Disabling the alternator on a car




No, that schematic shows how the electronically controlled low voltage 'stuff' interfaces to the high voltage. jsw
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On Sat, 13 Oct 2012 19:38:01 -0400, "Jim Wilkins"

You replying to me or the previous poster? I didn't look at the diagram shown (which has nothing to do with controling the spark timing ) -it shows a simple 4 wire HEI system schematic, and it is incomplete and inaccurate as it does not show the battery or other primary power connections.
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On Sat, 13 Oct 2012 16:52:43 -0400, snipped-for-privacy@snyder.on.ca wrote:

Your illustration shows a distributor with both mechanical and vacuum control for ignition timing :-)
But I don't see why an additional 4 degree electrical retard for starting if the distributor already has a mechanical advance mechanism.
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You would need to compare the actual advance curves that the centrifugal and vacuum mechanisms produce with the optimal measured values. I don't have them and couldn't release them if I did, since I signed an NDA when I worked as a test engineer for GM engine and brake controls. jsw
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On Sun, 14 Oct 2012 08:33:43 -0400, "Jim Wilkins"

Yes of course. I was only commenting as various other engines have gotten along with mechanical and vacuum advances over the years.
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wrote:

Yes, they were 'good enough' for cars, but not optimum. The controls for late 1940's large aero engines are better examples of what could be done mechanically to maximize performance and economy, though they didn't have to consider the lower end of the power band or emissions. http://www.enginehistory.org/Wright/Kuhns/CurtissWrightTC18/TurboCompounds.shtml "Cruise fuel consumption could be as low as 0.40 lb/hp/hr." This is 243 g/kW-h, http://en.wikipedia.org/wiki/Brake_specific_fuel_consumption not much worse than a TDI Diesel: http://forums.tdiclub.com/showthread.php?t 8125
I recently removed the catalytic converter on my 12 year old car. There was NO soot in the pipe ahead of it. jsw
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On Mon, 15 Oct 2012 06:04:20 -0400, "Jim Wilkins"

I never worked on the 3350-compound engine but I did work on the 3350 fuel injected engine and I did talk with guys that worked on the compound engines. From what I could see, the engine came too late in the period that reciprocating engines were used and the maintenance costs of the compound engine were not only higher then the injected engine but higher then for the R-4360 engine.

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wrote:

Not my diagram. and the actual purpose of the 10 degree retard was for emission control reasons (on the 5 terminal units) - but it makes starting a high compression engine easier and allows an otherwise unmodified distributor to provide more total advance for performance and fuel economy - while not breaking the nose off the starter or striping the drive gear when starting. I cannot remember the application of the 4 degree automatic advance module or the purpose of the 4 degree advance. I DO know that they were often replaced with the non-advance units without any serious effects.
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wrote:

The "and wait" means another thought. The injection requires more electricity than the ignition. Dead stop. And wait - New thought. A magneto IS really just an alternator or generator - and it takes power as well.

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On Sat, 13 Oct 2012 16:32:56 -0400, snipped-for-privacy@snyder.on.ca wrote:

You really seem to have a problem understanding English, don't you.
The "as well" refers to the previous subject, the need for electrical power.
But given that you have this problem understanding, what I would call, simple English there isn't much sense in prolonging this conversation as I'm sure you will demonstrate further problems with comprehension if we continue.

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wrote:

John - I have no problem understanding what I wrote. It was ME who wrote it. anf I DO understand how magnetos work, having worked on them on old farm machinery 50 years ago, and on current aircraft engines as recently as last summer. I also understand how much (electrical) power electronic ignition and electronic fuel injection take to run, and how much physical power it takes to produce that electricity in an automotive environment, having been a licenced mechanic since 1971.
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wrote:

Did I say electrical power???? No. It takes ENGINE power to run a Magneto The faster you run it the more power it absorbs - just like an old generator or an alternator or Dynamo. It is basically just like a Kettering ignition with it's own generator, all built into a nasty little case.
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On 10/13/2012 6:20 AM, John B. wrote:

