DIY_EFI Digest Monday, 19 August 1996 Volume 01 : Number 235 In this issue: re: Electric vehicle hardened valve seats Re: Rover engines Re: Truck parts Dynamometer. Re: hardened valve seats Re: Truck parts Dynamometer. (Why not a water brake?) hardened valve seats Spark Ionisation to determine Combustion Characteristics Leaded Petrol Re: Truck parts Dynamometer. Re: Leaded Petrol Re: pressure measurements with piezoelectric transducer Re: hardened valve seats See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: "Hans Hintermaier" Date: Sun, 18 Aug 1996 14:11:36 +0000 Subject: re: Electric vehicle > > Consider this, 4 off the shelf electric motors. Ridgidly mounted > > to chassis and connected to the wheel via cv joints. A battery > > pack per current electric vehicle standards, and one off the shelf > > small gas engine DC generators. I think you know where I'm going. > > Generator is sized to propell the car at 55mph, stand alone. > > Generator and battery pack combined might give you 0-60 in 3 > > seconds. Of course, all of this would require micro-processor > > control. Ok experts, what are the real world physical limits? > > > > Thanks, GMD I heared about a hybrid city-bus study somewhere in germany, they used 16-phase (or so) AC-motors directly driving every wheel, a magnetic loaded storage flywheel. A 70HP diesel drives a dynamo which drives the flywheel(or the flywheel direct?). Lots of electronics... Who knows more about this project? I think it was named "Magnetmotor Bus" Thanks Hans hiha@xxx.de Munich / Germany ------------------------------ From: "Hans Hintermaier" Date: Sun, 18 Aug 1996 14:11:36 +0000 Subject: hardened valve seats Hi there, metallurgists and engine-recyclers. Does anybody of you know what (generally available) material I can use for unleaded-fuel-valve-seats? I am just working on an old motorcycle with aluminium head, which needs the valve seats to be replaced. Could be X210 Cr Wo 12 the right thing? (I hope it's international standard) Thanks Hans hiha@xxx.de Munich / Germany ------------------------------ From: DJohn77284@xxx.com Date: Sun, 18 Aug 1996 12:05:14 -0400 Subject: Re: Rover engines Martin, here's what I know about the Rover V8 and it's various engine sizes. 3.5 88.90mm bore, 71.00mm stroke 3.9 94.04mm bore, 71.00mm stroke 4.2 94.04mm bore, 77.00mm stroke These are variations that have been or are in production in the UK. Australia have had the V8 in 4.4l. This was derived from a 88.90mm bore and 88.90mm stroke. As far as I know race engines have been taken out to 5.0l by using a bore of 95.50mm and a stroke of 89.90mm. This was achieved with a P76 crank shaft and the engine was put together by Leyland Australia and Repco in for Formula 5000 in 1973 and was put in both Lola and Elfin chassis. Hope this helps, Dave DJohn77284@xxx.com ------------------------------ From: jonas.hageberg@xxx.se (Hageberg Jonas) Date: 18 Aug 1996 18:42 +0100 Subject: Re: Truck parts Dynamometer. >> If the engine is in a car, all you need is a stopwatch, a tach, a tap= e >> recorder, and a hill. Why not use some kind of data logger connected to the tachometer (or=20 speedometer), a spreadsheet program and a straight road? Out of this info, you would=20= easily be able to calculate the power with a good enough precision. Anyone who has tried to build such a logger? /Jonas ------------------------------ From: "Michael D. Porter" Date: Sun, 18 Aug 1996 11:58:13 -0700 Subject: Re: hardened valve seats Hans Hintermaier wrote: > > Hi there, metallurgists and engine-recyclers. > Does anybody of you know what (generally available) material > I can use for unleaded-fuel-valve-seats? I am just working on an old > motorcycle with aluminium head, which needs the valve seats to be > replaced. Could be X210 Cr Wo 12 the right thing? Wie gehts, Hans-- Unless you've have a milling machine or the right set of piloted cutters, it's doubtful you're going to be able to install the seat inserts yourself. Visit your local automotive machine shop and tell them what you'd like to have installed. Most auto machine shops can get inserts from their suppliers in almost any size. As for the composition of an insert for unleaded use, I'm doubtful the above would be suitable--if the Wo is meant to be wolfram (tungsten), 12% would make the material far too brittle, I think. I would guess that the material is extremely low sulfur, high chromium, some molybdenum, with a small amount of nickel and an even smaller amount (0.2-3%) tungsten. We may have it in what SAE papers we have at work--given a bit of time, I'll check. Cheers. - -- My other Triumph doesn't run, either.... ------------------------------ From: Paul Neelands Date: Sun, 18 Aug 1996 15:05:39 -0400 Subject: Re: Truck parts Dynamometer. (Why not a water brake?) I've been reading this dynamometer thread for a bit and though I would add my 2 cents.