WARNING!!! Rebuilding GPW/MB Engines

[Wolfman]

Try to keep as many things working in my favor that I can.
I have been lucky over the years when it really counted but when it comes to gambling, I have not had a very good track record.
There is a first time for everything.
A favoritte saying an old friend of mine likes is, I would rather be lucky than good anytime !
I like a more positive approach.
May not be by the book, but if you like, you can add this to " Wolfman's bag of tricks " .

[OldGPW]

All this sleeve talk is timely; I have been talking to someone about sleeving a bad cylinder (looks like broken ring scarred it) but it doesn't sound like just any shop can handle the special care needed for a G503 block

[Joe Gopan]

Automotive machine shops have the proper tools and do get a lot of practice, the procedure is not new to them and they have plenty of charts to go by. Even I used to bore out Jeep engines.

[OldGPW]

True, but not all shops are equal. But there isn't much you can do about that.

[Chuck Lutz]

OldGPW....

My advice would be to sleeve all four cylinders and bore the block back to standard. I know this is not cheap but it is the best way to effect a trouble free running engine. You get a much more perfect bore with today's machine tools/tolerances and you prevent any unseen issues in the other three bores from causing problems anytime soon.

Its not my money, but you only want to rebuild the engine ONCE in your lifetime so do it right the first time. With that in mind, I suggest the following:

Magnafluxing the block (and the head of course!)
Pressure test the bore for unseen cracks/leaks (maybe the distributor hole leaks?)
Clean out all passages/new freeze plugs
Mill the head/deck the block
Install sleeves/bore to STD
Balance each rod/piston
Balance crank/flywheel and pressure plate w/disc

[OldGPW]

Hi Chuck,

I agree about sleeving all the cylinders, but finding the shop that can do it isn't as easy as it used to be.

[Chuck Lutz]

I think you might have some luck talking to the "Old Car Guys" in your area. Cars from the 50s and 60s and Muscle Car hot-rodders....not the ones who just put in a GM 350 'crate motor" but those who want the ORIGINAL matching numbers engine restored. Check the hot-rod speed shops and the like for a lead on a shop equipped and knowledgeable about sleeving older engines.

Good Luck

[OldGPW]

Hi Chuck,

Thanks, I am going to need that luck I think. The last block I took to a shop, ended up having a crack that was unrepairable. Of course it was not discovered until the coolant was being added to the radiator. It had been magnafluxed, but didn't show up. So this time around I will have to find someone who will pressure test it. That shop didn't do that since it didn't seem necessary to them. They are out of business now anyhow. Good machine work, but should have pressed for more testing before proceeding.

[Chuck Lutz]

Yup...always a crapshoot with blocks you have no history on.

[Joe Gopan]

There are Automotive machine shops in just about every state in the USA, they can't be all that bad. There are some repairs that some will not undertake.

[OldGPW]

Yeah, a few years ago I ran into some automotive machine shops that just did not seem interested in anything that old.

[OldGPW]

The big problem with antique engines is that the people at the machineshop do not always take us serious.
They say : don't worry to much, that engine won't run much anyway!

Luc

Very true, that is about the standard reply from many shops.

[Joe Gopan]

It also depends on the impression you present at the shop. Leave the horror stories you hear on the internet behind.