Timing two engines in series.

[TJ]

Yesterday a buddy of mine showed me a video of his neighbor's latest project.  The guy found a 1928 model A body to make a rat rod using two chevy 327's installed in series (one in front of the other). 

I was wondering how would a person set the timing on each engine.  I'd think the curves would need to be identical so that one engine doesn't push the other...probably use an electronic box to operate both?  Also guessing the carb tune for each would be critical.  Or does it matter if one engine pushes the other a little?

The guy building it says it will be for street use...not drag racing..he might be a half bubble off plumb.     

BTW, this is just a curiosity for me because I'll never do it.  Though it might be a nice topic to discuss.

Edit:  For the sake of discussion, let's pretend I said two Ford 427's...

[BattlestarGalactic]

Interesting project.  Never really though much about how to keep the two "in tune" together and how critical it would be.
I suppose you'd need two MSD boxes and be very critical of springs in the advance plates and try to blueprint them.  A distributor machine would be real handy!  If not, I don't really think it would really hurt that much.

How are the two motors joined?  Homemade coupler between flywheel flange and the rear engine crank snout?  I suppose that would be the weak link if one motor was tuned that far off from the other.   One working harder at different rpm kind of thing.

With all the multi engine designs in various motorsports, it makes me wonder how critical it actually is.  Is it much different then say one low cylinder in a V8 engine.  Or multiple low cylinders, while the others run normal?  What stresses does the crank see and how long does it put up with it before it creates problems(other then running bad/rough).

[FirstEliminator]

 I've heard about people coupling engines inline to run irrigation pumps on a farm. Never seen the set-up, but it might be similar. 

[jayb]

I think it would be easy to do.  Run all the timing off one distributor, and just use the second distributor to distribute spark.  A coil for each engine, and an MSD or equivalent for each engine.  Feed the main distributor pickup into both MSDs.

[Falcon67]

That and lock the timing on both.  I'd tend - depending on the coupling method - to start with each engine individually and set the timing, rotor phase, etc.  Similar to how you can do a dual carb setup.  Then link and adjust in tandem as required. Depending on the resistance requirements, it might be possible to fire both coils off the same MSD box.  Unlikely, but worth a call. 

[Tommy-T]

I don't think it's that critical at all. Get 'em pretty close and let 'em rip. I say this because as a youngster my favorite class was Top Gas and multi-engine cars were fairly common. My personal favorite was the Odd Couple with an early hemi in the rear and a small block Chev in the front. How close can that tune really be?

A good friend of mine has used the GM V12 irrigation engine in his rat rod T pickup. The engine is based on the GMC big V6 that was used in a gazillion early 60's GMC pickups. They made quite a few of the V12 versions for pumps. It's wild!

[TJ]

I've seen some version of the coupler BattlestarGalactic mentioned.  They have a rubber center like the old steering column flex link.  Maybe that's enough to isolate any harmonics so one engine doesn't damage the other. Also,  I was guessing there'd have to be a flywheel for each engine with its own starter?

Jay makes timing sound easy enough though I bet I could mess it up 

I thought about what Falcon67 said about locking the timing.  Definitely okay for racing but maybe not optimal for street?

The one question I had about TommyT is what happens when one engine is pushing the other.  Does the one being pushed act like an engine brake?

[shady]

Where's TV Tommy Ivo when you need him.

https://youtu.be/8Rn5a0PgkEw

[Falcon67]

>I thought about what Falcon67 said about locking the timing.  Definitely okay for racing but maybe not optimal for street?

Most modern boxes have a provision for start retard.  If not, you just leave the ignition off, spin the motor up and switch on.  Also with modern PMGR starters, the issues can be minimal.  My Falcon is locked at 38 with 10 degree start retard, no issues at all. 

[cjshaker]

A drag car would be very different than street driving. With 2 engines at WOT, each engine is trying to rev to meltdown point, so one won't be pushing the other, it'll just be producing a little more/less "push", but it will still be producing a load. When cruising at part throttle, like a street car would do, I think you'd run into issues if one engine was "off" from the other. One engine will always be the "lead" engine, if it has a direct coupling. If it was some sort of fluid coupling, you'd still have the same difference in power issue, but the coupling would absorb that. JMO.

[cjshaker]

Most modern boxes have a provision for start retard.  If not, you just leave the ignition off, spin the motor up and switch on.  Also with modern PMGR starters, the issues can be minimal.  My Falcon is locked at 38 with 10 degree start retard, no issues at all.

I've never understood why guys with locked out timing didn't have start issues. If a regular engine is even a few degrees over ideal initial, it can create a hard start issue, so even at a retarded 28*, that's quite a bit over what a standard engine would see. I don't think your Falcon has such a big cam that it bleeds off that much compression, does it Chris? I'm obviously missing something here.

[TomP]

Ivo is around and you ask but lots of others have run twin or more engines without issue even on street cars. There was an Austin A40 with two small block Chevs a magazine photographer drove.

They could be coupled crank snout to flywheel flange with a double row chain that drives two single row gears. You don't need the second flywheel and one engine could have the starter.  You would want them close together but if they were spaced apart you could use a circle track in and out box to be able to run the rear engine without the front running.

It doesn't have to be expensive.... check these guys... look for the video where they first add a second engine...
https://www.youtube.com/watch?v=jGWHZecSiXc

[Henrysnephew]

Tom, I LIKE them guys!  Was that you in the back seat working the throttle?  Randy M

[shady]

Crazy Russians. That's one way to get through those long winters. Only thing keeping them out of the 5s was the front end alignment.
Take that Road Kill.

[Heo]

How about this? A 4 cyl BM Bison and a 2cyl BM Victor Coupled together
https://www.youtube.com/watch?v=HHN0cjikM3Q