Engine Technology

[Curious Kid]

Here's another link referring to Revetec's cam engine design -

http://www.autofieldguide.com/articles/050302.html

Can anyone imagine an idle of 300rpm, or even a proposed 120rpm?

 

[Lazy JW]

Oops, my memory is obviously failing, I stand most humbly corrected about the T-Model tranny. I will need to dig out my old Dykes manual and see which vehicle used the variable drive, it had a curved cone shaped drive with clutch material on it and a driven wheel that could be moved back and forth to get the varying ratios. It was not commercially successful due to poor materials, etc. but the concept was valid.

The Oliver posted an "Economy" rating of 11.99 gallons per horsepower hour rating on the ten hour part-throttle (cruise?) run. Can anyone tell me how much gasoline weighs per gallon? I certainly don't want to rely on my memory

Joe

 

[Shipo]

quote:

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Originally posted by Lazy JW:
Can anyone tell me how much gasoline weighs per gallon? I certainly don't want to rely on my memory

Joe

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Gasoline is generally considered to be about six pounds per gallon. That having been said, I've seen some formulations that were nearly a half of a pound below that and some that were a tenth or two above that.

 

[Shipo]

quote:

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Originally posted by XS650:
Union Pacific Rairoad ran a gas turbine locomotives for awhile. They was very powerful, and not as efficient as a diesel. The stopped one under an overpass once and melted the asphalt pavement on the road above it with it just idling.

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That was one of the challenges that Chrysler had to deal with when they designed their turbine car. They managed to solve the problem of high EGTs by implementing a heat exchanger between the intake charge and the exhaust. As I understand it, not only did that solve the "melting ashphalt" problem, it also improved engine efficiency significantly. Apparently turbine engines like a hot intake charge.

 

[Shannow]

Shipo, that's transferring heat from the exhaust to the already compressed air, just prior to the combustion chamber.

Rover/BRM had similar issues with their Le-Mans car, and the heat exchanger seriously helped economy.

 

[XS650]

quote:

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Originally posted by Shipo:
That was one of the challenges that Chrysler had to deal with when they designed their turbine car. They managed to solve the problem of high EGTs by implementing a heat exchanger between the intake charge and the exhaust. As I understand it, not only did that solve the "melting ashphalt" problem, it also improved engine efficiency significantly. Apparently turbine engines like a hot intake charge.

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Shannow got it right, gas turbines like cold intake air as much s any internal combustion engine.

 

[Shipo]

quote:

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Originally posted by Shannow:
Shipo, that's transferring heat from the exhaust to the already compressed air, just prior to the combustion chamber.

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My bad.

I wrote that from a very fuzzy memory as it's been years since I looked at the drawings.

 

[XS650]

quote:

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Originally posted by Lazy JW:

The Oliver posted an "Economy" rating of 11.99 gallons per horsepower hour rating on the ten hour part-throttle (cruise?) run. Can anyone tell me how much gasoline weighs per gallon? I certainly don't want to rely on my memory

Joe

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It varies quite a bit, from about 6.1 to 6.7 lb/gallon IIRC. That's what rating engine efficiency on gallon/hp-hr isn't good engineering practice. The results will vary all over the place depending on the density of the fuel.

The energy content of gasoline is much more closely related to it's mass then it's volume, which is one reason good test organizations give results in lb/hp-hr instead of gal/hp-hr.

 

[Lazy JW]

Just looked it up in my handy-dandy Pocket Ref. Gasoline is listed there at about 6.14 lb/gal. Using that figure the Oliver 1800 used about .47 lb/hp hour.

There were a total of 32 tractors tested that showed fuel consumption figures at 12 hp/hours per gallon or better. The oldest was in 1939, the venerable Farmall "M" at 12.24

!2 hp/hours per gallon = about .51 lb/hp hour at 6.14 lb/gallon.

Not bad for ancient technology available to every farmer in a 'user friendly' package. Remember, these things all used updraft carburetion, heated intakes, breaker point ignition, the older ones used magnetos.

Agreed that good engineering practice is to use lb/hour but the intent of the Nebraska tractor tests was to protect farmers from ripoff tractor makers in the early 1900's. The gallons per hp/hr was meaningful to the average farmer of the day, most citizens today still calculate fuel consumption per gallon because that is how it is normally sold.

Too bad there isn't an unbiased testing procedure for cars like the old Nebraska tractor tests.
Joe