=20 It is probably easier to use a water brake than to deal with all the wear and heating problems of a truck brake. However a truck rear axle is probably a good source of parts. The general concept (straight out of my Standard Handbook of Mechanical = Engineering) is to mount a series of perforated disks to the shaft one wishes to load. The disks alternate in being attached to shaft (disk 1), fixed to the frame(disk 2), attached to the = shaft(disk3). The number of holes in the disk and the size of the disks are = proportional to the amount of power to be absorbed. Put the entire thing in a tub of water, preferably with the disks vertical and the shaft = horizontal and vary the water level to control loading. For long runs = and high power levels a radiator and circulating pump may be necessary. For some ball park type numbers, try 12 inch disks with about 50% of the = disk as 1/2 inch holes. Say 3 or 4 disk in all. Gives a very stable load and allows independent adjustment of load and rpm Paul Neelands ------------------------------ From: dave.williams@xxx.us (Dave Williams) Date: Sun, 18 Aug 1996 18:54:00 +0000 Subject: hardened valve seats - -> Does anybody of you know what (generally available) material - -> I can use for unleaded-fuel-valve-seats? Cast iron works just fine. The bronzes appear to work fine too. Beryllium/copper is the material of choice for very high output engines, but it's hard to obtain small quantities of appropriate shape. Inconel (trade name for high-nickel alloy) is a wonderful seat material, but one of its characteristics is very low expansion, leading the seats to fall out unless they're the screw-in type. They're sometimes used for large Diesels. Stellite is a popular replacement seat material, but Stellite seats are sintered to near-net shape since they're very hard to machine. Stellite is what most machine cutters used to be made of. ------------------------------ From: RABBITT_Andrew@xxx.au Date: Mon, 19 Aug 1996 09:33:44 est Subject: Spark Ionisation to determine Combustion Characteristics >If you are happy with information one spark in the past you could >probably (not havin actually tried it) glean something from the >current waveform of the actual spark, should be able to indicate >spark voltage as well and might give a clue as to the mixture. There are many papers on this subject guys, and here's just a start for you! SAE #'s, 860485, 910719, 930390, 950003, 960045, 960337. Ford has done research on this as far back as the mid-seventies and also has a paper or two about various aspects of the technology. As far as I know, this is a current (no pun intended!) method for misfire detection for OBDII, although I don't know who or if anyone is using it. Andrew Rabbitt Orbital Engine Company PERTH, Australia ------------------------------ From: RABBITT_Andrew@xxx.au Date: Mon, 19 Aug 1996 09:37:26 est Subject: Leaded Petrol >What I meant was lubrication, the lead is added to be a lubricant. >Bad things are said to happen without it. I think the 'upper cylinder' lubrication effect of lead has been somewhat overstated in the past. ------------------------------ From: edygert@xxx.com (Ed D) Date: Sun, 18 Aug 1996 18:58:05 -0700 Subject: Re: Truck parts Dynamometer. You wrote: > > >-> I've built my own engine dyno's a couple of times. Utilizing a >-> Stuska waterbrake, load cell, and gauge. The rest was basically >-> frame work. > > How much was the Stuska brake? SuperFlow wants $10K for the bare >brake, which was slightly more than I wanted to pay... > > Dave I called Stuska last year and asked this very question $3,450 includes... water brake brake temp gauge trunion bearings eng tack & cable load cell & gauge Stuska Engineering Englewood CO ph 303-762-0553 - -- ************************************************************************* * . --------++-------- * * * ED ._______|_______. __¦¦_ * * Flyaway Ranch \(*)/ /_/ /=======X * * Sunny Tennessee o/ \o `---' * * `----- * ************************************************************************* ------------------------------ From: "Michael D. Porter" Date: Sun, 18 Aug 1996 20:46:03 -0700 Subject: Re: Leaded Petrol RABBITT_Andrew@xxx.au wrote: > > >What I meant was lubrication, the lead is added to be a lubricant. > >Bad things are said to happen without it. > > I think the 'upper cylinder' lubrication effect of lead has