Found something I didn't know they made.

[Guest Gramps-xrds]

While looking for some parts to try and resurrect an old Scat-city dodge, I found this in a box w/ the 70 dodge super bee. I've never seen a dual over cam hemi.

I also found a 70 AMX & a 70 AMC Hornet way up on the top shelve. I'll have to see if I can find the interior tub for the hornet

[LDO]

Wanna get rid of it?

[Guest Gramps-xrds]

Thanx Lee, but I think I'll hang onto it for now. Sorry

[george 53]

Bill, up in Auburn Hills (about 20 mi. from Deeetroit) they got a museum at the Chrysler World Headqrts, An they got one of them rascals on display! I don't know if they own it or it's on loan from a private owner,But it is real!

[Jantrix]

From what I've read, the DOHC was one of two prototypes in response to a OHC engine made by Ford to be used in racing. However, Nascar said "no way" so the project was scrapped by both companies. That kit engine builds up real well. Here's mine in a MPC 67 Charger, using that Superbee chassis/engine. Let us know what you have planned for it.

[CAL]

most DOHC are hemis, but most Hemis are not DOHCs.

[Guest Gramps-xrds]

Thanks George/Jantrix. I just knew I'd never seen one before. As of right now I don't have any plans for it. That one looks pretty good sitting there. Nice wiring and plug boots.

Man I've found all kind of stuff I'd forgotten about having. I should check those top shelves more often. Just found a 63 ford galaxy that's almost complete. Except for the fender ornaments and a broken piece of the windshield chrome, and a 65 plymouth fury & a dodge monaco, don't know what yr yet. Looks like I have some resurrecting to do. I think I'd rather do that, than build a new one. :lol:

It's a 65 monaco.

Edited May 22, 2008 by Gramps-xrds

[Guest zebm1]

That engine was part of the Mid-60s NASCAR Wars....slated for those Winged Mopars......Ford had a DOHC on tha drawing boards too,,,either tha 427 or maybe it was tha 429..... they were going into that long-nosed Torino.....

[torinobradley]

The difference was that Ford actually went into production with their 427 SOHC. Though it didn't come in any production vehicles, you could buy it from the Parts Counter and slap it in whatever you wanted. Lots of em ended up in the gassers and drag cars of the day. There is even now, conversion kits for real 427s to SOHC, gear drives and all the other goodies. But, alas, NASCAR said "no way" and that was that. Imagine if NASCAR had not started to limit engines, speed and other factors in the races... Twin engined 3000hp cars hitting well over 300 on 80 degree banked curves and accidents taking out whole sections of spectators... Okay, maybe not...

[Harry P.]

  Gramps-xrds said:

While looking for some parts to try and resurrect an old Scat-city dodge, I found this in a box w/ the 70 dodge super bee. I've never seen a dual over cam hemi.

NASCAR wouldn't let Chrysler get away with that! They would have eaten the competition alive. That engine never made it into production...it's just a "might have been" from the Chrysler engineers.

From ALLPAR.com: "A 426 dual-overhead cam Hemi was actually produced - two of them, in fact, and both were made in 1964. The DOHC Hemis were made to counter Ford's response to the 1964 426 Hemi, the 427 SOHC, but when NASCAR ruled against Ford's engine, there was no need for the overhead-cam Hemi.

Neither of the DOHC Hemis were ever placed in a car; one was destroyed, the other moved to the Kansas City area. (source: Muscle Car Review. Thanks, Stéphanie Dumas.) Recently, famed engine builder Larry Shepard told us that he has the A-925 cylinder head and other related parts, purchased from the late Dan Napp.

An article by Tom Shaw in Mopar Muscle went into more detail. The DOHC Hemi was project A-925, and it would need to be much more powerful than Ford's SOHC 427, but still rugged enough for racing - and able to conform to NASCAR's rules. Two possibilities were considered, according to Shaw - one using two cams positioned between the heads, in the "valley;" four valves on each cylinder were operated by lifters, pushrods, and lifters. This expensive setup was an unused contingency plan. Nearly as ambitious was an engine with aluminum heads, dual overhead cams, and, again, four valves per cylinder, with pent-roof chambers. (Chrysler had been working with four valve per cylinder engines for a never-completed Indy run in 1963.)

The dual-plane intake manifold had eight runners per side (Chrysler was into efficient and innovative intakes) and made of magnesium - but designed for a single four-barrel carburetor, as required by NASCAR.

The cams were driven by a cog belt, using external cog wheels at the front of the heads. Because the cams were directly above the valves, valvetrain mass was low, so the engine could rev high - a 7,000 rpm redline was specified, high for the era.

Shaw wrote that no DOHC Hemi ran under its own power; they were driven by an electric motor to check the valvegear. Research stopped in 1964 when NASCAR banned the SOHC 427 and Chrysler's own race Hemi. One DOHC Hemi still exists".

[Robert81]

That is some great info, Harry. I wonder how the DOHC Hemi would that look under the hood of Lindberg's Petty 64 Chrysler? That would make a sweet "what if" racer.

Edited May 22, 2008 by Robert81

[Harry P.]

  Robert81 said:

That is some great info, Harry. I wonder how the DOHC Hemi would that look under the hood of Lindberg's Petty 64 Chrysler? That would make a sweet "what if" racer.

How about building one and showing us how it would look???

[mikelo]

I always thought that Hemi was short for hemispherical (being half a circle). I thought that was the shape of the top of the cylinder (the shape in the head), and it wasn't named for where the plug goes. If that is so, then most DOHC would not be a Hemi then right?

Edited May 22, 2008 by mikelo

[Harry P.]

