DIY_EFI Digest Friday, April 30 1999 Volume 04 : Number 252 In this issue: Re: Fuel injection plugs SV: Fuel injection plugs Re: cam grinds for SC Re: Fuel injection plugs Re: Fuel injection plugs Re: Fuel injection plugs Re: SV: Fuel injection plugs Re: Direct Injection Re: Direct Injection Ignition Sensors Re: Direct Injection Fuel Pump Check Valve... Direct Injection Spark Plug Sorta RE: Fuel injection plugs RE: Fuel Pump Check Valve... RE: Fuel Pump Check Valve... Re: Fuel injection plugs Re: cam grinds for SC Re: Fuel injector choice? Re: Fuel injection plugs See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- Date: Fri, 30 Apr 1999 08:29:54 -0400 (EDT) From: Pat Ford Subject: Re: Fuel injection plugs Previously, you (James Ballenger) wrote: > > > Howard Wilkinson wrote: > > > The most reasonable way to control engine power output is by > > gearing so that RPM is controlled by load. A continuously variable > > transmission system could allow an engine to operate at full throttle > > all the time except at idle when it would need to be throttled. > > Allowing the engine to always operate at WOT would greatly increase > > efficiency. H.W. > > Ok, I know this isnt right. If we had continously variable transmissions, > we would be running them at peak torque not at wot. VE is greatest at peak > torque, the reason we rev engines higher to acheive high horsepower is to combat > inefficient gearing. At wot, there is significantly reduced ve and not enough > time to get good mixture and combustion, therefore lower torque. The reason > this is an asset is because it produces more torque per unit time, ie power. > With a continuously variable transmission we could run the engine all day long > at peak torque and get double or triple the gas mileage, more power, and reduced > wear. Again, im just a student so tell me where i goofed but I have discussed > this with others before and feel somehat confident that this is right. > > James Ballenger > years ago when the Subaru Justy came out and had the ECVT ( I worked at a subaru dealer at the time) the engine would if you tromped on the gas would go up to the peak of the torque curve and stay there. It was amazing, the damn things were only a bit slowwer then a bmw M3 ( the dealer was also bmw and saab dealer). We actualy had drags with the bimmer and saabs and the 3 cyl justy was at the top of the cars we sold. The fuel economy was great just the lifetime of the tranny wasn't so good. The ECVT was like a snowmobile pulley system but the belt worked under compression, and there was a magnetic clutch that used iron filings to transfer power. The othe funny thing was reverse was just an idler after everything else, the early justy would go as fast in reverse as forward. ------------------------------ Date: Fri, 30 Apr 1999 14:40:13 +0200 From: Arentz-Grastvedt Tom Subject: SV: Fuel injection plugs Hello I'm a newbie... ..But what about en electric gearbox? Swap the original box with an generator, and then put an electromotor near the driving wheels. Drawback is the added weight, but it could be a cool hybrid thing. What is wot by the way? Tom.Arentz-Grastvedt@xxx.no > -----Opprinnelig melding----- > Fra: Espen Hilde [SMTP:mwichstr@xxx.no] > Sendt: 30. april 1999 10:43 > Til: diy_efi@xxx.edu > Emne: Re: Fuel injection plugs > > Hi! > I agree with using a variable transmition to keep the rpm at max torque > but > we have to have a variable size engine to, to get max torque we have to > have wot.if we drive at wot the output will be to high for our use. > Variable stroke is a help but it will be a ineffichent combustion camber > with > the short stroke and the compression ratio will not be good still running > wot. > VW made a variable compression ratio combustion camber, dont ask me how > they did it.....variable combustion camber and variable stroke would > do the trick .....easy uh....Ore several independant engines coupled > together > Espen > > ---------- > > From: James Ballenger > > To: diy_efi@xxx.edu > > Subject: Re: Fuel injection plugs > > Date: 30. april 1999 04:47 > > > > > > > > Howard Wilkinson wrote: > > > > > The most reasonable way to control engine power output is by > > > gearing so that RPM is controlled by load. A continuously variable > > > transmission system could allow an engine to operate at full throttle > > > all the time except at idle when it would need to be throttled. > > > Allowing the engine to always operate at WOT would greatly increase > > > efficiency. H.W. > > > > Ok, I know this isnt right. If we had continously variable > transmissions, > > we would be running them at peak torque not at wot. VE is greatest at > peak > > torque, the reason we rev engines higher to acheive high horsepower is > to > combat > > inefficient gearing. At wot, there is significantly reduced ve and not > enough > > time to get good mixture and combustion, therefore lower torque. The > reason > > this is an asset is because it produces more torque per unit time, ie > power. > > With a continuously variable transmission we