Technical 21 stud deck cracks

The problem with running it as-is, is that there will be no concentrated clamping force on the fire rings for a significant part of the circumference of the two cylinders.

It might work if the head is really rigid, so cast iron would be more likely to seal than aluminum.

 

Suppose that piece were missing altogether. Would everything seal correctly, but you would have nothing to screw the stud into?

Suppose you used a bolt for that location instead of a stud. Wouldn't tightening the bolt simply draw that cracked piece up against the underside of the head, or vice versa, leaving that section of the head relatively unsupported, but with everything sealing properly?

I'd V-grind the cracks and use a TIG welder with nickel rod or a rod made specially for welding cast iron. Ping after welding each crack. Surface the welds with a block and sandpaper, or grind them to slightly below the block surface.

 

Well if you need to have the block machined then you need to check for any other cracks, if this is the only one have it proper welded and get to machining.

 

Gentlemen, if we really want to help this guy, instead of encouraging him to beat a dead horse we need to help him find a replacement engine.

 

A crazy idea perhaps however, if enough ledge on the undersides of the coolant openings a bar or x shaped bracket with a tapped head bolt sized center hole could be snaked in & the original tapped hole drilled out to permit a pass through longer head bolt to engage it.

 

I love reading some of these Band-Aid ideas. Gives me something to Chuckle about the rest of the day.

 

I don't get this attitude. There are less and less flathead blocks around, especially 21 studs, so any one that can be saved is a huge positive. To scrap a repairable block is sacrilege. Every effort should be made to repair them; even the supposedly unrepairable ones should be saved in the event new technologies are developed. There was just a post on the "Ford Barn" about this same issue. A guy had a 59A block that looked good except for a couple of "part number" cracks, a small chip out of a lifter boss, and some unknown anomaly on one waterpump mounting surface. The initial responses were to "scrap it and get another", but later posters came around and suggested pressure testing before making any decisions. I know that there are guys out there with 10-12 extra blocks stashed away. They may have the luxury of scrapping marginal blocks but most of us don't. And these guys won't sell any in any event.

Fix what you can, save what you can't.

 

Looking closer at the photo's I would be tempted do very little to further weaken it, since the bolt hole is cracked all the way through, as the head bolt is tightened down it would appear it will wedge & close the gaps near the the coolant passages

 

But know when to stop.

Having had several heads and blocks repaired over 50+ years I tend to place a value on the final product before opening Mine or a Customers wallet. I'm all about saving parts but get some good advice from the shop that will actually do the job. There's more to a good repair on Cast Iron than dragging your Mig gun over and ,making a nice Looking weld on it.

 

I don't know much about the inherent issues with flatheads, but this post brings to mind a practice in the early days of NHRA Pro Stock.
"Back in the day" Pro Stock used to be on a weight to cubic inch factoring system and there were a bunch of different configurations. (They used real cars then. Not carbon facsimiles). Particularly interesting in regards to this flathead issue was what they were doing to Cleveland Fords, and some AMC motors.
In those days, aftermarket heads were not a "thing", and racers used factory iron castings. Heavily...HEAVILY modified. The Clevelands, although they had huge intake ports, were pretty poor on the exhaust side. It was common to mill off the entire exhaust side, and use what was referred to as a "high port plate." The heads would undergo a process called furnace brazing. The entire head would be brought up to the melting point of brass, and it would be flowed in. Both to seal up the plate and some to build up port walls to get better port flow. And sometimes to close up water jackets.
Maybe I'm just pissin' into the wind here, certainly thinking out loud, so to speak. but perhaps that type of process could be a solution. I reckon the problem would be finding resources. I know the Gliddens did stuff like that as well as Jack Roush way back when he was a drag racer.

 

Tubman, if you don't "get my attitude", please, let me explain. First off, the owner never mentioned that this particular engine was a priceless family heirloom or that it had any important historical value (as in it was once owned by someone famous. or infamous, like Clyde Barrow), it is simply one of untold thousands manufactured so sending it to the scrap yard is not a "sacrilege", it is an economic necessity due to the inordinate amount of money required to rebuild an early flathead balanced against the risk that the repaired block will fail.

 

I still don't "get your attitude". Sorry.

