Ok, here's the story. On a recent visit back home, I got the crazy idea to drag the old 53 Desoto home that my dad used to drive when we were kids. Got to looking at the 56? Custom Royal, and was thinking maybe that engine would be appropriate for the Desoto. Question is, what actual engine is that in the Custom Royal? I'm pretty sure it's a 56, and the valve cover has the remnants of a sticker that said "Super Red Ram". What cubic inch could it be, and is it true that the bottom end is the same as a Hemi? Well hopefully some of you guys will chime in here. Thanks - Karl
that's the coldest FL shot I have ever seen. Global warming has really affected FL in a negative way. But to answer your question, I think you can pop hemi heads on the block and change a few minor things and make it work, but I'll let the other more knowledgeable experts chime in. Hemi's are cool for sure and I have a 392, but personally if that was my dad's car, I would just run the motor the way it came.
I think it would be a 325,,we have one in a 57 Convert.and pretty sure you can just bolt hemi heads on it but you need to use the hemi intake.,,might be more to it than that but thats the basic.
Uhmm, "back home" means where I grew up (North Central Washington) "home" now means Miami Thinking about a road trip this summer with the Dually and trailer, depends on Diesel prices now.
315 ci dodge i believe 57 was when they went to 325 ci, 270 ci stopped in 55 i think. by changing the pushrods and putting hemi heads/rockers (maybe a cam, not positive) on you got a hemi. the intakes are the same but the exhaust manifolds are not. let me know if your going to ditch the heads. my dad is running a hopped up 325 poly and it goes like a raped ape, i like em. peace
In 1956 'Super Red Ram' means 315. 218 hp @4400 rpm. Yes you could convert it but they make respectable power with the usual hot-rod parts, and you have a good 4-bbl intake to start with. The Hemi version makes 280 hp @ 4800 rpm. Easy to see that there is not a major power difference in 1956 trim. You didn't indicate if the DeSoto has a v-8 but if it does you also might consider rebuilding the original DeSoto 276. If the DeSoto has the 6 then you'll have plenty of other things to swap around. Good Luck, keep us in the loop.
There's an article on these engines which relates what parts interchange with the hemis , in this months issue (May '08) of Street Rodder mag.
Should be a code & casting #s on block, plus casting #s on the intake. Did you decide what year? '57 DeSotos used Dodge Polys & DeSoto Hemis. '56 Dodge is 315,'57 is 325. Pistons have to be changed to go hemi, along with the total haed assembly.
A '56 Super Red Ram is indeed a 315. Grab the intake if nothing else as they are worth big money. I don't know how long it has been sitting but without a carb is not good. With all the things you have to change to make it a hemi and the price of rebuild kits it is easier and cheaper to just find a hemi. If you going to part it out I would be interrested it some of the side trim.
It has a 2bbl carb, so it's a 270. If you find hemi heads, they'll work, 241-325 cube engines. The block will need a bit of grinding in the pushrod holes, the hemi's have ovaled out holes, the poly's are round. Intakes and exhaust manifolds interchange, the pistons will work but the flycuts for the exhaust valves are in the wrong place. A minor bit of machine work. Cam works for all heads. The poly heads are okay, too, superior in my mind to the newer 318-360 wedge heads. The 1962 313 Dart engine had 260 HP, only 15 less than a 340! We had one once, went like a raped ape.
Ok, just to clarify, the Poly motor is in the Custom Royal, the Desoto has an inline flathead, believe it is the 6. Talked to my brother today, he's going to start the "lost title" paperwork to get me a title for the Desoto, and the Custom Royal is his, he says the motor is mine, no prob. So now, I need to know what's involved in swapping the motor, will I get lucky and find that there are stock motor mounts and tranny mounts to do the swap? What year did Dodge go to 12 volt? What tranny came behind the Poly motor, or is there anything in the way of adaptors to put a modern tranny behind it? 73RR, can you elaborate on what you know I'll need to swap around? Thanks everybody, interested in hearing any more knowledge on the subject!
poly probably has a 2spd powerflight auto trans or a 3spd manual. Could also be a 3spd manual with an overdrive. I think Fluid drive (basically uses an impeller instead of a clutch) was still an option in 56 I know it was in 55 at least.
