General Hemi Info Part 2

[Mike P]

Chasing the wild goose (HEMI)


Ready to go hunting for a HEMI? This can be fun and very frustrating. I’m going to gloss over the 426 and New HEMI and just tell you to check E BAY, Hemmings and the parts counter of your local Chrysler Dodge dealer.

If you “HAVE TO HAVE” a 392 HEMI yesterday and your pockets are deep enough, PAW sells a 392 engine kit for $6000 (normally aspirated not including shipping). What this gives you once you get it put together is a long block. You still need a bunch of other stuff to actually get it bolted to a transmission and put in a car. For grins one day I added up what you would need to complete the engine and I came up at about $10,000 (including the engine kit) to actually get it running.

If you have your heart set on a particular displacement HEMI, you could be in for a long search. Yes Chrysler made the early HEMI engine for 8 years, but many of the HEMIs were ONE YEAR ONLY in passenger cars. Just as an example:

331 1951-1955, However, the extended bellhousing was 51-some 54s, short bellhousing some 1954s and 55

301 1955 Only

354 1956 Only

392 1957-58.

Besides passenger cars, Chrysler also used the 331 (both extended and short bellhousing versions) and 354 in “Industrial” and Marine versions. The industrial versions were found in Dodge trucks and stationary applications (pump motors and even air raid sirens). Many of the industrials have a data tag attached to the bellhousing giving the pertinent info. In some cases however the industrial/marine applications may not be suitable for hot rod application due to extra water jacket openings in the front of the block (refer to the references I listed above for details on this).

Many of the Dodge Hemi’s were also used in industrial/truck applications.

There were NO 392 Industrial HEMIs (although some did find their way into marine applications) nor to my knowledge were any Desoto HEMIs used in industrial applications.

Unlike the New HEMIs and 426s, your chances of finding an early HEMI locally may be pretty good, but remember chances are the ones that were easy to find are likely already gone. One source may be E Bay where they do show up (along with parts) on a regular basis. You want to keep in mind that shipping one of these a long distance can make even a “good deal” pretty expensive.

The next recommendation I would have is put keep your ear to the ground and put out the word that your in the market then be prepared for a lot of wild goose chases. As I mentioned before you would be surprised at how many people have never seen a HEMI in real life.

Unless the person is really knowledgeable or have done their research they likely don’t know what they really have. IT WILL BE UP TO YOU TO IDENTIFY WHAT ENGINE YOU ARE LOOKING AT. Take your references (serial number info, casting numbers etc) with you.

Go on even the absurd hunts even though you know the information cannot be correct (i.e. a friend of a friend who has an old 426 hemi off an irrigation pump, the “factory” 392 in a 56 Plymouth, or even the 440, 413 or 383 HEMI in the old Chrysler). What you mostly hear is it’s either a 426 or 392. What you mostly find are either old Poly, Wedge motors, Flathead or even 6 Cyl motors ( If it doesn’t have the BIG valve covers with the plug wires in the center IT AIN”T A HEMI) At a glance the Early HEMI is easy to distinguish from the 426. The Early versions had the distributor in the rear and the 426 located it in the front of the engine. In most cases if the original valve covers and wire covers are on the engine (or lying beside it) you can narrow down what engine it is. If it says Chrysler Fire Power, Chrysler Industrial, Imperial, or Chrysler Marine it’s the Chrysler version. If it has an extended bellhousing it’s a 331 Chrysler. Dodge engine are generally marked with RED RAM (but remember it must be a HEMI valve cover as the Poly version also used the red ram label) and the Desoto’s were marked as Fire Dome. I have however run into some HEMIs with no name valve covers and that where your reference material comes in.

If the engine is in the car (and looks like it is original) another dead giveaway is the make of the car it’s in. With one exception that I’m aware of Chrysler engines were in Chryslers, Dodge in Dodge and Desoto’s in Desoto’s. The exception to this is the 1957 Dodge D501s which used the 56 version of Chryslers 354 Hemi (from the 56 300B). Since there were less than 100 of these cars made chances of coming across one are petty remote.

