#8 stud on a diamond block engine.
 

As I was working on a diamond block out of a Gleaner combine I found that the #8 head stud was the slightly longer one for the distributor cable clamp.

Since this is a 1937 engine built 6 years after Model A's ceased production it seems odd that they would still be installing the long stud, especially on an engine that was destined to go into a combine.

Re: #8 stud on a diamond block engine.
 

Possibly it had started out life in a used car or truck installed at a dealership and ended up in an agricultural application. Or depending upon the date of manufacture (1937), perhaps it had been purchased in the private market after Ford's Model A production ended as a replacement engine for a used car or truck. It may also be that the post-production engines had a build sheet that specified that this bolt be used anyway, no matter what the intended application.
Otherwise, you are right - why would that longer stud be needed if the engine had been in a combine since Day One? Certainly not for a long pop-out ignition switch cable.
Marshall

Re: #8 stud on a diamond block engine.
 

I have one of those engines too, built in 1937 and production of those engines were beginning to wind down. Best I can tell is that Ford built the Diamond block as REPLACEMENT engines for automotive applications, and they used stock parts for that purpose which included installation of that stud. I'm fairly certain that Gleaner simply purchased them "as-built" and made minor modifications to adapt to their machinery.

Re: #8 stud on a diamond block engine.
 

Gleaner Baldwin model A, R, NA, & NR pull behind combines were equipped with "off the line" engines as Ford assembled them but those engines came with no serial number. Gleaner used a "G" prefix on their own serial number to ID them and stamped them in the same place Ford did so folks can tell they didn't come from a Ford car.
This link has a Photograph
https://www.fordgarage.com/pages/gleanerbaldwin.htm

It's been a while since I looked at one that my uncle owned. They had a conventional type distributor so they didn't use that stud for an ignition cable like the Electro-Lock. They had a control panel that was mounted on a post on the left side of the engine. The coil was mounted on top of that post and overhung the cylinder head a bit. They likely used that stud for a stabilizer strut for that control panel that had the coil on it but my memory isn't good enough to confirm that.

Most tractors used in that era had no PTO drive built in so they had to have a power plant to run the cutting and threshing systems on those combines. There were self propelled combines in that era but they were expensive and they weren't as reliable as later self propelled combines. The pull behind units were used quite a bit and even after the war for a good bit. My Grandad used the Gleaner Baldwin combines till he retired in 1948. My Pop used them until he purchased his first Massey Harris model 27 combine.

Re: #8 stud on a diamond block engine.
 

Got a couple of diamond B engines. What’s interest is no one has identified the diamond foundry mark, where the parts were cast is a mystery as far as I know.

Re: #8 stud on a diamond block engine.
 

Now that you mentioned it I looked back through some of my pictures and found one that shows two of the studs (#4 & #5) being used for the control panel and the #8 stud for the radiator support brace.
Wonder if Gleaner specified the longer stud or just utilized a still "standard" longer #8 stud.

Re: #8 stud on a diamond block engine.
 

Studs were easy to get in those days since they were a lot more common than they are now. I have the longer #8 stud in my 29 Sport Coupe's engine but I didn't use the clamp so I put one of those thick exhaust manifold washers on there last time I torqued up the head. It makes it easier to remove the distributor without pulling that nut on that stud. That particular stud location can have head gasket failures so I only want to torque it up once per head gasket change.

I looked up foundry casting marks some time ago for the 1930s era and found that there were several foundries that used a diamond shape in variations. None were exactly like it but close. Those were close enough to Detroit to have been possible suppliers. Ford only set up to cast high production engine blocks in that time frame. The model B may have been produced by Ford till the end of 1934 production but even they went in to an outsource after that. Ford pretty much outsourced all low production cast parts. They could justify keeping an assembly line for them while they were being produced for industrial power plants but I'm sure that need bled down to a minimum amount just before War Department production started so they finally shut that line down.