Hey Guys, I've been seeing alot of different V8 sizes done by Dodge here lately. It's been making me think of my old '55 5 window 1/2 ton swb stepside Dodge truck with the V8 w/ 3 on the tree. The original owner said it was a 260 something? I was thinking maybe 270 something. All the literature I have for this truck, nothing ever mentions this engine, just the "red ram", and the "fire dome" hemi's. I've been told it was the same hemi engine block, but with different heads, they was a hump for each sparkplug on the valve covers/heads. I also head that it was called a "poly", and also reffered to a "semi hemi". What exactly was the size, or sizes of this engine, and is any Hamber's currently running this engine in there ride? I'm thinking of using this model engine on a future build up. Also how much does this engine share with the early hemis? TIA, David
I was looking in the book, Dodge Pickups History and Restoration Guide 1918-1971. It says, "On June 1, 1954, a V-8 became available...The 241 ci light-duty V-8 was an ohv engine with polyspherical heads." That's all I saw but maybe someone else can help you out too. I know I read other info about these engines but I can't find it now. Jay
i've got a 270 poly motor in my 56 plymouth. i know in 56 there was the 270, and the 277. the 270 was the same as the hemi, sans the hemi heads. i think the 277 was different. the best way to tell the 270 from the 277 is by the location of the thermo housing and radiator hose location. the 270 has it comming off the water pump, and the 277 has it comming off the intake manifold. they make some speed stuff for it(or the hemi stuff bolts right to the poly motor, and vice-versa), but its a little costly. dave s
In 55 Plym had 2 polys 241 & 259. Both are built on Dodge Hemi blocks & can be converted to Hemi using Dodge parts. You have to change pistons & the total head ***embly, inc push rods. The 259 is a unique size for Plym, no Dodge equivelent. Someone might make custom pistons for it, or mod the poly pistons. In 56 Plym had a 270, also a Dodge Hemi block, & the 277 an early "A" small block.
I didn't know that. Thanks guys, i'll definately keep my eyes out for the poly's. Also when I had to change bellhousings, I noticed that the only way you can remove the flywheel is to use a combo wrench in between the oil pan, and the fly wheel, why did Dodge do this? I ended up pulling the belhousing far as I could away from the block, and had to hacksaw the alignment pins(just the tips) just enough so I could slide the bellhousing straight upwards. Which Hemi heads can only be used on this block? I know there was differnt blocks for Desoto's, Chrysler's, & Dodges. My Dad & I are wanting to build a father & son project out of some early iron from the 20's/30's sometime after moving. I was thinking about using this engine as either the poly, or if possible as the hemi. Looks like there is a early hemi in our future!! TIA, David
Not to hijack the post but I have a '55 dodge royal with what should be a poly 270. I just read somewhere else that 53-54 241" hemi heads and intakes will bolt right on. First does anyone know this for a fact, and second will the pistons work. Is there an advantage to using the '55 270 hemi stuff ? My motor is locked up I think just from sitting, I was going to pull it and s**** it, but maybe I will hold onto it if it can be made into a hemi easily. ***uming of course once I get it out the block is okay, I understand the cranks were prone to breaking. Rick
Dodge heads will fit high & low blocks. You will need hemi pistons, the valve relief is different. Check out Doc Fromader's 315 build on Webrodder.
The cranks are not prone to breaking. The low deck engines did not have a harmonic balancer. When the revs go up the crank goes south due to the lack of the balancer. The low deck dodges(241,259,270) can only use the 241/270 hemi heads. The high deck heads have a different pushrod angle and deck width. It throws everything off.
Also, the Dodge Windsor and Plymouth poly motors are different. The Dodge has very deep scallops around the plugs. The Plymouth valve covers have shallow reliefs. The Plymouth poly heads actually bolt on to a (LA) model small-block Mopar, but the water p***ages are different. Dodge had it's own blocks.
The Firedome Hemis were all DeSoto engines, Dodge engines were all Red Rams, whether or not they were Hemis. Just about none of that '50s Mopar stuff interchanges between makes! Except I believe the Dodge heads could be used on some small-cube Plymouth blocks, and some people ran this combo on Bonneville to enter specific cl***es. You'll have to swap Hemi pistons into a Poly block to get it to bolt on the heads. And you can only do this between the same engine make, and deck height. They're a real pain in the ***.
You need to keep in mind there are 2 different Poly Early & "A" type. The early ones were built on Hemi blocks (displacments same as Hemis except Chr. 301 & Plym 259)& can be converted. The "A" type are simular to the Hemis, but can't be converted, displacements are different than the hemi.
Thanks for the info guys, keep it coming . So the big question is should I hold on to this 270 poly for a future hemi conversion ? Rick
Year for sure hold onto it, George is speaking the correct language here on poly to HEMI conversions. Von MoPar!
I have 2 270 Poly's right now, one running in a '55 Dodge Royal and one froze up in a '56 Dodge Coronet. I've been told that the intakes are the same but the heads, exhaust manifolds, and pistons need to be swapped out for a Hemi conversion, and the parts can only be swapped between engines of the same displacement. 270 Poly engines aren't worth much. They do have some value since occasionally early Dodge Hemi engines are found with cracked blocks and such. But the Hemi-specific 270 stuff doesn't come cheap unless you buy a whole parts car to get it. I'm not going to s**** my extra 270 but I don't expect it to be worth much either.
The Jalopy Journal