Beware of the “special order” stories. It usually goes something like this. “Yeah, the car was special ordered by (pick one; the local hotrodder, local sheriff, local cop, police department, state police officer, retired police officer etc) with the 392 HEMI.” There has been NO DOCUMENTED case of Chrysler putting a “special order” Hemi in a model other than what was available to the general public. I tracked one of these down at one point only to find it was a plain old 325 Dodge Hemi in a 57 Dodge Custom Royal.

Something to keep in mind if the engine turns out to be certain Poly engines is that they can be a donor for a HEMI build. While not all Poly’s will accept HEMI heads (the 318 Poly being a good example) some will. Generally if an engine was available in both a POLY and HEMI version (i.e. Chryslers 354 HEMI and 354 “Spitfire”, the 315 and 325 Dodge Red Ram Poly and 315/325 D 500 HEMI) the bottom end of the engines are the same. All that’s needed to convert one are the right heads, valve train, manifolds and pistons (the valve reliefs are located differently between the Poly and HEMI pistons.

If you hear of an old 50’s MOPAR (Except Plymouth) sitting in a shed or barn some where it can’t hurt to go look, there were more Poly than HEMI cars produced, but you never know. It is not even really surprising to find a complete HEMI powered car sitting in the old part of some junk yards. Believe it or not I found the complete 55 331 HEMI that’s going in my 37 Dodge sitting in a 55 New Yorker in a junk yard where it had been since the 60’s. My 354 was originally bought out of a big Dodge Truck and only had 5000 miles on the rebuild (I'm still going to go through it).

If you happen across a HEMI powered car and the engine is already gone, spend a little time looking around in and beside the car and see if anything was left that you can use. I recently found a pair of early 331 heads and factory windage tray left in the trunk of a 53 Chrysler (the windage tray will find a home in one of my engines).

Speaking of which if you happen to come across early HEMI parts that you don’t have an immediate use for but they are cheap enough and you have storage room, pick them up. Most early HEMI owners (myself included) are pack rats. I have some parts lying around that although I probably wouldn’t sell, I would trade for something I felt I needed.

HEMIs can also sometimes be found in incomplete or poorly done projects. A few years ago a friend of mine scored a complete running 392 that some one had put in a mid 70’s Dodge truck. The drive shaft had not been done properly and the truck vibrated. He paid under $1000 for it and latter sold the body.

Once you finally find your HEMI, be sure to give it a good check before spending a lot of money. Just because they are a HEMI it does not mean they don’t have cracked blocks because someone let them freeze with water in them, or a thrown rod or any of the other problems associated with any other engine. Also keep in mind that if it’s still in the car there was likely a reason they stopped driving it (like maybe it was completely worn out, used oil and had burned valves??? )

Basically old HEMIs is where you find them.

[Mike P]

I’ve always enjoyed saving a few bucks by making/modifying something myself. Generally when I build/update an engine I tend to try to use readily available over the counter parts. Besides generally being cheaper, if something breaks it’s simply going into a parts store and getting a replacement. One example is the electronic ignition conversion using stock Chrysler parts, should I have a part fail even on a Sunday, it’s simply walk into a part store instead of waiting for a replacement part hat must be ordered from a speed shop or mail order catalog.

If you’ve got a non-extended bellhousing 331 a 354, or 392 HEMI you can just about pick up everything needed to build modify or update the engine from one of the suppliers listed above. Compared to the engines listed above some of the other engines may be a bit more challenging.