  Bluesman Mark said:

Part of that information is inaccurate. NASCAR never banned the SOHC Ford engine, but instead a weight penalty was slapped on it in 1966, leading to Ford's NASCAR boycott that year,

The Hemi was not banned in 1964, as that was the year that Richard Petty won the Daytona 500 & his first NASCAR championship driving a Hemi powered Plymouth. The Hemi was banned for most of 1965, which is what lead to the Mopar boycott of NASCAR for that season.

More to come later, but I have to go to work now!

Hmmm...and here I thought that allpar.com was a pretty reliable MOPAR site. Go figure...

[Harry P.]

  mikelo said:

I always thought that Hemi was short for hemispherical (being half a circle). I thought that was the shape of the top of the cylinder (the shape in the head), and it wasn't named for where the plug goes. If that is so, then most DOHC would not be a Hemi then right?

Whether the cams are single, dual, overhead or in the trunk is all irrelevant to whether an engine is a "Hemi". And the plug placement also has nothing to do with a "Hemi" being a hemi.

A "Hemi" is a hemi because the combustion chambers are hemispherically shaped-they are "domed" on top.

[mikelo]

Thanks Harry. Thats what I thought, just worded it differrently.

[CAL]

  mikelo said:

Thanks Harry. Thats what I thought, just worded it differrently.

Typically, due to the nature of there design a DHOC tend (the I valves and E valves oppossed), not always, but tend to be hemispherical (or semi-hemispherical) in nature. Often called “Kidney Beans.â€

Correct it doesn't have anything to do with plug placement; however, most of the time they are centered somewhere near the middle of the "dome."

It is not a new concept, It's been around for a over 100 years. And it was Ford who is considered to have the American V8 Hemi with their AM Ardun Flathead head.

It was just Chrysler who trademarked the name Hemi.

The huge down side to the Hemi for racing is it does have a limited mechanical compression ratio (12:1) compared to other designs (like a Heart Shape which easily can go above 15:1 natrually asperated). It is why they need to be compressor (Turbo or Supercharged) motors to get the full benifit from them.

Incidentally, the “new†modern Hemi, isn’t really a hemi but more of a Polyspherical or semi-hemi also called a Pinched hemi.

Porsche was probably the most prolific in using the Hemi head, though 1963-1999 in their 911 Boxer engine.

Edited May 22, 2008 by CAL

[Jello]

It is cool that AMT chose that engine to be included in the hemi power model kits in the '90s and it sure did cause plenty of confusion since many people never actually saw one before! I have a bunch of them myself and was & still amazed at the detail level. Its also found in the Roadrunner kits.

The big 3 all had "top secret" engines for the Nascar wars and the DOHC Hemi engines were believed to produce well over 800 HP ( at that time 400-500 HP was the normal) and Chrysler kept hiding the actually power numbers from Nascar..then Ford came out with a similar engine and finally even Chevy jumped into the fray...Nascar became alarmed at the powerful engines and the cars ( chassis) themselves were not capable of handling all that power including the tires. Smokey got to work on the Chevelle and came out with the first 'stock car' that could handle the power but Nascar put a quick end to that idea for obvious reasons. Nascar finally told everybody to go back to the basic engines and allowed the regular Hemi, BB Chevy and Ford 427-9 engines without special parts. Chrysler kept working on secret engines for the drag strips afterwards, street test cars like the famous '67 Coronet Silver Bullet and lots of winning was made in S/S classes...makes ya wonder eh?

Theres lots of great reading on this subject and part of this is what made Nascar so great in the good ol' days and today, its all boring and same, same stuff...Lots of cool history and darn good reading to be had!

~ Jeff

[Harry P.]

  CAL said:

It is not a new concept, It's been around for a over 100 years.

I'd bet 99 out of 100 people would associate the "Hemi" with MOPAR, but Cal is right, they weren't the first to use that engine design. But they trademarked the name and used it extensively in their advertising, so they became linked to the hemi in the public's mind.

I was curious so I did a little research.

Hemispherical cylinder heads were used by Belgian car maker Pipe in 1905, the Peugeot Grand prix Car of 1912, the Alfa Romeo GP car of 1914, Daimler, Riley and Harry Miller. There were others too, so Chrysler's early Hemis of the late 50s were a little late to the party!

[CAL]

  harrypri said:

I'd bet 99 out of 100 people would associate the "Hemi" with MOPAR, but Cal is right, they weren't the first to use that engine design. But they trademarked the name and used it extensively in their advertising, so they became linked to the hemi in the public's mind.

I was curious so I did a little research.

Hemispherical cylinder heads were used by Belgian car maker Pipe in 1905, the Peugeot Grand prix Car of 1912, the Alfa Romeo GP car of 1914, Daimler, Riley and Harry Miller. There were others too, so Chrysler's early Hemis of the late 50s were a little late to the party!

I don't doubt that any.

Premier also had one in 1903

I'd have to go back and do some digging, but IIRC a German Dr of Enginerring had drawn plans for a hemi engine before Karl Benz built the first Gasoline engine in 1889.

Edited May 22, 2008 by CAL

[Guest Gramps-xrds]

Man, what I didn't know about hemi's, I sure do now. It seems we have some very knowledgeable ppl on here. Thanks everyone for your input

[lordairgtar]

Now I have a strange desire to obtain one of those little DOHC Hemis.

[Brian_R]

Are you sure there's only two of those DOHC hemis? - you just never know when another one of those might show up

Brian

[george 53]

Brian,Brian,Brian, Now youv'e gone an done it.Show the rest of the build up. It's no fair to just tease like that.Now your obligated to let us see the rest of the car.

[Brian_R]

It's a simple looking Dart - built for a club contest

Brian