Fixen block cracks ...

[Ross F-1]

Originally Posted by Karl Wolf

The pressure in the cooling system is as you say, not very high- BUT the combustion pressure is a LOT higher than that. This is what we are looking for-

Karl

Agreed, but with the pressure tests, you are subjecting the water jackets (side of block) to pressures they "may" not have been designed for.

[elwood]

Hey Ross,
My thinking is I want to stress the suspect block, couse Id rather it fail under my pressure test than after Ive put 30 or 40 hours in building it.

[funrunr]

What is a reasonable price to pay to have cracks repaired say under the valve seat like Elwood originally posted?

[dumb person]

Originally Posted by Pete

In the old days before portable sonic testers I ported through many many blocks. After practicing on a few junkers, I became very adept at silver soldering holes and cracks. All this became a big necessity because it usually happened after you had 40 or 50 hours in the port job.
If you can gas weld, you can learn to sliver solder cast iron in a reasonable time. The big trick is to NOT get the base metal red.
And yes it will stand up in exhaust ports also as long as there is water behind it.
Cracks are easier to fix than holes which sometimes require backup slugs.

Smart man.

Originally Posted by Russ/40

I have always felt we tend to overreact to the cracks we find. When they happen, they usually don't get any worse, and a significant number of good running engines are found to have cracks when taken down.

Yes i have been saying that for a long time. Thankyou for confirming this.

Originally Posted by Keystone 34 3w

For your consideration. One guy up in my area was taking apart engines with a low success in finding perfect blocks. He started buying good running engines from restored cars and when he freshened them up, he would still find small cracks in them although they were running just fine. Many of the blocks he junked most likely would have run just fine.

Exactly.

[tubman]

When I was a young college student with no money in the early sixties, I had a '52 that started burning oil like crazy. I tore it down, and found a bunch of broken rings. The local engine rebuilder had a set of 7 pistons from an unsuccessful rebuild that I bought for a song. I matched them with one from the junkyard, honed the cylinders, and added a cheap set of rings from Sears. When I put it back together, I noticed what looked like cracks between the valves and cylinders in several places. Not having the knowledge I now possess, I shrugged my shoulders and finished the job. The car ran satisfactorily for me for two more years, when I sold it to a friend because I no longer needed it. Sometimes ignorance IS bliss.

[Shu47]

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I remember the first flathead I took apart with my Dad's guidance. I was a teenager.... long time ago. Anyway, I saw some cracks in the typical places. We were not doing a complete rebuild and the goal was to get it running again with minimum expense. Dad checked out the cracks and said "wasn't leaking or causing a problem before taking it apart. It won't cause a problem after being put back together. Replaced the piston and rings in the 1 cylinder with an issue after honing the bore and put it back together. Ran for years with no problem. Not saying that will always work but for us it did.

[elwood]

Hey tubman, I agree, sometimes ignorance is bliss, and on the same hand, sometimes a little knowledge is a burden,
and I've got just enofe knowledge to worry me, lol ...

[Ol' Ron]

'm not sure if he's still around anymore, but, Frank Casey on the east coast is the man. Can't find his contact information handy. will look for it.

[s nichols]

I have 3 8ba blocks that have been magged ok in IOWA

[elwood]

^^^^^^^^^^^ someone is lucky in Iowa ^^^^^^^^^^^