could run the engine all > day > long > > at peak torque and get double or triple the gas mileage, more power, and > reduced > > wear. Again, im just a student so tell me where i goofed but I have > discussed > > this with others before and feel somehat confident that this is right. > > > > James Ballenger ------------------------------ Date: Fri, 30 Apr 1999 07:21:48 -0600 From: bearbvd@xxx.net (Greg Hermann) Subject: Re: cam grinds for SC >To my mind, roots type or centrifugal type superchargers would both benefit >from small overlap cams. This is because these are the only engines that >have greater intake pressure than exhaust pressure. Too much overlap just >blows intake out the exhaust. > >Gary Derian >> I think maybe even a bit milder cam for a centrifugal than for a roots--The centrifugal has very little boost at low rpm, so needs cam help down low. The centrif. has LOTS of boost at the high end, so is able to counteract a mild cam pretty well up top. For either, I would think rather wide lobe centers would be in order--114 or even 116. Regards, Greg ------------------------------ Date: Fri, 30 Apr 1999 07:46:12 -0600 From: bearbvd@xxx.net (Greg Hermann) Subject: Re: Fuel injection plugs >Greg: > I must point out that this statement is erroneous: > >> Gasoline also has more energy per unit >>>volume than diesel fuel, right? >> >>They are really quite close on a volume basis! within 2% or so, with >>gasoline a bit ahead. > >Actually on a weight basis they are quite close..... by volumn diesel >has considerably more energy. There is actually a fairly close >correlation between fuel energy and fuel weight. H.W. > > I think the truth of the answer depends upon the individual blends--the numbers are pretty close. According to Obert-- Lower heat of combustion: iso-octane: 19065 Btu/lb.; hexadecane (cetane): 18,898 BTU/ lb. Specific gravity: iso-octane: .692; cetane: .773 I think I may have mis read the s.g. for the cetane before--this looks like the cetane would come out a bit ahead on a heat of combustion per gallon basis. Regards, Greg ------------------------------ Date: Fri, 30 Apr 1999 07:59:02 -0600 From: bearbvd@xxx.net (Greg Hermann) Subject: Re: Fuel injection plugs >I like that idea. A variable displacement hydraulic pump at the engine >and four variable displacement pumps (one at each wheel), along with an >accumulater would allow you to size the engine for the maximum sustained >load (say 100 MPH up a 7% slope fully loaded). Size the accumulater so >that it can store enough energy to accelerate the vehicle's mass from 0 >to 100 MPH. > This is called a "hydrostatic drive" . A common implementation of it is on the large snow cats which ski areas use as groomers for their slopes. I think the big problem with it is that the drive's efficiency is low enough that any gains in engine efficiency are negated. DKW once built a little 2 cycle car with a variable speed belt tranny--which was a bit of a curiousity. Regards, Greg ------------------------------ Date: Fri, 30 Apr 1999 08:04:41 -0600 From: bearbvd@xxx.net (Greg Hermann) Subject: Re: Fuel injection plugs >Howard Wilkinson wrote: > >> The most reasonable way to control engine power output is by >> gearing so that RPM is controlled by load. A continuously variable >> transmission system could allow an engine to operate at full throttle >> all the time except at idle when it would need to be throttled. >> Allowing the engine to always operate at WOT would greatly increase >> efficiency. H.W. > > Ok, I know this isnt right. If we had continously variable transmissions, >we would be running them at peak torque not at wot. VE is greatest at peak >torque, the reason we rev engines higher to acheive high horsepower is to >combat >inefficient gearing. At wot, there is significantly reduced ve and not enough >time to get good mixture and combustion, therefore lower torque. The reason >this is an asset is because it produces more torque per unit time, ie power. >With a continuously variable transmission we could run the engine all day long >at peak torque and get double or triple the gas mileage, more power, and >reduced >wear. Again, im just a student so tell me where i goofed but I have discussed >this with others before and feel somehat confident that this is right. You are mostly correct here, James. You would want the engine to operate somewhere close to its torque peak for best efficiency (light throttle openings) and then speed up to its power peak for WOT, so as to get best power. Greg > >James Ballenger ------------------------------ Date: Sat, 01 May 1999 00:14:09 +1000 From: Matthew Harding Subject: Re: SV: Fuel injection plugs >What is wot by the way? WOT = Wide Open Throttle ------------------------------ Date: Fri, 30 Apr 1999 08:21:09 -0600 From: bearbvd@xxx.net (Greg Hermann) Subject: Re: Direct Injection > >1937 Damiler Benz 601 A 1100hp, 1344lb >1940 Rolls Royce Merlin Series II 1030hp, 1335lb > >(From Fighter, by Len Deighton) > Hi Tom-- Did the book list the "Griffon"--which I believe was the name for the