TwoIntoOneIntoTwo carbs manifold?

Being a scrambled brain case the sane part of me is put in terror/horror shocked with insane part snapping throttle w/o even asking first. So sane part is scared of the Drouin and extra mass to drag back out of ditches and bushes by crash cage. Still even the sane part likes harsh snappy acceleration with leveling out torque rise instead of blower exponential spike. Seeking advise insights on an X manifold to hang two mid 30's mm Lectron carbs on. With just a pair of carbs on Peel she'd be about 25 lb lighter. Thinking 3D printing may be best way to make such a X manifold, if not by casting in JBW.

A couple decades back, Axtell suggested that I try an intake manifold with a large plenum chamber between the two intakes and the carbs. He thought it might improve mid-range performance, but hadn't tried it himself. I don't think he ever did give it a try. I never tried it, partly because it would be challenging to find room for it in a Commando. Mostly, I was worried it would actually reduce top end horsepower because it would compromise the individual intake tract tuning effects. On a street bike that doesn't rely as much on resonance tuning effects, it might be OK. But on a race bike where intake and exhaust tuning has a significant effect on top end power, it didn't look so good to me. If you were going to build such an intake with a large plenum, you might as well just fit a single large carb. No reason for duals unless you couldn't get a single large enough. Just idle speculation on my part now. I like dual carbs (or injectors?) just fine, probably with a small balance tube between them to help out at idle speeds.

I'm guessing the Jim Comstock has already played around with this while developing his EFI system. Anything to add, Jim?

Ken

Got 2 carbs on hand and thinking to splay them outward to avoid frame filter fouling. After seeing-sensing the arrgressive tractor tires I'm no longer hardly even picturing hwy twisties lines-flight times of Phase Three and Four but committing via the ditches and culverts and Steve Mcqueen off into the wild scenery others only stop and take pictures of. So more interested in trackable low-mild power, light mass with 60'+ lean angle clearance. If I could get ahead of failure recoveries would like to have comnoz test dual carbs X manifold on dyno. I'd not tapper them down to head but flair to bigger OD than port to combine both my own surprising flow factor along with comnoz tappered tube tests. I'm a QuadraJet spread bore and Holley small bore pumper 4 barrel kind of guy. Here's Drouin manifold to ponder. Maybe hand craved lost wax casting?



Short sleeve temps, Peel ready to accept engine install, polishing stand motor recovered to recover years of nice parts handling, Trixie ready to just seal all back ready for spring, got Suvee fuel hydro lock check list down now so time to spend a couple more weeks on mower rebuild instead.

Why ? Are you taking it to the salt ?

Steve, That looks like an old Bendix carb like I had on my '74 StupidGlide. A horrid primitive mixer, :evil: akin to a beer can with a nail hole in it. Is that what the Drouin kit was supplied with?

concours said:

Steve, That looks like an old Bendix carb like I had on my '74 StupidGlide. A horrid primitive mixer, :evil: akin to a beer can with a nail hole in it. Is that what the Drouin kit was supplied with?

Click to expand...

No the drouin had a "lake" type fuel injector it was a lot less complex than a Bendix ..........baz

Dudes, the Drouin photo is not mine, only show it for the size-shape of the manifold to help picture an X version with 2 smallish carbs rather than one bigger. For daily use I want harsh acceleration up to the ton or so rather more than hi speed potential. For commutes-errands I don't want to slow down much or at all through the sharper turns like all other cycles must, which requires 60'+ lean angles not to hi side off road, unless intended for some real thrills. Reading decades of reports of Lake Injector on cycles and aircraft say its a wonderful performer slow to fast, death valley to cloud tops - as long as the flat slide operation prevented from sticking, which I've solved by pull-push dual cable throttle. Alas the Drouin Lake is part of the impeller housing which is part of the bulky primary case mount that sticks out a couple inches beyond factory cover which limits L leans to 55' AND I dare not run it in public w/o crash cage as dogs or goats or deer, ruts or mud or ice take out couple $1000 in unreplaceable parts. As no one seems to have ever tried 360' twin with two carbs on single manifold there may be a reason so likely Peel easy way out is a biggish single flat slide like Bruce McGregor did - after he started up on Drouin/Lake in garage and felt the slick sticking on throttle realease so put on the flat slide before ever riding it. Hill climbs, Texas Mile, salt runs and flat tracking beg for boosted power but can only do so much of that. Good Grils good to haven but Bad Grils Go Everywhere, if dressed for the occassion... Next Peel has spiked functional dog collars too.