Old to fuel-saving New to here

[GeorgeWiseman]

Originally Posted by GeorgeWiseman

Propane is typically vaporized before being fed into the airstream going into the engine.

Some additional thoughts that may help people who already have propane fuelled engines.

First, make sure your propane is actually being vaporized. A lot of pre-heaters are insufficient to raise the temperature of the propane high enough to assure the liquid turns to vapor (flash boils) once it is metered into the airstream. If some of the propane is still liquid, it will suck the heat out of the air trying to become vapor. Less heat (enthalpy) in the air will reduce the efficiency of combustion.

You aren't likely able to do much about increasing cylinder pressures (maybe turbocharger?) or change valve timing but you can be sure that the ignition timing is optimized for propane. Some engines will allow the ignition curves to be modified. Sorry I can't be specific, my reference books are in storage 2500 miles away, but such information should be available online and from propane fuel system experts.

Be sure your propane fuel tank stays 'warm' (but no more than 90°F or it could over-pressurize). As propane is removed, the remainder of the propane cools down, as it cools down, the tank loses pressure that your fuel system may be depending on to maintain a correct air:fuel ratio. The tank usually reheats by gathering heat from the ambient air, but sometimes fuel draw can cool the tank faster than it can recover. Just something to watch for.

I've also noticed that quite a few propane powered vehicles use too much fuel, making a stinky exhaust. Properly combusted fuel has almost no smell (at least for me )

In any case, a careful study of your fuel system and how it works can often turn up a few places where efficiency upgrades can be made.

[wdb]

Is anyone besides me getting a 70's vibe?

I get the feeling that Mr. Wiseman found some simple methods to improve the absolutely abysmal performance of 1970's and early 80's carbureted engines, and has been trying to ride those successes to fame and fortune ever since.

A piece of hose here and a tee fitting there might have improved mileage on those cars (almost certainly with a concurrent rise in emissions), but technology marched on, and Mr. Wiseman found himself with a rapidly shrinking target market. Perhaps that's when the PVC pipes that promise to double mileage, and the conspiracy theories about car companies and oil companies being in cahoots to snooker the planet for their profit, took hold.

[Frank Lee]

I wanted to be able to understand then duplicate or at least approach the success of the 32-36mpg Ford pickup- I too have a '60s pickup shell and several old V8 engines laying around and boy would I love to get better MPG in that old pickup than I do in my Tempo!

It appears the data gathering phase is over. That's OK because what Mr. Wiseman had was made by 1977 with a lucky combination of stock components: '63 Ford pickup body and chassis, 361 Ford V8 with 2bbl carb, stock three (later four) speed manual transmission, stock wheels and perhaps stock or nearly stock-type tires, and a 2:1 axle from a car... and that's it, no special mods at all as far as fuel delivery, vehicle weight, vehicle aero, etc. AND no special driving techniques like P&G.

The '63 was an utterly stock combo except for the rear axle ratio of 2:1, which allowed for 45mph cruise @ 700 rpm. Well, I ran into a couple of roadblocks when attempting to come up with my own 32-36mpg combo, first one being that 2:1 axle ratios do not exist. At least, Google couldn't find me any. The lowest I was able to locate was 2.21:1, for a DANA gearset used by AMC in the '80s- OOPS, too new for a truck assembled this way by 1977. (1982 87 AMC Jeep Dana 35 Ring Pinion 2 21 1 Gear Ratio 7 1 2 Dia 19 42 Tooth | eBay) George's truck wore all four of it's original wheels- kind of points to a Ford axle- and the lowest Ford ratio in that era was a 1970-only 2.33:1 but the source (Ford rear ends) doesn't say what model that was for. Otherwise the lowest was the 2.47:1 from the Granada. Another bit that points toward the axle being from a Ford is that everything else- wheels, springs, shocks, and presumeably the driveshaft- bolted right up (that li'l car axle had the same sized u-joint yoke, spring perches, and wheel bolt pattern as a pickup? ). We are told the rear wheels tracked inside the front due to the narrow car axle; the narrowest Ford axle of all was the Maverick's- yes, it's even narrower than Pinto and Falcon at 56.5" wide- not enough to cause the rear wheels to completely track inside the fronts, but they would be a few inches in on each side. The lowest Maverick ratio was 2.95:1. Ahh, the mystery continues.

Anyway, even though it appears I will never be able to source a 2:1 axle, let's continue under the presumption that's what the '63 somehow had. It had the stock three-speed manual transmission at first, and this is the transmission that gave us the 36mpg figure. Later the truck got a four-speed but that would have no effect on cruise rpms, as both transmissions have 1:1 top gear ratios, and this truck was not equipped with an overdrive.

With a 1:1 top gear and a 2:1 axle, the only unsolved variable for gearing to get 700rpm @ 45 mph is tire size. Plugging in these known variables into an automotive performance calculator (Wallace Racing - Automotive Calculators) tells me a 43.2" diameter tire is required... Ummmm... 43.2"?!? Most common tires of the era were 25-28" diameter (Tire Sizes and Dimensions (plain text version)) so that is quite a large discrepancy. Just for reference, plugging a 27" tire into the calculator gives us 1,120rpm @45mph.

