Technical 8BA RODS 59AB CRANK

Hello , I have a 59A Block and Crank will rods from a 8AB Work/fit with a 59A crank and block?

 

Not compatible—-59 crank should have “full floater bearings” meaning bearings (twice normal width) spin on the crank and rods spin on the bearings—-everything is a spinner—-crank has oil supply holes in middle of journal for floater style bearings. 8 BA rods have a “tang” locking them in place(to prevent them from spinning) and 8BA crank has holes to accommodate each bearing pair. Either you need a 8BA crank for 8BA rods or 59 crank for full floater rods. Won’t work if mismatched. 2 8BA rods have 4 bearing halves and 2 —-59 rods have only 2 extra wide bearings for both rods on 1 crank journal.

 

Unless you are trying to save that particular crank because you won't need to buy bearings for it, I'd suggest finding an 8BA crank. The 3-3/4" cranks are almost free nowadays since everyone wants a Merc crank. Put out feelers locally and I bet you can find one.

 

Thank you Flatheadjohn47! I apologize for my ignorance on this but can I use a 8BA Crank in my 59A block ?

 

Yes, if you use 8BA rods and bearings. A 4" Merc crank assembly will fit as well.

I believe the 59A rod/bearings will also work on an 8BA crank with some fitting. The 8BA bearings re much easier to work with, easier to find, and less expensive as well.

 

If you decide to use a Mercury 4" crank you will need the Mercury pistons. King pin height is different.

 

8BA Crank will fit in my 59AB block Without modification ?

 

Yes. perhaps. Pardon my comment about the Mercury pistons. Pistons don't have king pins, they have wrist pins. I had just come in from the shop where it's 12 degrees below zero. My old brain froze up.(the original brain freeze) You say it's a 59A block. The 59A designation was used from late '38 - '42 and had 2" diameter rod throws on the crank and 3 1/16" bore.. The '59AB engine had larger throws and 3 3/16" bore. The main bearings are the same diameter but the tang is different (wider) on the 59 series engines. You have to use the 59 main bearings. The 8BA crank and rods will work in the 59AB engine but will not work in the 59A with a stock bore size. I have made it work by installing the rod/piston assembly from the bottom but it's a huge pain in the ass and not worth the effort. The big end of the 8BA rod will not fit down the stock bore of the 59A.
(Frozen in Wyoming)

 

@Glenn Thoreson I think might mixing the 221 and 239 up?

Or were all 59a’s 221s?

 

Ok, my block has 59 on the bell housing. The heads have 59AB( but I don’t know if they were originally came off the block and I just mic’ed the bore at 3.210” I need rods and found 8BA rods and I can get a 8BA crank

 

"59" means designed in 1945 with a 239 ci displacement.

There were 221 ci 59 type blocks, but they seem to be factory replacements for the earlier cars. Unless the OP has one of these (which is very unlikely), the 8BA stuff will fit. 3 3/16" (239 ci) bore is 3.1875", so it looks like he has a .030 overbore on a 239.

 

I got this engine from a guy that bought a ‘47 pickup and the engine came with it and in the middle of a rebuild. It has been relieved and has adjustable lifters, I’m missing 2 rod caps that’s why I’m looking for rods which brought me to my original question

 

Yes. 59AB main bearings and 8BA rod bearings with 8BA rods. You are referring to a stock Ford 8BA crank, right? As someone mentioned, 4" Mere crank will also work but you need 4" stroke pistons.

I believe the center and front mains are the same for a 59AB & 8BA, but the rear bearings are different.

 

I took apart a 59 engine, sold the bare block, rest of it is along side the shop. Be happy to send you two rod sets for the postage

 

Awesome! Thanks!! How does that work ?

 

You pm me your address, I send them to you, if lucky they will fit in a Flatrate box via USPS. (Assume you’re in the states?) then send me the shipping cost when we know the price.
I can live without 15/20 bucks for a week or so

 

Yes I’m in Michigan. I literally just signed up for this forum for this question. Learning how to navigate lol

 

Lol. Little far to pickem up. Click on my name. Then look for “start conversation “.
And hey, hang around awhile. You might like the joint.

 

I just sent you a pm. Thanks again

 

Yes I will hang around I have a ton to learn

 

A very nice gesture from Mr Budget36, however if you can get the 8ba crank and rods I would go that route. The floating bearings in the 59 style bottom end are getting expensive, and you need to know how to set them up. not just a drop in like the modern bearings. Look for two oil holes in the rod journals to ID an 8ba crank

 

That’s true, as I was told fitting the full floaters was an art/or?
I’ll still send them. I’ll never need’em

 

Cygnus, take a look at your crank rod journals. Are there two oil holes in a row or just one. You may have an 8BA crank in there already since it was in the middle of a rebuild.

 

Yes I very nice of him.

Hi, yes I did i got two cranks with this engine and both are single oil ford cranks. I was hoping 1 was a merc but no such luck

 

My 1946-59A block is fitted with 4" Mercury crankshaft and stock 59A rods on "floating" bearings.

There are no modifications needed to install the later crankshaft aside from purchasing the correct piston set for your chosen crankshaft stroke. You'll also need a 59A flywheel as the 8BA flywheel has a different offset on the ring gear and won't mesh correctly with your starter motor.

Personally I'd recommend purchasing some books before going much further with acquiring parts.

“Full Race Flathead” by Jerry Havens is a GREAT book that explains the crank swap in simple terms
also
"Nostalgia Modifying and Rebuilding The Flathead Ford V8" by Ron Holleran explains everything in simple yet well detailed fashion also.

 

That's Jerry Hagens. He's a HAMBer, his handle is @HAGY39.

 

Thanks, I agree totally

 

Thanks for all the comments and info. I am building a 59ab engine as well and I had the same exact question. My 59 ab rods were oval on the big end so I’m going with a set of 8ba rods that checked out. My 59 ab crank is fine but I have 2 other 8ba cranks to choose from so I’m going that route instead.

 

Where did you get the engine stand mount to bolt into the side of the engine? I need one of those.

 

Most of the Canadian sourced C59A engines we had here in NZ had two hole cranks and ran 29A rods with shell bearings and can take 8BA rods. Useless bit of information. J