I really don’t see how not having vacuum advance would prevent lugging. Lugging is a combination of high manifold pressure and low rpm. When the manifold pressure is high, the vacuum advancer goes to full retard.
The vacuum only advances the timing during high vacuum operation, which is the opposite of lugging conditions.
I imagine that the ECU can also back off on throttle opening if the knock sensors detect detonation.
Heavy duty vocational trucks use Allison automatic transmissions with pushbutton shifting
I don’t think it’s a moronic idea at all
The car I learned to drive in and in which I took the driving test to get my drivers license had a push button shifter.
It was a 1959 Plymouth Fury.
The only difference was that the buttons controlled a maze of rods and levers instead of switches.
In the case of the Allison automatic transmission, the shifting is controlled electronically anyway I believe, so using a lever to control it would be complicating it instead of simplifying it.
My parents had one of those Plymouth station wagons that had a push button automatic. I think some solenoids still mechanically put the transmissions gear selector in the right position. That was definitely a Rube Goldbergization of a car, or perhaps Wurlitzerization would be a better term.
You could almost imaging some film studio orchestra performing the tune “Happy Go Lively” when stepping into a late 1950’s car.
If you’re unfamiliar with that tune, here it is.
Vacuum advance makes the engine accelerate more responsively at relatively low rpm @B.L.E. And without it the engine must be cranked up into a narrow power band to perform reasonably well.
Only when the vacuum is high (nearly closed throttle). Floor it at low rpm and you get the same spark advance that a pure centrifrugal advance mechanism would give the spark.
Think of it as manifold pressure retard instead of vacuum advance.
If you floor a 36hp engine pulling a 3,000 lb car it may be a while before the centrifugal advance made any noticeable change unless the engine rpm was near peak torque when the accelerator was pressed. Similarly a 200 hp engine pulling a 12,000lb truck must be kept in a narrow rpm range and while vacuum advance would give some increased responsiveness at lower rpm it would do so at the risk of detonation.
“On the 1955 Plymouths, the oil pressure and temperature gauges were located on the right side of the dashboard”
I’m not sure about the placement of the temperature gauge, but I do recall that the oil pressure gauge on our '55 Plymouth was located so far to the right that it was essentially impossible for the driver to monitor it. For those who have never seen the dashboard of these cars, suffice it to say that if the oil pressure gauge was any further to the right, it would have been on the right front fender.
;-))
My first automotive task when I was a kid was monitoring and reporting the oil pressure periodically while my father drove our '55 Plymouth.
VDCdriver
"My first automotive task when I was a kid was monitoring and reporting the oil pressure periodically while my father drove our '55 Plymouth."
Cool! Great exposure to the important habits of monitoring the essentials of motoring that so many of the youngers folks seem to be missing.
Did you call out, “MarkTwain” or anything?
CSA
“Did you call out, “MarkTwain” or anything?”
Good one!
No, I just read-out the numerical indications whenever Dad asked.
On a related note, one of the books that I am currently reading is Roughing It, by Mark Twain!
Somehow, I missed this one of his classics when I was a kid, and the humor–while often subtle–is just amazing–and frequent.
My dad explained to me what the gauges meant. When I was 11, we were taking a 300 mile trip to visit relatives. From the back seat I noticed that the oil pressure was dropping quickly. I said something to my dad. He immediately pulled the car off the road and checked the oil. The dipstick didn’t show any oil. My mother and brother stayed with the car while my dad and I walked about a mile and a half each way to a filling station to buy oil. I know that my dad had checked the oil before we left home and we had gone about 200 miles. At any rate, my dad was so appreciative that I got an extra quarter that week in my allowance–I got 75¢ instead of the regular 50¢. It pays to read the gauges.
It’s an automatic transmission shifter. Like it or not, you don’t need to touch it nearly as much as a diy shifter. Besides, there are those big letters indicating the current mode of the transmission. There’s essentially no excuse for getting out of the driver seat while the transmission is not in park.
Speaking of park, vocational truck transmissions have no park paws. And yet I haven’t heard of investigations regarding runaway trucks and buses. At least I had not experienced a runaway myself.
@chunkyazian Unfortunately, there was a tragedy in Indianapolis, Indiana due to a,runaway bus that jumped a curb and killed the school principal that was pushing children out of the path of the runaway bus. The tragic accident was attributed to driver error. I don’t know what kind of shifter the bus had, but I am certain it was,an automatic transmission.
And you touch on one big advantage of a manual transmission. It takes two steps to get the car or truck to move, so accidental acceleration is rare. The car going through the store window because the driver “got confused” is rare in Europe.
To design a new shifter that looks just like the old shifter, but doesn’t work like it, is nuts. Buttons? OK. Rotary knob? Ok. But PRNDL shifter that doesn’t work like the hundreds of millions of PRNDL shifters? NUTS.
Speaking of manual transmissions in,school buses, I remember hearing about an,accident about 65 years ago where the school bus was hit in the rear end by a fuel truck and there was a big fire that engulfed the rear of the bus. The thinking driver put the bus in the “creeper” gear, jumped off the bus and had the children jump to him one at a time and then run away from the scene. No child was even injured. The bus was ultimately destroyed By the fire. You couldn’t do this with an auto transmission bus. The driver may have pulled open the hand throttle as well. I haven’t had a hand throttle since my 1950 Chevy pickup.
I haven't had a hand throttle since my 1950 Chevy pickup.
My 1976 Fiat 128 had a hand throttle that worked passably well as a cruise control on mostly level roads. With its 1.3L and 65 hp, the Italian style of driving was to pull the hand throttle out and bend in down.
;-]
No one knows who really came up with this line first, but it seems appropriate here (again).
Genius has its limitations; stupidity has none.