a technical discussion, engine efficiency |
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a technical discussion, engine efficiency |
r_towle |
Aug 15 2005, 08:27 PM
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#1
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Custom Member Group: Members Posts: 24,624 Joined: 9-January 03 From: Taxachusetts Member No.: 124 Region Association: North East States |
so, I have been thinking (not always a good thing)
If an engine is basically an air pump, and the objective is to make it as close to 100 percent efficient, why is the exhaust valve so much smaller than the intake valve? Forget emmisions, forget fuel delivery, just want to understand why this is so...it is so on most engines... Rich |
Brando |
Aug 18 2005, 06:58 PM
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#2
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BUY MY SPARE KIDNEY!!! Group: Members Posts: 3,935 Joined: 29-August 04 From: Santa Ana, CA Member No.: 2,648 Region Association: Southern California |
I disagree. I believe L-Jet (Air-Flow Control Injection) has some of the same limitations as D-Jet. For instance, if you go with a wild cam there will be problems with fuel delivery. Like D-Jet and unlike CIS, the injectors only pulse for a certain amount of time. I'm not sure what that duration is, but someone more knowledged on the technicalities of L-Jet can elaborate. If you have a wild cam with some overlap on intake, or more duration on intake, the injectors don't open up longer. So you end up running lean on your air-fuel mixture. Unless there is a way to change the duration the injectors are open. That's the only way I see a fix for using L-Jet on a larger engine (my first idea before buying carbs). |
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