Go Back   EcoModder Forum > EcoModding > Off-Topic Tech
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 04-07-2018, 06:21 AM   #1 (permalink)
Master EcoModder
 
Join Date: Nov 2013
Location: Texas
Posts: 278
Thanks: 7
Thanked 76 Times in 68 Posts
Two Stock CB750 engines, One Transmission?

Will the Honda CB750 transmission handle double the power without breaking?

The two engines being phased 90 degrees apart, would be putting out one single power pulse every 90 degrees, rather than one double pulse every 180 degrees as they would if they were phased 0 degrees apart, therefor each pulse would be no stronger than a pulse from a single engine, not twice as strong, as in two engines firing in sync.

The pulses would just be coming twice as often.
Would the transmission see this the same stress as with just one engine, or would the transmission need to be beefed up?

Attached Thumbnails
Click image for larger version

Name:	Twin Hondas Firing Order.jpg
Views:	7
Size:	35.5 KB
ID:	23859  
  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 04-07-2018, 06:54 AM   #2 (permalink)
It's all about Diesel
 
cRiPpLe_rOoStEr's Avatar
 
Join Date: Oct 2012
Location: Porto Alegre, Rio Grande do Sul, Brazil
Posts: 6,415
Thanks: 0
Thanked 626 Times in 556 Posts
Just a remind: the so-called "universal Japanese motorcycles" usually have an unitary contruction of engine and gearbox, so it would require a lot of re-engineering to match 2 engines to a single gearbox.
  Reply With Quote
The Following User Says Thank You to cRiPpLe_rOoStEr For This Useful Post:
Xist (04-09-2018)
Old 04-07-2018, 07:07 AM   #3 (permalink)
Master EcoModder
 
Join Date: Nov 2013
Location: Texas
Posts: 278
Thanks: 7
Thanked 76 Times in 68 Posts
Yes, the front engine would have it's gears removed, and be connected by a chain from it's crankshaft to the crankshaft of the rear engine, perhaps between cylinders 2 and 3. (and again, 90 degrees out of phase.)
  Reply With Quote
Old 04-07-2018, 07:19 AM   #4 (permalink)
It's all about Diesel
 
cRiPpLe_rOoStEr's Avatar
 
Join Date: Oct 2012
Location: Porto Alegre, Rio Grande do Sul, Brazil
Posts: 6,415
Thanks: 0
Thanked 626 Times in 556 Posts
I've already watched videos featuring small motorcycles with car alternators adapted to them, with a pulley attached to their original magnetos.
  Reply With Quote
Old 04-07-2018, 07:45 AM   #5 (permalink)
Master EcoModder
 
Join Date: Nov 2013
Location: Texas
Posts: 278
Thanks: 7
Thanked 76 Times in 68 Posts
I'm not sure how that relates to my original question.
  Reply With Quote
The Following User Says Thank You to Angel And The Wolf For This Useful Post:
mannydantyla (04-13-2018)
Old 04-07-2018, 12:31 PM   #6 (permalink)
Master EcoModder
 
Join Date: Nov 2013
Location: Texas
Posts: 278
Thanks: 7
Thanked 76 Times in 68 Posts
The thing is, if alternating the firings from the two engines can maintain the standard pressure on the transmission, two, or more engines can be safely routed through one standard transmission. (The following illustration shows three engines phased 60 degrees apart.) Can someone show me why this won't work? Prefer actual test data.
Attached Thumbnails
Click image for larger version

Name:	3 fours firing order.jpg
Views:	2
Size:	37.4 KB
ID:	23862  
  Reply With Quote
Old 04-07-2018, 07:52 PM   #7 (permalink)
EcoModding Apprentice
 
Piotrsko's Avatar
 
Join Date: Sep 2013
Location: 1826 miles WSW of Normal
Posts: 176
Thanks: 13
Thanked 51 Times in 39 Posts
The only difficulty I forsee is ensuring you don't end up with 2 X torque for some reason which would eat tranny.

Having said that, the pinto drivetrain survived suprisingly long after we shoved a built 302 into it. Snapped the axles on a launch.

The other question is synchronizing power output like multicarbed british cars.
__________________
2000 F250 7.3 CC 20+ MPG @ 10000 #
2013 Golf tdi 50+ mpg
1988 Ranger EV Volt batts>> 12,000 MPG and climbing. HMMM ADDED A QT OF ATF does that count?
  Reply With Quote
Old 04-07-2018, 08:50 PM   #8 (permalink)
Master EcoModder
 
Join Date: Nov 2013
Location: Texas
Posts: 278
Thanks: 7
Thanked 76 Times in 68 Posts
Yes, the torque. Synchronizing the engines would be by chain driving them together, But you may be right about the torque. Since there is only one firing at a time, the torque should be ok at the input, but with the ability to put the torque of two engines to the rear wheel, might break the output gear. I know I could use a compact car transmission, but I would lose the ability to shift and clutch with one pedal. I would have to use one of my hands to shift.
  Reply With Quote
Old 04-07-2018, 09:26 PM   #9 (permalink)
(:
 
Frank Lee's Avatar
 
Join Date: Jan 2008
Location: up north
Posts: 12,200

Blue - '93 Ford Tempo
Last 3: 27.29 mpg (US)

ShWing! - '82 honda gold wing Interstate
90 day: 33.65 mpg (US)

F150 - '94 Ford F150 XLT 4x4
90 day: 18.5 mpg (US)

Sport Coupe - '92 Ford Tempo GL
Last 3: 69.62 mpg (US)

Moon Unit - '98 Mercury Sable LX Wagon
90 day: 21.24 mpg (US)
Thanks: 1,410
Thanked 3,035 Times in 1,934 Posts
I wager the second crankshaft is a weak spot, vulnerable to breakage.
__________________


  Reply With Quote
Old 04-08-2018, 01:51 AM   #10 (permalink)
Master EcoModder
 
Join Date: Nov 2013
Location: Texas
Posts: 278
Thanks: 7
Thanked 76 Times in 68 Posts
I don't know why that would be.

  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com