stroked Merlin ?? Greg ------------------------------ Date: Fri, 30 Apr 1999 08:25:14 -0600 From: bearbvd@xxx.net (Greg Hermann) Subject: Re: Direct Injection , while the SU >caburettors of the Rolls Royce would starve momentarily due to some sort of >gee force effect. > I would bet that these pieces are the 3" (or so) SU's--Passini talked about them a bit for use as a nearly ideal draw thru carb for turbocharging--he said something along the lines of "With inlets the size of a sewer pipe and needles with about the heft of a tommy bar!" Regards, Greg ------------------------------ Date: Fri, 30 Apr 1999 09:36:36 -0500 From: TManson@xxx.com (Manson, Tom) Subject: Ignition Sensors Howdy folks, I am brand new to the list as of yesterday. I work for Micro Switch/Honeywell where we make all sorts of ignition sensors, I build test equipment to test these sensors. We have dozens of styles of sensors, both gear-tooth and vane, that we supply to Bosch, Ford, GM, Chrysler, etc. Functionally they are all pretty much the same, the packaging(mounting) and connectors used are what makes them all unique. If any of you working on your own control system would like some 'engineering' samples, let me know. Tom Manson Micro Switch/Honeywell ------------------------------ Date: Fri, 30 Apr 1999 10:49:34 -0400 From: "Bruce Plecan" Subject: Re: Direct Injection Well once again Doc is muttering,, something about SU's and inverted flight. He's never really liked them much right side up........ Sneezy > , while the SU > >caburettors of the Rolls Royce would starve momentarily due to some sort of > >gee force effect. > > > I would bet that these pieces are the 3" (or so) SU's--Passini talked about > them a bit for use as a nearly ideal draw thru carb for turbocharging--he > said something along the lines of "With inlets the size of a sewer pipe and > needles with about the heft of a tommy bar!" > Regards, Greg ------------------------------ Date: Fri, 30 Apr 1999 09:50:26 -0500 From: "Kurek, Larry" Subject: Fuel Pump Check Valve... Another quick question for you guys... :) Anyone know of a source for an inline, high pressure check valve...in either a 5/16" or 3/8" (dual barbed), or -6AN? Reason I am asking, is I have an older (about 8 years old) Bosch pump (that used to be sold by Accel for applications up to 420HP) on my 67 Camaro TPI, that had a few problems. I think the pump was built before they had any idea that MTBE and other such nasty additives would be added to fuel...so they used plain old buna-N O-rings to seal the pump internally. Well...when I was moving the car around a bit ago...I noticed a nice stream of gas pouring out the back of the car...about where the pump was (with maybe 300-400 miles on the pump). Knowing that raw fuel dumping on my hot exhaust system was not a good thing ;) I immediately shut down the motor and verified it was the pump. After quickly moving it back onto my lift, I pulled the pump and noticed the gas was coming from between the outer housing and the pump outlet housing end plate (?), right around where the crimp is. So..I undid the crimp, and pulled the pump apart. There are two O-rings which seal the suction from the pressure side and the pressure side from the outside of the pump. Both were hard as rock and cracked...hence, the leak. So, I replaced them with Viton O-rings, put the pump back into the housing, put down a nice bead of epoxy around the housing and end plate and rebent the crimps down. Well...I should have checked the check valve as well...since it also is a rubbery material. I guess it leaks as well, since after I had the pump together, I could blow through the pump both ways...although backwards WAS harder, it didn't seal :( . I did verify this with a pressure gauge as well..when I put the key to on, the pump runs for a couple of seconds and the pressure rises nicely to 42psi. As soon as the pump shuts down, the pressure drops...takes maybe 3-4 seconds to drop back to zero. Since the check valve is in the outlet of the pump, and this particular one cannot be pulled from the outside, I need to rig something up to maintain my fuel pressure for startup purposes. Any ideas? TIA!! Larry ------------------------------ Date: Fri, 30 Apr 1999 15:03:12 GMT From: bob@xxx.com (Robert Harris) Subject: Direct Injection Spark Plug Sorta First two cycle vs four. The middle size and above diesels are all two cycle. When you think big block - check this puppy out. http://www.pacifier.com/~rboggs/SULZER.HTML The biggest advantage a diesel has over an Otto is efficient and FAST combustion of fuel. Look at an Otto engine - typical spark advance is around 30 degrees before TDC whereas a diesel fires very close to TDC or Oh NO after TDC. All this wonderful spark advance does is make negative power by building pressure opposing the piston so the maximum pressure can occur just after TDC at the power sweet spot. So why. First - all droplet combustion occurs at stoic. No exception - no matter how finely atomized. Sorry guys. The combustion burns local stoic until either fuel