Whoa- so much misinformation all in one thread! I've almost blown a vessel for how many days now?
el: dozens have tried the injector cut-off, and failed. Dozens more will try it again in the future... and still fail. The reasons why it doesn't work have been discussed. It revolves around pumping losses... always has. If a simple injector cut-out worked, everything would have displacement on demand since the late '80s. The pumping losses have to be reduced for this thing to work, either as a permanent conversion or as a dod setup. That means no air in/out of the cylinder.
If A-B-A testing is gonna happen then none of the mods can be permanent in nature i.e. no grinding off lobes and whatnot.
saand: you only have to look a few posts up to see that the pistons on a parallel twin rise and fall in UNISON.
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Originally Posted by oly
With two cylinders not producing any power, that leaves much more loading against the two that are producing power, which changes the transitional piston speed during the power stroke, and results in the lugging.
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What? Piston speed is related to loading how? Stroke and rpm, with a lil rod angularity effect too. That's it, and the geometry of all that isn't changing. Loading is not a factor.
Change the spark advance why? Each individual cyl works as hard or as little as required, no matter how many more are helping it.
Re: epoxying dead intake man ports: with closed valves on the ends of the runners the worst thing that could happen is maybe some sort of helmholtz resonant phenomema- which tends to dampen pulses right? Who knows, maybe that would help?
phantom: removing an ex valve and venting the cyl to the atmosphere eliminates pumping loss? We gots a piston going up with an open port so it's gonna expel what's in the cylinder. That's pumping. Then the piston will go down and it'll draw charge back in. More pumping. In and Out and In and Out; I.E. pumping losses.
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Originally Posted by ed
There a lot of things working against ya, the whole intake and exhaust system is optimized for 2.2L , running only 1.1L and intake manifold plenum and TB are to large along with exhaust system pipe diameter .
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That may be; I wonder how detrimental it really is vs optimized? After all, much of the time stock engines are operated outside of the narrow rpm band where any sort of in and ex tuning helps flow.
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Perhaps ideally what we'd want is a home-made displacement on demand system. I do think it's doable. There is a lot of field experience with them now so we know what to expect performance-wise, econo-wise, NVH-wise, and longevity-wise.
Perhaps less ideally, perhaps not, is the more or less permanent disabling of cyls. If the reduced hp is tolerable there should be efficiency benefits vs dod by totally eliminating- not just reducing- pumping losses and internal friction.
Oh, maybe I'll get to the rest later...