59a - or 59ab
 

Is there any way to tell if a 59A on the heads and block is 3-1/16 or 3-3/16? Just stare at it I guess. Walt

Re: 59a - or 59ab
 

pencil test?

Re: 59a - or 59ab
 

Only way is to remove the head and measure the bore.

Re: 59a - or 59ab
 

I never trust what the heads say, most have been swapped around over the years. The only sure thing is that you'll know what the heads are. I know I'm not telling you anything you don't already know Walt :)

Re: 59a - or 59ab
 

I never think of pencil test on a 59 block, I've built so many of these things in my many years but I'll I tell when I get the heads. Thanks Walt

Re: 59a - or 59ab
 

The 41A block (has 59 on bell & was 221 replacement block beginning in 1944) does have characteristics of the prewar 221 engines but I haven't yet studied one to see how close they are. It would be interesting to note these differences.

Re: 59a - or 59ab
 

I have a block on my stand that's '59' and 221 cu in, 3 1/16. Heads are still off. I could get good pics if I knew what to shoot or measure.

Re: 59a - or 59ab
 

This engine I just started on 59 on the bell and 59AB on the heads, a rebuild tag on the back built by shop in Boston Mass. I'm sure it's oversize, I have got about half doz of those tags kicking around the back of my bench, the heads stuck pretty hard,been socking, trying to get them off today, let you know, Walt

Re: 59a - or 59ab
 

Walt,
The small bore 59's pass the pencil test, not seen one that didn't pass.
Martin.

Re: 59a - or 59ab
 

Well guys I got the stuck heads off this 59 block, 3-3/16 + .030 it won't hold a pencil, so it's just a 59AB block with 59A heads, 46-47-48 crab dis. So I'll check pencil from now on, never know if anyone has changed heads. So if it holds the pencil test chances are it's a 3-1/16 or something, What if it was bored 3-3/16 and cain't tell? Then you go and bore another 1/8, dose anyone know if the walls are the same thickness? chances are there all the same block and the factory bored some 3-1/16 cause they had alot pistons left over. Walt

Re: 59a - or 59ab
 

I'd sure like to see one of the 41A blocks so I could be sure for my own information but some folks say they are very much like the prewar 221 blocks and have thin cylinder walls like they were using the prewar cores in the post war core box. I hope someone comes up with one to photograph for the block ID thread some day. It would be nice to know what all the true characteristics are.

Re: 59a - or 59ab
 

OK, so what's the pencil test?

Re: 59a - or 59ab
 

Its my understanding that if a pencil will lay on the block just above the timing cover that its a '40 221 block. I have one in my stack.

Re: 59a - or 59ab
 

That's what it is. The post war engines had a different design on the front of the block so there is no pronounced flange there for the timing cover. The timing cover itself it all that protrudes there. Prewar engines had a bit of flange protrusion making for a pretty good step in that location.

Re: 59a - or 59ab
 

An other difference, I built a 59 engine a couple years ago for a 35 pickup, it had a rear oil slinger rather than a rope seal. I used an 8BA crank and rods with the 59 aluminum seal. Never so that before. Walt

Re: 59a - or 59ab
 

My 59AB had a oil slinger too. Found that out when I pulled it out of the pickup and it poured oil out the back end. At the time it seemed it would be easier to drain the oil with the engine on the lift, who knew. We just figured it had a previous Frankenstein type rebuild because of all the miss matched parts we found.

Re: 59a - or 59ab
 

Just went down to the shop and looked at the timing cover area. There is no way a pencil could sit there if the timing cover wasn't on. It just slopes down to nothing. The bell housing has a '59' cast on top. Don't recall what the cyl heads were, but it's 3 1/16 for sure... .060 over. Has a tag from rebuilder ford authorized which reflects the specs of the engine. Not sure if that helps.....

Re: 59a - or 59ab
 

I've not seen any blocks with just 59 on the bell housing that passed the pencil test - only the early blocks (pre-war). I'm not saying they don't exist - just never seen one.

Usually when a see a block with just the 59 on the bell, my hunch is that it will be a 3 1/16 bore block (replacement) - just the way I've seen most of them over the years.

Re: 59a - or 59ab
 

Gonna have to check the 59 block I have stashed, my reply about the pencil test was from memory, so could be bolox. It is a mish mash of pre and post war casting box's.
I'll check and report back.
Martin.

Re: 59a - or 59ab
 

The pencil test is to exclude the 59 block not to confirm it.The pencil test works on the first generation 24 stud blocks,late '38,39 and 40 41.