Old School Engines and Fuel Efficiency

[cleanspeed1]

Flatheads, Hemis, straight 6s and 8s, Nailheads, foreign, domestic.

Where these engines and others from back in the day that poorly designed?

Given some modernization, could they do just as well as what's out now?

If you have or had an old school ride that actually mpg'd well, share the story.

[Joenavy85]

my dad had an old Chrysler 300 (I forget what year, may have been a Hurst 300) with a 392 Hemi that got around 20-22MPG, may not seem good but it was a 4200+ pound car after all, and it had the aerodynamics of a smooth brick. And I'm pretty sure he never tried for mileage in the thing

[JRMichler]

My very first car, purchased for the grand sum of $100, was a 1961 Rambler American with the flathead 6 cylinder engine. As best as I can recall, it got 30 MPG when I first got it. However, the top speed was only 60-65 MPH.

Then I fixed the accelerator linkage so the throttle plate would go full open. After that, I drove 70 MPH and averaged 24 MPG.

I've always wondered what that car could have done with some aero work and an overdrive transmission.

I won a race in it without exceeding idle speed in first gear. It was through a frozen plowed field and the other guy did not have seat belts.

[cleanspeed1]

What got me wanting to start this thread was an article I was reading last night about the Oldsmobile Turnpike Cruiser package from the '60s. There have to be more stories about combos like that and it just raises the question about how far we have come in terms of auto design. I know the stories are out there about simple engines that mpg well.

[Kodak]

Originally Posted by cleanspeed1

...it just raises the question about how far we have come in terms of auto design. I know the stories are out there about simple engines that mpg well.

I recall having heard that the Ford Model T's did fairly well. Can't remember an mpg figure though. A quick net search gave varying figures ranging from low/mid teens to mid 20's, although I wonder about the validity of the figures.

Of course, conditions like congestion and poorly designed traffic lights, which were less of an issue in 1908, make for artificially lower real-life mpg than what modern vehicles may actually be capable of.

[Arragonis]

Being 'foreign' I would have to nominate a foreign engine - BMC / BL's A-series engine - 803-1275cc. The one used in the class Mini Coopers, the MG Midget / AH Sprite and hundreds of other cars.

I had the 64 MPG car in this advert



back in the day - 998cc, 46 bhp, 82 mph and 0-60 officially in 18.2 seconds.

Needless to say it didn't manage 64 every day as I was 17 and stupid, but I did have the odd tank of 50+ mpg, which was very useful as it only had a small 5.5 gallon fuel tank. The developments that gave it the potential for 60+ were simple - high compression and a long (for the day) top gear of 18.6 mph/1000 rpm.

It also had the superbly economical single SU HIF carb - and I know that people who remember the unreliable setups of MGs of the 50s and 60s will be curing that statement - but this version did away with the side float chamber and actually remained in tune for more than the time it took to drive away from the garage.

The A-series was efficient enough to remain in production for a long long time - 1952 to 2000+ and whenever a replacement came along it was always just "good enough" to not be replaced even though it was a pushrod OHV design in the days of DOHC/16v units. Honda had been making VTECs for 2 decades by the time it was phased out.

It wasn't light (Iron block / head) and it had inefficient siamese ports but the combustion chamber design was very effective, plus being a long stroke unit it was good for low and mid range torque and made better use of the fuel it did burn. It also only had 3 main bearings so it didn't have a lot of friction lossed but at the expense of reliability at higher engine speeds - but then again did I mention the siamese ports ?

Later ones in the run-out classic Minis actually got port FI, ECUs and catalysts as well as electric cooling (for noise reasons) but with the low gearing of the Mini they weren't going to be especially good at FE.

[cleanspeed1]

Originally Posted by Arragonis

Being 'foreign' I would have to nominate a foreign engine - BMC / BL's A-series engine - 803-1275cc. The one used in the class Mini Coopers, the MG Midget / AH Sprite and hundreds of other cars.

I had the 64 MPG car in this advert



back in the day - 998cc, 46 bhp, 82 mph and 0-60 officially in 18.2 seconds.

Needless to say it didn't manage 64 every day as I was 17 and stupid, but I did have the odd tank of 50+ mpg, which was very useful as it only had a small 5.5 gallon fuel tank. The developments that gave it the potential for 60+ were simple - high compression and a long (for the day) top gear of 18.6 mph/1000 rpm

It also had the superbly economical single SU HIF carb - and I know that people who remember the unreliable setups of MGs of the 50s and 60s will be curing that statement - but this version did away with the side float chamber and actually remained in tune for more than the time it took to drive away from the garage.

The A-series was efficient enough to remain in production for a long long time - 1952 to 2000+ and whenever a replacement came along it was always just "good enough" to not be replaced even though it was a pushrod OHV design in the days of DOHC/16v units. Honda had been making VTECs for 2 decades by the time it was phased out.

It wasn't light (Iron block / head) and it had inefficient siamese ports but the combustion chamber design was very effective, plus being a long stroke unit it was good for low and mid range torque and made better use of the fuel it did burn. It also only had 3 main bearings so it didn't have a lot of friction lossed but at the expense of reliability at higher engine speeds - but then again did I mention the siamese ports ?

Later ones in the run-out classic Minis actually got port FI, ECUs and catalysts as well as electric cooling (for noise reasons) but with the low gearing of the Mini they weren't going to be especially good at FE.

53 mpg ( US ) from a single carbureted, non feedback style engine with an SU carburetor that worked. That is impressive.

[Arragonis]

Originally Posted by cleanspeed1

53 mpg ( US ) from a single carbureted, non feedback style engine with an SU carburetor that worked. That is impressive.

True, but when you consider it only weighed 1800 lbs and if you compare the performance to say a 3 cyl late model 5 sp Geo it comes off not so good.

But it was a nice car at the time.

[JasonG]

While not real impressive, my 1979 Yamaha XS750 gets around 50MPG (if I stay off the throttle )

Air cooled, carburated, steel everything. Same engine basically from 1962.
Most new aluminum watercooled injected bikes run 40-50 MPG.

My opinion is same story all around. Most manufactuers don't engineer FE into their engines.

[cleanspeed1]

I wouldn't go that far, the manufacturers do it but unless you care heavily about it, you'll never know about it. I never looked in to the old school engines for mpg capability because, at the time, I never cared about it. But with all the complexity involved with modern engines, I find it hard to believe that prior to the advent of computer controls that the OEMs didn't have combinations that were fuel efficient, yet possibly limited because of the technology of the time.