 

I'm very familiar with these heads and this exact process. The cost after this work of surfacing 3 sides of a head is a drop in the bucket next to re machining a total motor block. To furnace a block then requires line honing a cam bore then over size cam bearings just as a starter. Go price just that part and let us know what you find. Never hurts to dream but at some point you gotta get real.

 

I would not put a dime of machine work in this block.
First, I would check it to see how much taper it has. If it's within spec or maybe a little over...I would put it together as is and test it. If it had compression, I would go further with bearings and run it.
If it ran well, with no issues I would consider boring once I knew it was a runner.....
Going this route, you give it a chance and you are not out gobs of cash for machine work. Also, a lot of the internal parts can be used for another block.

 

@F-ONE the engine was reported to be rebuilt and unfired. I looked again at the bore pic, originally looked honed, but not so sure now

 

- He told me to run it as is even with the cracks as they are and said that’s what he’d do.

I say good luck with that.
I'm not being sarcastic. I'm guessing it's wedged in not going anywhere other wise you I'm sure would have showed us the casting chunk.

 

Well, fun to think about anyway. Like I said, probably pissin' into the wind with that idear!

 

Well I spoke with two more flathead building shops today and both of them said the same thing. Leave it be. If the cracks were heading toward the cylinder wall or valve seats it would need to be addressed. Cracks at the water jackets are very common with these old blocks. I will bounce some of these ideas off the machinist but I am inclined to heed the advice of these builders. Compression check will most certainly happen, but it looks like I’m going to take the gamble. Thank you everyone for all the ideas.

 

Well, I ain't no machinist, but before I junked the block, I'd try drilling about 3- 7/32 inch holes right smack in the center of each crack and tap them to 1/4. Then I'd loctite studs in them flush with the deck. Seems this would make a better purchase for the head bolt.

 

I’m with Denny ,
Now,,,I understand that the op might not want to spend a large sum of money .
Neither would I,,,,,but,,,,,with some technology that might exist now or in the near future,,,,,I don’t think it should be just automatically scrapped .
It probably can’t be made into a race block,,,,,,but,,it could possibly be repaired and live a normal life at 100 -120 HP ,,,maybe more .
Who knows?
New welding tech comes along every so often,,,,,somewhere there is a thread here about spraying bronze for repairs .
That thread was maybe 10 years old,,,I can’t remember.
But,,,,a bronze repair is extremely strong,,,,and would probably work on many cracks ,from,,,decks ,,to pan rails.

And they aren’t making any new blocks .
That block could sit under a work bench for a long time,,,,and not cost any money sitting there .

I know Indy Cylinder Head used to do iron repair,,,,they repaired a Mopar head ( 906),,,for me over 30 years ago .
It had a hole in the chamber,,,,,3/8 wide by about an inch long,,,,,,they made it like it never even happened,,,,beautiful work .
That cost 250 bucks back then,,,,,but good work cost money,,,,,(that was a fair amount back in the day ),,,LoL .
There are craftsmen out there if you know where to call .

Tommy

 

Maybe I wasn’t clear. I’m not scrapping the block, I am going to run it just like the 3 flathead shops said I should do. But I will bounce some of the suggestions from this thread off the machinist. I’m sure that these cracks were assessed when this engine was built years ago and must have been determined acceptable because there’s evidence of balancing on the rotating assembly. It’s quite shocking but the flathead guys say it’s fine.

 

I like a lot of the ideas mentioned. If welding I agree with the silicon bronze theory as it would help with expansion. I have made quite a few repairs with the lock and stitch system with great success. I feel that putting in at least 4 pins.. 1 near each corner of the cracks on the cylinder sides would help stabilize as well as draw the block together. I feel that the flatly experts are probably correct but the stitch pins would help.

 

Sorry 433 ,
Yes,,,I read your earlier post,,,,but I really just posted my comments for any other guys that might be in the same shape .
These threads are on the internet for many years to come .
Type something about Flathead into a search engine,,,,,,,odds are very good the results will be a answer to a post here on the HAMB .

Try it,,,,,I have gotten results that sometimes were my old posts of questions from years ago .
Sometimes the posts are from some guys here that have been dead for several years .
There was,,,,and still is,,,,a lot of talent on the Hamb,,,,( myself excluded ) .

Tommy

 

I really do appreciate all the feedback on this, just like with anything else I like to explore all angles of attack before I jump into something, and this is great place to discover new angles. What I don’t know could fill a library.