Posted on 04/28/2003 6:10:21 AM PDT by John Jamieson
On the other end of the speed range, the open/shut nature of this valve would require a separate idle air control system. Actually, you would need a throttle plate too. Camless engines are coming, but the ones I've seen have continuously variable, electrohydraulic acutators.
Bingo. I see this as a less-efficient means of turbocharging - except, as the author noted, the idea is to increase efficiency by artifically requiring the engine to run at WOT. So, amending your remark, how is this more efficient than a turbocharged 4-cyl with cylinder deactivation? Or for that matter, a hybrid?
BTW, the valve control would be very, very interesting. I'm thinking a 2-stroke engine's reed valve setup, modified with a clamp "shut-off," may be appropriate. And the loss in exhaust temperature will have the enviro-nuts a little upset.
Thinking some more, a rotary engine does not require a valve to shut-off. There could be multiple ports for the intake of the "slave" rotor through which the scavenged exhaust could be alternately routed, which may make the valve control a little simpler.
The old "hit and miss" engines did this. The carb did not have a throttle plate in it. Speed was regulated by a governor that interposed an escapement kind of mechanism in the exhaust valve pushrod. The intake was just a poppet valve on a light spring. As long as the engine was running at sufficient speed, the escapement held the exhaust valve open, and the cylinder just pumped air in and out. When the speed dropped enough, the exhaust valve would be allowed to close, and cylinder vacuum would suck the intake valve open on the intake stroke, and the engine would fire again.
Huff.huff.huff..huff...huff....huff.....Slurp.POP!.huff.huff.huff..huff...huff....
Fair enough, let's drop it then. One last thing though:
Solenoid valve train is laughable, only electrically controlled hydraulics can do it.
Laughable? It was done five years ago at Southwest Research Institute. See SAE Technical paper 981908. Expensive and complicated, yes, but not laughable. SWRi might be a good place to air your idea.
50-400 bucks each, and probably not as fast as JJ needs.
You might try there.
www.mcmaster.com
Unlike some of the parts houses, they will sell to anyone with a Master Card. I get stuff from there all the time.
But I DO have last year's Grainger catalog handy, and I just looked it up(I should have looked it up before I posted, but I should have read the whole thread before I posted, too), and the on/off solenoids are all more than $50 and the directional solenoids are all more than $200.
Now, I only know a little about hydraulics where it has been incidental to other areas of interest, but I do know a fair amount about EE, and I feel very comfortable saying that a solenoid that has the kind of response time JJ needs against the forces with which he is dealing will be very hard to come by.
Dale ... where?
The industry term for the response time is "operating speed." Be informed that most of the hydraulic control solenoids are pilot-type, so that apparatus will ALWAYS be way too slow since the solenoid acts on a small valve which in turn controls the valve that does the grunt work(no heavy lifting). The solenoids that control them will be too weak, since they don't do the grunt work. I think 0.005s operating speeds exist, but not with any kind of load, and certainly not with significant displacement.
I won't hold it against you if you can't find anything(I don't mind being right ; - ) ), but if you DO fin something, I would really like to know about it, so please ping me.
Bump for later read
I toyed with the idea of using two of the cylinders as compressors for the others in much the same manner that a gasoline 4-8 cylinder air compressor operates by shutting down the fuel to the center cylinders and porting their output on full-throttle loads to the remaining cylinders with an O2 sensor to provide the extra fuel only at those times.
I drag raced a 57 Pontiac that would "float" the valves at 5,000RPM every time; I switched out the valve springs for a set of Ford Interceptor springs for an FE block and wiped out the camshaft in three weeks - didn't "float" the valves until then though and that old POS sounded great at 6500RPM.
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