Tom Carrigan's 1375 HP V12 Powered '39 Chevy – The Allison Car

Ronnie Schreiber
by Ronnie Schreiber

Full gallery here.

The Detroit Autorama has a definite blue collar vibe. Even those of the half million dollar cars competing for the Ridler award that are “bought, not built” are paid for by couples who obviously are affluent, but who have made their money not as doctors or lawyers or financiers but rather from operating some kind of small business enterprise. Most owners participate one way or another in their builds and most also have some experience working with their hands. Last year I had the chance to visit the facility where Chevy has the COPO Camaros built and I was present to watch two owners take delivery of what is essentially a $100,000 toy. One of them, Dan Sayres, of Waverly, West Virginia, now owns a number of automotive related businesses, including a collision shop and a recycling yard. He told me that he started with a single tow truck. It takes some smarts to go from one used tow truck to buying purpose built drag racers. Of course, you don’t need deep pockets to come up with a big idea. From the mid six figure Ridler competitors to the unfinished projects in the basement, there are lots of big ideas at the Autorama, not all of them successful. One of the biggest ideas, both figuratively and literally, is the car that Tom Carrigan built because he thought he could do it.

Full gallery here.

Tom Carrigan is a retired pipefitter and has a familiar, almost “aw shucks” and somewhat self-depreciating affect. Don’t let that fool you, Carrigan is a very smart guy. How smart? He’s wrapping up a project building a 1,375 horsepower, V12 powered midengine car in his garage. Okay, that’s impressive you may say, but with 1000+ horsepower cars like the Bugatti Veyron or Koenigsegg’s amazing vehicles, or the supertuned engines from Hennesey, Lingenfelter or Callaway, that’s not completely outrageous in this day and age. However, Carrigan’s doing it by putting a 70 year old Allison V-1710 aircraft engine built for a WWII era P-40 warplane in a car even older than that engine, a 1939 Chevrolet two door Deluxe.

The Allison engine is sitting on a frame he fabricated himself out of box steel sections, the front end of a full size GMC van converted to rack and pinion steering, and a 9 inch Ford rear end. Now most of us would be happy, if we were into such things as powering old cars with huge airplane engines, just to see the thing run. That wasn’t enough for Tom as he’s cooked up his own sequential multiport fuel injection system, managed by a Megasquirt electronic fuel injection controller that he’s fine tuning so he can run that Allison reliably on the street. As a guy who wants to build a low-buck Lotus Se7en inspired do-it-yourself sports car, only using a V12 Jaguar as the donor for the suspension and powertrain instead of a four cylinder Ford Ranger, you can understand why I like Mr. Carrigan and his car. Some ideas are just too silly not to do.

Full gallery here.

Carrying a 1,300 lb powerplant on a wheelbase that’s been stretched 4 feet to accommodate it, one might think that what Carrigan calls simply “The Alison Car” won’t handle well once it’s on the road. With a 163.5″ wheelbase, it certainly won’t be set up to win any autocross events, but all that weight is nicely distributed. The front, well actually the rear face of the engine (remember this is an airplane engine whose propeller drive is in its front) sits well behind the front axle line, at least a foot and a half, hence my midengine classification. Also, the inline Chevy six that it replaced is no lightweight itself, weighing in at 630 lbs dressed. I bet the finished project doesn’t handle worse than the original 1939 Chevrolet did. My guess is that it will have less body roll and could probably pull higher g forces on a skid pad than a stock ’39 Chevy could as well. There are a few other advantages to the engine swap, 1,375 of them.

With the heavy engine along with the 6″ frame sections and 4 feet of sheet metal added in (Carrigan says that the project used more than six 4′ X 10′ sheets of steel), the finished car weighs 6,300 lbs. That’s a lot of weight but last year I tested a Land Rover that weighed 5,400 lbs and with ‘just’ 370 hp, it could move rather smartly. Even at over 3 tons, the power to weight ratio of the Allison Car is still going to be better than just about anything on the road.

For comparison’s sake, at 700 hp and 3,472 lbs, the Lamborghini Aventador has a power:weight ratio of 0.202. The Bugatti Veyron is nearing the end of its production run with engines currently outputting 1,200 hp. The Veyron is not a light car, over two tons at 4,162. That gives it a power:weight ratio of 0.288, which is impressive, but significantly lower than that of the Swedish supercar with the unpronounceable name, the Koenigsegg Agera R. With 1,114 hp and a weight of only 2,844 lbs, the Agera R has a power:weight ratio of 0.392. In between the Aventador and the Veyron are the Porsche 918 and McLaren P1 hybrid supercars at 0.217 and 0.270 respectively. With a P:W of 0.320 even the Ferrari La Ferrari comes short of the Koenigsegg .

Full gallery here.

At 0.218, Carrigan’s Allison powered Chevy won’t be able to keep up with the quickest of today’s production supercars but it will get down the line in less time than Lamborghini and Porsche’s most powerful sports cars. What it loses in the corners it will certainly make up and then some on the straights. That’s at the tune that Carrigan thinks will be appropriate for the use he plans. He does have the option of tuning for more power.

