I am posting this in hopes of reaching those who have done this before. I recently built a hot 8BA that took me a couple years and a pile of cash. Turned out to be a cracked block(Was Magnafluxed) so I am back to square one for now. I have a 21 stud flatty(37-38) that I want to do a distributor conversion. I have a old Scintila mag that I had redone for my 8BA that I want to run on the 21stud. I bought the Offenhauser conversion that goes on th end of the early cam to run a late distributor. Looks like this will interfere with the stock water pump pulleys. I have the extended pumps from my 8BA to help. the main issue is what crank pulley to run. Since the pumps extend, I'll need a pulley to match. Since the early flatheads dont have the extended crank like the later flattys, seems choices are limited. I had a borrowed a dual crank pulley from a friend and it looks like the double pulley seems to put the belt just fore or aft of the water pumps. To add to the mix is I want to run the 8BA style generator which is in the same place as the 21 stud but the pulley is extended out further to match the extended water pumps I know quite a few people have done this before. What pulley will work best? Or is this an issue where I have to make a custom pulley or pulley spacer for this? Any feed back from those who have done this before? Fryguy
I would believe the obvious answer is to find a good 8BA block. I am sure there are lots of guys out there that would be glad to swap a good 8BA for the 21 stud. If that won't happen, I think that you could sell the good 21 stud for a lot more than a good 8BA would cost. There are a lot of anal-rententive restorers out there.
I'm going through pulley issues myself. Different from your set up. I don't want to confuse the issue so I wont go into it here. I can tell you this, if you are keeping the 8ba type dizzy you will need to use the 8ba water pumps also, to clear the dizzy with the belts. That leaves you with the crank pulley problem. 8ba c.p. will not fit on the early cranks. What I would do is take both an 8ba and earlier c.p. to a machine shop and have them modify the 8ba one to fit the early crank and belt location. Make sure the timing marks line up with the key way. If the generator lines up with the water pumps you are all set. You didn't state what you are doing for a fan. With my fan I needed to push the shaft in the holder more to get things to line up. My press wouldn't handle it, so it was back to the machine shop and they were able to move it.
Not sure if I want to try and throw another 8ba in there. Looking for what my options would be for a Crank Pulley to work on the 21 stud. I have the 8ba extended water pumps and I have an 8ba generator that I put 37 style pulley on to run the stock 37 fan. Thanks Solidaxle, I have no problem running to a machine shop and try and get something done. I was hoping there was a stock year flathead pulley that was THE one to have, lol.
Why would you not want to use all those good parts in a different 8BA block? I can bring a good block to Hershey for you.
Are you running the narrow belt or the wide? I running double wide truck pulley's. I'll send pics on my modified crank pulley. I don't think you can find one that will bolt right on for the extended reach? It will need to be modified. Did you do a search in the Ford Barn site? They have a sharpe bunch of guys over there.
SA, I am running the wide belt pulleys on the pumps and generator. If you could send me pics of your modified crank pulley that would be great
I did the 21 stud modification using a '48 double pulley and the 21 stud sleeve. Careful use of a parting tool on my lathe and soon I was slipping (pressing!) the 59 A pulley into position. Spot welding and turning on the lathe got it concentric with the sleeve... Final attaching was stitch welded, (mig) and it worked great. This was a mod for a customer. If you have a machinist to do this op for you, make SURE your sleeve is bottomed on the crank gear. A slight error will spoil your day...
At first, I read your post and was reminded of a slick ignition trick I pulled, from a discarded GM HEI out of a Buick. (or Olds, it was '78; CRS.) Anyway, the distributor turned counter clockwise, so was natural for the flathead's geared cam. My machinist neighbor, Larry, cut the shaft at my spec'd length, likewise the housing mast jacket. I rough cut a 3/8" piece of aluminum plate for the base (covering the front timing plate) and Larry cut some rotary slots to adjust timing, like a Kong Jackson setup. The shaft was cross drilled to accept a VW pin, along with the VW drive dog, offset the same as the flathead cam drive slot. (wonder if Henry and Dr. Ferdinand Porsche planned this: Bosch ign. on a V8?) The HEI bearing just below the main body was not 'lengthy', so we made an inner cap bracket for an upper bearing, just below the rotor, like the ACCEL design. Took a little time, but the curve was so adjustable (springs and grinding the backs of the weights) that old pal Bud Jones put it on his flathead streamliner. Ran very well, but class was very competitive... Sorry for the 'voluminous writing', but had to tell it! Would have REALLY been cool with a large crab cap...
I had the Bubbas HEI distributor Chevy dizz but never used it. I have a 49-53 Scintila Mag that I want to use on my 21 stud 37 motor. I have a cam gear conversion part from Offenhouser that bolts to the cam and gives you the the 8ba style cam gear. Not sure if this is even possible to do?
Couple things; 1. This is an excuse to spend some bread...Ron on Fordbarn has done this and can describe the cuts. A late crank, meaning '39-53 but preferably a Merc 4", can have its journals cut down a lot and I think the rear one lengthened slightly by fairly conventional grinding practices and then fit in place of the '36-38 short crank. This is ALSO an opportuntity for an offset grind if you have a really good crank, OR an opportunity to use a Merc crank too undersize for its original use. 2. I once bought a '48 pulley with an obstruction in it. I drove out the lump...and it was an adapter!! It was a keyed slug matching the difference between short and long crank. Instead of having a through bolt the threaded extension to go into front of crank was integral...don't know how they expected to line up the keyways. I'd use a through bolt...
Thanks Bruce. I usually don't need an excuse to spend some dough. I am still up in the air on what to do. I'd like to adapt some of the 8bA stuff to the 21 stud. I'd like to use the cam if possible but I think I need the button to lengthen the cam shaft as they are shorter than the 21 stud(?) or is it the other way around.
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