Cyl. bore question

[big job]

I may have posted this before I took this engine apart, that runs fine but
just want to check it out. I am into 49-53's all products, even have a
marine Hercules 175hp next on the list. Kind of brain dead on the middle
year engines. What I have is a 24 stud, raised deck (intake) it has a
46 type distributor, but with a plate behind the dist that is tack welded??
Along with the distributor I snapped the bore and that comes out to 3.146+-
so thats not 221 or 239 right. All pistons are stamped .825. My son tells
me they removed liners and fitted factory weird size pistons. This was done
by Cody Ford authorized builder in Boston Mass...At my age this is a first.
But I do know Chrysler was know in the 30's to tweek rejects /odd bearings
and bores a common practice back then to save waste. So I ask just to educate the old man as, what do I have here, nothing makes sense. Think its a 41 or 42??
Also with my finger nail I can just feel a ridge (at the top) but looking down at
it I see the same ridge on the top about .010? that can't be a liner ? or could it?
sam

[Ken/Alabama]

That raised deck block is 41. Std bore is 3 1/16. They did make odd size Pistons to use after removing the sleeves. The ones I've seen were 3 1/16 +.083

[Ronnie]

What is the bore size at the cylinder bottom?

R

[big job]

I haven't measured the bottom bore, I decided to just run it as is cause I doubt I'd
find pistons unless I bore it. Its only to go in my 46 while I rebuild that one.
Still curious about the timing cover with a tacked (in 3 places) plate between the
cover and distributor. new one on me.. sam

[Ken/Alabama]

Originally Posted by big job

I haven't measured the bottom bore, I decided to just run it as is cause I doubt I'd
find pistons unless I bore it. Its only to go in my 46 while I rebuild that one.
Still curious about the timing cover with a tacked (in 3 places) plate between the
cover and distributor. new one on me.. sam

Probably got a long nose cam with a later distributor. If you put an early distributor on a later engine that has a short nose cam you must install a button between the cam and distributor to make up the difference.

[TomT/Williamsburg]

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I think the tac welded plate is an adapter for a 2-bolt timing chain cover for the diving helmet style distributor to the three bolt for a crab distributor. Makes sense along with the savings everywhere else back in the day. I do not know why they tacked it - maybe wanted to conserve on 3 bolts?!?!

[rotorwrench]

It might have been a home fabricated adapter where they didn't have bolt holes to attach. I might be wrong but the tin can sleeve engines may have had a small step around the top of the bore. They just pulled the sleeves and honed it for those special pistons. I think I would remove the tack welded adapter and find a bolt on one or just go back to the divers helmet. The 41 models were the last to have the divers helmet distributor.

[Walt Dupont--Me.]

With the raised intake surface ( accually it's lowered ) it's 41-42 block, it had the 3-1/16, tin can sleeves, .040 thick, remove the sleeves and you have a .080 bore, same as the 8n--9n Ford Tractor, Ford made a ,0825 piston SO, you just hone the bore ,002 .003 and slap Tractor together. those piston are hard get so I bore another .020 and use .100 over EAB pistons for the Tractor, I've built a lot of them. On the 40=41=42 block I remove the sleeves and bore another.045 to 3-3/16 and use stock EAB pistons

[big job]

Just what I though rotorwrench >diving helmet< equals 1941 This engine came out
of a 1947. They may have had to use 42-48 dist for the fan or fan belt clearance
my guess.

And Walt, I know I'm a going brain dead, but seems to me all N tractors are
3 3/16 bores. And I do have a 1949 my father bought new, till this day its
never ever been apart. talk about gettin your moneys worth ! sam

[JWL]

The .0825 oversize pistons were available for both the 3 1/16 and 3 3/16 sleeved engines.