Why No Aircooled Cars?

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Originally Posted by Rmay635703
Agreed EPA does not allow air cooled cars,


Does the EPA really not allow a certain technology? I'm sure they ban a few things, but my understanding is that they are all about what comes out of the tailpipe. If one wanted to come up with active shutters and maybe electric heaters on the cooling fins so as to better regulate temp... why would the EPA care? End user might not want that (might not be willing to pay for it) but I don't think it's the EPA "prohibiting" air cooled as much as it's just not feasible to make it work.
 
Emissions?
Our '81 Vanagon met the newly tightened '81 EPA standards with no more than a Bosch electromechanical FI system (the computer was huge by modern standards) and a cat.
NVH?
The VW Type IV had a nice mechanical note and sounded good. Of course, in the Vanagon you usually couldn't hear it, since it was buried under the very spacious luggage area and covered with a full-width metal hatch with sound deadening and a thick pad of carpet over that plus the engine was way back there.
Heat?
The VW produced adequate heat on cold weather highway trips although it wasn't really a shirtsleeve environment. The available gas heater provided great heat and used but a liter an hour.
Operating efficiency?
The VW easily averaged around 20 mpg, and the Vanagon is a big box of a vehicle with interior space that makes a joke of modern minivans.
Also, as Cujet correctly notes, air cooled aircraft engines are very efficient and fairly long-lived considering the percentage of power which they're normally expected to maintain for hours on end. With many of these engines, you can simply shove the throttle all the way forward and leave it there with no concerns beyond what the fuel costs might be.
Turbocharging?
I guess Chevrolet didn't get the memo that you couldn't do this with an air-cooled engine, since they sold two generations of turbo Corvair engines.
Apparently Continental and Lycoming didn't get the memo either, since many aircraft engines are turbocharged. Earlier air-cooled radial transport engines were mechanically supercharged. You want to see a wild design? Google Wright Turbo-compound engine which was used in the last generations of piston airliners.
A fiendishly complex eighteen cylinder radial. Imagine a plug change with 36 plugs per engine.
Why aren't air-cooled cars offered these days? The motorcycle excuse doesn't hold water, since any air-cooled car uses fan-forced cooling as a rule along with ducts and shrouds. Overheating isn't really an issue with forced air cooling.
One might just as well ask why we don't see rear-engine vehicles these days, especially sine the Vanagon demonstrated the advantages this configuration offers in efficient space utilization in a one-box vehicle.
Impact protection/safety?
The Vanagon had the second lowest passenger fatality rate of any vehicle on American roads back in the eighties, lower than any of GM's big boats, lower than any pickup and second only to the Volvo wagon.
I think the answer is that the engineering staffs of the various major makers are too lazy and too comfortable to think outside the box and revisit engineering solutions that are now regarded as passe. If the big boys won't tread there, the little ones are afraid to do so.
Easier, cheaper and safer to continue the current line of development involving liquid cooled engines and FWD.
Unless some adventurous management level engineer willing to bet his career wants to make the case, we'll not see any more air-cooled engines in road vehicles nor will we see a renaissance in rear-engined vans without regard to the advantages either might offer.
 
Plenty of modern air-cooled engines
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The Zetec thermostat housing likes to explode, thereby splashing all your coolant away, making it an air-cooled engine. Plenty of other random coolant loss where you can't figure out why
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The 3800's intake gasket issues, of course you lose all your coolant. A lot of GM cars that used Dexcool/Deathcool where the coolant sludges, now it's air-cooled

The Northstar may also be air-cooled

And of course, Subaru's head gaskets
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I agree about your Vanagon example. I once had a 1970 VW Westphalia camper with a 1600cc engine. It probably made 65/70 hp. I drove that heavy van over the mountains in western NC/eastern TN many times in the summer. It was a slug going up and white knuckle scary on the way down but it never overheated. It also had a nifty gas heater which made plenty of heat. I worked for VW as a line mechanic for four years and probably worked on a thousand air cooled VWs. Never once did I see one seized up from overheating. I had a 180 hp Corvair which was turbocharged and the engine never suffered from inadequate cooling although it finally broke after too many weekend gymkhanas. All of the above is just anecdotal evidence and only proves that at least one owner had a few air cooled vehicles that were reasonably reliable in all sorts of weather but there were lots of us.

With advanced engineering and creative thinking by automakers the objections voiced in this thread could be overcome and the air cooled car, front or rear engine could be reinvented. The problem today is that the car manufacturers are followers not innovators. Think about why modern music is so bad (the millennial whoop). Everything is poll and group tested. Only ideas that are sure fire commercial success will escape the R&D department. Nobody is willing to experiment.

Your last sentence makes me sad because it is likely true.
 
Originally Posted by Dave9
"Thermal efficiency" is a completely nonsensical concept.

It's actually not, and is a very important concept. Of the energy input, what percentage of that is converted to useful work?
 
