99 Merc block done

4tford

4tford

Well-known member
I ended up with three of these blocks this summer. (all are .045 over bore) Completed this one today. 99 USA block factory relieved. Heads are Canadian Aluminum 91A. Did the aluminum peas and the tightest spot was .053 Gasket is .059 and I assume when compressed it is .050. That means my tightest spot over a piston will be .044. Had to mill the block .012 due to a gouge. Now I am wondering if one of these intakes would happen to be the right one to go with this setup. Thanks Bill
 
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I have a 99a in my 33 at the moment,4 inch crank and .040 over bore,I used the 33/34 manifold and 97 carb, that engine has a pile of torque and is so nice to drive.
I know it could do with a bigger carb ,but where I do most of my driving it is very nice.
lawrie
 
4tford said:
I ended up with three of these blocks this summer. (all are .045 over bore) Completed this one today. 99 USA block factory relieved. Heads are Canadian Aluminum 91A. Did the aluminum peas and the tightest spot was .053 Gasket is .059 and I assume when compressed it is .050. That means my tightest spot over a piston will be .044. Had to mill the block .012 due to a gouge. Now I am wondering if one of these intakes would happen to be the right one to go with this setup. Thanks Bill
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Looks to me like that manifold on the right might flow more air, looks like it takes the long push rod 8-7/8. I don't like that one on the left with the heat riser hole, I've seen to many of them burned out. Walt
 
Bill,
The cast in raised 99 on the right deck
makes that a Canadian block, doesn't it?
US 99 had only a stamping on intake surface
1939/1940, if any.
Does the flat intake surface date the block
39/40 as opposed to 41/42 (so called raised)
as US blocks.
Yours came from 1942?-- or is set up for
crab distributor.
Interesting variety of intakes---1939 or
earlier?
Nice build!
Gene Tulsa
 
Nice looking block. I also have a 99 Mercury block but unlike you I have the 99A aluminum heads that came with it. Could anyone explain to me the difference between the 91A and 99A aluminum heads for this engine?
 
42panel said:
Nice looking block. I also have a 99 Mercury block but unlike you I have the 99A aluminum heads that came with it. Could anyone explain to me the difference between the 91A and 99A aluminum heads for this engine?
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I can't explain the difference in the heads, but I can say the '1' in 91A makes it a Ford part number, and the second '9' in 99A makes it a Mercury part number
 
My guess is that the combustion chamber would be a little larger. Since the engine is bigger, the chamber would be larger to keep a similar compression ratio.
 
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