or air runs out. See Irwin Glassman - Combustion Third Edition or similar text on Combustion - not putt putts. An Otto sort of hopes that enough of the fuel will be in small droplets and "atomized" so that the flame will consume all of them. The Otto starts from a small plasma explosion "spark" at controlled point (s) and moves in a leisurely wave from there. Mr Diesel, on the other hand, starts his flame by blasting the entire fuel into the chamber in high velocity small droplets that penetrate and ignite throughout the entire chamber, starting droplet combustion from literally millions of points - counting on physical not electrical force to cause the ignition. Mr Diesel, by extremely fast burning of much more of his fuel near the ATDC 'sweet" spot makes much more pressure at the point that it counts than any Otto can. Much larger flame front and higher temperature and pressure WHERE IT COUNTS. Ignore peak theoretical nonsense. A very lean mixture makes incredible heat - near bottom dead center just as the exhaust valve opens. Heat, temperature and the other theoretical stuff don't move the piston - pressure laddies, pressure - applied timely and properly does and all other factors aside, Mr Diesel makes much more pressure where and when it counts than Kick Sand in My Face Otto. The most efficient burning of fuel is around 10 to 20 per cent "weak" or lean. This allows droplets/vaporized molecules best access to oxygen. But at 20% weak, the flame front is 22% slower than at stoic and slows even more as we go weaker. If instead of air, we use exhaust as the dilutant, the flame speed falls 55% for the same amount of dilutent - remember that EGR is actually water injection at ~ twice the percentage of EGR ( ~ 1 gallon of fuel makes about 2 gallons of water - what did you think happens to hydrogen and oxygen in combustion ????). Courtesy of John B. Heywood. Compound this with the flame speed is inversely proportional to the pressure and Mr Otto may take more time than available even at low speed to burn his fuel. Ever wonder why lean combustion is so hot yet makes so little power? Much longer exposure of flame to metal and mixture may even still be burning as it enters the exhaust. Flame speed of gasoline is about .3 meters per second at atmosphere. At part throttle light cruise, many engines don't exceed 3 atmospheres at TDC. Consider that as a clue. Mr Diesel however, has maximum pressure at all times. This markedly increases flame speed. Also, as temperature goes up, so does the flame speed. Sissy Otto has to worry about denotations so is carefully about temperature. Mr Diesel simply uses the extremely high temperature at around TDC to not only ignite his fuel, but to radically speed the combustive consumption of fuel - again right near TDC at the piston sweet spot. Diesel wins Power Torque Efficiency by applying more pressure when and where optimum than Otto can. Note I did not say total - just much better timed. Think of pushing a swing. Its not only how hard you push - but when you push Otto takes over at very high loads because it can burn more fuel at peak loads than Mr Diesel. 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: Fri, 30 Apr 1999 10:37:22 -0500 From: Don.F.Broadus@xxx.com Subject: RE: Fuel injection plugs And when you go down a hill the drive motor can be a generator dumping into batteries for dynamic braking. The neat thing about the Gen. motor set up is that the engine can run at a steady RPM while you vary excitation on the generator to speed up and slow down. An engine at a near constant RPM will most likely get better mileage. Don > -----Original Message----- > From: Arentz-Grastvedt Tom [SMTP:tom.arentz-grastvedt@xxx.no] > Sent: Friday, April 30, 1999 7:40 AM > To: 'diy_efi@xxx.edu' > Subject: SV: Fuel injection plugs > > Hello I'm a newbie... > > ..But what about en electric gearbox? Swap the original box with an > generator, and then put an electromotor near the driving wheels. Drawback > is > the added weight, but it could be a cool hybrid thing. > > What is wot by the way? > > Tom.Arentz-Grastvedt@xxx.no > > > -----Opprinnelig melding----- > > Fra: Espen Hilde [SMTP:mwichstr@xxx.no] > > Sendt: 30. april 1999 10:43 > > Til: diy_efi@xxx.edu > > Emne: Re: Fuel injection plugs > > > > Hi! > > I agree with using a variable transmition to keep the rpm at max torque > > but > > we have to have a variable size engine to, to get max torque we have to > > have wot.if we drive at wot the output will be to high for our use. > > Variable stroke is a help but it will be a ineffichent combustion camber > > with > > the short stroke and the compression ratio will not be good still > running > > wot. > > VW made a variable compression ratio combustion camber, dont ask me how > > they did it.....variable combustion camber and variable stroke would > > do the trick .....easy uh....Ore several independant engines coupled > > together > > Espen > > > > ---------- > > > From: James Ballenger > > > To: diy_efi@xxx.edu > > > Subject: Re: Fuel injection plugs > > > Date: 