[TransAm400]

Just got the new 455 in my Catalina. Filled it up with water and heard a drip. Crawl under the car and find water seeping out of a crack between the freeze plugs on the drivers side. Block was supposed to be magnafluxed at the machine shop but I guess it wasnt done or missed. So whats the next step? Pull it out and tear it down? Can this be fixed if it is the only damage?

[thepontiacman]

Usually can be welded.

Some people run block seal temporarily.

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[78w72]

ive seen cracks around freeze plugs before, should be able to have it repaired by a welder that can do cast iron properly. or can try a block sealer as mentioned as a temp or maybe permanent fix. but the block should not be "junk."

[455dan]

A possible alternative is the cold cast repair using metallock
( lock & stitch ) procedure...

https://youtu.be/CL3Rl911900

[Dragncar]

MarineTex has fixed a lot of those.

[TransAm400]

I think I have some MarineTex here already. May try that first. I’m thinking second option would be a liquid sealer in the cooling system. I dont really like the idea of putting something like that in a fresh motor but hate to pull everything out again. My first call will be the machine shop tomorrow. Found the receipt and I definitely paid them to mag it.

[geeteeohguy]

Originally Posted by 455dan

A possible alternative is the cold cast repair using metallock
( lock & stitch ) procedure...

https://youtu.be/CL3Rl911900

This, or if you don't want to pull the engine, etc, you can use KW head and block sealer and it WILL fix it permanently.

[lust4speed]

Had that happen to one of my blocks. Guys checking the block gets so preoccupied with the inside of the engine they fail to check the outside. One thing about the pinning is you could take the engine down to a shop assembled for the repair. For a long term repair I'd trust the pinning process over a temporary block sealer or welding.

[F ROCK]

Originally Posted by geeteeohguy

This, or if you don't want to pull the engine, etc, you can use KW head and block sealer and it WILL fix it permanently.

x2 on the KW. I used the version in the can.. Follow instructions to a T.
Works real well.

[DarcyL]

Have it stitched at a machine shop. They will drill and ream a series of small tapered holes on each side of the crack, and then drive tapered pins into the holes, slightly expanding the block metal, squishing both sides of the crack together. It works. Water tight. No need to disassemble the engine-

[Cliff R]

Welding these blocks is difficult and often not successful. I've had excellent results a few times, but more times than not welding them causes cracks to run away from the original crack when they cool down.

Drilled/pinned or brazing is probably a better solution before you scrap it for another one......

[steve25]

After having it stitched up be sure to use Brass freeze plugs since they apply a little less force around there OD, and they also move / pop out when they are called to should the block freeze again, that is if it did not crack due to over heating which maybe the case also.

[TransAm400]

How much responsibility would you put on the machine shop for not finding an obvious crack? The fix might be the same but it would have been alot easier before I assembled and installed the engine.

[steve25]

Hard to say, I mean you paid them for the check out, but in the end the determination will be looking at the crack very closely for rust deep in the crack.

If you find that issue then they missed the crack during the Mag check out before hot tanking the block, in my opinion!

If there's no deep rust in there then the block may have been mis handled and took a hit when moving it around for whatever purpose in there shop.

Are there any signs around the cracked area that looks like the block took a hit?

[TransAm400]

No signs of impact around the area. Talked to the machine shop this morning and he has already offered to machine a new block at no cost or possibly reimburse me for stitching. It’s just going to put me back at least a month. I guess there would be no adverse effects to try epoxy on the crack and a liquid sealer before I remove and replace?

[critter]

If it was good enough for Paul Harvey it ought to be good enough for you. JB Weld.

Seriously, I used some on a radiator tank with pin holes and it held for years. Shouldn't that be the same pressure/temps? I'd think it would work for a short term fix.

[steve25]

Yes, there's no harm, but try and stay away from ciramic type sealers as they can coat things you don't want them to coat like the internals of your a Radiator if it's not pristinely clean, which then cuts down big time on heat exchange.

It seams a ton of folks have great luck using 3M panel patch adhesive is situations like yours!

[4dblnkldude]

My friend and I built a SBC 400 for his nova and it was leaking. I cant remember where it was cracked, we ground it out a tad and used PC-7 and then ran a 10# cap. It didn't leak...ran 11's.

[STEELCITYFIREBIRD]

The extent of work in the block, type of use (#correct, etc) and availability of a suitable replacement would be the factors I would weigh as to weather to repair or replace

Stitching is the only repair method I would recommend from my experience...

...but the question that would always be in my mind is are their any other cracks that were missed.

🤙🏼

[steve25]

Well the good thing is that if there are no other cracks and this just goes from freeze plug to freeze then it can not spread any further.

The heat cylcle/ expansion and contraction rate is what will eventually take out and cause the failure any kind of sealer or epoxy used in fixing this.

The great thing that stitching up a crack does is that it keeps the crack expanded a good amount more then it would expand under the normal heat of the motor running.

This minimizes the heat cycle flexing in that crack area and keeps it sealed up for good from what I have seen from crack repair work done by stitching !