The turbo-compound version of the V-1710 engine could put out more than 2,800 hp.

Late production V-1710 engines used in P-38L aircraft were rated at 1,600 hp, and if that’s not enough, it should be noted that there was a version that Allison developed called the V-1710-127, which replaced superchargers (and turbosupercharging in some models) with exhaust driven turbines that returned that recovered energy to the crankshaft. That “turbo compound” engine was static tested at 2,800 hp. Installed in Carrigan’s two-door Chevy Deluxe, that would yield a power to weight ratio of 0.444, capable of blowing the doors, gullwing, scissor, Lamborghini style, or conventionally hinged, off of any production car on the road today.

Full gallery here.

Power, though, isn’t everything. With that much weight sitting that far back in the chassis and the 2,400+ lb-ft of torque the Allison generates, my guess is that when Carrigan does take it to a drag strip, he’d better mount some wheelie bars because with that much twist, the overpowered Chevy can probably do wheelies all the way down the 1/4 mile track. I hope he does take it to the drag strip because the car’s provenance includes famed exhibition drag racer E.J. Potter, the “Michigan Madman”, notorious for his small block Chevy V8 powered motorcycles. Potter had a thing for Allison V12s, using them in a couple of insanely fast drag racers. Potter also used an Allison engine to power the generator for his “ Super Slot Car” electric drag racer. Allison produced over 70,000 V-1710s from 1930 through the end of WWII so they were available as surplus well into the 1960s and popular with extreme drag racers and unlimited hydroplane boat racers before jet engines supplanted them.

The water-cooled 1710 cubic inch 60 degree V12 in Carrigan’s car is one of several that he bought from Potter. Like many WWII era aircraft piston engines, the specifications sound fairly modern even by today’s standards.

The heads, crankcase and water jacket are made of aluminum, while the oil pan is made of magnesium. Forged aluminum pistons are located inside steel cylinder liners. It has four valves and two spark plugs per cylinder. The valves are operated by one overhead cam per cylinder bank, it has a dry sump lubrication system, and to perform well at an altitude the ’39 Chevy will never achieve, the 1710 has a two stage supercharger, with 7 pounds of boost.

Being the kind of guy who prefers 289 Windsors or 351 Clevelands to small block Chevy V8s in Ford hot rods, I like the fact that Carrigan kept it in the family – when the V-1710 was designed Allison, just like Chevrolet, was part of General Motors.

To get access to the engine, the entire front end is forward hinged and two hydraulic cylinders and a 12 volt hydraulic pump scavenged from a marine application open and close the engine compartment. He’s still using the original dashboard but he’s had to add more than a couple of new gauges to monitor the new powerplant.

While the Allison Car does have a radiator up front, a much larger main radiator is mounted in the trunk, cooled by a fan run by a two cylinder 16 hp gasoline engine. Through a Rube Goldberg combination of belts and pulleys the same engine drives a 24 volt alternator for the engine’s electrical system, an auxiliary water pump, a 12 volt alternator for the car’s electrics, and a power steering pump. Carrigan has no plans currently to fit an air conditioner, but if he decides to do so, he’d add another pulley and use the auxiliary engine to also run the compressor. Since the car will be used primarily as a show and parade car, Carrigan has contingency plans to add electric fans to the front radiator should it overheat at parade or cruise night speed.

Wherever it goes, it will get attention. Anytime you’re going to stretch a car four feet between the cowl and the front wheels, the result is going to look cartoonish, and the Allison Car indeed looks like it could have been in Who Framed Roger Rabbit? or on the cover of a Little Feat album, but I mean cartoonish in a good way. It’s exaggerated but the widened front end looks fine from a front view and even the weird proportions work, at least for me. Some of the most classic car designs have short rear decks and stretched out front ends. Carrigan has given the car a terrific stance and from the rear 3/4 view, that long continuous line from the trunk’s bustle to the front grille looks great. I don’t think I’ve ever seen a pair of more purposeful and ominous looking side pipes.

Bugatti Royale, Henry Ford Museum

Earlier, I compared the Allison Car to a Bugatti Veyron. While it’s in the Veyron’s class in terms of engine power, Carrigan’s car actually reminds me of another Bugatti, Ettore and Jean Bugatti’s majestic Royale. The Royale is even bigger and heavier than the Chevy with power by Allison (6″ more wheelbase and about 600# more weight), but with its very long hood and passenger compartment set far back on the wheelbase, it’s not too much of a stretch to say that the Allison Car and the Bugatti Royale share at least some proportions.


After starting the video, click on the settings icon to select 2D or your choice of 3D formats.

