Roadcar transmissions and differentials to handle 5000 hp?

[OO7]

The Devel V16 is a 90 degree engine and it's interesting to see that they have gone with an 8 arm (when viewed from head-on) crank design, which would make it equivalent to a cross-plane V8. From the video it appears to have a cross-plane like V8 rumble to it. I think they could have also used a four arm design (again when viewed from head-on. The other 4 arms would be in the 'shadow' of the first 4), this would make it equivalent to a flat-plane V8, with the crankshaft resembling an Apache tail rotor as shown in the following image:


Devel V16 crankshaft:

[Brian Coat]

Various people have done street legal V8s over 3000hp so 5000 will be achievable.

Trans ideas of varying daftness:

Custom Lenco-Style epicyclic?;

TH400 pro mod based trans with unobtanium-style material upgrades (and maybe some torque clipping)?

Or a custom DSG? The DSG FOR THE Bugatti was all new, so the people in The UK who did that one should be able to help.

PS is it me or is the TV damping going to be a challenge?

[Tommy Cookers]

The Devel V16 is a 90 degree engine and it's interesting to see that they have gone with an 8 arm (when viewed from head-on) crank design, which would make it equivalent to a cross-plane V8. From the video it appears to have a cross-plane like V8 rumble to it. I think they could have also used a four arm design (again when view from head-on. The other 4 arms would be in the 'shadow' of the first 4) ....
Devel V16 crankshaft:
http://roa.h-cdn.co/assets/15/50/768x11 ... 06-sm2.jpg

bound up with the already awkward question of crankshaft design ....
one might think that one of the few attractions of the V16 eg relative to a V12 is the value of possible different bank angles

at or around 45 deg (more compact via width and simplification of valve gear etc)
or at or around 135 deg (allowing a 5 main bearing design for more compact length, less weight and friction)

btw
I once worked for someone who (I think) had use of a V16-powered MGB
a Motor Gun Boat with 3 diesel engines hurriedly developed (the crankshafts broke every week) from V12s
he was severely shot up (I think taking ammunition and demolition explosives to Sweden for the Danish resistance in late 1943 - when a Red Army breakthrough seemed possible and some in Sweden seemed to ignore their own neutrality)
the rumour mill said he earned a VC (apparently denied by the super secrecy remaining even today because of the neutrality aspect)

[OO7]

The Devel V16 is a 90 degree engine and it's interesting to see that they have gone with an 8 arm (when viewed from head-on) crank design, which would make it equivalent to a cross-plane V8. From the video it appears to have a cross-plane like V8 rumble to it. I think they could have also used a four arm design (again when view from head-on. The other 4 arms would be in the 'shadow' of the first 4) ....
Devel V16 crankshaft:
http://roa.h-cdn.co/assets/15/50/768x11 ... 06-sm2.jpg

bound up with the already awkward question of crankshaft design ....
one might think that one of the few attractions of the V16 eg relative to a V12 is the value of possible different bank angles

at or around 45 deg (more compact via width and simplification of valve gear etc)
or at or around 135 deg (allowing a 5 main bearing design for more compact length, less weight and friction)

btw
I once worked for someone who (I think) had use of a V16-powered MGB
a Motor Gun Boat with 3 diesel engines hurriedly developed (the crankshafts broke every week) from V12s
he was severely shot up (I think taking ammunition and demolition explosives to Sweden for the Danish resistance in late 1943 - when a Red Army breakthrough seemed possible and some in Sweden seemed to ignore their own neutrality)
the rumour mill said he earned a VC (apparently denied by the super secrecy remaining even today because of the neutrality aspect)

In terms of perfect balance and smoothness (firing order/angle), I think there are 4 possible bank angles, 45, 90, 135 and 180 degrees and 3 possible crankshaft designs (I think 1 of the 3 designs will result in unevenly spaced firing within each bank however). The 45, 90 and 135 degree bank angles can use 2 possible crank designs each and the 180 degree bank has only 1 crankshaft design for a perfect fit.

The idea you mentioned of having only 5 main bearings, if I understand you correctly this would mean only 4 crank journals, with each one occupied by 4 rods?

The gun boat you mentioned, was it a one off design. Triple V16s!

[Tommy Cookers]

In terms of perfect balance ..... the 180 degree bank has only 1 crankshaft design for a perfect fit.
The idea you mentioned of having only 5 main bearings, if I understand you correctly this would mean only 4 crank journals, with each one occupied by 4 rods?

The gun boat you mentioned, was it a one off design. Triple V16s!

I think there was about 10 such MGBs with triple V16s (from an established engine V12 of around 750 hp)
over 100' long and 40 kt, seaworthy and good range
RN commanded, mostly crewed by RNVR ? ex-trawler, the main activity being the better-known 'ball bearing' runs to Sweden


Ferrari won WCCs WDCs and WECs ? with '180 deg V12s' with 4 main bearings (they were said to have tried 3 mains)
Alfa Romeo emulated this with 3 mains in their 'WEC' and F1 1973-78, as did Tecno with a 3 main '180 deg V' 8 cyl engine
something like this should work with a 16 ie 5 mains and with maybe 150-135 deg, iirc I was guessing 8 throws
agreed you might use or be able to use 4 throws with a 180 deg angle
(the 1950s 180 deg F2 watercooled Andersen had 8 cyls and 2 mains, aircooled Porsche 8s had 9 mains and the 917 had 7 mains ??)