30. april 1999 04:47 > > > > > > > > > > > > Howard Wilkinson wrote: > > > > > > > The most reasonable way to control engine power output is by > > > > gearing so that RPM is controlled by load. A continuously variable > > > > transmission system could allow an engine to operate at full > throttle > > > > all the time except at idle when it would need to be throttled. > > > > Allowing the engine to always operate at WOT would greatly increase > > > > efficiency. H.W. > > > > > > Ok, I know this isnt right. If we had continously variable > > transmissions, > > > we would be running them at peak torque not at wot. VE is greatest at > > peak > > > torque, the reason we rev engines higher to acheive high horsepower is > > to > > combat > > > inefficient gearing. At wot, there is significantly reduced ve and > not > > enough > > > time to get good mixture and combustion, therefore lower torque. The > > reason > > > this is an asset is because it produces more torque per unit time, ie > > power. > > > With a continuously variable transmission we could run the engine all > > day > > long > > > at peak torque and get double or triple the gas mileage, more power, > and > > reduced > > > wear. Again, im just a student so tell me where i goofed but I have > > discussed > > > this with others before and feel somehat confident that this is right. > > > > > > James Ballenger ------------------------------ Date: Fri, 30 Apr 1999 08:55:25 -0700 From: "Stowe, Ted-SEA" Subject: RE: Fuel Pump Check Valve... - -----Original Message----- From: Kurek, Larry [mailto:lkurek@xxx.gov] Sent: Friday, April 30, 1999 7:50 AM To: 'DIY EFI Main List' Subject: Fuel Pump Check Valve... Another quick question for you guys... :) Anyone know of a source for an inline, high pressure check valve...in either a 5/16" or 3/8" (dual barbed), or -6AN? Reason I am asking, is I have an older (about 8 years old) Bosch pump (that used to be sold by Accel for applications up to 420HP) on my 67 Camaro TPI, that had a few problems. I think the pump was built before they had any idea that MTBE and other such nasty additives would be added to fuel...so they used plain old buna-N O-rings to seal the pump internally. Well...when I was moving the car around a bit ago...I noticed a nice stream of gas pouring out the back of the car...about where the pump was (with maybe 300-400 miles on the pump). Knowing that raw fuel dumping on my hot exhaust system was not a good thing ;) I immediately shut down the motor and verified it was the pump. After quickly moving it back onto my lift, I pulled the pump and noticed the gas was coming from between the outer housing and the pump outlet housing end plate (?), right around where the crimp is. So..I undid the crimp, and pulled the pump apart. There are two O-rings which seal the suction from the pressure side and the pressure side from the outside of the pump. Both were hard as rock and cracked...hence, the leak. So, I replaced them with Viton O-rings, put the pump back into the housing, put down a nice bead of epoxy around the housing and end plate and rebent the crimps down. Well...I should have checked the check valve as well...since it also is a rubbery material. I guess it leaks as well, since after I had the pump together, I could blow through the pump both ways...although backwards WAS harder, it didn't seal :( . I did verify this with a pressure gauge as well..when I put the key to on, the pump runs for a couple of seconds and the pressure rises nicely to 42psi. As soon as the pump shuts down, the pressure drops...takes maybe 3-4 seconds to drop back to zero. Since the check valve is in the outlet of the pump, and this particular one cannot be pulled from the outside, I need to rig something up to maintain my fuel pressure for startup purposes. Any ideas? TIA!! Larry ------------------------------ Date: Fri, 30 Apr 1999 08:56:50 -0700 From: "Stowe, Ted-SEA" Subject: RE: Fuel Pump Check Valve... something like this exists, In fact I am trying to find a one-way check valve myself for my v8 xj6. I had a mechanic put some of those on my 911 once when I had a hot starting problem. If you find a source for a one way check valve please let me know. Ted. - -----Original Message----- From: Kurek, Larry [mailto:lkurek@xxx.gov] Sent: Friday, April 30, 1999 7:50 AM To: 'DIY EFI Main List' Subject: Fuel Pump Check Valve... Another quick question for you guys... :) Anyone know of a source for an inline, high pressure check valve...in either a 5/16" or 3/8" (dual barbed), or -6AN? Reason I am asking, is I have an older (about 8 years old) Bosch pump (that used to be sold by Accel for applications up to 420HP) on my 67 Camaro TPI, that had a few problems. I think the pump was built before they had any idea that MTBE and other such nasty additives would be added to fuel...so they used plain old buna-N O-rings to seal the pump internally. Well...when I was moving the car around a bit ago...I noticed a nice stream of gas pouring out the back of the car...about where the pump was (with maybe 300-400 miles on