Discussion
Questions for the engineering types.
What i am referring to is two fully independently functioning engines connected together onto one drivetrain. Whether that be via crank chain to a common input shaft, crankshafts bolted together in a longitudinal manner, etc.
I am sure i have read this somewhere before, but obviously two engines wont ever run identically.
When this is put into the concept of two engines being connected together, at first glance you would say the two engines being differing power output would not work, however i believe as they are permanently connected together it would most likely just mean the engines will work together rather than fighting each other if set up correctly?
Basically, if i had 2 V8s connected inline, both 350 SBC for arguments sake, and one is set up for optimum power and torque production at 2-4k RPM, and the other is set up for 4-6k RPM power, would they compliment each other and make a V16 which produces more power than either could individually across a 2-6k RPM powerband? Or would the one in the power band always be struggling with the one which isnt?
I know its completely nuts and pointless, and achievable much easier and cheaper with other options, but i like mad ideas!
Thanks in advance,
Jordan
What i am referring to is two fully independently functioning engines connected together onto one drivetrain. Whether that be via crank chain to a common input shaft, crankshafts bolted together in a longitudinal manner, etc.
I am sure i have read this somewhere before, but obviously two engines wont ever run identically.
When this is put into the concept of two engines being connected together, at first glance you would say the two engines being differing power output would not work, however i believe as they are permanently connected together it would most likely just mean the engines will work together rather than fighting each other if set up correctly?
Basically, if i had 2 V8s connected inline, both 350 SBC for arguments sake, and one is set up for optimum power and torque production at 2-4k RPM, and the other is set up for 4-6k RPM power, would they compliment each other and make a V16 which produces more power than either could individually across a 2-6k RPM powerband? Or would the one in the power band always be struggling with the one which isnt?
I know its completely nuts and pointless, and achievable much easier and cheaper with other options, but i like mad ideas!
Thanks in advance,
Jordan
I used to know someone who had a Westfield with two Kawasaki ZX9 engines fitted, one in front of the other and slightly offset. The output from the two gearboxes was fed into a two speed with reverse gearbox which was, in turn, attached to the diff through a regular propshaft. This parts were supplied by a company called Z-Cars. ISTR the biggest problem was keeping both power units' gearchanges synchronised. It didn't really seem to matter if they were in different gears, though, but one would obviously be spinning faster than the other and so the throttle requirements would be different. FBW throttle control would have solved that. It had two gear levers (one per PU) which could be connected together or used independently.
HTH
HTH
When I saw this thread, it reminded me of the twin engined Scirocco;
https://www.vwheritage.com/blog/2015/04/09/factory...
https://www.vwheritage.com/blog/2015/04/09/factory...
I did a photo shoot for a local paper in the late 80’s about a guy who had Fire engines in a shed in his back garden, modest house but incredibly long back garden. A Rolls Royce Fire engine had 2 large 4 cylinder engines joined together by the rear of 1 crank and the front of the other, 1 gearbox behind them, what made this a bit different is that the 2 engines where joined about ½ a revolution out, this apparently delivered more torque low down and made for a very smooth engine.
Twin bike engines to a single drivetrain has been common in autograss racing for a few years. Some awesome engineering in some of these
https://www.bing.com/images/search?view=detailV2&a...
https://www.bing.com/images/search?view=detailV2&a...
http://www.fullonfabrications.co.uk/
https://www.bing.com/images/search?view=detailV2&a...
https://www.bing.com/images/search?view=detailV2&a...
http://www.fullonfabrications.co.uk/
Build thread here of someone trying to do exactly this:
https://www.pistonheads.com/gassing/topic.asp?h=0&...
https://www.pistonheads.com/gassing/topic.asp?h=0&...
In Russia, only the poor have only two engines in their car:
https://www.youtube.com/watch?v=jGWHZecSiXc
:-)
https://www.youtube.com/watch?v=jGWHZecSiXc
:-)
Z28JWR said:
Yeah, i know its achievable and been done. Its more a question of how different the two connected engines can be and if that would be a benefit to the overall performance or a hinderance.
Two engines, with different displacements and cylinders and ages - I would think - would output different horsepower at their cranks even at the same RPM. So the faster the RPM goes up, the bigger the discrepency would become. So either the one engine would be slowed down, or the less powerful engine would be pushed beyond a limit it could reliably take. PaulKemp said:
I did a photo shoot for a local paper in the late 80’s about a guy who had Fire engines in a shed in his back garden, modest house but incredibly long back garden. A Rolls Royce Fire engine had 2 large 4 cylinder engines joined together by the rear of 1 crank and the front of the other, 1 gearbox behind them, what made this a bit different is that the 2 engines where joined about ½ a revolution out, this apparently delivered more torque low down and made for a very smooth engine.
Very clever methodConverted two engines into one without welding the blocks together
Aerial Square 4 motorcycle has two crankshafts in one casing:
https://sumpmagazine.com/ariel/ariel-square-four.h...
http://www.arielnorthamerica.org/mot_hist7.htm
https://sumpmagazine.com/ariel/ariel-square-four.h...
http://www.arielnorthamerica.org/mot_hist7.htm
sgtBerbatov said:
Two engines, with different displacements and cylinders and ages - I would think - would output different horsepower at their cranks even at the same RPM. So the faster the RPM goes up, the bigger the discrepency would become. So either the one engine would be slowed down, or the less powerful engine would be pushed beyond a limit it could reliably take.
Why do people have so much difficulty understanding the concept of torque and power? If you had an engine producing say 200 lbft at 5000 RPM connected to the same engine making 100 lbft at the same speed, why would you think one engine would affect the speed of the other, rather than the torque outputs simply being added?
Suzuki RG400/500 2 stroke motor had independent crankshafts geared together (square 4) 
worked well too 
https://www.youtube.com/watch?v=rUiTNiiHqd0 or pushed to extreme 2 separate engines driving one car https://www.motor1.com/news/260373/insane-vw-golf-...
worked well too https://www.youtube.com/watch?v=rUiTNiiHqd0 or pushed to extreme 2 separate engines driving one car https://www.motor1.com/news/260373/insane-vw-golf-...Edited by Sardonicus on Wednesday 25th September 10:46
I can't really help with the ops question, although my hunch is it would work successfully, assuming you didn't try and spin one engine beyond it's operating capability.
As even an engine making most of it's power in the lower rpm, will still be making power at high rpm, you are never in negative power on an engine.
Anyhow, any excuse to post something like this!!!
I wonder if they do indeed do something similar to the ops proposal?
As even an engine making most of it's power in the lower rpm, will still be making power at high rpm, you are never in negative power on an engine.
Anyhow, any excuse to post something like this!!!
I wonder if they do indeed do something similar to the ops proposal?
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