DIY_EFI Digest Monday, October 11 1999 Volume 04 : Number 574 In this issue: Distributor Re:Up Up and Away Re: DIY_EFI Digest V4 #572 Up Up and Away Date: Mon, 11 Oct 1999 19:44:58 +1000 Re: DIY_EFI Digest V4 #573 33 foot propellers? That must be one big mother of an aircraft? See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- Date: Mon, 11 Oct 1999 11:43:22 EDT From: A70Duster@xxx.com Subject: Distributor << There are significant strengths on the spark management side that would be hard to accomplish with points and advance weights.... Mike V >> Yeah, it's called a magnetic pickup that fires a solid state coil controller, and a vacuum advance for part throttle cruise. ------------------------------ Date: Mon, 11 Oct 1999 08:56:49 -0700 From: "John Dammeyer" Subject: Re:Up Up and Away Hi Phil, > >Date: Mon, 11 Oct 1999 00:50:01 +1000 >From: Phil Lamovie >Subject: Re:Up Up and Away > >Hi John et al, > sorry 'bout the html had to reload NT (i moved the mouse)and got all >of the default settings. I've pressed a few wrong buttons too. ;-) >Please note the total lack of Patents for Altitude correction of >aircraft fuel injection computers. Also total lack of altitude sensors >on all Ford and GM vehicles. I suppose they don't have mountains in >the >USA. That GM and Ford don't use them is irrelevant. They also didn't use overhead CAM engines until the Japanese and European automakers started impacting their bottom line. Once fuel prices changed in the US their attitude did too. Most California polution testing is done close to sea level and they have the most stringent specifications. The tests are done at idle while the O2 sensor is in closed loop mode. A rich mixture at Full Torque RPM is never tested for and most vehicles don't run in that mode anyway. An engine idling at a high RPM because it was tuned at sea level but tested at 5000' ASL would be sent to the shop where the engine would be adjusted to pass the tests at that altitude. An inability to patent basic physics is not an indication of the lack of basic physics. > >My company has also supplied ECUs for Aircraft that have flown from >England to Australia, film is available from National Geographic. >I promise they were all fitted with absolute sensors. The engine were >all dynoed on a thirty foot tower (they had very big props about 33 >feet >span) 650 hp at sea level)) and then flew half way around the world. The reduction gear would have to keep the propellor tip speed below the speed of sound and in either case the aircraft propellor is primarily interested in best fuel economy at maximum torque - not maxium horsepower. As I said before, it's not that the MAP-RPM doesn't or won't work; it's just not the optimum solution and the pilot that might have to land his aircraft 100 metres from the runway with empty tanks would prefer the optimum solution. > >Hope the simplicity of it is not too hard to fathom. >Phil I think I'll leave this discussion rather than retort on simplicity verses complexity and perhaps we can just agree to disagree. Regards, John ------------------------------ Date: Mon, 11 Oct 1999 13:37:19 +0100 From: Ade + Lamb Chop Subject: Re: DIY_EFI Digest V4 #572 Sorry about the repeated messages.... Think I have fixed the problem now.... Ade ------------------------------ Date: Tue, 12 Oct 1999 02:59:11 +1000 From: Phil Lamovie Subject: Up Up and Away > Or - altitude could be faked out by reading the MAP while the engine > is stopped. Then you could account for it. Of course this assumes > > that the car is stopped every once in awhile (probbaly a reasonable > thing). I know for a fact that some outboard marine engine > controllers do this. If you map the engine properly and assume that it's wear rate is zero then you can infer barometric pressure from your manifold absolute pressure/rpm/tps/air temp association. if 30% tps at 3000 rpm at 20 deg C produces 35 kPa instead of 38 kPa MAP previously you could safely state that there is going to be a storm soon as the barometer is down 30 points or 3 kPa (30 millibars) The marine engines will go blind if they don't stop it. Comparative states of rpm vs MAP and TPS are used for error checking of sensors, Acc enrichment, gear selection and so on. Regards Phil Lamovie Injec Racing developments ------------------------------ Date: Mon, 11 Oct 1999 19:44:58 +1000 From: "Warwick Anderson" Subject: Date: Mon, 11 Oct 1999 19:44:58 +1000 This is a multi-part message in MIME format. - ------=_NextPart_000_00B2_01BF1421.19CCED40 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable silly as it sounds but dose my multi point fire all injectors at the = same time or only as each valve opens??=20 - ------=_NextPart_000_00B2_01BF1421.19CCED40 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
silly as it sounds but dose my multi point fire = all=20 injectors at the same time or only as each valve opens??=20
- ------=_NextPart_000_00B2_01BF1421.19CCED40-- ------------------------------ Date: Tue, 12 Oct 1999 03:25:00 +1000 From: Phil Lamovie Subject: Re: DIY_EFI Digest V4 #573 > What about effects on exhaust back pressure caused by lower > barometric... I'd think it would reduce the residual pressure > in the cylinder at the end of the exhaust stroke, allowing > more air in for a given MAP. > Orin. Except for the fact that back pressure of the exhaust is not a function of the outside pressure as much as a function of exhaust manifold configuration and pipe diameter/length/rotation. Exhaust pipes are too long and the exhaust event too short for the atmosphere to effect it much. The entire event at 280 degrees of duration at 3000 rpm is 280/360/20 msec or 15.55 msec. And of course this is no flow for the first or last 20 degrees of cam lost in taking up the slack. now 220/360/20 or 12.22 msec The in cylinder pressure at the time of the exhaust opening would be in the order of 250 to 400 psi. (varies a lot with engine load.) As for allowing "more air in" the air flow is a function of the pressure differential between the in cylinder volume and the plenum chamber pressure. The piston has been past top dead and the chamber has been purged of exhaust. In fact about this time some new air fuel mixture is following the exhaust gas out the still open exhaust valve courtesy of a small "low pressure" event in the exhaust manifold. This pressure event is exhaust gas speed/density/temp related though not immune to air pressure out side the effects would be more mechanical as the "spring" value of the air would alter and this would detune the tertiary part of the wave trap. Phil Lamovie Injec Racing ------------------------------ Date: Tue, 12 Oct 1999 03:44:18 +1000 From: Phil Lamovie Subject: 33 foot propellers? That must be one big mother of an aircraft? 'Tis a Vickers Vimmy 1918 Model Bomber 2 x 454 chevy big blocks with from memory a 4:1 redux giving about 2500 ft/lbs or about 90 mph flat stick One section of the trip was aborted due to 100 mph head winds !! they were flying backwards !!! The test stand was for US certification of the redux which was required to be "bench" tested for 30 hours. The aircraft had to be registered somewhere and as it was designed in England and built in Australia it seemed only fair to register it in the country that has the most lax aviation rules. The prop had to be used to "simulate" the cyclic loading on the box The engines were mounted between the upper and lower wings about 20 feet off the ground. The tower was built and paid for by National Geographic funding. (so it was free) The size of the props was "calculated" on the predicted available torque at rated rpm. The "engineers got it about 25% wrong. (they guessed too low) Net result was that the pilots used the extra (non certified) power trying to out run a monsoon and busted a crank. Apparently this caused " some noticeable vibration" Regards Phil Lamovie Injec Racing ------------------------------ End of DIY_EFI Digest V4 #574 ***************************** To subscribe to DIY_EFI-Digest, send the command: subscribe diy_efi-digest in the body of a message to "Majordomo@xxx. A non-digest (direct mail) version of this list is also available; to subscribe to that instead, replace "diy_efi-digest" in the command above with "diy_efi".