Every time I see a Viper V10 engine I can’t believe at what a beast it is. How do the physical dimensions of one of these motors compare to a V12 from Ferrari, Lamborghini, Aston Martin Etc.
The Viper V10 is a OHV engine, meaning it has a single camshaft that operates the valves via pushrods.
The European V12s are DOHC, meaning they have two camshafts on top of each cylinder head (for a total of four camshafts) operating the valves directly.
Locating the camshafts on top of the cylinder head makes the engine taller and much wider.
I don’t have a picture of these two engines specifically, but here’s a picture comparing a Chevrolet LS (OHC) and a Ford Coyote (DOHC) engine.
Notice how much narrower the Chevrolet OHV on the left is. Yet the Chevrolet is a 6.2 liter and the Ford is only 5.0.
http://cdn.speednik.com/files/2015/12/2015-12-21_22-37-23.jpg
A quick google search shows the following:
Viper V10 engine
- Displacement 8.4 liters
- Dry weight - 650 lbs
- 640 HP
- 600 lb-ft torque
Ferrari V12 F140 engine
- Displacement 6 liters
- Dry weight 498 lbs
- 660 HP
- 514 lb-ft torque
The resources only give weight, not physical dimensions. I’m sure they’re out there somewhere but I couldn’t find them with a quick search.
The Viper V10 has a cylinder bore of up to 103mm. The Lambo V10 used in such cars as the Gallardo and the R8 has a bore of up to 84.5mm. Disregarding differences in cylinder wall thickness and accessories, the Viper motor is going to be about 100mm longer, or 4 inches. That would be about as much room as an extra 2 cylinders on the Lambo engine, so I’d say a Viper V10 and a Euro V12 would be roughly the same length.
Missed the edit window: The Chevrolet LS is of course OHV, not OHC.
I’ve had no luck finding the external dimensions, so the best I can do is find images of someone standing near them. they look broadly similar in size. The Viper engine has larger cylinders, but a V12 has one more in each bank so it’s close to a wash.
the Ferrari one is probably not as tall due to being a shorter-stroke engine.
I think the real issue with the Viper isn’t so much the physical engine dimensions, but the layout. The Ferrari F12 Berlinetta, for example, looks much more svelte because it has a transaxle in the rear. Modern Corvettes are the same way, as is the Nissan GT-R. This allows them to push the engine back under the firewall, which allows the front wheels to be moved closer to the passenger cabin, etc. The Viper uses a conventional transmission, which takes up that valuable real estate between the front seats and in the firewall area. This necessitates a wider track (occupants sit aside the transmission and require pesky things like legroom, which are in short supply even with the Viper’s prodigious width) and pushes the engine forward of the firewall, which in turn pushes the wheels even further forward still.
OTOH, V-12s are typically a 60-degree cylinder angle and the Viper engine is a very strange 72-degrees (nearly all engines are inline, 90-degree from V8 roots or 60-degree from V6 roots). I suspect the extra spread is to make room for those enormous cylinders, but it would add to the Viper’s engine width over a V-12 of equivalent displacement.
Ever seen a Ford 427 SOHC? Makes a Viper engine look svelte, especially when it’s shoehorned under the hood of a Cobra.
I love Vipers almost as much as the other raw musclecars, but I have to smirk slightly that you can’t get a decent exhaust sound from them because of the odd firing order. So Cobras rumble, Ferraris and Lambos scream, and Vipers… just kinda have a gassy whine. 
The Viper engine is 90 degrees, it’s based on the LA-series (273/318/340/360) V8. It’s also an odd-fire engine since opposing cylinders share a crankpin. The ideal vee angle for a V10 is 72 degrees.
Bit of trivia: although the block is 90 deg, the crank is engineered as though the engine was 72 degrees.
Makes for a cool sounding loping idle.
Yep, akin to the old Buick odd-fire V6. The Ford Triton V10, on the other hand, uses split crankpins to even out the firing interval.
The Ferrari and Lambo engines have dry sump oiling too which will reduce both the weight and height of the engine as located in the engine bay, depending on what you want to include as part of the “engine”.
Back in Ye Olden Dayes I put an odd-fire Buick V6 in a Porsche. With a very tall cam and an appropriately high flow exhaust. The engine was old enough to not need a catalytic converter, recirc pump, etc.
The lope at idle was very obvious. But distinctly different from the traditional late 60s V8 sound. The funny thing was nobody else waiting at the light could figure out which car was making that noise. Until it went green. 