Willie Noonan from Kaponga (Taranaki) built a reverse rotation Chev V8 to run in his Speedway Modified. Won the NZ title in it in the 90's and is still running and keeping up with todays technology. The theory of reversing the rotation was to do with turning left and with the inertia of the Chevyengine running in the oposite direction than normal it would be pulling the car in towards the pole line and not out towards the wall, was a good idea but cost him plenty of coin to do back then
40wav,
Feb 19, 6:51pm
Yes, but I'm planning on mounting it on a mountain bike so it will be 'off side' from the sprockets etc. I am toying with turning the pedal crank round and removing the pedals, turning the back wheel around and fixing the drive, and re-attaching the deralieur somehow. Thanks all for your comments.
lookin4ord,
Feb 19, 7:33pm
nope the position and shape of the intake and exhaust are in different places
jsbike,
Feb 19, 7:43pm
they are, but no matter what way the engine is rotating, the ports dont change what they do, ie the exhaust ports will be the exhaust ports no matter what way the motor is turning
skin1235,
Feb 19, 7:46pm
also quite common on twin engine marine applications, mirror image the cam and remount the points, otherwise the twin engines will throw the boat sidewards( the screws walk across the water) when you give it a poke, have one turning clockwise the other anti, keeps it pushing true
skin1235,
Feb 19, 7:47pm
and for the outboards too, theres not a lot needs doing to counter turn them, theres a lot of twin outboards around - maybe ask at the local marine shop
steve312,
Feb 19, 7:56pm
Right.not.
The port timing doesn't change at all regardless of the direction of rotation.Because of the way a 2 stroke works it is the piston closing the cylinder ports that replaces the valve effect of a 4 stroke engine.Reversing the crank rotation does not mean the inlet ports become exhaust ports and vice versa. Never thought I would agree with anything Intrade said but he is dead right about the ignition timing being the only thing that would need changing.And yes, some of the crank and clutch nuts will work loose unless locked somehow.
Find TDC and mark where the flywheel timing marks are then redrill the stator plate and turn it so the timing is set the same amount ATDC instead of BTDC.
The engine will run exactly the same backwards.
steve312,
Feb 19, 7:56pm
Right.not.
The port timing doesn't change at all regardless of the direction of rotation.Because of the way a 2 stroke works it is the piston closing the cylinder ports that replaces the valve effect of a 4 stroke engine.Reversing the crank rotation does not mean the inlet ports become exhaust ports and vice versa. Electro2000 is dead right about the ignition timing being the only thing that would need changing.And yes, some of the crank and clutch nuts will work loose unless locked somehow.
Find TDC and mark where the flywheel timing marks are then redrill the stator plate and turn it so the timing is set the same amount ATDC instead of BTDC.
The engine will run exactly the same backwards.
planespotterhvn,
Feb 19, 8:30pm
A two stroke with piston port or reed valve sub piston induction will run equally as well if you alter the spark timing to the other side of TDC. Rotating the barrel is not necessary or desirable. Rotary disc valve sub piston induction won't run backwards as the induction timing is assymetrically optimised for one direction, where-as a reed valve will do what is required of it either way. And piston port is symmetrical and so cannot be different for either direction.
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