Thread: Early Hemi 331 engine

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I have always been interested in putting a hemi in my 37 and even though I'm a chevy man I have the chance to buy a early 331 hemi out of a 1954 car. This has a 4 barrel and is rated at 235HP and the torque is 330 with a compression of 7.5:1. Since I'm not to familar with the early Hemi, can these be built up to put out 450Hp and torque of 500. I don't know yet without taking it apart how much thickness I have in the cylinder walls. If I do get this engine, I will ask my good buddy streets to help me build it.

The early Hemi's were a pretty respectable in their day, and a lot of vintage hot rod and even new tech can be applied to acheive very respectable HP and torque for their displacement. The HP and Torque your talking about may be possible to achievable out of a 331 but chances are it won't be streetable or last very long.

I have a little advice for what it's worth if you are looking for an early hemi. Chrysler made 13 diffrent displacement Hemi's from 1951 to 1959. There is almost no interchangability between the Dodge, Chrysler and DeSoto versions.

1. Unless your doing a restoration stay away from the Dodge and DeSoto versions. These are not well supported by the aftermarket and parts can be very hard to find and VERY expensive when you do.

2. Likewise I would avoid the 51-54 331 Hemi's. First they have an extended bellhousing which limits the transmission options to either the original transmission or if you can find an one, Offenhauser transmission adaptor for an early ford transmission. Additionally they have a small valve head (compared to the 55 and latter engines) without the front and rear water outlets resulting in a very limited number of intake manifold choices.

3. The 1955 331, 1956 354 and 1957-58 392s are your best choice as far as parts availablility. Besides car and truck engines don't overlook the industrial versions of these engines (mostly in the 331 and 354 versions. While generally lower compression (no big deal if your going to bore them anyway) they are virtually the same as their passenger car counterparts. Stay away from the marine engines though, as most have extra water passages in the front of the block which do not allow the use of standard passenger car timing covers water crossovers etc. Some are also reverse rotation.

Finally do to a lot of ignorance out there about the early hemi, do you research to know what your buying. (I actually saw a guy buy a 331 industrial Hemi once because he was told and believed that it was a 426 Hemi). I would do a google search for "Hot Heads Powerplay" and go to that site and download their Hemi identificatin charts before you go shopping.

Hope this helps.

Mike I thank you for your info. That's exactaly what I was looking for especially about the extended bellhousing. If I had bought this motor, I was planning to use my present 350 tranny which wouldn't have worked. A good friend of mine also warned me away from the early Hemi's and said the best were the later 392 and 426. Well I guess I'll keep looking.

Originally posted by chevy 37
Mike I thank you for your info. That's exactaly what I was looking for especially about the extended bellhousing. If I had bought this motor, I was planning to use my present 350 tranny which wouldn't have worked. A good friend of mine also warned me away from the early Hemi's and said the best were the later 392 and 426. Well I guess I'll keep looking.

how about newer HEMI's say a 426 HEMI.

Actually, the 392 is also an early Hemi based pretty much on the same block as the 331/354. The major difference is that the 392 has a taller deck height to accommodate the longer stroke. An interesting feature is that the 331/354/392 manifolds interchange. Instead of making different intake manifolds to make up for the increased width they made the 392 heads wider!

The 426 Hemi is based on Chryslers later Raised Block (RB) design (the same basic design used for the 413/426 wedge and 440).

A family crisis forced me to sell my 37 Dodge PU Hemi project today. As the trucks are actually pretty close in design if you do find a HEMI and run into questions just post here.

Originally posted by chevy 37
said the best were the later 392 and 426. Well I guess I'll keep looking.

Like Mike said, these are two different engines. The 392 is highly sought after (read pricey)................and the 426 style is insane!!!!(read, higher than balls on a giraffe) As some may recall, I've been looking for a 426 style for a couple months now. Very hard to come by, in high demand (muscle cars are hot). I had a deal on one a couple weeks ago and the b@$tard sold it to someone else before I could get it (two days). Probably for more dough.

I got the adaptor plate from hot hemi heads it worked great and
I could of got starter for either side. Someone once said something about the 54 verses the 53 but Im not sure? I tell people I don't know anything about cars just love to working on them! But I have built a few cars with a lot of advice.

Chevy 37, while I agree with Mike P., a Hemi is a Hemi. I would not let that 331 get away, especially if it's in decent condition and a reasonable price. In my opinion, a stock 331, 4bbl Hemi is cooler than the generic 500HP/350 or BBC. It would also be more reliable, and when you get to the show or cruise in, and people see that Hemi, the horsepower will not be an issue when it comes to the WOW factor , and Hot Hemi Heads has about anything you could need for the 331, 354, and 392.
Keep in mind, I'm an "older" hot rodder, and while I realllly LOVES me some big HP, it's not my number 1 priority anymore
Jack

Hi Jack, you might want to look at the date of the original post.

".... A family crisis forced me to sell my 37 Dodge PU Hemi project today...."

This old post is like a "way back machine" for me. Funny how a lot of things can change. There was a lot of family turmoil at that time having to do with my Grandson's custody and some quick cash was needed for lawyers.

For those who aren't aware I ended up buying the truck back a while after I sold it and set it on the back burner for a number of years. It is now back in the shop and actually being worked on.

OPPS, perhaps I should have.
Glad you got your truck back, and hope that all turned out good with custody of your grandson.

Wish I had bought the engine, but didn't and now regrete it.

Tough to say which is more desireable, i've got a 331 i'm working with now, a 354 tucked away for another project. A 392 would be nice if you were doing an old gasser, i would not trade either the 331 or the 354 for a 426. The 426 is worth way more, no question, but when they moved the distr out front the motor lost soul.

I enjoy the first Gen Hemi's and IMHO those and the 426 definately have a lot more visual appeal than the latest generation.

I've worked on both the first and second Gen Hemi's and if I have enough lifetime left at some point I would like to do a swap into something with a 3rd Gen.