The first thing I built was a way to hold the engine and move it around. As a certain friend of mine likes to gleefully point out is “Hell when you take the heads off you’ve got a small block” (which is pretty much true). I don’t mind building the short block on an engine stand, but when you have the complete engine on the stand it’s really a lot of weight, especially when you have torque the heads or move it around. As you can see in some of the picture’s I’ve posted I made a couple of stands on 4 heavy duty castors to store and move the engines around. The picture below (sorry about the quality) shows how simple the stand is with the engine off of it. As the uprights catch the motor mount lugs, the short block can be placed on it once it’s assembled and then the heads installed and torqued

[Mike P]

Intakes: Intake manifolds for the 331-354-392 HEMIs are available in just about any configuration you could want. As far as the intakes for these engines they all physically fit even though the 392 is a tall deck motor. Instead of making the manifold wider to fit the tall deck and keeping the heads at the same physical dimensions Chrysler made the heads wider. (I’m not sure, but I believe in the case of the Dodge and Desoto tall deck motors the intake was wider).

If you don’t mind or even desire to run just a single 4 bbl on your HEMI, don’t discard the factory intake out of hand. As far as I know there was a single 4 bbl manifold available for every early HEMI (even though a lot were produced with a 2 bbl). These manifolds are generally a good dual plane design and can produce respectable results. To run a latter style carb on them will require the use of an adaptor plate, and for best results the ports should be matched/blended to the throttle plate throats.

Many of the early HEMIs also were available with a factory dual quad set-up. I personally am not very impressed with them. IMO they were a pretty poorly designed single plane unit and while they do have a marked improvement on top end power the part throttle response leave a lot to be desired. Personally I would look for a more modern intake if you have your heart set on a dual quad set-up.

LOTS of CARBS and MECHANICAL INJECTION: Many of the induction systems produced in the late 50’s and through the 60s for the early HEMIs were designed strictly for drag racing. They only had to idle and have part throttle response enough to get to the starting line. They can be made to work on the street, but a lot of playing and fine tuning will be required. Just something to keep in mind when looking at them.

Shown below is on the left an early wet style intake (note the thermostat housing built into the intake) and a latter dry style 2 bbl intake.

[Mike P]

One thing to watch for Chrysler HEMIs is making sure you have a way to get the hot water out of the block. On the early 331, the water exited through the thermostat housing in the intake, there was no provision for a water crossover in the front of the heads as on the latter HEMIs. While an earlier 51-54 wet intake can be used on latter 55 and up Chrysler HEMIs and the water crossover deleted, a 55-up dry intake has to have provisions made to get the water out of the block is it’s used with earlier heads. A way some people get around this is to tap the intake manifold over the water jackets like the Drag Star shown below has (the brass pipes coming from the intake just above the valve covers.

[Mike P]

Built one yourself

I wish I could take credit for building the manifold shown below. Instead I bought it with a load of HEMI parts I got several years ago. It does show what can be done with a lowly 2 BBL intake with a little work. This basically started out as a 2BBL passenger car manifold (like the one shown in the picture above) that was originally converted to 3 carbs by milling the ends off, building end caps from pieces of pipe and adding (originally) 3 bolt Stromberg bases. Welding was accomplished through brazing due to the dissimilar metals (cast iron and steel). I have since converted to larger Rochester 2GC carbs (large base center and small base ends)

[boristheblade]

Mike, I am interested in the design of the intake you have pictured above, as I too, have a 2BBL manifold off of a '54 331. Unfortunately, this is the wet- style manifold, with built in water passages. Currently I am looking at all intake options, and thinking about the Hot Heads log style combined with anImagine 48 IDA EFI system. However, that system would probably run a pretty penny, so this intake modification has me interested. How were the passages blocked off to correctly route the A/F mixture, and do you think this method would be possible on a wet-style manifold?
Thank you for the wealth of knowledge,
Ilya Leontovich

[Mike P]

The dry type intakes lend themsevles very well to this mod as the upper and lower runners lay in top of each other so when the holes are milled it's basically just into the correct runner (maintaining the intregitry of the dual plane design.

I don't have any of the wet type manifolds around anymore to look at but doing this modification would depend on whether the milling could be done without going into the water runners.

Although not necessarly optimum due to a bit of port mismatch, the latter 331-354-392 manifolds will also bolt to your heads. This opens up a wide varity of different intakes for your Hemi, including the latter dry style intakes that occasionally show up on E Bay and sell for very little.

