Fighting WVO residue in prechambers
 

5 years ago right after buying my 87 300D with a #14 head I bought a used #17 head just in case. Now that the #14 is blowing smoke out the coolant bottle, its time to rebuild that spare #17 head and pop it in. The seller failed to mention that the #17 head was heavily coated in WVO residue. I got the injectors out pretty easily but but the collar nut won't budge. I'm using acetone to dissolve the WVO goo which is pretty damn effective but the nuts aren't coming out. All the torque in the world and even an impact gun can't do it. I only removed 1 nut and damaged it in the process. I can deal with all the visible WVO residue but I think its down in the threads and I can't get to that stuff with acetone, it evaporates too quickly. I need some better ideas before I start doing real damage to this thing. Yes I, using the correct screw in collar nut tool.

The one on the left is cleaned out with acetone and not coming out. You can see where the keyway in the nut is getting bent because I'm applying so much torque to it. The one on the right isn't cleaned out yet. Ideas?
https://i.imgur.com/gpvLtnK.jpg?1

The idea that WVO is all upside is, obviously, wrong. While Diesels can run on a lot of different fuels each has its downsides (for Diesel fuel it's the cost).

Anyhow, it might take some serious heat to get those to move. Again, upsides and downsides. Heat moves pretty much everything but too much in too concentrated a spot can cause cast iron to crack. So try as little as necessary and if you need a TON of heat plan to use the torch and slowly allow the area to cool back down. You may still need the impact but at least the bond will be broken.

Good luck!

Dan

i'd go with a little Blaster

Try saturating with some methanol or Kroil first.

Jeff

What prechamber lock ring tool are you using?

Those nuts are bastards. I used the correct tool and still killed half of them.

Dan is spot on, heat is your friend here. Think about heating the head in a tank of water, mounted in such a way that you can put some torque on it, or be able to quickly extract the head from the hot bath and then apply torque. Another approach would be put the head into an oven (gas fired bar-b-q?) and bring up the temperature that way. Safety is a big issue with either approach.

Aluminum is very good at transferring heat, so only heating a small area with a torch is very hard to do.

Alternatively, I'd think about a method to clean out the residue short of removing the pre-chambers, like having a shop hot-dip the head. Probably will need to do that anyway to clean out the oil and coolant passages.

Tightly twist in a cotton rag into the injector hole.
Apply 50/50 Acetone ATF mix (great cheap penetrant) to the rag.
Can't get Kroil in CA.
The next day, use a brass bottle brush to scour out the residue.
Repeat the above steps until the threads are clean.

After the collars are clean, apply heat and impact gun to aid in removing the lock collar.

If the lock collar gets FUBARed switch to an air chisel

Why the pre-chamber needed to be removed? Spray some simple green and leave it over night. Use a small brass brush to clean out the injector thread. Blow out debris with compress air. Done IMHO. Others may beg to differ.

Thank you to everyone for all your suggestions. A friend came over and after seeing the problem I was dealing with he laughed at the size of my breaker bar. I thought a 2.5 foot breaker bar was perfectly adaquite but apparently not. A 5 foot cheater bar (hydraulic floor jack handle) did the trick. Lesson learned: size matters.
https://i.imgur.com/xPsWmyM.jpg
I tried that along with just about every other solvend I had stashed in the garage.
This one. Ipicked it up on eBay a long time ago, don't remember the seller.
Because these prechambers are just as filthy on the inside, and I want to have it resurfaced. I'll probably end up reusing the prechambers from the #14 head. Even the valves looks pretty awful although I haven't found any damage to the seats. Just need a cleanup I think.

Is there any special considerations when having an om603 head resurfaced other than removing the prechambers and valves?

There ya go. More POWER! And a beer

Yes, according to the FSM you must use a thicker "repair" head gasket that restores the head-block separation to make up for the missing head material, and the amount of material removed is supposed to be equal to the thickness specified in the FSM (and equal to the increased thickness of the gasket).

The head does not need to be perfectly flat, per the FSM, so I'd make sure that a re-surface is even needed. Aluminum will allow a certain amount of flex when torqued down, more than what an iron head would.

This does work for MANY tough jobs.


Also, if you have a container large enough to hold the head (like a pan with top, consider using xylene instead of acetone.
Don't smoke and do it outside.

The head was just sitting on the table like that? It needs to be well secured when torque is applied.

https://i.imgur.com/xPsWmyM.jpg