Could use some info on gear or chain drive systems for dual side by side engines. Tractor pull stuff is waaay to expensive and overkill. 2togo website has no info only pics. Just wanted to get that out of the way to save you guys time on info i already have. Any help on a practical easy way would be appreciated... Thanks
One common method was to simply run one in reverse-rotation & mount them so that the flywheel ring gears meshed. Longevity...probably not the best....but for drag racing, who cared? Power was taken off one engine. Obviously one engine has to be modified to do the reverse-rotation deal....and synchronization is an issue...but since the engines were exotic anyway....
You're right, they wont last on the street which is where this is going. Without an oil bath you'd burn them up quick. Ivo ran that set up, and as you said, good for the 1/4 mile only. Thanks anyway.
In the one or two cases I've seen for street use, they were coupled in-line, which would be much easier to do, and they used a six-wide roller chain with double sprockets on the balancer & flywheel. I suppose you could fab up some kind of short stub drive off each flywheel, with sprockets, using engine plates & mid-mount plates, & chain them to a common shaft, well supported, going to the gearbox...cover the whole thing with chain guards, it might not look terrible. All of the originals were custom deals anyway. The only off-the-shelf stuff I know of (as much as it can be, anyway) IS for pulling, and priced accordingly.
Just add headlights... Howard Cams Special approx. 1963-64 Minnesota Dragways I remember seeing an article on a car with side by side engines with 2 transmissions and driveshafts into two differentials on a single rear axle.
A guy might look into the heavy hy-vo chain which was used on setups like Toronado's and Jeep Quadra-Trac transfer cases.
There was a car built not too long ago, Model A coupe, dual SBC's. It pretty wild looking, 60's drag car lookin. I heard the owner died no too long ago and the car was stolen. This won't help you much, but if you figure out what car I am talking about you might be able to see how he did it.
Back in the early eighties in the UK a guy named Nick Butler, [Auto Imagination] built a promotional car for Wolferace Wheels. It featured twin side by side V8 engines and transmissions. I don't know if two drive shafts and some special twin diff was used or if they were somehow mated at the trans, but I do remember they were computer synchronized. That kind of technology was in its infancy back then, and the computer, I am sure, would seem archaic by today's standards, never the less he was successful. With almost 30 years technology to build on and the large number of computer savvy hot rodders out there, maybe this is a direction worth pursuing.
I remember seeing one car with two diffs & a balance pipe between the intakes so both motors reved the same (in theory) I never got to see it run, It got me thinking though!!
the America's Most Beautiful Roadster winner at Oakland in like '64 or '65 was called The Invader. It had twin pontiac engines side by side, with two trannies, running back to a rear axle with two diffs, a small double splined shaft between them. somebody 'round here's gotta have a pic.
this seems like the cheepest and least hassle way to do it. outher than the connecting axle all junk yard parts.
I'd consider meshing the flywheels together, like the dragster above and the Dragmaster Two-Thing, and use a dry-sump oil system for longevity. You may have to do some exotic work on the block and heads for oil drainback, but I think this may be the cheapest way out. - one trans - one rear diff - one reverse rotation cam - two dry-sump setups Another plus is that there is only one driveshaft and it can run offset to the side, instead of under the driver. Tell us more about your project, any two-engined car is going to be bitchin!
It was a show car so who knows if it would live on the street but it had two automatic transmissions, driveshafts and rear ends with an "axle shaft" between the two rear ends and one of the rears had a differential and the other was a locker so it could (hypothetically) run on either engine or both. Wouldn't work on one engine with older transmissions with rear pumps because both driveshafts are going to turn all the time, I think.. Or maybe I dreamed all that...
When boats use two motors side by side they use the reverse rotation on one engine. So it shouldn't be hard to get the right cam and dist gear. Might want to look into how the tie the engines together on those. I remember seeing a dragster once that had dual Pontiacs. It didn't have a frame under the motors. The back half of the frame bolted to the rear of the motors and the front axle and wheels bolted to the front of the blocks. Probably not a good setup for the street but it looked neat as hell.
In the boat world it is done that way so you can use opposite propellers in an effort to have them cancel out torque-steer. Usually when you have twin boat motors with outdrives, one drive is setup reverse-rotation - allows right & left hand props, but both engines are standard rotation.
