After magnefluxing my '53 flat head block, they found some minor cracks (three of 'em) between the exhaust valve bowls and the cylinder bores. Cracks only extend down the bore a quarter of an inch or less. Any one out there used the Lock-N -S***ch cast iron repair system on these kind of cracks? Just curious to see how effective this system is at stopping crack migration.
I dont believe that curiosity about a repair methods effectiveness, is a good basis to decide to take a chance on an engine you are going to spend thousands on rebuilding. I would chalk it up to experience, and go and find another block. Cracks into a cylinder are very hard to repair without resleeving , and three sleeves and a bore job arent cheap. the chances of any other block being cracked too are pretty high (Ive found that 99A blocks are the least suseptable to cracking, followed by 59As, and the worse are 8BAs.) Now we dont have the added issue of frozen water cracks here in Australia, but anectodal evidence says 8BAs seem to crack the most ,wherever you are. if you just want to practice the lock and s***ch thing, go for it..and publish the results! but I wouldnt then build an engine to be relied on out of that block.
I'm not a machinist, just an old dirty-neck hotrodder and as such I don't know of the latest high-zoot, molecular changing tricks...just what we've always done and I say it the crack extends into the block's bore, it will either have to be sleeved or turned into a nice coffee table. I'd replace that block. Maybe there's a new way of repairing these "junk" blocks I don't know of. If so, maybe the new-age scientists will chime in. The repair procedure would be welcome as we need all the usable flathead blocks we can get.
I have cold repaired several similar blocks. This will require an experienced machinest Because of the crack migration to the cylinder it will need a dry repair sleeve installed. The valve seat area will need to be repaired first. Irons***ch will work. Remove seat, repair the area then re-cut seat pocket thru the irons***ch unit and install new oversize repair seat with blue loc***e. A correct thin wall dry repair sleeve (Melling) will have to be used in the cylinder. The cylinder is rough bored to fit the OD. of sleeve with only .001" press fit max, bottom step. The block/sleeve is coated with a co-polymer sealer (Goodson) and carefully pressed into the hole. Finished to desired spec. The sealer will keep coolant from seeping and retain the sleeve. The light press fit keeps the crack/repair from migrating. I have one of these repairs in a 40 Ford that is used daily in the summer. Over twenty years on repair.
I just s****ped two complete engines cause of the same problem. They both were actually really decent low mileage rebuilds. Not sure if they were cracked before the rebuilds and not fixed, or if they were just weak. Anyway I tried to justify doing the sleeve thing, and both would have needed heavy duty valve work after diss***embly. -the 59a had those mushroom valves which I basically ruined. -the 8ba I let sit a little too long and 2 of the valves were rust welded in place. should have oiled and spun it more. After years of dragging them around, it was a bummer to let them go. Each one had a good couple hundred bucks worth of parts - adjustable lifters, rods etc, only cause I can't see myself doing a flathead engine again soon. Still have to s**** those dang blocks though! TP
I hate the idea of s****ping this block, other than the cracks it was a good running engine before the tear down, it is stock bore and I'm pretty sure it's never been rebuilt. There are several competent machinists here in Spokane that could do the machine work that's required for the repair. I'd sure like to save this one if possible. I guess I need to see what the cost would be to sleeve three cylinders. Thanks for all the advice so far.
I would be interested to hear what it costs to sleeve a cylinder. If it wasn't too expensive, I would not be afraid of s***ching up the cracks. At least you know the problems of this block. The odds are the next block will also have a crack, but probably not three. Neal
Here’s the thing the way I see it / IMO Right now its not worth fixing blocks that are cracked like yours. But someday it will be worth it … so the way I look at it set the thing aside and find another …. But don’t s**** it. If you cant stand it and do s**** it … save the main caps.
Sleeve it and move on. I had to put a sleeve in my 352 FE last year. $80 installed. Even $240 for 3 holes, it is a small price to pay when you are looking at spending $4000+ to completely rebuild a motor.
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