the pump). Knowing that raw fuel dumping on my hot exhaust system was not a good thing ;) I immediately shut down the motor and verified it was the pump. After quickly moving it back onto my lift, I pulled the pump and noticed the gas was coming from between the outer housing and the pump outlet housing end plate (?), right around where the crimp is. So..I undid the crimp, and pulled the pump apart. There are two O-rings which seal the suction from the pressure side and the pressure side from the outside of the pump. Both were hard as rock and cracked...hence, the leak. So, I replaced them with Viton O-rings, put the pump back into the housing, put down a nice bead of epoxy around the housing and end plate and rebent the crimps down. Well...I should have checked the check valve as well...since it also is a rubbery material. I guess it leaks as well, since after I had the pump together, I could blow through the pump both ways...although backwards WAS harder, it didn't seal :( . I did verify this with a pressure gauge as well..when I put the key to on, the pump runs for a couple of seconds and the pressure rises nicely to 42psi. As soon as the pump shuts down, the pressure drops...takes maybe 3-4 seconds to drop back to zero. Since the check valve is in the outlet of the pump, and this particular one cannot be pulled from the outside, I need to rig something up to maintain my fuel pressure for startup purposes. Any ideas? TIA!! Larry ------------------------------ Date: Sun, 2 May 1999 09:20:47 -0700 From: "Howard Wilkinson" Subject: Re: Fuel injection plugs Pat: It has been said that the greatest efficiency is achieved in terms of fuel burned per hour as related to horsepower output at WOT. Engine power output is more or less proportional to CFM airflow in a spark ignition engine. Thus power must be controlled by regulating airflow as mixture is fairly critical. Airflow may be controlled in one of several ways. The common way is to apply a vacuum and resist induction....throttling..... this has the side effect of reducing effective compression ratios at the typical 20% or so throttle at which we cruise most cars. Variable displacement would be another, but so far has not been introduced. Another is turbocharging a small engine on the theory that it will develop greater efficiency at lower power settings, and the boost will help it develop enough power when needed. This has several downsides.... Compression must be lowered, or high octane fuel must be used or timing must be retarded, or all three to prevent detonation... Lower compression drops efficiency when the turbo isn't boosting... retarding the timing doesn't help output or efficiency, and high octane fuel is expensive. Turbocharging or Supercharging are not the answer to our prayers unless an engine is developed which has variable chamber size. Even then there is the downside that the smaller pistons and or shorter stroke will reduce the ability to convert the cylinder pressure into torque. We all know Pi*Rsquared....... figure the piston surface area and multiply it by the combustion pressure to get the push on the rod..... The longer the stroke, the greater the leverage available to turn the push into torque....... I like cubes....they make power. The other way to reduce engine output is to load it down to an RPM where the induction air flow is just enough to develop the power needed to sustain the load. The belt drive transmission you describe is probably the simplest sytem available to do this, and in conjunction with a stepped transmission (automatic) one should be able to accomplish this. In this scenerio the throttle (the one you step on) would be directly in control of the transmission.... as you press the throttle the transmission gears down to allow the engine to rev up and develop power as needed. The engine is always at full throttle except at idle when it is throttled due to lack of any sort of load. Such a system should work within reason....it may require conventional throttling at very low power settings (dual mode operation). It would be more ideal with some sort of variable camming so that the engine would develop efficient power throughout it's RPM range. None of these things is new or untried technology. The belt drive is not a very efficient system, but has a great virtue in simplicity. It has been used for many years in such diverse applications as combines, skid steer loaders, variable speed machine drives, and automobiles...... The Dutch built DAF used such as system. Camming of an engine so that it will breath well at low RPM and also at high RPM can be handled in several ways. The issue is overlap. The greater the overlap the less efficient at low RPM, but the better at high RPM. The simplest approach is the Rhodes type lifter which contains an oil chamber and bleed hole.... at low RPM the oil bleeds out more than at high RPM simply as a function of time. I have greatly changed the running characteristics of several engines which were over cammed by simply changing over to mechanical rather than