I have found a 241 (259?) poly engine of 1955 vintage. it has attached flexplate & torque converter. We want to put this and a TF4 (?) speed I also have from a 225 truck engine. Into my nephews 54 dodge -currently 6 cyl 230 cuin & 3 speed. I have no manual bell housing nor flywheel for the 241. My questions are, 1) what bellhousing will fit to the 241 Poly engine? (The flathead 6 one?) 2) what flywheel will fit? If it comes to the crunch, machining a bellhousing is certainly possible, but a flywheel may have me stumped re balancing etc. Also, is it true that Hemi Heads can be fitted to these motors?? If so what heads and what is involved?
Its basically a hemi block with poly heads. That's a bit understated but you catch my drift, right? Those bellhousings are not that hard to find, or you can get the same adapter that adapts the baby hemi to what you want to use. IE same adapter for the same year hemi to whatever you're lookin' at. They are not an externally balanced mill [like a cast crank 440 or a 400 SBC). I don't know that the 6 flywheel will bolt up but you can give it a shot, I've gotten lucky on other stuff that way, I'm sure that your bellhouseing won't match. Now if the real experts will step up to the plate we can clear this up and build another budget beater with HAMB knowledge.
The 6 flywheel will work just fine. I don't know about the bell housing but there is an excellent chance it will too. You have the al. horse coller adapter? The bell housing will be too deep for most transmissions. All the Hemi adapters will work except the ones for the early extended bell Chryslers. You have a 55 Plymouth engine. One year only for Plymouth.
Double check the numbers and make sure it is a HyFire 241 and not the HyFire 260. The 241 motors are pretty rare, but you never know. The post above is correct, it is a Dodge Hemi block with the Poly heads. They ran the same block (larger cu.in.) again in 1956, but only in the lower level cars. When the 1955 Plymouths came out, Plymouth's engine plant wasnt ready for production so they used the Dodge plant to tide them over until the new plant opened in 1956. Only problem was Plymouth sold TONS of them (Over 60% of sales had V8) and this obviously didn't sit well with Dodge as it clogged up the Dodge engine factory with Plymouth engine orders. Hemi heads can be ran on this car, but with all the changes and parts it is MUCH cheaper just to buy a Dodge Hemi. HyFire
Tranny adaptors for the Chr. Hemi are supposed to fit Dodge/Desoto Hemi blocks. To convert it to Hemi you need to change the head assemblys & pistons. The 259 Poly was never a factory Hemi so you'll need to check with Bob Walker @ Hot Heads about pistons. I understand a lot were converted to race in the under 260 CID class at Bonnieville. Might post casting # of block to make shure what it is.
The flat 6 flywheel should work just fine as the 241 is a hemi based poly. Bugman used one on his 392 hemi, and I can't remember if he had to modify it a little or not, but I do remember it wasn't an issue. At any rate, the bellhousing is likely to fit as well, but don't quote me on that. I'd give it a try at very least. About the hemi conversion... the hemi based polys were introduced in '55 and were available until '58. These were the 241, 259, 270, 301, 315, 325, 331, and 354. To convert them you need to sub pistons, heads, rocker arm assemblies, pushrods, headbolts, intake and exhaust manifolds. Plymouth, Dodge, and Desoto engines require Dodge parts, and Chrysler require Chrysler parts. If you're serious about converting your poly to a hemi, I'd recommend picking up a copy of Tex Smith's "Complete Chrysler Hemi" Book... lots of good info and a chapter about polys.
The flat 6 flywheel will work. It only has 6 studs instead of 8, but the pattern is the same, just with 2 missing studs. If your concerned about strength, any machine shop could drill for and press in the 2 missing studs. The 6 cylinder bellhousing IS different though, and will NOT bolt up to an 8 cylinder block(not even close). Many of the trucks though did use Polys with manual transmissions, so thats where I'd start my search.
Thanks for all the info. Very much appreciated. I have a friend with a 241 Hemi in his car so I will take a look at that too.
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