Hi All, I'm rebuilding a 21-stud flathead with my grandpa and I recently picked up a pair of original aluminum heads that I think look serviceable. I'm planning a mostly stock rebuild, but with a few speed upgrades (dual 97's on an eddie meyer high rise, valves, etc.) and I thought the aluminum heads would look good compared to the cast iron ones we already have. My grandpa remembers his dad (owned a service station in KS from the 30's to the 80's) having to take a chisel to these things sometimes to get them off the block, which explains why they were phased out eventually. I've also read in the early ford v8 books about the different types, e.g. flat top vs. domed piston, A, A1, A2, etc. and I think I've got 2 mismatched heads. (1) appears to be a 33-34 and the other a 36...the combustion chambers are different. I've attached a few photos below of what I've got (after I've cleaned them) and I'm wondering if: (1) can I use the different year heads together or should I try to match them (I'm open to trades if this is the case), (2) are these in fact serviceable if I have them surfaced? Any info helps, thanks.
They are for different pistons... the 40/34 is for flattop, the other dome. Can't read the PN prefix on dome on..48 or 68?. Anyway, any of the 221 dome top pistons can be used if you get another domed head. They are reproduced, but scary expensive.
Hi Bruce, I think they're both for flat top pistons. The passenger side head has PN 40-6049 and the driver side head has PN 40-6050-A2. I read that the 48 or 68 prefix on the PN was for domed pistons, does this seem right? Also, the A2 heads are a later model, from what I've read, and have a different shape chamber for the valves. Wasn't sure if this would change the balance or power of the engine if the chambers were different on each side. Thanks.
OK...domed pistons were used in partial production '35 and 6...a 40 heads should all be flat, I think. If you lay a straight edge across the dome area beyonf the flow area, are they the same?? Shape of the lower chamber looks like the general shape used for years beyond but my eye is probably assuming the dome there.
Yeah, it's flat all the way until you get to the flow area. I guess that's the part that I'm wondering about, the bottom head in the photo has a flow area that's shaped like a heart (IMO) with a square bottom and the top head is shaped more like a heart with a baby bootie on the bottom. The 35-36 ford v8 reference book calls the latter a "modified combustion chamber" that was introduced in late 36.
The late '36 one I think was the move to dome. Since yours are both flat, I think the one that looks more like the domed type was just an earlier shot at Ricardo type chamber. The one with the more angular shape over piston is a version of the several '32-36 flattop heads. I don't think that using different chambers R and L is a good idea at all.
Ricardo type chamber...interesting. I feel the same way about bolting on 2 different type heads, even if they are both for flat-top pistons. Anyone out there want to trade?
Keep your eyes peeled to cl and the classys on here and the ford barn. These things pop up from time to time. I scored 2 n.o.s. 21 stud factory replacement heads on the same day from two different places!
The head without a suffix in the part number is 33 slightly later after the introduction of the cast iron head the suffix -A was added to the part number in 34 and carried into 35. The -A2 indicates it is modified combustion chamber about April 36 production. The number inside a circle is the Mfg of the head for Ford. The A2 head is a replacement for the other head so they can be used together. IMO it would look better with matching pair.
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