Tom said that it’s very close to being on the road. It can run well enough to go up and down the driveway under its own power, but Carrigan is still working on “the tune”, as he calls it, before he drives the Allison Car in earnest. Once its running to his satisfaction he says that the first thing he’s going to do is see what kind of burnouts the V12 powered Chevy can do. Then he’s going to take it to Onondaga Dragway near his home in Vermontville, Michigan, where it’s already undergone a safety inspection and approval. He also plans on measuring fuel economy, figuring it should get better mileage than the 5 mpg Jay Leno gets in his fuel injected M-47 Patton tank engine powered Blastolene Special, which at 9500 lbs. is quite a bit heavier than Carrigan’s Chevy. When I asked about converting gallons per hour from the Allison’s aircraft specifications, Carrigan said that data doesn’t correlate well to earthbound fuel consumption. He does calculate that at 60 mph, the Allison will be turning a leisurely 1,000 rpm, in part because the half-speed gear reduction propeller drive has been flipped around to get an output shaft speed suitable for automotive use. Peak power is at an engine speed of 3,000 rpm, so to go from cruising speed to the car’s top end shouldn’t take very long. I didn’t ask Carrigan about that top speed, but the Chrysler 727 RWD transmission he’s using isn’t usually an overdrive unit so you can probably calculate theoretical top speeds based on the final drive ratio and the circumference of the rear tires. With that much power and torque, I’m sure the Allison will pull all the way to the redline, though my guess is that the Chevy’s body will need some aero appurtenances to stay on the ground at full speed.

Tom’s invited me to see the finished project and he said that as long as everything works safely he doesn’t see any reason why I can’t drive it. Would you pass up an opportunity to drive a 1,375 hp ’39 Chevy? Would you pass up the opportunity to drive anything with 1,375 hp.

In the meantime, you can watch the videos that Carrigan has posted about the project and even hear the big V12 start up and roar.

When I asked him if he thought the Chrysler Torqueflite automatic transmision he’s installed will hold up to that much power and he said, “we’ll see”.

To get a feel for Carrigan’s automotive look on life, I’ve included a gallery below of photos from the build and his own Q&A on the project:

I used the GMC Van for a start because I car pooled with an electrician for 10 years and it was a wonderful time. The electrician is the brother of Max Simson of tractor pulling fame. His whole family are geniuses and every time I sit in the seat I will remember all the good times and technical discussion we had.

Why am I doing this?

  1. I love engines, The bigger the better.
  2. I want to be the guy that anyone who sees this car at a show will never forget.
  3. As a retired pipefitter who very seldom got to use his talents and abilities at work, I get to use them now.
  4. After riding in a B17 bomber and when they started the first engine a smile started on my face that did not leave for over a week.
  5. How much fun it will be to give people rides.
  6. Because I think I can.
  7. 1 % for all those folks who said “ It will never work” “you will never succeed” “ why don’t you sell that junk before it is not worth anything” ect. Know anyone like that?

The next project will be the T-53 Lycoming turbine engine. I am thinking of a T-Bucket, but that may change. (not much body work). After that I have 3 more Allison engines and am considering building a replica of one of E J Potter’s drag cars, but who knows. When I get this all done I am sure I will dream up something else to do. P. S. If you had a chance to drive [Billy Gibbons of ZZ Top’s] Caddzilla or my car witch would you choose?

Ronnie Schreiber edits Cars In Depth, a realistic perspective on cars & car culture and the original 3D car site. If you found this post worthwhile, you can get a parallax view at Cars In Depth. If the 3D thing freaks you out, don’t worry, all the photo and video players in use at the site have mono options. Thanks for reading – RJS















Ronnie Schreiber
Ronnie Schreiber

Ronnie Schreiber edits Cars In Depth, the original 3D car site.

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  • CanadaCraig You can just imagine how quickly the tires are going to wear out on a 5,800 lbs AWD 2024 Dodge Charger.
  • Luke42 I tried FSD for a month in December 2022 on my Model Y and wasn’t impressed.The building-blocks were amazing but sum of the all of those amazing parts was about as useful as Honda Sensing in terms of reducing the driver’s workload.I have a list of fixes I need to see in Autopilot before I blow another $200 renting FSD. But I will try it for free for a month.I would love it if FSD v12 lived up to the hype and my mind were changed. But I have no reason to believe I might be wrong at this point, based on the reviews I’ve read so far. [shrug]. I’m sure I’ll have more to say about it once I get to test it.
  • FormerFF We bought three new and one used car last year, so we won't be visiting any showrooms this year unless a meteor hits one of them. Sorry to hear that Mini has terminated the manual transmission, a Mini could be a fun car to drive with a stick.It appears that 2025 is going to see a significant decrease in the number of models that can be had with a stick. The used car we bought is a Mk 7 GTI with a six speed manual, and my younger daughter and I are enjoying it quite a lot. We'll be hanging on to it for many years.
  • Oberkanone Where is the value here? Magna is assembling the vehicles. The IP is not novel. Just buy the IP at bankruptcy stage for next to nothing.
  • Jalop1991 what, no Turbo trim?
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