hydraulic lifters, and adjusting lash until I was satisfied with the result...... One such engine has run over 50K so far with .035 lash on mechanical lifters running on a hydraulic lifter high performance cam (FE series Ford engine). The other option would be a dual cam system of some sort set up with centrifugal advance/retard. This would allow one cam to advance the opening times, and one to retard the closing times of two sets of valves. This would not be difficult to accomplish with some engines. Caterpillar uses such a system on injector pumps on some engines for timing advance... it is located right on the drive gear. Just some ideas....... H.W. - -----Original Message----- From: Pat Ford To: diy_efi@xxx.edu Date: Friday, April 30, 1999 7:40 AM Subject: Re: Fuel injection plugs >Previously, you (James Ballenger) wrote: >> >> >> Howard Wilkinson wrote: >> >> > The most reasonable way to control engine power output is by >> > gearing so that RPM is controlled by load. A continuously variable >> > transmission system could allow an engine to operate at full throttle >> > all the time except at idle when it would need to be throttled. >> > Allowing the engine to always operate at WOT would greatly increase >> > efficiency. H.W. >> >> Ok, I know this isnt right. If we had continously variable transmissions, >> we would be running them at peak torque not at wot. VE is greatest at peak >> torque, the reason we rev engines higher to acheive high horsepower is to combat >> inefficient gearing. At wot, there is significantly reduced ve and not enough >> time to get good mixture and combustion, therefore lower torque. The reason >> this is an asset is because it produces more torque per unit time, ie power. >> With a continuously variable transmission we could run the engine all day long >> at peak torque and get double or triple the gas mileage, more power, and reduced >> wear. Again, im just a student so tell me where i goofed but I have discussed >> this with others before and feel somehat confident that this is right. >> >> James Ballenger >> > >years ago when the Subaru Justy came out and had the ECVT ( I worked at a subaru >dealer at the time) the engine would if you tromped on the gas would go up to >the peak of the torque curve and stay there. It was amazing, the damn things were >only a bit slowwer then a bmw M3 ( the dealer was also bmw and saab dealer). We >actualy had drags with the bimmer and saabs and the 3 cyl justy was at the top >of the cars we sold. The fuel economy was great just the lifetime of the tranny >wasn't so good. The ECVT was like a snowmobile pulley system but the belt worked >under compression, and there was a magnetic clutch that used iron filings to transfer >power. The othe funny thing was reverse was just an idler after everything else, >the early justy would go as fast in reverse as forward. > > ------------------------------ Date: Fri, 30 Apr 1999 09:19:07 -0700 From: Jason_Leone@xxx.com Subject: Re: cam grinds for SC <> Well, each engine is different...and each cylinder head is unique. That doesn't help answer your question, so hopefully this will. A good generic forced induction cam has a lober angle of about 114 Deg, has a medium lift, and the exhaust duration should be longer than the intake duration. Example: On a VW VR6 engine, using a Vortech V-1...we see about a 30hp gain (@xxx. Power goes from 270hp up to 300hp+, just by swapping in the cams. The head is only a 12v head, so "breathing" at high rpm is very important. A ported big-valve head does wonders for that particular engine, when boosted or in atmo form. Typically, most cam grinds that are set-up for forced induction will have similar specs, regardless of what type of blower is used. If you have a DOHC head(s), then you can usually use adjustable cam sprockets to adjust the torque and power curve either up or down (by altering the cam timing). This technique works very well for setting the car up for the drags, or daily driving. By experimenting on the dyno, you can figure out a lot about how the cams perform (at various timing settings). My engine has a camshaft sprocket cover bolted to the end of the cylinder head, and capped by the valve cover...so I can't use adjustable sprockets (unless I wanted to tear the upper engine down between adjustments!). One of the most important factors in cam selection is the valve opening and closing timing, and duration. Very often overlooked, but it's probably the most important spec! Each engine responds differently, so stick with a company that has a lot of R&D using the forced induction cams, and ask to see some dyno sheets with your engine, hopefully with a centrifugal blower like you have. Good luck on that, but it can't hurt to ask. Since you have a domestic car (I assume), you'll have no problem getting an off the shelf cam from any large cam company (Crane, Isky, etc.). Talk to their techs, and explain what you have...and what your driving style is. Tell them what you want (high rpm power, low end torque, etc.). They should be able to access