been > somewhat overstated in the past. I've been led to believe that "lubrication," is a bit of a misnomer. Lead deposits have been less for lubrication that cushioning. While the effects of unleaded gas may be made less a problem by adding alum. bronze guides, etc., the effect on valve-to-valve seat contact can only be minimized by making the seats harder in the absence of lead. Would like to offer more than just hearsay, but the above is all I've been able to glean on the subject in a number of years. Cheers. - -- My other Triumph doesn't run, either.... ------------------------------ From: Darrell Norquay Date: Sun, 18 Aug 1996 21:49:55 -0700 (PDT) Subject: Re: pressure measurements with piezoelectric transducer At 12:15 PM 8/15/96 +1000, Craig wrote: >Wow, I bet that made a bang just right for 4am ;-) Ya well, we ha a BIG muffler on the end (an old 300 barrel oil tank filled with firefighting foam) Still, you felt it more than heard it... >What's the flame arrestor? I've heard that a fine mesh will stop a flame >front (specifically, a friend had a 13B turbo rotary on propane, but the >gas mixer was before the turbo. It wrecked the engine when 15PSI of >compressed mixture ignited (& it bent the pipe from the turbo to the >manifold.. I'm wondering if some mesh will stop this). It was basically a tube of tightly rolled stainless steel mesh. The principle was that the stainlees steel absorbed the heat of combustion as the flame front propogated through it. In fact, it absorbed enough heat to put out the flame. This is the principle behind most flame arrestors, they consist of a mesh, screen, or other series of small holes which break up the burning gas into small "packets", which are easily reduced below the temperature necessary to sustain combustion. There are other problems, however. If the flame front is allowed to propogate down a tube, it will eventually reach a velocity which causes the mixture to detonate, rather than burn. If this happens, pressures skyrocket. The main reason for extinguishing the flame is to prevent the whole pipeline from being destroyed if an accidental fire occurs. The entire system must be sized to contain the resulting pressures, however. As far as using this in an automotive application, even if you put out the flame, you still have a residual pressure pulse (which does all the damage). Also, the mesh needs to be several layers thick to be effective, which would give far too much restriction to flow for any practical sized unit. Some propane carburetion systems have some sort of a rubber flapper valve which is held closed by normal manifold vacuum, but can blow open if you have a backfire, thus preventing damage like you describe. IMHO, having a suck-through turbo setup with gaseous fuel is just asking for trouble. Temperatures inside the turbo housing can reach the autoignition temp of propane, turning the whole thing into a rather large pipe bomb... regards dn dnorquay@xxx.com ------------------------------ From: Darrell Norquay Date: Sun, 18 Aug 1996 22:06:02 -0700 (PDT) Subject: Re: hardened valve seats At 02:11 PM 8/18/96 +0000, Hans wrote: > >Does anybody of you know what (generally available) material >I can use for unleaded-fuel-valve-seats? I am just working on an old >motorcycle with aluminium head, which needs the valve seats to be >replaced. Could be X210 Cr Wo 12 the right thing? (I hope it's The material generally used in north american vehicles is called Stellite. I'm not sure exactly what it's chemical composition is. These seats are available as drop in replacements for standard seats, you simply machine out the valve seat pocket in the head and press in the replacement seat. BTW, for the information of the people asking about valve recession, it is caused by high temperatures causing the valve to "spot weld" itself onto the seat when the valve closes. When the valve opens again, the spot weld is ripped out of the seat, leaving a small pit. The valve usually rotates in the seat to even valve wear, thus as the spot weld/break process occurs all around the seat, the net result is that the seat depth begins to increase. The valve is essentially burning a hole into the head where the seat used to be. Leaded fuel eliminates this problem, as the lead coats the valve/seat and prevents the welding process from occuring. regards dn dnorquay@xxx.com ------------------------------ End of DIY_EFI Digest V1 #235 ***************************** To subscribe to DIY_EFI-Digest, send the command: subscribe diy_efi-digest in the body of a message to "Majordomo@xxx. 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