Date: 19 Jan 2005 22:02:26 GMT From: Dave Hinz <DaveHinznospamcop.net> Subject: Re: Opened DI Casette - For those interested
On Wed, 19 Jan 2005 21:36:24 +0000, Colin Stamp <colinnospamp.plus.com> wrote: > On 19 Jan 2005 19:34:45 GMT, Dave Hinz <DaveHinznospamcop.net> wrote: > >>I'm thinking that the peak pressure would ideally come as late as possible, >>so the cosine of the angle is the highest - most downward force turns >>into the most rotational force that way. > > Yep, but only up to a point. Go too far, and the tail end of the > pressure pulse gets wasted, either by trying to push the piston past > BDC or by leaking out through the (by now open) exhaust valve. Not > sure which - maybe both. So, then, I think integrate the area under the pressure curve between TDC and whenever the exhaust valve opens. No, correct for the force imparted to the crank based on the crank angle and integrate _that_. Still reasonable math. >>It might be a fundamentally flawed idea, though. It either breaks the >>symmetry of the combustion chamber, or it puts the spark plug off-center. >>Not sure there's enough reason to justify it. > > I'm pretty sure it could be made to work. Alfa manage to get their > T-spark engines to work quite nicely with two spark plugs per > cylinder. Also, the pressure sensor could be flush with the > combustion chamber top. You're right though. There's no need to do it > with the current emission standards. Ion sensing works well enough. Well, by playing with cam profiles, I'm sure they're already imparting a swirl into the combustion chamber, so yeah they could probably work around something like this. >>You're an engineer or technician of some sort, I assume, Colin? > Damn - spotted again. From a mile away. > I started out with electronics, but now I'm > writing low level driver software for digital TV set-top-boxes for my > sins. Reallllllllly...are they a brand that I might recognize? > I'd like to be playing with car electronics, but it hasn't happened >:o( > I have to console myself by trying to build a car in my garage... I've toyed with that idea. I have a '71 Sonett which would benefit greatly from a new Sonett, only out of stainless.
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