WE featured Ian ‘Elvis’ Davis’s ’32 Ford coupe back in SM, August 2009. What made it special was that it was powered by a GMC Twin Six – a sixties truck motor displacing a 702ci!
Not too long after the producers of Mad Max: Fury Road came knocking and the rod went off on a trip that would take it to the other side of the world! But don’t worry, that glossy body and mint interior didn’t get wrecked in Africa. “We removed the body, interior, wheels, the grille, the headlights and all the jewellery from the V12 car,” says Elvis.
“I put on a new body on it, plonked in a bucket seat and fitted some basic wheels to the car and that is what they used in the movie. A customer then ordered a turn-key car using the shiny body and trim, so I built a new chassis and fitted it with a small block Chev, it’s a nice car! The GMC motor in the movie car blew up at some point – you can’t rev them very high for very long - but I’ve managed to get it back.”
But that isn’t where the story ends. “We actually ended up making two extended ’32 coupes for the film,” says Elvis. “For starters, they had to roll the car at one point, so they needed another to finish the close-ups. So we built another extended chassis and body, and they took a mould from the V12 and fitted a fiberglass dummy motor over the top of some other basic engine. We also made four chassis for the bare metal ’34 Chev coupe that one of the main baddies drives, the one with the big cross fitted onto the front.”
You can read more about that in the latest SM mag, but for now, read on to see how and why Elvis created this monster in the first place.
THE first thing you do when you see a hot rod like this is ask why. “Because I can,” Ian ‘Elvis’ Davis says. “All the cars I’ve built over the years have been a bit different. Especially because at my business, Rod Bods, we’re pretty much a production line building early model Fords, from Model A to ’34. When it comes time to do something for myself I do have a bit of a weird taste, if you want to put it that way.”
Weird, maybe, but this ’32 Ford is tasteful too. In the side view, there’s no hiding that monstrous powerplant. It’s the focus, the heart and soul of this rod, so let’s get the other stuff out of the way quickly.
The body is a Rod Bods chopped three-window coupe with exposed hinges and door handles. Due to the amount of stuff under the dash, this one has a smoothed cowl. Rod Bods handled all of the bodywork and laid on the DeBeers Wine Red paint.
The inside, including roof lining and late-model BMW seats, was swathed in black leather by Trik Trim. Half a dozen Dolphin gauges keep an eye on things while a Lokar shifter swaps cogs in the beefed-up Turbo 400. A Limeworks column and modern Banjo wheel keep everything on the straight and narrow. And now that motor.
Ladies and gentlemen, boys and girls, this is a 702 cubic inch GMC V12 that’s usually found in full-size trucks and is commonly called the Twin Six. These things were workhorses, so performance wasn’t a priority. But this is a hot rod and Elvis is a rodder.
“They had an oil governor to restrict revs to 2400rpm. I took the stock oil pump out; I’m running a Moroso external pump. It’s still a wet sump but we modified a Holden red motor pick-up that bolts on where the pump used to go. I used the holes where the external cartridge oil filter went and it was quite easy to make a plate with fittings on it. It was a simple thing to do but nutting it out took some time.
“With the oil pump gone, the governor was thrown out. We balanced and totally rebuilt the motor. I’ve taken it up to 4500rpm, which doesn’t sound like much but they’re 4 9/16in pots — that’s a lot of friction. People think a V12 should rev but it’s not like a Ferrari that has two-inch pistons.”
While it may not rev, this sucker has torque — bog stock they made 630lb-ft.
“Horsepower’s around the 300 mark but when you put your foot down, you see the motor rock over to the side and you can feel the power just wanting to grumble,” Elvis says.
And no, it’s not an oil burner; this sucker runs on petrol — and lots of it! Elvis says the fuel economy isn’t great.
“We’re getting a couple of kays a litre but we should be able to double that with a tune-up. I’m going to put a 2.5 centre in it, so with the height of those tyres, every 1000rpm I’ll be doing 34mph, which should help.”
Getting the motor into the chassis wasn't exactly straightforward. One of the main issues was the deep sump, which held around 20 litres of oil.
“Because I’ve grafted the Turbo 400 to it, we needed to get it down. We put a winged keel on the sump so it still holds 20 litres,” Elvis says.
The sheer size of the engine required some clever engineering.
“It weighs 1485lb [675kg] dry and my engine hoist was having a tough time. The final lift I did with my forklift, then rolled the chassis underneath. I’ve centre-boxed the chassis with a 4mm plate on the inside as well. The extra weight of the car is a bit of an unknown.
“Painting the motor was a problem — we couldn’t put it on an engine stand. It took huge work to get the motor to where it is now. Because it’s a truck engine, they didn’t worry about making it pretty.
“The finished car weighs 1740kg [about the same as a new Falcon]. A ’32 with a small-block Chev and Turbo 350 weighs 1100kg.”
Parts are another problem: “We had to sleeve every pot because it was hard to find pistons. They stopped making them nine years ago, so trying to find a full set was a big drama. It was three or four weeks of numerous phone calls every day.”
Surprisingly, this behemoth breathes through two 350 Holley two-barrels.
“People think the cubes mean you need big carbs but it’s not a revving motor so that’d be an absolute waste. I’ve got it jetted right up because I didn’t want to lean it out, due to the rarity of the pistons, but even with the 350s, this thing has petrol pouring out the tailpipes.”
Another obstacle was the ignition. Standard, the Twin Six has twin distributors running off a common shaft, one turning clockwise, the other counter-clockwise, controlling one bank each. Tom Carson at the local TAFE converted it to electronic ignition. The ’plug wires run underneath the intake as the sparkplugs are on the inside of the head. Great idea!
Keeping it cool is one of the biggest hot rod radiators Aussie Desert Cooler has ever built. “There are two radiators, one in front of the other, with one top and one bottom tank. I have no idea how much water it holds but I was standing there filling it up with a mate, and we were talking and I asked him: ‘Is that bloody hose still going?’ He pulled it out and it was flat out. I had to put an extra leaf in the spring just to take the weight of the fluids in the motor.”
It’s a wild creation and that’s not surprising as Elvis has a head full of wild ideas. Next he wants to build a 1927 Model T Tudor done up as a police paddy wagon, as a keeper. It’ll have another V12 — a flathead Lincoln — a top loader and a Dutchman quick change.
BUILT between 1960–’65, the GMC Twin Six was the largest in a family of truck engines that included several V6s ranging from 305ci all the way up to a massive 478ci, as well as a 637ci V8.
The 702 V12 used in Elvis’s hot rod is effectively two 351 V6 engines but they’re not bolted together. Although the two engines do share common heads, intake and exhaust manifolds and rocker covers, the block, crank and cam are one-piece.
The smaller V6 engines were commonly found in GMC pick-up trucks, while the V12 was for the heavy duty stuff. They were built to last too, with rugged internals, an extra-heavy duty block and heads that are clamped down by six bolts per cylinder.
As well as being used in several forms of heavy transport, the engines were often used to drive stationary pumps, drawing water up from deep wells to irrigate farmland, running 24/7 for years at a time.
“Diesel came of age in the 60s. These things were humungous in their torque and one of the biggest production motors ever built. The fuel just priced them out of the market. Because of the torque they could put monstrous irrigation pumps behind them,” Elvis says.
There are plenty of videos of these things on YouTube, including one that Elvis put up. Make sure you check it out — it’s pretty wild.