And one more thing about the axle: it had ball bearings. Bearing drag- ball or roller, or ball vs roller- is considered to be so insignificant it is not even factored into performance simulations.

OK, let's set aside for the moment the unavailability of 2:1 axles and the unlikelihood of the '63 having 43.2" diameter tires on 15" wheels... Yeah, let's say it had those things. It had a 45mph cruise @ 700rpm and was able to out-accelerate the hot muscle cars of the era from 50mph on up WITHOUT DOWNSHIFTING. The idle specification for the 361 was 500rpm; at 45mph it was only turning 200rpm above idle; at 50mph it would have been at 778rpm; and at 80mph it would be 1,244rpm. Have you ever looked at a tach and gotten a feel for the difference between 500 and 700rpm? Have you floored an engine in top gear from idle speed? I don't even need a dyno chart to know these rpms are way, waaaay below peak HP and torque; in fact, at just above idle very little torque is available, then to top that off it is being fed through only a 2:1 reduction- instead of the more common 3 to 4:1- PLUS those ginormous double-sized tires- so "flooring it" would only result in the sound of intake "waaaaaaaaa" with no discernable acceleration taking place. On a closely related note, the 3,200-3,400lb truck did not enjoy a weight advantage over these cars.

Incidentally, a reasonably attainable redline rpm for such an engine- 3.50" stroke, hydraulic tappets- in street trim would be about 6,300, which if obtained in top gear would send the truck hurtling down the road at 405mph. Clearly I would have to go with an electronic speedometer, as speedo cables twist off at about 100 mph. Is that because the speedo needle hits a stop and the speedo gears won't let it go any faster?

Do we have some issues to sort out? Yes we do, and we haven't even gotten past the basic stuff yet. I can hardly wait to dig into the 200-2,000mpg stuff.

iveyjh- Is this too mean?

[elhigh]

Thank you, Frank.

I had looked at that 2:1 ratio and thought it was a typo. Then I looked at the 700 rpm claim and thought THAT was a typo. I've never seen a 2:1 and actually your find of such a low rearend for the AMC surprised me.

I didn't want to get into the math of it. No ambition. But it points up a disturbing trend: if this is the kind of accuracy in basic math we can expect from Mr. Wiseman, what other errors have crept into his information?

A rearend ratio like that would leave top gear just useless. Unless the top gear was on the order of about 1.5:1 (where most trucks of that era have 2nd or 3rd), it would only be there for looks.

405mph. Nice! "Are we there yet, Daddy?"

"Yeah!"

[Frank Lee]

Yeah, I too was shocked at finding those low axle ratios; all I was familiar with was about 2.9:1 on up.

Even with those seemingly "advantageous" ratios, the fact remains they are hypoid gearsets, turning the power 90 degrees; as such they suffer higher friction losses than, say, the gearsets commonly found in FWDs.

[MetroMPG]

Thoughts on splitting the pickup discussion from this thread to a separate one? Are they too intertwined?

[Frank Lee]

I'm ready to move on from it and leave it here if George- OR ANYBODY- has no additions or corrections. Or, it would make for a very entertaining stand-alone thread.

Either way, I really, REALLY want to talk about the 200 mpg pickup and the 2,000 mpg four-passenger car!!!!

[sarguy01]

Originally Posted by Frank Lee

I wanted to be able to understand then duplicate or at least approach the success of the 32-36mpg Ford pickup- I too have a '60s pickup shell and several '60s V8 engines laying around and boy would I love to get better MPG in that old pickup than I do in my Tempo!

It appears the data gathering phase is over. That's OK because what Mr. Wiseman had was made by 1977 with a lucky combination of stock components: '63 Ford pickup body and chassis, 361 Ford V8 with 2bbl carb, stock three (later four) speed manual transmission, stock wheels and perhaps stock or nearly stock-type tires, and a 2:1 axle from a car... and that's it, no special mods at all as far as fuel delivery, vehicle weight, vehicle aero, etc. AND no special driving techniques like P&G.

The '63 was an utterly stock combo except for the rear axle ratio of 2:1, which allowed for 45mph cruise @ 700 rpm. Well, I ran into a couple of roadblocks when attempting to come up with my own 32-36mpg combo, first one being that 2:1 axle ratios do not exist. At least, Google couldn't find me any. The lowest I was able to locate was 2.21:1, for a DANA gearset used by AMC in the '80s- OOPS, too new for a truck assembled this way by 1977. (1982 87 AMC Jeep Dana 35 Ring Pinion 2 21 1 Gear Ratio 7 1 2 Dia 19 42 Tooth | eBay) George's truck wore all four of it's original wheels- kind of points to a Ford axle- and the lowest Ford ratio in that era was a 1970-only 2.33:1 but the source (Ford rear ends) doesn't say what model that was for. Otherwise the lowest was the 2.47:1 from the Granada. Another bit that points toward the axle being Ford is that everything else- wheels, springs, shocks, and presumeably the driveshaft- bolted right up (that li'l car axle had the same sized u-joint yoke and wheel bolt pattern as a pickup? ). We are told the rear wheels tracked inside the front due to the narrow car axle; the narrowest Ford axle of all was the Maverick's- yes, it's even narrower than Pinto and Falcon at 56.5" wide- not enough to cause the rear wheels to completely track inside the fronts, but they would be a few inches in on each side. The lowest Maverick ratio was 2.95:1. Ahh, the mystery continues.

