DIY_EFI Digest Thursday, April 29 1999 Volume 04 : Number 249 In this issue: Direct Fuel Injection - la Bosche Control of Direct Injection. Re: Direct Injection Re: Fuel injection plugs Help - Pickup Circuit MC6840 timer specs. Re: Fuel injection plugs Re: Direct Fuel Injection - la Bosche See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- Date: Thu, 29 Apr 1999 05:12:03 GMT From: bob@xxx.com (Robert Harris) Subject: Direct Fuel Injection - la Bosche Automotive Fuel Injection Systems - a Technical Guide. Jan P. Norbye ISBN 0-87938-130-8 Page 55 M-196 - a mid fifties straight eight na racing engine. DOHC desmodronic, 10,000 rpm Hemi head 2.5 liter Grand Prix engine " The Mercedes Benz M-196 was an in-line eight cylinder engine with dual overhead camshafts. It was used in 2.5 liter form in the W-196 Grand Prix car of 1954-55, and in three-liter in three liter form in the 300SLR sports prototype of 1955. The M-196 engine layout permitted the use of long and straight induction pipes, giving considerable ram effect. The injection pump was made by Bosch. It was an eight-plunger design, gear driven from a central power take off on the engine The M-196 nozzles were of the pintle-valve type with a single delivery hole. Fuel pressure unseated a spring-loaded one way valve at the right moment and no return line for leakage was needed. The injector nozzles were carried in holes drilled in the cylinder barrels. Extensive experiments were necessary to determine the optimum position of the jet itself and the shape of the spray. Finally the nozzles were placed on the inlet side of the block at an upward angle, aiming the spray DIRECTLY AGAINST THE EXHAUST VALVES". Later "There was little freedom with regard to injection timing since the pistons shrouded the nozzles at top-dead-center position. This left no more than 120 degrees of crankshaft rotation available for effective injection, which corresponds to only .002 seconds at 10,000 rpm" Subtle hint? The production 300 SL Naturally Aspirated MFI used 1100 PSI spraying directly across the cylinder from an in block injector aimed again at the valves on the other side of the head ( from several useable drawings) . Of course you need to understand that the block deck was milled at a large angle similar to the Lincoln 462 which caused the entire combustion chamber to be contained in the block and piston with the head being virtually flat. So much for high pressure supercharged aircraft engines only. Again - atomization is not a problem when you shoot the fuel in at 1100 PSI against the exhaust valves - common to the automotive setups. 1963 Ford C-600 Prison Bus Conversion "Home" 1971 Lincoln Continental 460 "Christine" 1972 "Whale" Mustang awaiting transplant 1978 Dodge Long Bed Peeek Up "Bundymobile" Habaneros - not just for breakfast anymore ------------------------------ Date: Thu, 29 Apr 1999 05:18:01 GMT From: bob@xxx.com (Robert Harris) Subject: Control of Direct Injection. Actually, as soon as you dump fuel centicity, it becomes quite easy. Think of a four barrel carb, where the primary is linked to the throttle lever of the diesel injector. The "secondary" is controlled by the computer. What's the difference between tweaking the air and the fuel other than what fluid you control? Use an EGO for example, and use the output to control the air flow thru an Idle Air Controller. As long as the primary and the diesel pump are linked such that its always rich, what's the difference between bleeding off fuel like EFI or adding air the dark side way? Simple philosophy. It becomes very simple - much less so than defecation complication fuel side control. 1963 Ford C-600 Prison Bus Conversion "Home" 1971 Lincoln Continental 460 "Christine" 1972 "Whale" Mustang awaiting transplant 1978 Dodge Long Bed Peeek Up "Bundymobile" Habaneros - not just for breakfast anymore ------------------------------ Date: Thu, 29 Apr 1999 08:20:20 MET From: "Kapocs Attila" Subject: Re: Direct Injection Hello, I am sorry, maybe I didn't read all your messages about this topic, but I saw nothing about the Mitsubishi GDI (Gasoline Direct Injection) and the Toyota D4 engines. These are direct injected engines now on the roads in Europe and Japan. Mitshubishi first introduced GDI last year or two year ago and use it in Carisma 1.8 GDI cars. They work well> 20 % more power at full load, 20 % more economy at partial load and lower emission values. There are some articles here in Europe about these technics. What I know are Hungarian, but there must be some English ones, probably in British automotive journals. Regards Attila Kapocs ------------------------------ Date: Thu, 29 Apr 1999 02:30:47 EDT From: Regnirps@xxx.com Subject: Re: Fuel injection plugs In a message dated 4/28/99 6:26:49 PM, wsherwin@xxx.com writes: >>This is what I have in mind. Liquid propane injection with a dual > >>injector/spark device. > >> > >>Charlie Springer > > > > > > > > > > > >Is there a commercially available "dual injector/spark device", such as >you > >describe, that one could purchase over-the-counter? Where would a person > >look/call/read to find out more about it? > > > >Walt. Hey! Thetas what I'm trying to find out. Charlie ------------------------------ Date: Thu, 29 Apr 1999 09:14:16 +0200 From: miketo@xxx.com Subject: Help - Pickup Circuit Hi, Please help, I have seen some of the discussions on the subject of Inductive pickups for spark. I have a system where the signal from a inductive pickup is fed into the mic input of a pc, to count the sparks. The problem is that the software gets confused, for every spark puls consists of a number of pulses that is picked up. Can anybody please supply me with a circuit to convert the input to one single spike per spark ?? Thanks Michael. ------------------------------ Date: Thu, 29 Apr 1999 10:27:58 +0200 (MET DST) From: "Daniel R. Henriksson" Subject: MC6840 timer specs. Hi I need the specs. on the MC6840 timer IC, i've searched around on the net with no luck, there must be some datasheet pdf's out there... (Weber Marelli WD48.08 uses one of those 6840's...) BR Daniel Henriksson ------------------------------ Date: Thu, 29 Apr 1999 10:30:29 +0200 From: "Espen Hilde" Subject: Re: Fuel injection plugs I tought the bennefits from diesel was the fact that its run under full compression during part trottle.making for a compleat and fast burn. The down side is that the exess air is cooling the combustion . a gasoline engine on part trottle is run at low compression (less air) the burn is slower ,we have to try to compensate with more ign.advance, and gets more negative work done and expose the internals of the engine with heat for a longer period.(low rpm, high advance =long time period for negative work) The cars are run at part trottle most of the time :-).......exept from some folks like myself trying to be effective....(scratching my speed itch) We are running ineffichent engines all of us that uses gasoline ,most of the time when we are cruising at part trottle.This is really not acceptable.We are accepting it because at low output the engine is not using that much fuel so a increase is not that much. One way to solwe this is to cut cylinders.Making it possible for the cylinder to operate closer to max torque where its most effective. Espen Hilde ------------------------------ Date: Thu, 29 Apr 1999 10:44:05 +0200 From: "Espen Hilde" Subject: Re: Direct Fuel Injection - la Bosche Hey! Do you want atomisation? go to propan fuel! Thanks I apresiated your previous flame a lot! Espen Hilde ------------------------------ End of DIY_EFI Digest V4 #249 ***************************** 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".