59A rotating assembly swap-?

V

vikingapg

Junior Member
Hi folks, can someone please advise me if I can put an 8BA crank ,rods & pistons into my 59A block, thus avoiding having to deal with the floating rod bearings that require shimming? I am not a hot rodder or "customs" enthusiast, but just wondering if I can make the engine rebuild on my 1947 59A block a bit simpler. Thanks! John
 
Sure can! You'll need to use the 59A style rear main bearing, but otherwise all that 8BA stuff will drop directly into that block. Use the 59A flywheel/ clutch assembly too
 
Wow! Thanks Brian, so, I will still use all of my 59A-B bearing caps, clutch & flywheel, just change the crank & rods? Are the new pistons going to have to be 8BA as well? I really appreciate the help! John
P.S.> I welcome any & all replies from anyone out there who can help me sort this out. Thanks everyone! John
 
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You've got it mate;Use the main caps that come with the block, and the main bearings that suit the block; the front and centre bearing shells are common between 8BA and 59A, but the rear main bearings differ, so use 59A type there. The 8BA crank rods, big end shells and pistons will all fit. Ain't flatheads neat?
 
No shimming needed or even possible on the floating rod bearings! Never heard of such a thing. There were, however, aftermarket shims specially made to reuse worn bearings on the 8BA style rods on an el gyppo overhaul.
 
Great! One last (?) question: is there a significant difference in the 49-50 crank & rods versus the 51 thru 53 ones? Thanks, John
 
The only differance in the 49-50 and 51-53 rod is the early ones didn't have the squirt hole in the rods that squirted oil up on the cam and cyl. walls. The later 8BA rod had them. BUT, I never worried about it. I can't see that the later engines lasted any long than the early 8BA's. Walt
 
I think you are going to have to use the 8BA flywheel because of the difference in ring gear spacing.
 
Don't know which year 8BA crank you plan on using but be sure to check the crank gear as the 8BA used a reverse cut gear putting the thrust on the cam out front instead of at the rear as on earlier blocks
 
59A block with a 4" Mercury crank installed. Block has been align honed, crank has been turned. If you'll notice the crank has 3/8 clean out plugs, maybe this was a Canadian thing? It sure spins nice and everything is perfect spec wise. I am using floating bearings on the rods and the 59A flywheel with the lip trimmed off and balanced. Clutch and pressure plate are stock pieces that I picked up at a swap meet and had rebuilt locally before being balanced.
 

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Yes, the only thing you have to watch out for is the cam gear. Use the one from the 59 crank, that will match the one on the cam. If it's a fiber gear, you might as well change it, If using heaver valve springs use an alum one.
 
Jason M. said:
59A block with a 4" Mercury crank installed. Block has been align honed, crank has been turned. If you'll notice the crank has 3/8 clean out plugs, maybe this was a Canadian thing? It sure spins nice and everything is perfect spec wise. I am using floating bearings on the rods and the 59A flywheel with the lip trimmed off and balanced. Clutch and pressure plate are stock pieces that I picked up at a swap meet and had rebuilt locally before being balanced.
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Jason, looks like some extra oil drain back holes drill in the lifter gally under the cam, or am I seeing things. Also there is a big hole on the front of the block, looks about the size of quarter from the pan rail surface. That looks a little strange. Is that a Canadan block? What does it say on the bellhousing, just 59 or 59L or something else? Walt
 
I think there are 2 diffences in crank after 1950...first change was adding a pilot socket in rear of crank to accept Fordomatic, second was a change resulting in a smoother finish on cast surfaces. Neither change matters on interchange 1939-53.
 
Walt, All Canadian blocks from the 36 LB series on feature that hole at the front, also another the same size at the back. I guess their purpose was to locate in some fixture during machining operations. Makes identifying 36 LB blocks so easy!
 
I am sure that the hole in front of block in third pic makes it a Canadian block.Or do US blocks have this as well?(beside gear cover on pass side)I have two merc cranks with 3/8 plug and bean shaped imperession on front throw.
 
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