking and lubricating the heat risers on exhaust manifolds.
I've shot a bunch down every hole, warmed things up with the heat wrench, and, in the case of bikes, "bump started" them in top gear. Sometimes it takes a couple tries, but it's always worked for me.
Once freed up, however, the work has only begun. I'm not advocating this as a fix, merely a step to get it unstuck so one can conduct triage followed by remediation of the damage or humane destruction of the poor terminally ill engine.
07-19-2006, 11:05 AM #6
You need something thin.....why not diesel fuel?
If moderate prying won't work, remove the head,
make an aluminum slug that's 1" thick and 1/8" smaller than the bore. Large countersink in middle of slug.
Put some wag to work on it with an air chisel inserted in the countersink (a blunt piece of
softer bar instead of a chisel tool is safest).
Rattle each piston with this setup for....????....
hours and it may work loose. Let it soak with diesel on top of the pistons first. Apply moderate heat with a torch, rattle, heat, soak, repeat.
Had a 6cyl that was in a flood in 72, freed it up with this method after it sat for over 10 years.
A 8ft pipe on the crank wouldn't budge it.....
Worst case, being a detroit, maybe you could take off the rod caps and pull piston WITH liner in one shot. Prolly not worth the effort.......or cost to
07-19-2006, 11:23 AM #7
I told my pal that this would be a long shot.
The crankcase oil is clean and at normal level.
A local diesel guy echoed what George & Forrest said too.
It looks as though we'll pull the injectors and fill with maybe a mix of ATF & diesel and see what happens? Marvel Mystery may be just as easy?
I'll report back as to our success or lack thereof.
Thanks Gentleman for your assistance.
07-19-2006, 11:49 AM #8
The last time this came up the opinion was to use used oil from a diesel. It will have some of the fuel dilution and a little nitric acid. I would use it if I were in your shoes.
May not work, but then you can use the AFT and Diesel fuel.
Let us know I have a few engines that maybe stuck and will be working them over this winter.
07-19-2006, 04:23 PM #9
A friend once told me that he used "oil of Wintergreen", if I remember correctly. He claims that this oil will dissolve the rust and free up anything. Has anyone ever heard of this? Some times, I don't know if he's full of it, or not.
07-19-2006, 05:28 PM #10
07-19-2006, 06:12 PM #11
Coke syrup is one trick i have used. It will eat rust and not good metal. Still the pitting will take a lot of hours off the life of the machine. Also on old machines the pitting can let oil get by the rings and cause a runaway.
07-19-2006, 08:13 PM #12
the mopar heat riser stuff works good, especially because it comes out a little thick from the spray can.
I freed up the stuck pistons in an old diesel tractor with Kroil (sp?) - orange container.
07-19-2006, 08:21 PM #13
At 600cfm Im guessing thats what, a two stage screw? Ive had customers give up on the gearsets in the JOY screws because JOY is gone and nobody seems to have the knack for hobbing their gears and not to mention getting the other parts. I mention this because if making air is the goal getting the engine to run may just be the beginning of his troubles.
07-19-2006, 08:22 PM #14
It may be a good idea to put something (diesel?)into the cylinders and try and free the engine - then remove the cylinder head for inspection and clean-up (assuming you want this engine to be useful).
I only mention this, because once the head is off, you don't want to disturb the liners unless you have no choice. And trying to free an engine without the cylinder head will usually disturb the liners. You can (must?) clamp the liners so they don't move when the engine is turned.
Note: I don't know if this is all true with Detroits, but it got me into trouble with a wet-linered Standard engine many years ago. The liners moved and wouldn't return to their correct height.....
Detriot mechanics, am I making sense here or talking rubbish?
07-19-2006, 08:30 PM #15
Pull the airbox covers and look at the intake ports. You should be able to see the rings on some cylinders, the piston head or skirt on others. This is the quickest way to have a peek at the internals. If you do pull the heads you will have to clamp the liners down before trying to turn the engine or the liners may unseat.
On edit: If you pull the injectors and try to flood the cylinders with penetrant it will run out the intake ports and into the airbox on any cylinder with the piston low enough to uncover the ports.
07-19-2006, 08:40 PM #16
Better have a peak in the blower too...
07-19-2006, 09:22 PM #17
Great replies guys!
The contractor that gave this machine to my friend vouched that the clock was correct at 3800 hours!
I was disappointed that someone would park and forget this machine. The guy used it to power 2 sandblast and after the RJR account dried up they returned to a smaller machine.
The plan is to fill up the cylinders and let her sit a few days and then bump the starter or turn the crank.
07-19-2006, 09:27 PM #18
Pull the injectors and pour diesel and oil of wintergreen into the cylinders and wait several days after thsi has worked it' way down into the crankcase drain it out and fill the engine with clean oil. Intsall a breaker bar on the crank and rap it with a rubber mallet.
Since the engine is a 6-71 you can pull the airbox covers and examine the rings.
07-19-2006, 10:10 PM #19
BTDT. Was given a 2-53 GM diesel (1957, pre-Detroit) Lincoln welder. Had been sitting and was stuck. I poured a few gallons of various penetrating oils, used oils, diesel fuel, JP-4, Marvel oil, and even gasoline down the exhaust, in the blower and everywhere else in an attempt to loosen it up. Let it sit a week, try again, a month, two months. No dice. I finally traded it to a friend that swapped me a day's use of his Bobcat to dig out and grade the floor of my shop in preparation for concrete.
Turns out I made the right decision. He kept trying but eventually took the head off. It was REALLY rusted up solid. In the end, he was standing on a 6ft cheater bar with a block of aluminum on one of the pistons and wailing on it with a 10lb sledge when it finally began to move. Water had gotten in the blower, frozen and broken one of the lobes clean off.
He does equipment repair for a scrapyard, so he managed to salvage a 3-53 for pistons, liners, rods, and such, then found a guy with some surplus new parts, head, blower rotors, new injectors, etc... For about $750 he got it running.
I wish I had been there when it finally fired off the first time. A lot of that stuff I had poured in the exhaust was still in the muffler.. heheheh. He said it looked like he had struck oil. A nice rusty/black geyser of nasty, used motor oil, JP-4, etc... He was covered. Then it smoked the whole valley up as it burned off.
He also had to have some electrical work done on the generator, but in the end, he had real nice 400amp DC welder for under $1000. It is used daily now.
Point is, you can make this a pretty good deal if you can find enough used parts to get it running right. If it's too far gone, it can get real, REAL expensive with new parts.
07-19-2006, 10:37 PM #20
Old used oil from a diesel engine is the best.It has an acid in it that will loosen the rust.This does work.Take airbox covers off as someone said and spray down the cylinders also.I use to work on the screaming detroits.Use to watch the pistons going up and down with an air box cover removed.Cool to see.
Peter S ..Yes the liners will move sometimes but not very often.They pbobably get carbon bits broke loose when they unseat and then when you push them back down they are standing higher than they were.