I've seen both ways...I can guarantee that some Y blocks, MELs, & SuperDutys are reverse rotation. However, I've seen plenty of conventionals, with the drives doing the work of reversing one prop. I suspect that most or all modern setups are this way....cheaper to do. For whatever it's worth...
Meshing the flywheels sounds like a recipe for disaster! Most multi engine pull tractors use elaborate gear boxes, so expense would be high. Using a chain drive between them will probably be too much horsepower, or speed for the chain. I just don't see an inexpensive solution to this, except for the engines being in line. If you built the right rear axle, a dual driveline might be the best overall solution. You could explore the use of a gilmer belt, but logic would put it between the engines and the trans, which is another problem. On fuel dragsters they deliver about 800-1,000 horsepower to the blower. Maybe a rev limiter on the secondary engine, in case the belt breaks. If you use an automatic trans, the shock loads on the belt might not be as bad.
Way back a bunch of years ago my brother and I was trying to build a budget tractor with side by side engines. The problem ,if I remember correctly, was the Flywheel /flexplates were not large enough to mesh with the engine at any reasonable angle,(oiling problems). Now a flexplate could be fashioned that was large enough if the starter was relocated. We ended up with them end to end ,that is pretty simple.
FWIW, twin-engine dragsters, even four-engine dragsters were always heavier and less reliable than they were fast. On hearing this "What if I put two in it?" wouldn't a true H.A.M.B. friend take you to Hooters, buy you lots of beer and wings, talk football until those good looking women caused this inspiration to fade? As always, your money, your decision, but maybe AA had it right about someone to call in the middle of the night when a drink seems like the answer. thnx, jack vines
True enough. Nearly all of the twins had decent traps but slower elapsed times, and they never could quite catch up, performance wise, with the singles, lightweight or not. By the same token, 90+% of the street stuff out there would run smoother, and "better" (however one wants to define this: quicker e.t.s, faster trap speed, better fuel mileage....etc.) with a single well-adjusted modern four barrel & good intake.....and yet people keep throwin' on them Strombergs & log intakes. Must be a reason for that.
The biggest reason that top fuel cars break belts is that the blower pulley is to small. If your engines are going to be 4-500 hp each you could easily hook them together with a 3 or 4 inch wide toothed belt on some pulleys that were 10 to 12 inches in dia and you could do it on the front crank snouts, so it would almost be like connecting them together if they were in tantum. Probaby could do it fairly cheap and it would be quiet and about as reliable as you would expect and better than chain. Rex
We're currently doing an exhaust for a customer who installed 2 engines in his Ford truck. The truck is still a project so it doesn't yet run or drive. The engines are mounted side-by-side, backwards (the flexplates point toward the front) in the bed. There are 2 automatic transmissions pointing forward to a modified transfer case. The gears in the t-case have been modified/reversed (?) to that each auto trans feeds into separate input yokes on the back of the t-case, then there is an output shaft in the center of the t-case that connects to the main driveshaft which is then connected to the single rear axle. The customer is an old-school machinist who has done all of the work himself, and it actually looks like it might work. I'll try to remember to take pics and post them tomorrow. Hank
Some of my useless knowledge: Mercruiser Marine V8 engines are SBC 350's. They come in RH and LH. Most are the reverse type because single engine torque keeps the boat closer to level (sideways) when the driver is on the right side. The cam is regular, just 2 gear drive (which reverses it). The crank is drilled for oil timing on reverse rotation. They use a regular starter, just plugged in the bellhousing from the rear (which reverses it too). MY CHOICE: Use 2 SBC engines. Put one forward and one backwards. Connect them at the front with a Gilmer belt (Inlines transmit double torque thru one crank all the time). One trans, simple hook up. Trans offset to passengers side, rear axle diff offset too. As for belt durability? Remember, The belt load will only be what the tires are actually transmitting......and for the short duration your on it. Good luck, keep us informed. MIZ
I think the first twin engined dragster was The Bussel Bomb which had an olds in the front and a cadillac in the rear driving a swing axel from either side of a single center section that had one ring gear ane two pinion gears... I sure would have liked to seen how they made that work?
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