Should Chevy Join The Chain Gang?

[iluvcamaros]

I'm a Life Science major, not an engineering major, but chain drive seems kinda silly.

When you lengthen the typical 2ft chain to say 8ft I'd say you are multiplying the normal chain problems exponentially; rather than 4x it is like 16x more complicated.

It may sound way off topic but I'm reminded of the Tacoma Narrows bridge. This is the suspension bridge from 1940 you see on TV that collapsed simply because of wind blowing the deck around. Building bigger/lighter bridges like that resulted in the revelation that a bridge design needs to take aerodynamics into account. Who could have forseen that a freaking bridge needed to be aerodynamic? You couldn't until you built one and it collapsed. Nobodys fault, $hit happens.

If GM were to push ahead with a front engine, rear wheel drive, chain driven car the exact same situation would arise. During development engineers would address all the problems we are discussing, but then MORE completely unpredictable problems will come up. They may be corrected during development, or they may not show up till the production cars are on the road resulting in disaster. It WILL be blamed on GM, it WILL be "all their fault", and Toyota's $hit doesn't stink or include chains.

Sometimes the risk is worth it and can be accounted for. Electric cars are an example. GM used the EV-1 to learn about electric cars. Toyota released the Prius in Japan before the United States. I'm sure both benefited from those experiences when launching (or preparing to launch in the Volt's case) the new technology in US production cars.

So GM could potentially spend millions (billions?) to produce this new drivetrain. It may be a success or absolute failure but unlike the previous examples they would essentially be reinventing the wheel. Worth the risk? No.

Interesting conversation here, but in my opinion it is a bad idea in every sense. The money would be better spent on alternative propulsion (worth the risk) or perfecting already existing technologies (not risky).

[Hunid Racks]

Chain drive transmissions are dead.

Since the electronic controls allow better clutch to clutch shifting thre is absolutely no reason to go chain drive. And a three axis transmission is much smaller with zero compromise on capacity.

No way there will ever be chain drive to wheels. It would be almost impossible to defeat the noise created. There is a reason why belt drives have short gaps between pulleys. Harmonics set in at a long gap. For a chain long enough to run to a rear axle, the tricks that would be used to quiet the drive would cost so much it simply wouldn't make sense.

[wescoent]

Originally Posted by Hunid Racks

Chain drive transmissions are dead.

Since the electronic controls allow better clutch to clutch shifting thre is absolutely no reason to go chain drive. And a three axis transmission is much smaller with zero compromise on capacity.

No way there will ever be chain drive to wheels. It would be almost impossible to defeat the noise created. There is a reason why belt drives have short gaps between pulleys. Harmonics set in at a long gap. For a chain long enough to run to a rear axle, the tricks that would be used to quiet the drive would cost so much it simply wouldn't make sense.

Easy solution:

Small block + straight pipes.

[silvachris1]

Originally Posted by wescoent

Easy solution:

Small block + straight pipes.

WINNER!!!!

[chinamonty]

Really if you want to change anything then the engine should be just providing electricity for motors contained within the wheels. Developing those electric motors is what I see as the key until someone has an idea out of left field.

[Gm_Tooler]

Originally Posted by MonaroSS

.............
The chain runs in an air, water and oil-tight industrial grade plastic box connecting between the gearbox and diff.
The front sprocket is sealed off from the gearbox oil but the chain shares the diff oil
and is auto-tensioned electro-hydraulically for low maintenance and noise.
[/center]

Well that is my commentary on how GM could use a Chain Drive if they wanted to create some cheap but exciting compact RWD sports sedans and coupes. What do you think?

I think it could definitely be made to work. But I would say keep it simple.

I would forget about a chain bathed in oil. You'll never be able to keep the diff full. The chain and centrifugal force will sling oil everywhere inside the length of the chaincase. Go with a sealed and lubricated chain like an X or O-ring type for example. They also stretch much less. The cushioned front and rear sprockets should be in a dry (no lube) area. The chain/sprokets would be standard maintenance items, like a timing belt, etc.

You'll also need some opposing self-adjusting chain tensioners, more towards the midpoint, imo. Which also means the chaincase needs to be substantial enough (for safety reasons also). With a chain of that length maintaining proper tension is critical.

Do to its length, I think the the idea here is to make the chain/sprockets more like a driveshaft and less like a part of the transmission.