I have a few questions about different flatheads. I have a line on two different ones on is a 38 and the other is a early 50's. how much of a difference is there in 221 (21 stud) vs the 255. (24 stud) I am not power hungry, it will be in an 31 coupe. I would be happy with 100hp. I know that they are prone to cracking between the valves, what are other areas to look at? any guidance would be appreciated. thanks
The little 221 had thinner cylinder walls than the 239 engines that came along in 1939. They can't be bored out near as much. By the 8BA era of the late 40s early 50s, the engine lost the partial bell housing and gained a poor ignition system for performance purposes. Nothing that can't be overcome though. All flatheads are prone to overheating and the resulting cracks and they are all vulnerable to freeze cracks since they have no expansion plugs in the outside of the block. The 255 CID for the Mercury cars is just a 4-inch crankshaft versus the 3 3/4-inch stroke of the Ford cars. Not much of a change but it lends itself well to other modifications for stroking and combinations of larger bore and stroke. The older pre-WWII engines and the imediate post war 59 series through 48 will fit in a model A much easier than the 8BA family of blocks but all of them can be made to fit with the right combination.
what about things you could notice that would make you want to walk away. I heard that some have water pumps in the heads and some in the heads?
There is much more speed and dress up parts available for the 24 stud. I would not buy any block without removing the heads and looking for obvious issues first. If it's been sitting outside especially uncovered you can bet its done and will have issues.
MY 2 cents. Been running a stock 51 Merc for about 10 years and about 40,000 miles in my 31. It was put together stock, nothing fancy, honed cylinders, stock bore new rings and bearings, ordinary valve grind, no hardened seats, no port no relieve no, planed heads,no nothing. Reds headders, single newer 94 carb and 160 thermostats. Runs fine all the time about 110 hp thru a 38 trans with 46 car gears and 36 4:11. Sometimes the less you do the better. If It's youf first flatty less is usually enough! Just my 2 cents
By 38, even the 221" had it's pumps in the block. If all things are equal, I'd not use a 221" if I could just as readily get a 255". There just ain't a good substitute for cubic inches. The problem with the 255 is that, being an 8BA style block, you'll have to find either a '49 Merc or '48-'52 F-1 bellhousing to permit use of the early Ford top loader transmission and torque tube. f QUOTE=pdunn10;9295186]what about things you could notice that would make you want to walk away. I heard that some have water pumps in the heads and some in the heads?[/QUOTE]
The main thing that would make me walk away is the price.....I've seen guys asking $600-800 for a flathead that they don't know the condition.
Yep....last big swap meet I was at there were two complete motors....both were stuck and they wanted $600. The very next small swap meet I went to I found an 8BA for $50 that was stuck just inside the entrance. Bought it figuring it was a good deal just for parts....ended up being the best one I bought so far. It's at the machine shop right now getting cleaned and magnafluxed. Another one I bought recently off of Craigslist for $400 that's been on an engine stand as a display since the late 70s. The guy said it was in his dad's hay truck and was running when they quit using it. So there are still some good deals out there. Just be prepared for the cost of the rebuild and unless you can hear it run...assume it's just a core/parts motor and pay accordingly.
some people seem to think they are worth their weight in gold. I have found a few good ones. Tony- you are running yours as I plan to run mine.
Just 2 cents more. The experts know for sure but usually, truck engines 49-53 with RT heads i think all have 4 inch Merc cranks even tho they are out of Fords. the merc heads all say CM but watch out, many guys used to put them on Ford blocks and they dont have the 4 inch crank. Good luck, Tony
I like the 59a motors myself. They seem to be the most popular from what I've learned. Lots of after market bits available etc. I was fortunate to find a good running stocker that I could see running. That is not to say if I strip it down I won't find it's cracked or something nasty but so far it's all good - touch wood! That would be my advice as those old salvage yard flatheads can be a disappointing experience sometimes. I have a nice collection of V8 "boat anchors" laying around the place if anyone is interested....
just one thing..not all flatheads are prone to overheating,if taken care of and done right.Dont let the old "overheating" myth scare you
The Mercury cars from 1949 thru 53 in the USA were the only ones that came with the 4-inch crankshaft. Big 48 thru 51 trucks F7/F8 had the 337 Lincoln engine till 52. The first Y-blocks were used in 1952 in Lincolns and the F7/F8 trucks. All the smaller trucks either had 239 V8 engines or 6-cylinder engines. If you get lucky with a pickup engine from a 48 thru 50 F1, it will have the 10 inch Long type clutch that will work with the early top shifter transmissions since most of them had top shift transmissions with open drive. A 49 thru early 51 Merc is a good choice too and not just because it has a 4-inch crank since it had the Borg & Beck 10-inch clutch that will also work with the early top shift transmissions. Late 51 Mercs have a good bellhousing if you want to use a four speed or a T-5 but that would require an open drive rear axle set up.
Even if you hear it run it maybe considered a core. Flatheads will just run, 8 cyclinders... 2 cyclinders . I like the early flatheads. 59s and earlier. Depending what your putting it in. A 221 21 stud in a model looks great and is twice the power of the 4 banger. Good babbit fun. Building for best and most power.... You have to Start with cubic inches.
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