Can you make a 20b+20b?

RotaryProphet · 10-04-2009, 10:17 AM

Look into tractor pulls, it's not uncommon for them to couple a pair of big block motors producing shit-tons of power, front to back. It involves a flywheel like toothed disk on the back of the crank (and taking the place of the flywheel/clutch/etc) of the front motor, and in place of pulleys and whatnot on the nose of the crank of the back motor, a duplicate disc. When the motors are positioned front to back in the chassis, the two discs line up, and something similar to a double motorcycle chain is wrapped around them, producing a solid coupling. I don't see any reason this couldn't be done with a pair of rotaries. The back engine will need to have a remote mounted electric water pump, but that's probably a good idea for both of them, and personally I would remove the oil pump from the rear engine also, and use just the front CAS and a standalone ECU (make sure the engines are in sync!) and basically strip the front cover off of the rear motor entirely. Then use a large electric water pump pumping into both engines, and a dry sump oil system pumping into both motors; you could pump into the rear iron where your oil cooler returns.

And flex isn't an issue, because a properly done setup will have -each- motor solid mounted to the chassis 4 times, with front motor mounts on either side, and with a block plate attached do the bellhousing bolt holes in the rear, so the car's frame absorbs any flex.

Then you just treat each engine independently for tuning and whatnot. It's probably worth tuning them separately on an engine dyno, to make sure their power output is reasonably similar, although it won't hurt you if one is; you just won't be at your potential.

Now personally, were I to attempt something so big, I'd go for serious gusto, and pair a couple of 4 rotor peripheral port engines that could crank out 400hp or more NA. An 800hp NA rotary? I would pay money to hear that. The temptation to even mildly turbo it and run double that or more would be pretty terrible, though. (On a side note, the sequential controller I'm working on has plenty of spare inputs and outputs... fully sequential quad turbo, anyone?)

10-04-2009, 10:17 AM	#15
RotaryProphet Rotary Fanatic Join Date: Sep 2008 Posts: 147 Rep Power: 17	Look into tractor pulls, it's not uncommon for them to couple a pair of big block motors producing shit-tons of power, front to back. It involves a flywheel like toothed disk on the back of the crank (and taking the place of the flywheel/clutch/etc) of the front motor, and in place of pulleys and whatnot on the nose of the crank of the back motor, a duplicate disc. When the motors are positioned front to back in the chassis, the two discs line up, and something similar to a double motorcycle chain is wrapped around them, producing a solid coupling. I don't see any reason this couldn't be done with a pair of rotaries. The back engine will need to have a remote mounted electric water pump, but that's probably a good idea for both of them, and personally I would remove the oil pump from the rear engine also, and use just the front CAS and a standalone ECU (make sure the engines are in sync!) and basically strip the front cover off of the rear motor entirely. Then use a large electric water pump pumping into both engines, and a dry sump oil system pumping into both motors; you could pump into the rear iron where your oil cooler returns. And flex isn't an issue, because a properly done setup will have -each- motor solid mounted to the chassis 4 times, with front motor mounts on either side, and with a block plate attached do the bellhousing bolt holes in the rear, so the car's frame absorbs any flex. Then you just treat each engine independently for tuning and whatnot. It's probably worth tuning them separately on an engine dyno, to make sure their power output is reasonably similar, although it won't hurt you if one is; you just won't be at your potential. Now personally, were I to attempt something so big, I'd go for serious gusto, and pair a couple of 4 rotor peripheral port engines that could crank out 400hp or more NA. An 800hp NA rotary? I would pay money to hear that. The temptation to even mildly turbo it and run double that or more would be pretty terrible, though. (On a side note, the sequential controller I'm working on has plenty of spare inputs and outputs... fully sequential quad turbo, anyone?) Last edited by RotaryProphet; 10-04-2009 at 10:20 AM.