The 392 tranny adaptors are supposed to work on the Dodge & DeSoto Hemis & Polys. All sorts of tranny choices stick & A/T. Check Hot Heads, Wilcap, TR Waters & QEC. According to his sig line 73RR is QEC.
does the Poly have a front motor mount or side mounts? I have a '55 Plymouth Poly and it has the front mount, I belive the I6 motors had a front mount as well.
Been fooling with those old Mopars for 45 years. They used the Fluid Drive up through 1953 (which is notable for having a clutch pedal as there was a clutch between the fluid coupling (later in '53 it was a torque convertor). In '54 Mopar introduced the two speed PowerFlite transmission which stayed through the late 50's. In '57 they brought out the cast iron Torqueflite (based on the PowerFlite). In 1962 they brought out the aluminum case TorqueFlite. Hope this helps
Hi karl..I took the weekend off so just getting back to the topic. The 315 has side mounts so you will need to do some fabricating, and if you use a late trans (highly recommended)you will need a mount for that. Depending on the trans style, you may also need to swap the rear axle for something newer. (If you do a simple search for 'rear axle width chart', or some variation, several sites pop up with lots of useful info so you can compare to the DeSoto. Don't worry too much about the spring perches, they are easily moved.) In stock form your DeSoto has the e-brake on the tail shaft, so if you do not want to change the rear axle then you will need to look for a motorhome type torqueflight with a similar e-brake. They do exist but not in great quantity. If you find a big block type trans the tail shaft can be swapped to a small block case, including a 63-64 unit with pushbutton shift. The 63-64 unit could be handy in terms of how to shift and where to install the shift. If you are a decent fabricator then you probably could make the existing column shift work with a newer trans. Also note that the 65 TF is a cable operated unit w/o the buttons. If you choose to go to a manual trans then the rear will need changing. Obviously, a new prop shaft will be needed. Since the car is a 6-volt system and the engine will want 12-volts you can use a 12v battery and drop the voltage to rest of the car, or just parts of the car. There is no weight related issue between the 6 & 8. What has been left out ?? Probably something, so keep the thread going or call if ya like. 888-Hemi-Parts. Gary
KK- I have a complete Hemi top end from a 1953 241 hemi, that would convert that 315 to a Hemi, all you would need is hemi pushrods check your email, I just sent you one
He'd need to change pistons also. 241 heads can be used on the raised block, but the head to block sealing surface is marginal @ the top. If you want to try this you might want to check out Doc Fromader's 315 build on Webrodder.
"The block will need a bit of grinding in the pushrod holes, the hemi's have ovaled out holes, the poly's are round" Backwards: the original round holes are placed correctly for the hemis, only 1955-58 poly blocks have the holes elongated to a figure 8. "the pistons will work but the flycuts for the exhaust valves are in the wrong place" The reliefs are both for the intake valve - it has 2 (like some Pontiac) so they can use the piston for both banks. It's in the wrong place (not centered in the bore), wrong angle, and may be too small. The poly doesn't have an exhaust relief since the exhaust stem is vertical, but the hemi exhaust valve may be small enough to fit safely. Note how the reliefs on the poly piston are offset opposite each other.
with the smallish cams under .450" lift that are usually used, piston/valve clearance is rarely a problem- the last time we actually tried to measure piston/valve clearance with a street cam with .450" lift, we had half a can of clay on the piston before it even made a little nick in the clay with valve wide open. Every engine is different and the proof is in the measuring- I've seen pistons in engines with no valve reliefs at all, complete total flat top no valve relief, and no interference problems with .500" lift cam- when stock pistons had reliefs.
George, could you possibly elaborate on the block to head sealing issue? Last night I read the entire article that Doc wrote on the Webrodders page about the Hemi that he built, and don't recall him mentioning that being an issue.
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