I have a 46-48 block at the machine shop. I had it hot tanked and checked for cracks. There is a couple small cracks from studs to water jackets, and one very small incomplete crack from a cylinder heading towards the valve seat. The block has 8 sleeves in it. The shop said that it was probably sleeved because of the crack. The shop says that it is a good block and the small crack doesn't matter because of the sleeve. Should I use this block? Does anyone that has built flatheads disagree with the Machine Shop that I am using? Thanks.
I think those cracks your talking about are very common and should not hold you back from using the block.
If you can, show a picture of the cylinder crack on Fordbarn. Those guys have the experience you seek.
Every Flathead rebuild / Hot Rodding book I have read says the cracks you describe are expected. Most Experts leave the small cracks alone. I would be very surprized that the block was sleeved for the cracks as it would be ceeper/easier to fix the cracks.
My block has a repaired crack that ran from a valve and down a cylinder. It is a mass remanufactured engine and all 8 cylinders are sleeved. It was simpler to just sleeve all 8 than pick and fart with different size bores, pistons, and rings. If sleeved correctly [and most pro shops did] there is no reason not to use it. Very common.
Your block may have been sleeved from the factory. It was that way on 41/42 blocks for sure. You can ask why but it is fact. Lots of guys used to remove the sleeves and hone to get the extra cubic inches. Cracks from the water jacket to the head stud hole are fine. Use thread sealant on the studs when rebuilding and forget about it. As for the crack headed torward the valve seat, you should have the crack drilled and pinned to prevent further creep. Daran Early Ford V8 Club 42 Ford Convertible 42 Ford Coupe 36 Ford 5W with 8RT Flattie
8RT is an 8BA-style truck engine with low-compression heads What's the bore of the sleeves? As mentioned, some 221 blocks were sleeved from the factory. Cracks - studs to water jacket = no problem. Cylinders to valves = problem. If sleeved correctly, might be OK - depends on the crack. Virtually all cylinder cracks can be repaired by one method or another...
I am starting my first flathead rebuild also and found a wealth of info in here by using the search function.Some cracks are normal and will not require repair.Some flatheads were sleeved from the factory and some people prefer the sleeved blocks.You can search and read for hours in here about flatheads.Bruce Lanchaster is a flathead GOD.Look for any post he has written.Good luck with your build.
I'm far from an expert...Bruce, on the other hand, is a walking early Ford encyclopedia! There are several very knoweldgable folks on here...
The one heading for a valve seat...it's gonna get there eventually, if it hasn't already! Your block should have all 16 hard seats...the one at the crack is going to come loose when the crack arrives, and crack may develop on down into deep recesses beyond fixing. My guess is they sleeved a cracked bore, and the crack then continued to propagate. Seriously scrutinize it with lots of light, cleaner, and wire brush. Wherever it ends...you want it drilled and pinned by a shop that does pin type repairs, can't think of name of the common brand. Killing it now shouldn't cost much, especially in comparison to fixing it after it goes on across the port into places a mouse couldn't reach.
Ol Deuce, An 8RT is the designation for a 49-53 Ford Truck motor. For a car it would be 8BA. The specific detail about the "8RT" arrangement in my case is that it is a truck motor so it has the truck water pumps that allow me to install the 8BA style block into a '36 Ford. I could have used the same truck water pumps on an 8BA or an 8RT for the install. The blocks are actually the same if you are starting with a bare block, however the 8RT comes from the factory with an extra compression ring in the pistons, which some may see as a benefit. You also need the truck (8RT) oil pan for this install, along with the adapter plate that comes factory on the back of the 8RT block (starter plate, bolt-on bellhousing, among other names) to mate the 8RT or 8BA to a '36 Ford transmission. The list goes on, but that is the whole 8RT blurb description. Thanks for asking.
Lock-n-Stitch has a great product. http://www.locknstitch.com/ The machine shop I take the flatheads to use it. Got their catalog & CD (lock-n-stitch) and was well worth watching the repairs made. Vergil
My flathead was sleeved from the factory and came in a flatbead that was used on an apple farm . It is the orginal engine and was never rebuilt or replaced . The owners bought it new . So I am going to use mine with sleeves and I know of many people that have small cracks in theirs too . Almost all flatheads have cracks !!! USE IT !!!!!!
Follow Bruce Lancaster's advice and repair the crack creeping toward the valve seat.....it'll only get worse as he said. The other cracks were common enough they had part numbers.
Hahahaha... A remark I would have expected from Bruce! Follow the advice about repairing the crack now, save yourself trouble down the road. Flatman
There could be any number of reasons why they used sleaves in all 8 cylinders. Listen to Bruce and others when they recommended that you pin/stop the crack heading toward the valve seat. Chances are . . . it is already there and the hard seats make it look like it stopped. What worries me is that your machine shop doesn't seem to think they have an issue -- which tells me that they have probably NOT built many flatheads. Fix it now and you'll prevent a very expensive future problem. Ask lots of questions about how experienced your machine shop is with these sorts of problems and how many they've fixed before? If they are new to the problem and flatheads in general - take the block to somebody who knows what they're doing, has the tools for doing the work, etc.. Also, you should have the block pressure tested once it is fixed -- to insure that it is correct.
Original sleeves are totally different from repair sleeves! Ford put very thin steel sleeves into many engines roughly 1939--41 to allow rebuilding by just popping in a new set with a simple hand press. Repair sleeves are thick iron. I don't believe that any original type sleeves were used after WWII.
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