Cracked 8BA Flathead Block

The plugs are cast iron. come in different sizes, like .200 to .590 They are tapered with a square head. You need a special reamer and tap. They have been around for ever. I think Goodson sells them. I have some that I have had for years, but they are over head in my shop. If I think of them when I am out there I will bring one in for a picture.

 

That's what I was talking about in my reply, George. Repairing problem blocks is new to me; most of my work is performed on excellent, qualified blocks for high-buck street and race motors. Doing a crack repair on a pal's block was interesting, informative, and fun; we have a few marginal blocks in the 'bone pile' at the shop that may deserve another look before they're scrapped.

Mike

 

Right you are, Mike. I used to collect "irrepairable chronic cracked blocks", I had 50 or so in '83, Rod Furtado was refusing them and I was repairing and re-using 'em.

Those pins have been around since 1959 (as near as I can remember) and Harry (Automotive Industrial Supplies, San Jose) had 5 on the bench at a time.

I used to love to hear, "Take it, Mike...It can't be fixed."
Some of 'em went to B'Ville. (and NOT as 'scrap'.)

 

Cool! Good to hear that not everyone's giving up on old problem iron. My shop partner, Kent Fuller, and I are taking a whole new approach to working with "damaged" blocks.

Mike

 

Can the block like the one pictured with the cracks into the valve pockets and to the bore be repaired? I have one like that with 2 cracks and thought it was junk. Does H&H do these kind of repairs?

 

Several years ago I offered for sale (on the HAMB) a completely machined and ready to build block that had been well cleaned (passages) and tanked several times.

I offered the fresh block up for the cost of machining which included pinning and sleeves.

Some joker from Vancouver sent an irate note saying that he could buy Flatheads all day for $250 and that my cost on machining/pins/sleeves (not including tear down and prodding/cleaning) was way out of line.

Moral of the story: Fool with the 30 Model A went thru multiple blocks, tear downs and the cost of tanking and mag testing but was ultimately happier to pay more in the long run while whining and bitching over the fact that I was looking to recover the costs shown on the 4 year old receipt.

Several month's later, Bob, a well known local business type had dropped off a complete engine to my friend Bert the machinist.
Bert charged him only partial time on tear down of the 60+ year old block plus hot tank/flux.
That block was a goner with a cracked pan rail. Bob had purchased the engine complete as a runner for $300.

I offered to sell my spare block to Bob in exchange for the bill/invoice from machining and was told that "I can buy complete Flatheads all day for $200"

Engine #2 was also a complete block brought from a 'friend' who said it ran fine when they had pulled it.. Another 5 or 6 hours shop time and $250 later, that block was stripped, tanked and mag'ed and also deemed un-useable.

Engine #3 was pulled from a 1948 Mercury Fire Truck that was bought at auction and hauled some 300 miles home. Again a completely assembled engine was taken to Bert and it was found to be a WWll rebuild and one of those odd ball blocks that displaced 221 cubes yet was cast ~5 years after the factory had upted the cubes to 239. Bob was looking at boring and stroking for maximum cubes and that block was deemed unworthy due to it's limited ability to be bored.

Block #4 also came as a completely assembled engine as purchased for $everal hundred dollars from an ad on craigs list. Bert charged the same $250 for tear down, tank and mag testing.

Somewhere in-between the costs of Bob's 2nd and 3rd "I can buy Flatheads all day" engine he surpassed the invoice price that I was asking for a bare block that I had taken for a simple tank, pins and sleeves.

Moral of the story, "I can buy Flatheads all day for $250" and most people seem to have considerable practice in doing so.

 

Yes it can that is where most of them crack. Put the pins in then a valve seat and a cylinder sleeve. A lot of them cracked in the old days because of plugged radiators and putting cold water in when hot.

Had a guy with a 1950 ? F8 Ford truck, it had the Lincoln flat head engine. He was haling hay from Mich. to Florida. After a few trips we had to fix the cracked block. I finally put dual exhaust on the truck, that fixed it. Was just to much heat pulling the hills with a over loaded semi truck.

 

Right on moefuzz. I just purchased two blockS from Joe Smith Early Ford in Richmond. Both blocks have been cleaned, magnufluxed, hot tanked, and shot blasted. At least I know what I have now.
AND YES, I AM KEEPING THE TWO BLOCKS THAT ARE CRACKED, AND WILL HAVE THEM FIXED, NO SCRAP YARD HERE.
THANKS AGAIN GUYS.

 

I found the HAMB because of a cracked unfixable 59a block …. Its now Luck’s mock up block.

My advice if you have time
Find the best one you can to build / put $$$ in... but please save the fixable ones even if you don’t plan to use them yourself.

 

on these ole motors, it ain't nothing but a thang!
Preheat your block, warm it up pretty good, get it good and equal thru the bore and the ports, drill a small hole at the ends of the cracks, where-ever they may end.
now, get a slicing disc in your air grinder, and get a good groove about 1/8 to 3/16 wide and almost the same depth. If I go into the water jacket, just clean the bottom really good.
Now then, fire up the wirebrush and clean the area.
Next, get your torch with a 0 tip, turn her down low, and preheat it just a touch, then throw your 1/8th flux covered brazing rod up into that groove and get it brazed up. If you have any trouble with getting small pin holes, go back over it and blend it in good, then, after its built up higher than the surface, get your ballpeen hammer and gingerly peen that brass a little while its warm and you have your torch on it.
if you brazed thru a seat, don't worry, it'll hold. If your squeamish about such things, you can have inserts installed, you might have to touch that crack up some and recut for your insert, but she'll hold.
I've done this so many times it isn't funny, especially on old military engines....and they have no problems.
You just have to clean, then groove then flux it really good. Once a good bond is made, its a done deal.

 

The Sea-lace crack repair works good, I've used those in the past, I've just been doing it old school for so long....
Braze up the cracks, install inserts and a cylinder sleeve. As good as new and ready to run for another 40 years....

 

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Ask around, and find out which machine shop the antique restorers use, and go there. Those guys understand flatheads, and anything else that others "don't work on".

4TTRUK

 

When I was a kid (say around 1955-57), we used to go have junkyard parties - spent the day finding "valuable parts". When it came to 8BA blocks (49-53), they all cracked in the same place, between the exhause valve & cylinder on the right side, as I recall. We usually took off that head first & around 5 out of 6 were already cracked.