Momma said there would be days like this!

Karl

Karl

Well-known member
As per my previous post we found a crack in the block of my Phaeton last week Fortunately I had future proofed somewhat by rebuilding an engine 3 years ago as a spare. It has sat un-run in my garage but has been turned over regulary.

Over the last week the shop my car goes to has (slowly) removed the old engine and installed the rebuilt unit. Two days ago the completed the job and filled the radiator prior to start up. As it was close to lunch time they waited until I finished work for the morning to start it up. By the time I arrived there was a puddle under the car and from what we can see water is leaking from the back of the block. There must be a crack in the block although this was not obvious to me or the engine builder prior, during or after the rebuild. Fortunately the rebuilder will stand by his work but of course we need to pull the engine again to repair things . One think is sure I will never get an engine rebuilt without insisting on crack testing the block !!
 
It's a very good thing that your rebuilder is doing the honorable thing and "standing behind" his work - complete new rebuild on a tested-good block? (that you provide?).

Crack inspectionn is always the very first thing to be done on an unknown-condition engine that is to be rebuilt (Head too!). - even on a "known-condition" engine because things can happen since a block and head were last inspected!

Earle
 
Our club the "Sonoma A's" bought a block testing pressure plate and kit, they are available from many of the parts suppliers. So far we have tested 4 blocks, 2 failed and 2 addtional are being tested now. You can magnaflux a block, but it should be hot tanked or cleaned very very well to get a good reading. The cleaning expense and magnafluxing cost may be nescessary later if needed, but could be eliminated early on if a pressure test shows the block is junk. One of our members bought a disasembled, completely rebuilt engine only to discover 2 exterior and one major interior crack but after we got our test equipment. I am thinking now we need a portable air supply so our members can test in the field before purchase.
 
You're sure it isn't the head gasket at the rear? A new rebuild needs to be run hot with block sealer in the water and retorqued a few times to stop the gasket leaks.

Even if it is a block crack, Model A blocks respond well to both metal stitching and welding for permanent repair of water jacket cracks IF the area is not corroded too thin. Unless the crack crosses a valve seat or cylinder bore, the repair will not necessitate any machine work.

Simple external freeze cracks on an unpressurized cooling system have been patched with marine epoxy by some guys and held for years. Please let us know what you find.
 
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Welcome to the "Cracked Block Club". :(

I also asked that the block be checked before any work was done to it. I got it home with new babbit and a turned crank, but as I was lifting it out of the back seat I thought I could see faint signs of a crack, so I slid it back in the car and headed to a local machine shop. Once the powder was applied the crack really showed up. It also has a crack by the front main saddle.

The shop was good about it and repoured another good block with no hassle. :)

Another GOOD reason to always use antifreeze!
 
MikeK said:
You're sure it isn't the head gasket at the rear?
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It's possible (and wouldn't that be nice!)but from what we can see with a mirror it looks like the block will let you know more when we get it out
 
Mitch//pa said:
agree very honorable rebuilder after its been sitting 3 years. i wonder if other rebuilders would do the same?
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Actually knowing the sort of guy he is I never considered for one minute he would not stand by it. Especially as since the rebuild it has never been run. If I'd driven it for 300miles before we found the crack then our discussions may well have been (justifiably) different.
 
MikeK said:
Please let us know what you find.
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Engine out and able to inspect it => On the rear of the block just where it curves back under there is a small (bigger now when we stuck a screwdriver in it) rust hole which has been leaking. Pretty hard to see as it is under the lip. It is repairable but raises some concerns regard the corrosion state of the rest of the block. Ideally I would like to change the block but financially I don't feel up that I want to go through the whole process of remachining and babbiting a new block ! Karl
 
Karl said:
Engine out and able to inspect it => On the rear of the block just where it curves back under there is a small (bigger now when we stuck a screwdriver in it) rust hole which has been leaking. Pretty hard to see as it is under the lip. It is repairable but raises some concerns regard the corrosion state of the rest of the block. Ideally I would like to change the block but financially I don't feel up that I want to go through the whole process of remachining and babbiting a new block ! Karl
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OK you should be smiling! Not a crack which will proliferate, not a leak across or even near any machined surface. It is also a place where you could access and examine the inside, through the corner water holes on the block deck. That would necessitate taking off the head.

If you want a good external fix without pulling the head or welding, clean the area to bare metal then shape and form a heavy sheet brass patch plate that overlaps about an inch to each side. Drill and tap each side for stainless screws. Put it together with high temp epoxy, paint and drive! I've patched holes in pressurized blocks that way, the A has no pressure.

I wouldn't worry too much about other leaks. It is a new rebuild, so you are going to run block sealer anyway.
 
I've seen a few blocks patched the way Mike suggested, one on a Packard light 8. They all held up fine. If the curve is a problem, you can also vee out the hole (rough surfaced for grip) and patch it with JB weld. In an non pressurized system, it has held up on many engines.
 
MikeK said:
OK you should be smiling! .
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Yep . They drilled the hole out Tapped it and screwed a brass plug in
Nice neat repair Then the block was pressure tested and all ok :) . Hopefully engine will be installed today and I'll start the running in process over the weekend
 
Keep a can of anti-rust/water-pump lube in the engine and you should stop further rust problems. Have fun with your A.
 
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