Answer To Engine Syncing Questions

Nearly unanimously the first question out of anyone after their eyes refocused when they heard about our double engine Corolla/MR2 project: “How will you synch the engines?” I heard this question so often, from the mechanical genius and inept alike, that I started to question whether the project was feasible. When I explained our theory, that synching would not be necessary since the systems would be completely independent like two coupled locomotives, they usually said “I guess that might work” with their mouth, and “you’re a batshit-crazy moron” with their facial expression.

A few would pursue the subject a little further and explain how if the engines were not synched they would contend with each other and drive the wheels at different speeds and chew up tires and put undue torque on drivetrain components and blah blah blah. As near as I could tell they expected our car to suffer the same problems manifest in a 4 wheel drive vehicle, with locked differentials front, rear, and center, doing 15’ radius turns on pavement.

My answer would be that any car has an endless array of forces operating for and against drive train: Going up hills, going down hills, head winds, tail winds cross winds, various load mass, collisions... Being welded to another car moving the same direction is just another external force on the first drive train. As far as one engine can tell, the combination of forward forces is no different than driving downhill.

My favorite is the people who speak with the authority of someone who just the other day was driving their own twin engine car and the axles snapped off on their way to work.

An endurance race proven example has been built and demonstrated. It works great. It ran hard all day. I personally flogged it. Not even an unexpected level of tire wear. If you want to build one that doesn't work just to prove us wrong, go nuts.

5 comments:

Joel said...

absolutely awesome project! i had tinkering with the idea of a twin 4age Corolla FX16, but alas, life has gotten in the way...

its a fairly simple mechanical problem. just not sure how the wiring would work out.

awesome job regardless! :)

Larry said...

Thanks! If you don't mind 2x gauge clusters and the harness riding shotgun, wiring is easy. ;-)

apardal said...

You guys RULE! :) Great ghetto engineering!

Kirk said...

Syncing front to back isn't really necessary. There are some hybrid/electric military prototypes out there that do this, and have no coupling between front and rear axles. I think what people are thinking about is when you stick two engines on the same axle (think twin-engine go kart). In that situation you could have some issues because the two rotating engines could potentially be trying to turn at different speeds even though they're directly coupled.

Happy Golucky said...

i have the most out much respect for your creation that has given me the motive to build again after i been retired and practically forced away from the auto world but now i can put my skills & education into full gear with a new generation and aspect at the level i will persue so thank you because you are good friends to the automotive world sharing detailed trial & error to help make the next mans project that much fun.