Using the latter intakes of course now poses the problem of getting the heated water out of the block. You can accomplish this either by using a variation of the plumbers nightmare shown on the Drag Star manifold above, or if your real brave putting outlets in the front of the heads similar to what the latter heads have.

[boristheblade]

On the Drag Star, you have the water outlets on the intake and on the heads, was the intake a piece that was originally modified for a wet intake, which you then put on a dry block? And again, were the passages from the original center 2bbl outlet somehow blocked off so that they would not flow into the other 4 ports, or are all of the ports still connected?

[Mike P]

It's an old picture that was taken shortly after I got the intake, and is setting on the block because it was a good place to store it (and it looked really cool). I used this picture because it was the one I had handy that still showed the water pipes when I wrote this stuff.

I picked up the intake at a swap meet years ago so I don't have any history on it. I assume from the plumbing that it was run a an early 51-54 Hemi. I have since removed the pipes and pipe plugged 2 of the outlets (the other 2 will be used for a temp sender and heater hose) for use on the 55 331 thats going into my 37 Dodge.




"...... And again, were the passages from the original center 2bbl outlet somehow blocked off so that they would not flow into the other 4 ports, or are all of the ports still connected?......."


If you look closely at the pictures of the dry intake, you will see the manifold is built with sets of runners. One set is on top of the others one feeds cyls 1-4-6-7 the other 2-3-5-8. BY the design of the manifold, 1 BBL feeds one set of runners and the other barrel feeds the other set.

When the manifold was modified a cut was made into the upper runner (as far as I can tell it was milled, that went thru the top and front side of the runner. A second hole was milled thru the top of the lower runner. Neither hole cut into the runner it was not intended to feed. Pieces were then fabricated to close the runners back (including internally) and connect then to the carb base.

In this configuration you still have two seperate sets of runners that are not inter connected. The picture below should help clarify it.

[Mike P]

This may help.

[boristheblade]

Ahh, ok. I'm pretty sure I understand how this intake is designed, but I need to run out to where my stuff is being stored and check it out. I think that once I get a different intake that I want to use, I may attempt this just for the heck of it.

[50 chevy]

Mike want 2 put hemi in my 50 chev gasser any ideas? thanx

[new 32 roadster]

Mike P - found this old post very informative. I have a question about this part - "With one exception that I’m aware of Chrysler engines were in Chryslers, Dodge in Dodge and Desoto’s in Desoto’s. The exception to this is the 1957 Dodge D501s which used the 56 version of Chryslers 354 Hemi (from the 56 300B). Since there were less than 100 of these cars made chances of coming across one are petty remote."

In 1967 I bought a '57 Dodge convert with a duel-quad hemi that turned out to have a flat cam. When ordering a replacement the parts man asked for the engine number, and then told me "that's not a Dodge number, its a DeSoto." Years later I recall seeing something online about a very small number of '57 Dodges having a DeSoto hemi with two 4bbls. Can you shed any light on this? Was the D501 a Chrysler or DeSoto motor?

Incidently, after 6 months of high school senior fun, I traded the Dodge in on a VW - I got $100 for it - and then totalled the VW the day before college started.

[Mike P]

As noted the D501s were a VERY limited production car, but their existance has been pretty well documented and as I said were powered by the Chrysler 354 "300B" engine.

Since I originally wrote this I have not come across any further information indicating there was any other "cross-breeding" between the different Chrysler division (not saying it didn't happen, just never have run across anything that is reliable documentation indicating it happened).

As I also mentioned even though the almost nothing is interchangable between the 3 divisions engines themselves, the entire engine assemblys are close enough to make the Hemi a virtual bolt-in into another car.

[new 32 roadster]

I always assumed that a previous owner had swapped in the DeSoto hemi. That is, until I saw that online comment a couple years ago about a tiny number (22?) of '57 Dodges having a DeSoto motor. I have searched in vain since then but can't find that article again. It seems like it was on a site called "57 heaven".