31pickemup
Senior Member
Hey guys I have a question about a 59AB flathead that I found. This 59AB is a 221ci not the 239ci. My question is can I just bore it out to 3 3/16 and just replace the pistons? Are the rods, crank etc still the same?
59AB flathead with 3 1/16 bore question!
- Thread starter 31pickemup
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OLD...BILL
Well-known member
I'll bet its sleeved?? punch em out and you there, hone to new pistons, all else is good to go...the trick is to find a shop/builder that know flathead and can prove it, with past customers ?? it's a big if...and post where you are, someone here will help....OLD.....BILL
supereal
Well-known member
Some blocks were sleeved because one or more of the cylinders had a casting defect such as a sandhole. Sleeving saved the block, and it was used as a "service replacement". This was common practice at both the factory and "authorized"rebuilders. You won't know what you have until the sleeves are pulled, then you would to resleeve the engine if any cylinder walls have been breached. If the sleeves are in good shape, I'd have a good shop inspect them and see if they can be honed. Most can't tell the difference in displacement, anyway.
31pickemup
Senior Member
This block has no sleeves in it. Its a low milage 1946-48 59ab 221 replacement engine.
Pete
BANNED
There is a very good chance that block will bore to 3 3/16 safely.
In the old days, we would just bore away to any size we wanted and 99% of the time all was well.
What with good blocks being scarce nowdays, I sonic test them first.
There is always a one in a thousand chance it was a core shifted block and they only bored it to 3 1/16 to save it.
In the old days, we would just bore away to any size we wanted and 99% of the time all was well.
What with good blocks being scarce nowdays, I sonic test them first.
There is always a one in a thousand chance it was a core shifted block and they only bored it to 3 1/16 to save it.
The one I have here looks like it has the meat to go 1/8" over (to 3 3/16") but I haven't sonic'd it yet. What Pete said about good blocks being scarce is good, I wouldn't bore it that far on a chance, get it sonic measured be on the safe side.
Most other parts in the engine are fine when going 3 3/6", some of these service blocks (the ones I seen just have 59 on the bell, no AB) have a slinger on the back of the crank rather than a rope seal, due I believe, to the crank being a pre war 2" rod crank. So if you want to flick an 59A or 8BA style bottom end up it, you'll need to swap out the seal housing/slinger castings.
Martin.
Most other parts in the engine are fine when going 3 3/6", some of these service blocks (the ones I seen just have 59 on the bell, no AB) have a slinger on the back of the crank rather than a rope seal, due I believe, to the crank being a pre war 2" rod crank. So if you want to flick an 59A or 8BA style bottom end up it, you'll need to swap out the seal housing/slinger castings.
Martin.
31pickemup
Senior Member
I thought all 46-48 motors were 239's til I found this one. I thought he seller made a mistake and measured wrong. Then I read Van Pelts page about some post war 59AB's being bored to 221 as replacements. Since it's a raised 59 number in the bell block I figured they used the same rods etc. but just bored it to 221. Block should be the same as a 239 so I should have tons of meat
31pickemup
Senior Member
Lol mine are round and its 3 1/16
Lawrie, these blocks arnt sleeved down to 3 1/16" they are cast as such. As John said above, they are different castings to the 3 3/16" blocks. In fact I believe they are different to all other blocks. They are an odd mix of cores, some parts of the casting are pre war, some post war. The one I have has 59 on the bell but a pencil ledge on the front, round water hole as the op's engine has, and post war valve angle. Real odd engines.
Martin.
Martin.
31pickemup
Senior Member
Is it worth rebuilding?
31pickemup
Senior Member
is it also a 3 1/16?
31pickemup
Senior Member
