Flathead pencil test
 

I have a 24 stud flathead up to 48. It is not a 49 to 53 engine. Mine passes the so called pencil test and will hold a pencil in the area above the timing gear cover. So please tell me what means. I'm starting to be a little forgetful.
Thank you very much. Jay

Re: Flathead pencil test
 

It means it's somewhere in the 37 - 41 range. In late 1940, too late for the '40 assembly line, the so called "raised deck" blocks were introduced. Those are '41 blocks.
The "raised decks" went on through 1948. However, the "pencil test" won't get a passing grade after 1941.

Re: Flathead pencil test
 

I'd like to ponder those statements a bit. :D

I think the term "raised deck" should really be called "raised intake surface" - the deck was never raised. The deck of the block has always been in the same location (dimensionally) to the centerline of the crank - from 32 - 53. So I think the term "raised intake surface" is a bit more accurate.

Also, the raised intake surface was only around for a few years and only on certain castings. It was most prevalent in around 41' to 42' - and I did not think it was done post war. BUT (as with all things early Ford - there appears to be exceptions), I've heard that some have seen 59x blocks with the raised intake surface. I've never seen one.

Here is a picture of a 41/42 Merc and WWII era block - notice the raised area around the intake manifold profile/surface. I've not seen this in later blocks . . . but some have.

Obviously, this block is highly modified in the valve/port areas (I tend to modify things just a bit) - just ignore that.

Attachment 518706

Re: Flathead pencil test
 

[QUOTE=Bored&Stroked;2233855]I'd like to ponder those statements a bit. :D

I think the term "raised deck" should really be called "raised intake surface" - the deck was never raised. The deck of the block has always been in the same location (dimensionally) to the centerline of the crank - from 32 - 53. So I think the term "raised intake surface" is a bit more accurate.

You are quite correct. That's why I'd stated "so called".

Re: Flathead pencil test
 

https://www.fordbarn.com/forum/attac...p;d=1686966564

Here is a picture of a 41/42 Merc and WWII era block - Bored&Stroked

Re: Flathead pencil test
 

Beautiful looking piece of iron, raised or not..

Re: Flathead pencil test
 

Thank all of you guys for such a quick response to my question, but I was not not wondering about the deck height. I was asking about the forward part of the engine where the timing gear cover is located and there is something of significance about that top edge if it will or will not hold a pencil. Sorry but I have no way to take pictures or to send them. My engine is all togerher and running fine. I installed it in my 34 Ford many years ago. Jay in Mass.

Re: Flathead pencil test
 

Pencil Test:





https://www.fordbarn.com/forum/showp...9&postcount=12

Re: Flathead pencil test
 

If I understand correctly (at long last) you are wondering if that ledge has any effect other than for identification purposes. Am I correct?

No, it doesn't have any effect. Just a casting design.

Re: Flathead pencil test
 

The pencil test is "general" way to tell the age of the block. Like many things Ford, it's not a steadfast rule. The 59L block I used for my motor passes the pencil test when, by all accounts, it shouldn't.

Re: Flathead pencil test
 

there are some early 59 blocks that also have the so called ledge and pass the pencil test. They have the big 59 on bellhousing and i believe they were identified as 41a cast during the 1944 1945 era. I have one here.

Re: Flathead pencil test
 

Is it a 221-replacement engine block - with 3 1/16 bores?

Re: Flathead pencil test
 

Attached is a pdf of a spreadsheet I have been making using the combined knowledge of the Ford Barn over several years. Across the top are the different engine blocks I am aware of, and in rows are all the different features to identify them. Maybe it is time to do another big engine identification thread since I think photobucket trashed the original?

Re: Flathead pencil test
 

Cadillac512
Thank you very much for the link to those pictures. They are great. I don't plan on taking mine apart, but now I have a better idea about what I have. Jay

Re: Flathead pencil test
 

Bored and stroked
I don't know anything about the engine.
I bought it many many years ago as a rebuilt and took a chance with it. I never opened it, took it home and installed it, and was not disappointed. It runs beautifully and does not burn oil and does not leak. That does not happen very often.

Re: Flathead pencil test
 

I think that you are correct but my block measures close to 239 bore size. It probably was bored at some time to the larger size.

Re: Flathead pencil test
 

Or maybe it had the tin-can sleeves and they knocked them out and put the larger .080+ pistons in it?

Re: Flathead pencil test
 

No. It measures close to 3 and 3/16 now.

Re: Flathead pencil test
 

.

This picture shows a flat surface just above the round opening where the cam cover bolts to the block, which extends FORWARD. This surface extends forward just enough that one could lay a pencil horizontally on that surface without the pencil falling off.

Coop


https://www.fordbarn.com/forum/attac...3&d=1642487943


The pencil would lay like this picture shows.


https://www.fordbarn.com/forum/attac...1&d=1643985552

Re: Flathead pencil test
 

That test generally refers to 36 or earlier than 37 21 stud engines that have insert main bearings.