your situation and needs...and offer you a couple solutions. Parts are inexpensive and in abundance for domestic cars, so you're odds are extrememly good that you'll get a great cam for a small amount of money. Flip through the Summit Racing catalog, see what the major manufacturers offer. Good luck, and get boosted! Jason '93 SLC ------------------------------ Date: Fri, 30 Apr 1999 09:26:00 -0700 (MST) From: d houlton x0710 Subject: Re: Fuel injector choice? Frederic Breitwieser wrote: > > Its actually not that difficult to do yourself... either with a proper > welder, or a product called durafix. Durafix comes in two flavors, > ferrus and non-ferrus, so you can weld steel/iron or > brass/copper/aluminum, etc. Its good to about 40,000 psi of pressure if > you are a pro, or I'd cut that figure in half. For welding bungs on an > intake, its great stuff, nice and fast, and doesn't leave a rotten stink > in the room (don't use the product in your living room however). > > All ya need is a stable surface, a $20 propane torch, and a pair of shop > goggles. > > torch welding products: www.durafix.com > > My intake (I tig'd it, but it gives you the idea): > http://www.xephic.dynip.com/dodge/dodge.html > Frederic, My biggest setback right now on making and intercooler is my lack of ability/equipment to weld aluminum. I do have a MIG welder and I know you can use AL wire in it if you're careful, but I'm leary of the expense to set it up and get the argon gas and stuff and then maybe not having it work like I hope. Will this Durafix work alright for "welding" up an IC core? What I've got now is an old air/air IC core that I've cut in half, rotated the halves, and stuck back together so the charge air is now going through the fins where the cooling air was before, the water goes through the cores where the charge air did before, and the whole thing is now twice as thick as before. I just need to weld the halves together and make end caps for it. I've been considering using one or two heater cores instead though since they're copper and I can silver solder these, but if the Durafix stuff will work, I'll continue with the AL IC core. thanks - --Dan houlster@xxx.com http://www.inficad.com/~houlster/amigo.htm ------------------------------ Date: Fri, 30 Apr 1999 12:20:44 -0400 From: James Ballenger Subject: Re: Fuel injection plugs Raymond C Drouillard wrote: > Don't make the mistake of getting volumetric efficiency mixed up with > engine efficiency. Engine efficiency is work in / work out. VE is air > in / (.5 * displacement) (for a four-cycle engine). Torque is highest > at the highest VE because you can get more fuel in for each revolution of > the crank. Power is highest at the point where you can get the most fuel > per unit time. At peak ve, you get the closest thing to perfect combustion. You get a good full charge of, hopefully, stochiomteric mix and can burn it making maximum force and maximum fuel economy. At max power, we are making less torque but making it faster. The problem here is that there are inherent combustion and frictional ineffeciencies. At max power (hp) we have to advance ignition and now valve timing to try to catch up. You get an incomplete burn of the fuel and have a very inefficient cycle, its just that you can do this enough per unit time to get more power. The only reason we do this is because of imperfect gearing. If we have a cvt, as discussed, the point becomes moot because we can have insanely high (numerically) gearing and torque multiplication. In this case we would not have a need for more power because the transmission could be controlled as the throttle, while the engine remains at its most efficient state. > If you are running at the highest torque point (max VE), you have to > throttle it down to reduce power. This throttling, of course, reduces VE > to the point where you get the desired power level. Of course, this > increases pumping losses. There is not throttling with a cvt, the transmission is the "throttle." > A more efficient way to reduce the power level is to reduce the engine > speed to below max torque. You will have about the same amount of air > per unit time, but more air per revolution. Actually, you will have a > little less air per unit time because it'll be running more efficiently. > It won't have to do as much pumping. You won't be receiving more air, below max torque you will be getting less air per revolution because it is not at peak ve. At peak torque, you get peak ve. At peak ve, you get the fullest charge of air and fuel possible from the engine and will be running more efficiently than at any other point in the engines range. > Other benefits are less wear and tear, lower windage losses in the > crankcase, lower losses at the oil pump, etc. If the engine is not throttled and remains where it will make peak power it will have significantly less wear on the engine. James Ballenger ------------------------------ End of DIY_EFI Digest V4 #252 ***************************** 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".