Anyway, even though it appears I will never be able to source a 2:1 axle, let's continue under the presumption that's what the '63 somehow had. It had the stock three-speed manual transmission at first, and this is the transmission that gave us the 36mpg figure. Later the truck got a four-speed but that would have no effect on cruise rpms, as both transmissions have 1:1 top gear ratios, and this truck was not equipped with an overdrive.

With a 1:1 top gear and a 2:1 axle, the only unsolved variable for gearing to get 700rpm @ 45 mph is tire size. Plugging in these known variables into an automotive performance calculator (Wallace Racing - Automotive Calculators) tells me a 43.2" diameter tire is required... Ummmm... 43.2"?!? Most common tires of the era were 25-28" diameter (Tire Sizes and Dimensions (plain text version)) so that is quite a large discrepency. Just for reference, plugging a 27" tire into the calculator gives us 1,120rpm @45mph.

And one more thing about the axle- it had ball bearings. Bearing drag- ball or roller or ball vs roller- is considered to be so insignificant it is not even factored into performance simulations.

OK, let's set aside for the moment the unavailability of 2:1 axles and the unlikelihood of the '63 having 43.2" diameter tires on 15" wheels... yeah, let's say it had those things. It had a 45mph cruise @ 700rpm and was able to out-accelerate the hot muscle cars of the era from 50mph on up WITHOUT DOWNSHIFTING. The idle specification for the 361 was 500rpm; at 45mph it was only turning 200rpm above idle, and at 50mph it would have been at 778rpm, and at 80mph it would be 1,244rpm. Have you ever looked at a tach and gotten a feel for the difference between 500 and 700rpm? Have you floored an engine in top gear from idle speed? I don't even need a dyno chart to know these rpms are way, waaaay below peak HP and torque; in fact, at just above idle very little torque is available, then to top that off it is being fed through only a 2:1 reduction- instead of the more common 3 to 4:1- so "flooring it" would only result in the sound of intake "waaaaaaaaa" with no discernable acceleration taking place. On a closely related note, the 3,200-3,400lb truck did not enjoy a weight advantage over these cars.

Incidently, a reasonably attainable redline rpm for such an engine- 3.50" stroke, hydraulic tappets- in street trim would be about 6,300, which if obtained in top gear would send the truck hurtling down the road at 405mph. Clearly I would have to go with an electronic speedometer, as speedo cables twist off at about 100 mph. Is that because the speedo needle hits a stop and the speedo gears won't let it go any faster?

Do we have some issues to sort out? Yes we do, and we haven't even gotten past the basic stuff yet. I can hardly wait to dig into the 200-2,000mpg stuff.
iveyjh- Is this too mean?

I am eating lunch and I shot coffee through my nose reading this...

Something else to consider, what kind of rolling resistance did 70's era tires have? Weren't they still bias ply or at least a good chance that the tires he had were bias? (A quick google search gave me this book with some charts that showed a higher rolling resistance in bias ply over radial tires.
Theory of Ground Vehicles - J. Y. Wong - Google Books) So, George was able to achieve this gas mileage using high rolling resistance tires. Imagine that truck today with a good set of Michelins and fuel injection...50 mpg at least!

One more thing that bothers me about this truck claim is the way he tested the mileage. Without fancy electronic gauges and GPS, how did George test his mileage? I am assuming he did the math at the pump, but with a speedometer that was most likely off from the 2:1 (or whatever it was) ratio rear, the math would have been more complex to figure out since the actual distance traveled would have needed to been calculated. With a 2:1 (or more likely a 2.95+ numerically) the speedometer would have showed fewer miles than actually travelled.

The truth isn’t mean. The way it is presented can be, but then again, George has had several chances now to provide some facts. Frank Lee has performed some actual fact based research for us to see that the truck, as George described it, didn’t exist. Could there be a chance that George found some random tractor axle that has a 2:1 ratio, sure, but not likely especially considering the RPMs vs truck speed are enough to prove George’s claim false.

[markweatherill]

Originally Posted by wdb

Is anyone besides me getting a 70's vibe?

I get the feeling that Mr. Wiseman found some simple methods to improve the absolutely abysmal performance of 1970's and early 80's carbureted engines,

Statements like this:
only about 10% of the fuel is vapor and mixed with oxygen when the spark plug fires; resulting in 90% of the fuel being wasted

may have been credible decades ago, although not true, but, here and now, presented as an actual fact, it's kind of ridiculous.

[Frank Lee]

Heh- Hadn't even gotten as far as the rolling resistance and odometer correction. But the odo would read far fewer miles than actual, and the speedo readings would be far, far too slow as well... unless George had a custom speedo drive gear made.

P.S. If speedo cables twist off on a truck with a 2:1 axle at 100mph, does that mean they twist off on trucks with 4:1 axles at 50mph?