also this V16 seems a good application for articulated rods, giving a very worthwhile saving of engine length, weight and friction

[OO7]

Ferrari won WCCs WDCs and WECs ? with '180 deg V12s' with 4 main bearings (they were said to have tried 3 mains)
Alfa Romeo emulated this, as did Tecno with a 3 main '180 deg V' 8 cyl engine
something this should work with a 16 ie 5 mains and with maybe 150-135 deg, iirc I was guessing 8 throws
agreed you might use or be able to use 4 throws with a 180 deg angle
(the 1950s 180 deg F2 watercooled Andersen had 8 cyls and 2 mains, aircooled Porsche 8s had 9 mains and the 917 had 7 mains ??)

also this V16 seems a good application for articulated rods, giving a very worthwhile saving of engine length, weight and friction

I'm going to looking into those engines you mentioned Tommy, as I've never seen a configuration with more than 2 rods per arm. As for the articulated rods, I've always liked the idea of the blade and fork style. I think the forks would have to absorb friction from 4 surfaces as opposed to 2 for the blades, perhaps this and structural issues is why the configuration isn't used for high revving application.

[Tommy Cookers]

..... as I've never seen a configuration with more than 2 rods per arm. As for the articulated rods, I've always liked the idea of the blade and fork style. I think the forks would have to absorb friction from 4 surfaces as opposed to 2 for the blades, perhaps this and structural issues is why the configuration isn't used for high revving application.

the Life F1 car in 1990 raced with a 3 bank 12 cyl 'W' aka 'broad arrow' designed by Franco Rocchi (ex-Ferrari & MV flat 4 prototype)
I believe it had 3 normal rods side-by-side on each crankpin
others have done similar paper designs eg Munday ? did a DFV-era W12 and Ferrari considered W18s (more than once imo)

some might not classify fork&blade as articulated
true articulated ie master & slave or link rod design gives less piston sideforce but unequal geometry
eg a typical radial (9 cyl) has reduced sideforce on 8 pistons
the Napier Lion W12 had master & slave rods, similarly old aero V12s had link rods
the Napier Cub was an unusual 16 cyl design

the c 55 litre W18 Isotta-Fraschini was available post WW2 in diesel form only ? (and race-winning gasoline V12)
a developed diesel V12 is still available, though the maker's name has changed

currently new 30 litre 9 cyl traditional design radial aero engines are available (from Poland ?), now aimed at natural gas-driven generation
and the 7 bank 56 cylinder turbocompounded marine diesel (Ukraine or Russia ?), in the usual paired setup giving 10400 hp

[bill shoe]

In terms of perfect balance and smoothness (firing order/angle), I think there are 4 possible bank angles, 45, 90, 135 and 180 degrees and 3 possible crankshaft designs (I think 1 of the 3 designs will result in unevenly spaced firing within each bank however). The 45, 90 and 135 degree bank angles can use 2 possible crank designs each and the 180 degree bank has only 1 crankshaft design for a perfect fit.

The bank angles are good in theory, but the theory assumes perfectly rigid crank and block. As the engine gets longer, the block and crank get more torsional compliance. This is a very long engine.

Typical tricks to reduce torsional compliance on long engines include taking the drive from the middle of the crank instead of the end, or using really really large diameter main journals. Don't see either happening on the Devel crank. The Bugatti Veyron used a really awkward W engine configuration to pump out 1200 hp with an acceptably short/stiff crank. The Devel is going to make much more power with a much longer crank? Skeptical, I am (Yoda tribute).

When the crank gets long and torsionally soft, it gets more and more resonances at lower and lower rpm. This is hell on engines, clutches, transmissions, the entire driveline. The guy in the picture can undoubtedly make a jewel of a crank in terms of dimensional tolerance, etc., but is he or anyone else looking after the vibration fundamentals? Or are they just turning what they know up to 11? Will be fun either way.

[Brian Coat]

I agree Bill, I made the same point a week ago - see above.

I'm sure it is addressable but it could be a challenge.

[OO7]

Typical tricks to reduce torsional compliance on long engines include taking the drive from the middle of the crank instead of the end, or using really really large diameter main journals. Don't see either happening on the Devel crank. The Bugatti Veyron used a really awkward W engine configuration to pump out 1200 hp with an acceptably short/stiff crank. The Devel is going to make much more power with a much longer crank? Skeptical, I am (Yoda tribute).

It is strange they didn't opt for a central PTO, as the image shows that the central main bearing is longer than the others, however SME is a small company so perhaps they'd rather go with concepts they are more familiar with.

The Bugatti crank has split pins, which is perhaps one of the reasons it is a low revving engine.

[Tommy Cookers]

The gun boat you mentioned, was it a one off design. Triple V16s!

I think there was about 10 such Camper & Nicholson MGBs with triple V16s
converted to cargo vessels for Operations 'Bridford' and 'Moonshine'
117' long and 28 kt
'Operation Bridford' was the 'ball bearing' runs to Sweden
the UK had a need for self-aligning bbs, but there was also some attempt to corner the market
'Operation Moonshine' was supply to the Danish resistance (via Sweden)

see this Paxman engine history link
http://www.paxmanhistory.org.uk/blockade.htm

[J.A.W.]

On the subject of large diesel engine automotive gear drives,
check this illustrated manual chapter covering the PTO particulars of the mighty 18 cyl Napier Deltic 2T..

http://www.pigeonsnest.co.uk/stuff/deltic/chapter7.pdf