59 block questions

[38 coupe]

Tim, thank you for posting pictures of your 59 block. Can you add a picture of the whole front of the block? I'd love to include that picture in the flathead block information file I keep adding to.

 

[CA Victoria]

Thank you all for sharing your knowledge.

 

[38 coupe]

Thank you! I have not before seen a 59 block that passes the "pencil test".

 

[Tim Ayers]

Here are photos of the 59 block. I believe the relief is a factory modification.
The other engine came out of a Ca car-1946 Mercury Station wagon.

The relief is indeed done from the factory. Legend has it that they were used in trucks to prevent valve seat cracks from overheating when getting overworked. LOL.

My 59L is also factory relieved. I'll try to get a pict of the pencil and the 59 L number of the bell.

 

[Bored&Stroked]

Thanks for the picture . . . it definitely has the "ledge" that was common in many pre-war blocks.

It just goes to show us all that for every story/rumor that comes about, there is a conflicting story to contradict it. I have a 59L - it came from Kenz and Leslie in CO, when I get back to Ohio, am going to have to check the front out. I also have a 59Z - that has the factory reliefs . . . time to dig it out as well.

Not that it makes a difference, just interesting to know all the nuances.

 

[Tim Ayers]

Here are picts of my 59L with the pencil test. Hard to get good picts since it's in the car.

 

[rotorwrench]

The 41A blocks had the "59" on the back bell when the post war engines began production due to sharing the same rear shell mold. The front is just like the pre-war 221. As far as other differences in wall thickness and all that, I don't know but they came with 3 1/16" bores when new. They will pass the pencil test since that is a 221 characteristic.

 

[tetanus]

Here’s my 59 block with 3-1/16 bores,and pencil test. I was told it was out of a40 which seems right on as all the parts on it were 40 ford. Also no factory relief. It did not have the rear main rope seal that threw me off for a bit. It has real thick cylinder walls compared to any other I have.

 

[tetanus]

Must be some kinda phenomenon around here I looked at another block I had and it’s the same thing 59 block 3-1/16 bore and passes pencil test. Feels like it has a lot of meat in cylinder walls also. This one does have rope seal on rear main. No reliefs either

 

[38 coupe]

Interesting, thanks for the additional pictures.

 

[Reds34]

I am by no means a professional, but what shape are the water outlets in the block? Are they round or trapezoidal?

Red

 

[tetanus]

They are the two round bottom and center and the triangle top one

 

[CA Victoria]

Curiosity has struck......
I had another block that was already machined when I bought it. It had a thin area in one of the cylinders. I was told about core shift, that the way the molds are made it could happen to one or both banks.

Sonic testing will confirm the cylinder wall thickness & any major irregularities in the aforementioned 59 block, (ie core shift).
What is the minimum wall thickness needed to maintain the block integrity?
One cylinder is sleeved with appx .090 sleeve showing and .160 cylinder wall left behind it.
Elsewhere I can get in to measure I am finding the wall thickness from .25-.31 (it is bored .060).

I’m assuming that the center two cylinders naturally run hot sharing a single exhaust port. I have also heard that sleeved cylinder do not cool as well. Is this a concern?

 

[rotorwrench]

Sleeved cylinders do just fine as long as the sleeve around .090 to .125". It's the ones that have a thin wall that may run warmer than usual.

 

[Bored&Stroked]

Cylinder Wall Thickness: I don't like to be below .150 - if at all possible. Back in the day, there were lots of guys that claimed that as long as you were over .080 to .100 you were fine (for racing engines).

The problem with that today is that a lot of corrosion may have taken place since new - so there can be heavier rust pockets around the cylinders and you run the risk of water coming into the cylinder the thinner the walls (even though you thought you were good with your .100 sonic test results). Sonic testing is an approximation and even with 12 test points per cylinder, you obviously aren't checking the entire cylinder wall for imperfections.

Also, if you're racing it really hard and/or with boost, you can split cylinder walls when you start getting them too thin. Also, the thinner the cylinder walls, the more tendency for ring sealing issues as well as more heat getting into the water jackets.

 

[CA Victoria]

A friend sent this to me....

 

[Seth Swoboda]

I learned this evening that this is more than likely a service replacement block 59A-6010-A.
(ford service bulletin 07-15-1946)
It will be interesting to see what the wall thickness is for this block.

I have an engine just like this. It was a 24 stud 221 cubic inch block of the 59A variety.

I had the block bored to a total of .125

That made this engine standard bore for a 59A enigine. Plenty of wall thickness and 59A pistons and rings in standard size are easy to obtain.

 

[GB SISSON]

A friend sent this to me....

Now that letter is a remarkable find. I have at least one of those blocks. Can someone tell us if that replacement block passes the pencil test?

 

[CA Victoria]

The 2 mentioned in post 20 do.

 

[Bored&Stroked]

Interesting that the letter mentions that SAME block for the entire 59x series. What has been common belief is that the 221 (90 HP blocks) had thinner cylinder walls that the 239 (100 hp blocks). I've heard for 40+ years that you had to be careful trying to bore a 221 CI 59X block due to thinner walls - that they wouldn't support a 3 3/8" bore. The above letter refutes that - claiming they're all the same. What we don't know is if the foundries all used the same patterns/core boxes or not.

Anybody have any first-hand sonic test experience with the 3 1/16 221 blocks? I've never built one?