Power - in the form or mechanical force...
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BTW, this is the sticker I have on the battery panel of my boat.
It is there so we can tell how much charge remains in the battery. Multiply the percentage by the current rating of the battery to determine remaining amp hours. (Do not use the cold cranking amps rating tho)
Under normal circumstances I never let it go below 60%. I was still using one of the original (20 years old?) AGM group 27 batteries until last year. It would still charge up to 12.45 volts. It didn't get charged for many months during the move, and I have to replace it now.
Another aside, let the battery set without the charger for 24 hours before taking the reading if you want to know the actual battery condition as far as life remaing.
12.60+    100%    green 12.50    90 12.42    80 12.32    70 12.20    60
12.06    50    yellow 11.90    40    
11.75    30    red 11.58    20 11.31    10 10.50    0
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You'd be better off to re-examine this with a few months of mileage/fillup recordings, both with the alternator working and with it not (and by that, I mean removal of the drive belt). This sort of statistical analysis is /very much/ dependent on sample size and consistency of data recording, so you need to be very precise.
Your basic thesis is not unreasonable: Honda has, for years now, been regulating its alternator charging using a device known as an Electrical Load Detector. The ELD lessens engine load by reducing alternator output unless there is high demand. However, the ELD is a US-only device, meant to boost Honda's CAFE ratings, not to boost fuel consumption as observed by the owner; its effects are unlikely to include anywhere near a 15% increase in gas mileage.

Have you done the arithmetic?
Suppose you normally get 25mpg; disconnection of the alternator brings you up 15%, or to 28.75mpg. Assuming you drive 12K miles per year, you'd save, assuming $3.75/gal, about $263 per year.
If you mean to run your battery down regularly as you drive (like in the days of the Model-T), then you need a marine/deep-cycle type that will survive repeated dips into low-charge territory. These go from between $140 to $400.
--
Tegger

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On Fri, 12 Oct 2012 08:59:25 -0400, "Existential Angst"

You would need to disconnect the LITTLE wire drom the alternator, not the big one - and it would throw a code on the engine control computer and possibly put it into a limp mode - not saying it would, but it could. Your alternator takes as much power as the loads connected to it - so fuel pump, ignition, injection, lights and heater fan if used, as well as cooling fan if it is electric. Mabee 600 watts on a cold night, and 50 or 100 on a mild day. Thats less than 1 HP. After starting the alternator needs to recharge the battery as well, so another 1000 watts for a couple of minutes, tapering down to nothing - say another HP for 5 minutes.
If you are going to save 15% on fuel consumption you would have to be able to drive on about 6 HP average without the alternator.
Not going to happen, methinks .
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On 10/12/2012 09:36 PM, snipped-for-privacy@snyder.on.ca wrote:

At steady-state, middling-speed cruise that's actually plausible. It's when you need to accelerate smartly that you actually use all the horsepower of your engine; at cruise it's only using a very small fraction of available power. Below speeds where aerodynamic drag becomes a significant factor, I would expect power consumption to be in just about that range.
I mean, I can ride a bicycle at 30+ MPH, and I doubt I put out even one horsepower :)
nate
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wrote:

I built an electric powered Fiat several decades ago. Very light car, with good aerodynamics. 6 HP would move me along at about 9 or 10 MPH. IIRC 10 HP would move me at 30MPH. Accellerating TO 30MPH in any reasonable time took significantly more. Something like 30HP to keep up with normal traffic away from a stop on a slight uphill grade.
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On Fri, 12 Oct 2012 08:59:25 -0400, "Existential Angst"

You may have only a single connection to the alternator which goes straight to the battery of to the battery via a connection on the starter. The reason is that the internal alternator regulator receives power from the battery via the main power cable.
If this is the case then in order to externally control the alternator you would need to cut into the regulator and jury rig some sort of external connection which would likely end up in bypassing the regulator.
This certainly is possible - I have done it with two alternators for marine use in order to use external regulators, however whether it is logical for an automobile can be argued.
If you have, say a 100 amp alternator, then: 100 amps x 14 volts 1,400 watts = 1.8 Hp. But the alternator is driven at a higher speed then the crankshaft so there is additional H.P loss due to the over-driving plus belt friction. For guessing purposes say 100% losses so Required H.P. then is 3.6 HP.
You then need to estimate the average amount of H.P. required by your driving style and compute required alternator power as a percentage.
Back in my days of unofficial, Sunday afternoon, drag racing it was common knowledge that disconnecting the alternator (and the fan) would result in a faster car.
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On Friday, October 12, 2012 7:59:52 AM UTC-5, Existential Angst wrote:

Many cars have a full-throttle alternator cutout circuit. I would try to determine if your Mazda came with such, and try to insert manual control in that circuit. There may be other conditions that trigger alternator cutout from ECM control. You may be able to fool the ECM into seeing those conditions.
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