Hey guys, I've been dreaming up plans to make my own hot rod from scratch. I wanted something different, though., so I thought, "What about chain drive?" So it's this: Engine to tranny. Tranny to driveshaft. Driveshaft to rear axle. HOWEVER. This axle, although totally normal, is bolted rigid to the frame at frame height. Where a tire would normally by would instead by a sprocket, mounted like a tire. From there is a chain on each sprocket to another sprocket. This sprocket is located around the drum. This axle is a trailer axle of sorts (or even a welded front axle). It has to be of some age too. In other words, the drum needs to stick out from the tire, like the old wood-spoke wheels, perhaps. The question everyone asks me is whether or not the differential will work. I say it shouldn't make a difference whether or not the tire is physically on the rear axle, instead there is a transaxle (normal rear) which leads to a trailer axle (which allows each wheel to spin independently of each other if there was no chains). I think when the wheel meets resistance trying to turn left for example, the differential will operate as planned. I'm also fairly certain that this is how the old American laFrances worked, too. I drew up some quick plans one day in some free time:
It would probably work but I wouldn't want to run a lot of power through it. Maybe a small four banger. The easy way to do it would be to run the brakes on the differential that is bolted to the frame and then bolt a drive sprocket to the drum there. Then have the driven sprocket attached to the hub for the wheel. The whole thing is going to have to look 1910 when you are done though. On this kind of deal farm equipment supply houses are your friend as they have the sprockets and chain you would need along with all sorts of hubs and axles. A scrap yard for farm equipment might even produce the axle you need with the sprockets already on the hubs.
hmmmm. kinda going backwards in an engineering kinda way it seems. and all this for what???? post some progress pics
Is there a reason you need to do this, or just because you think it would be "trick" to do it. Steve Grimes did chain drive a few years ago LINK TO THE THREAD
If we were concerned about going backwards, technology wise, we'd be into much more modern cars. A lot of what draws many of us into traditional hot rods IS ancient tech and the inherent charm that goes with it. This could be a really cool deal, of course, it could end up redundant and kind of lame.
My 1912 Metz had the differential mounted ahead on the frame, then chains to the rear wheels. In 1915 they came out with a slightly bigger model that went to a single chain. There is a reason car companies are not doing this anymore.
It appears the purple bucket has a irs/swing axle setup and that is something to consider. A chain drive to the outside of a of a straight axle will want to toss, wear, break chains and sprockets as the axle articulates and the chain stays straight, especially in a short run of chain. You'll need tensioners and guides to keep it all together and you'll still want to carry extra sprockets/chain and master links with you.
So you want to re-create an early 1900's Mack Bulldog? This arrangement was common on many early trucks.
I was thinking about putting a motorcycle engine in my old Mini at one time. Everything I read said to not do chain drive. It's noisy, it's messy, and it will wear out quickly. If you do decide to run a chain, you want the chain to be as long as possible to cut down on heat and binding.
If the front mounting point of the rear axle is close to the mounting of the driving sprockets than the motion of the rear axle will be close to the same as the chain. Chains should be run slack anyway. And the bigger the links the better to handle the difference in angles when the suspension articulates. This was done for years and years on big trucks. And brass era cars. Put the brakes on the rear axle so when a chain leaves, you still have brakes. and the braking force doesn't go thru the chain. The Thomas Flyer was chain drive and went around the world. And you got a built in quick change, too. A modern version might use blower belts. They run slack also. Or with a spring tensioner to keep the right tension.
Lots of mudboggers had chaindrive, i built one that had easily 1800hp and broke everything but the chain.
One reason chains were a bad idea where high powered engines were concerned. one famously decapitated the driver. See http://en.m.wikipedia.org/wiki/Babs_(land_speed_record_car)
Like Monogram's Beer Wagon? That mother had some old school big ol' ladder bar made from box tubing, which I think is key. Good Luck!! Keep us posted.
Just go to a antique truck show with all those old Mack and Sterling chain drive huge trucks for ideas on chain drive. It's said that a properly adjusted chain drive motorcycle is more efficient than gears and a drive shaft.
Thanks guys! Pretty much it is only an idea at this point but it is all for nostalgia, not practicality. As for power I was considering no more power than a chevy 250. This way the brakes like mentioned could be in the "modern rear axle" (transaxle), and can use more available, lighter, proven trannys too. And yes it would look very old style. I am fascinated with the engineering and ingenuity of brass era cars and trucks. Farm implement technology is surely the way to go too looking for chain and sprockets. It at be a while guys, but I have had this idea for a long time: it will happen someday! Anyone else have any input? Ideas? All welcome!! Thanks again! Vince
I know old 20's era fire truck had them, but they most definitely weren't small! American lafrances of that period had 14.5L T heads weighing about 6 tons and 25 feet long (I would kill to own an unrestored one), and I think a Seagrave model breaks the 1000ci barrier. One of the reasons why I decided to build one is because id rather have a laFrance but running they go for astronomical prices, so I decided one day I will build my own!
Look at the little Geo Metro that had a bike engine at the 24 Hours of Lemons. Or Z-Cars out of the U.K.
Definitely not a new idea. Lots of cars and trucks have had chains. The most recent production example I know of; in the '60s Honda had a sports cars with a fixed differential and a chain to each wheel. As was mentioned, suspension geometry relative to sprocket location is important. Chains are notoriously inefficient when not well lubed. You will need a fairly large chain to get reasonable durability. Finally, there is a reason more don't do it.
Our town has a LaFrance fire truck built on a Chevy chassis from the mid teens. Been here since new. It has chain final drive and I think the differential is a worm drive. The reason for chain drives on old big trucks was to get additional reduction past what they could get with a single gearset. My grandfather ran a garage thru the 20's and 30's, and he said chain drives were okay on fire trucks because they didn't get driven much, but on trucks in daily use the chain drives generally caused more problems than everything else on the truck combined.
This is great. I love old diagrams, and I love the fact it is RHD with the shifter on the right. I would love to do that on my own build too someday, but that seems very difficult to accommodate on today's transmissions. Remember guys too, this chain drive creation is not build with practicality in mind. As much as possible, sure, but there isn't too much practical about it. It's for my extreme fixation on it, and gits and shiggles. Vince
Those old Sterlings are some real monsters. Chain drive tandems with 24" wheels and I want to say air brakes. Oh,and a total loss oil system for the chains...
Pop Dreyer, noted sprint car and engine builder (Dreyer DOHC heads & engines based on Ford B) here in Indy, ran a DeSoto powered sprint car back in the early/mid '50s with chain drive.
As a boy (think early '50s) I saw many construction transit mix GMC trucks, and Chevy dump trucks in use destroying California. These were three axle ten wheel trucks. They weren't fast but they worked in rough and dusty conditions.
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