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running dual engines

35K views 67 replies 28 participants last post by  muddbogg 
#1 ·
I have never understood how you would run 2 engines. If I am able to discover a cheap realiable way to do this i might consider it but I doubt that is going to happen. Well anyways i have heard of different setups like one for each axle, side by side, and in a row. Those are the ones im intrested in. I know of some way using a transfercase but havent seen any pictures so its confusing. I have looked at Tommy Ivo and Mickey Thompsons old dragsters and they look great, great and expensive. So my question would be of ways to get them to run together simultaneously. Appreciate the help. Thanks
 
#5 ·
I read that some of the inline dragster engines were coupled using two chain sprockets back to back... one on the leading end of the rear engines crank... and the other on the back of the front engine's crank flange, where the flywheel would mount... with a double row chain wrapped around the two sprockets to join them. I don't know how well this would work for a long term coupler.
 
#6 ·
I just re-visited the website and there's some great pic's of his championship puller and it has 6-7 engines on it coupled with transfer cases. I'd like to show you a pic but their copyrighted. Click on "about us" on their site and you can see for yourself. :mwink:
 
#7 ·
The two sprockets with a double row chain locking them together has worked on many cars.

You know the Ivo twin engine has one engine running in reverse?

I have never understood the twin engine street car thing, yes it is an "oddity" but that is about it.

Brian



 
#9 · (Edited)
I put dual rotary engines in my Outlaw Dirt Latemodel...





The engines were bolted together with a 3/8" aluminum plate between ( you can see the center plate's "lifting eye" in the pic between the engines), and mated the e-shafts (rotary crankshafts) together with a homemade splined coupler...



The basic geometry is that of a tapered/pinned coupling, with a male and female component. The male half is machined into the front of the rear e-shaft, and the female half is machined into the rear of the front e-shaft. The total length of the mating tapers was exactly 1.000". The major diameter of the taper is 1.400", and the minor diameter is 1.200". Angle of the taper is 5 degrees, 43 minutes.
Arranged about the parting line of the taper were (12) 3/16" aluminum pins, evenly spaced on a 1.300" pin circle diameter. These pin holes were bored parallel to the e-shaft centerline. Total length of each of the (12) pins was 1.500", with .250" of each end of the pins rooted in the front and rear e-shafts. A 3/8" dia. draw-bolt passed completely thru the center of the front e-shaft, anchored in the internally threaded male component of the rear e-shaft (mine was conviently made from a section of 3/8x24 fine thread B-12 redi-rod). A nut over a hardened washer in the center of the front pulley was torqued to 35 ft/lbs to draw the two e-shafts together. A bit of sealer is a must to prevent oil internal leaks, as the center of the shafts carried oil.
 
#11 ·
aisr said:
I put dual rotary engines in my Outlaw Dirt Latemodel...

.
That is very cool. I have been a fan of the Rotory motor for years after hearing some of the early hp claims. I have never ran one mind you, but have had an interest and your car has my ears perked up.

Bolting two of those motors together is as close as you will get to simply making a bigger motor, not having two motors. It is like you are bolting on more rotors.

Brian
 
#13 · (Edited)
Alright, all this is great stuff. You have answered alot of my questions but I still have a few more. Using the transfer case idea: I believe any transfer case you use including the NP205 would break very easily with 2 engines, also a transfer case hooked up that way would be running backwards(if i have the picture in my head right) and there again another way to easily break it, you guys agree? If I were to ever run any of these setups it would probably be the one for each axle. I have run one caddy motor(472) in a sand rail and I loved it, I have always wanted to use another caddy engine. So with that I would like to know about setting up a engine in the front and back of something using caddy or olds like that....Fiero?VW? Like how hard would this be and how would I synchronize the engines together and im sure there would be many 'nickel and diming' on that style dual engine.Thanks

And by the way i posted this reply before reading all of the links.
 
#15 ·
TucsonJay said:
I read that some of the inline dragster engines were coupled using two chain sprockets back to back... one on the leading end of the rear engines crank... and the other on the back of the front engine's crank flange, where the flywheel would mount... with a double row chain wrapped around the two sprockets to join them. I don't know how well this would work for a long term coupler.
In my experience this style of coupling is very durable. We use them extensively on drilling rigs developing over of 16,000 lb.ft. of torque. Never broke one in 20+ years.
 
#16 ·
But, don't you just have to believe that with todays high horsepower engines, running inline that the torque from BOTH engines thru a single flywheel coupling flange (and all that extra load on the counterweights joints on the rear engine) would be a recipe for crankshaft failure? Wouldn't it be easier to simply build more power into a single engine, with a single premium crankshaft, and push the HP and torque values up to where they approach the crankshaft's limits, thus saving the weight of the extra engine? Or, are we simply discussing the kool factor?

Pat
 
#17 ·
Since I grew up (as far as I got) during the time of racing developement I did get to see some of the twins. The double row chain was from industry and quite capable of handling the hp of the day for the durations they had to have. The real advance came when the gear coupler was adapted to the crank flange and the crank snout. The early ones were cut and welded. There were a lot of guys fresh out the service that were highly trained welders so it was not a real problem. Even axels were cut and welded.

The 392 and BBC cranks were pretty stout but there were still few cases of the snout being twisted off. SBC were a problem but you couldn't tell with the likes of "the Freight train" and others. I think they broke more cranks than we see in the pictures. It wasn't unheard of the weld a BBC snout on to a SBC. You can even get them machined this way today for blown apps.

The flywheel meshing worked for a while however this caused a side loading of the rear main that it was not designed for and there were bearing failures. Even with a chain drive this still occured. Again we didn't always see the behind the scene things. There were some very good side by sides in the early days.


Try this for all the real twins.
http://twotogo.homestead.com/
 
#21 ·
What I want to know is how the hell do you install the pumpkins and axles? Especially the two stubs between the center pumpkin and the out pumpkins. :confused:

Brian
 
#22 ·
MARTINSR said:
What I want to know is how the hell do you install the pumpkins and axles? Especially the two stubs between the center pumpkin and the out pumpkins. :confused:

Brian
Maybe a single splined shaft from one outer pumpkins' inner side gear, through the center pumpkins' two, and into the other pumpkins' inner side gear - pushed all the way through from one side, then an axle installed on each side. I imagine it would likely be spools in all three.

Anybody notice that 1128 C.I. on the fenders means three 376 cube strokers made out of small journal 327's??
 
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