identify flathead crankshaft
 

Ok,I got for 10$ a rebuilt V8 ford flathead crankshaft,the tag says its for a 46 to 48 ford .I would like to use it in my 52 block. First how do I id it as a 46-48 crank? It does have large plug holes like a Mercury 4" crank. 2nd can I use a 46 crank on a 52 block? I think there is a change with the distrabutor that may have changed it. HELP! tony

This questions out of my range, prob if anyone knows try Number Dummy if he happens to not get to this one try PMing him.

Sorry if you don't want me to bring you up if you don't like it, I just hate to let a Flatheaders Q go unanswered.

Journal sizes are the same as your '52 block, so it will fit in there. As you noted the distributor changed in several ways. 46-48 turned directly on the end of the crank where the 48-53 is on a stalk and is gear driven off the cam.

If I remember right you can change the cam gear for the later one from the 52 because they both bolt on - they run opposite directions. Only thing I'm not sure about is overall length of the crank snout in the 52 application - it might be too long. A quick check should tell you.

46-48 merc and ford cranks are the same. If it's a later 49-53 merc crank the counterweights will measure about 6" across - fords are much smaller.

Check one other thing with the crank. See if the rod journal bearing surface have one oil hole in the center or 2 offset to the sides. The crank from the '46-'48 59A motor would usually have just one oil hole because they used a single floating bearing for the 2 rods. If you want to use the 8BA rods and bearings you should use an 8BA crank with the 2 oil holes -- one for each rod bearing.

looks like got a 4" merc! now a few bearings and merc pistons and I be set! thanks,guys!!!