An aircooled engine's head temperature will totally skyrocket if you keep your foot in it... Chevrolet did a study on this. This is challenging for the metallurgy involved, for keeping the valve seats in place in the head, etc... not to say the emissions. The very high head temps have to be prevented by generous fins and very effective forced air cooling. Oil cooling is a bit peripheral. Of course it, too has to be controlled... but for an air cooled VW engine, all shrouds and rubber elements and the thermostat HAVE TO be in place. In order to get the engine to last under a load, climbing a hill, you have to be in a lower gear - with a few revs on - with moderate throttle opening... and be patient.

I have a '79 Type2... i.e. van, with a 2 litre non-feedback AFC - airflow controled fuel injection system. The aluminum case on this "Type IV" engine was first offered in the line of VW vans in America and Canada in 1972 (in 1.7 litre size, carburetted)... It took Porsche until 1978 (in North America) to switch away from the magnesium alloy case that was in use prior... where head studs would pull-out unless it was TimeSerted (if memory serves).

The thermostatic air cooling on the Type IV engine was superior by way of temperature control to the aircooled 911 (under low load situations) - as the Porsche only had thermostatic oil temp control... no thermostatic air temps. The Type IV had, also, thermostatic oil temp control of a more simplistic form. Having said that temp control was superior on the VW - it was much, much less effective in shedding heat when under load than the Porsche... which had a mega-sized axial fan and fibregass shroud.

The key to getting the Type IV engine to last, was easy throttle, lower gear, higher revs, going up a sustained grade.

I really like my Type II VW, but it really has to be babied, to get it to go the distance. Not practical, I'm afraid. Call it a perverse love affair.
 
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Oh, and I really like the Vanagons... particularly the water cooled ones (though they are notoriously unreliable with regards to coolant leaks). Drive quality is 'real nice. The aircooled Vanagons are a challenge for the 2 litre engine. More weight and more bluff area - than the last of the "breadloaves" - of '79.
 
I may have overlooked it, but I didn't see anyone mention transmission cooling. Most people have automatic transmissions these days and (at least for trucks) I've never seen one that didn't use the radiator system for cooling. There would need to be a more robust passive cooling mechanism added to hold down transmission temperatures.
 
In case you couldn't tell from my post, I really liked the Vanagon.
The 2 liter was okay even with its rousing 67 bph. The VW was much quicker to 60 mph than my 240Ds were, but there was no point in flogging it other than to enter an interstate since you couldn't go all that fast anyway.
I usually drove the Vanagon quite gently and the payoff was in relaxed driving and pretty decent fuel economy. We did a number of long road trips with the VW and it always tooks us where we were going and brought us back home while using little fuel by the standards of time.
Kind of hard to believe that Porsche actually offered this engine in the 912E, something which we'd never see anything like these days.
Imagine a 911 shell with a 67 bhp engine installed.
 
The engine in the 912E utilized the same case, conn rods, crankshaft, cylinder barrels (not sure re the pistons) - but I believe the cylinder heads were Porsche-specific design. The 914 2.0 litre pre-dated this application... and in the 2.0 litre they were Porsche design, but on the 1.7 and 1.8 they were identical to the VW "Type IV" engine.

In any case, the 912E had, oh, about 91 HP if memory serves? Not a lot, for sure, but the 912E of 1976 apparently drove quite nicely.
 
Originally Posted by fdcg27
In case you couldn't tell from my post, I really liked the Vanagon.
The 2 liter was okay even with its rousing 67 bph. The VW was much quicker to 60 mph than my 240Ds were, but there was no point in flogging it other than to enter an interstate since you couldn't go all that fast anyway.
I usually drove the Vanagon quite gently and the payoff was in relaxed driving and pretty decent fuel economy. We did a number of long road trips with the VW and it always tooks us where we were going and brought us back home while using little fuel by the standards of time.
Kind of hard to believe that Porsche actually offered this engine in the 912E, something which we'd never see anything like these days.
Imagine a 911 shell with a 67 bhp engine installed.


VW actually developed a 6 cylinder "Wasserboxer" engine - more or less a lengthening of the four cylinder Wasserboxer. It had overhead valves, pushrods, just like the Wasserboxer 4. It never made it to production, unfortunately.

In Europe there are a number of folks who have fit 911 aircooled Porsche motors to the Vanagon. I should not say, just in Europe. Some in America, too.

Not to stray from the Vanagon - here's what I think is a neat picture of a Belgian Westfalia "Breadloaf" / Late Bay Window VW van... and a picture of an "Amescador" rear tent.

1610020_888916034557359_7739333689596453359_n_zpse0fsklzm (1) - C.jpg


IMG_3007_zpszo2tnosd (1) - D.jpg


IMG_5427_zpsxdc0kkim - A.jpg
 
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Originally Posted by Cdn17Sport6MT
The engine in the 912E utilized the same case, conn rods, crankshaft, cylinder barrels (not sure re the pistons) - but I believe the cylinder heads were Porsche-specific design. The 914 2.0 litre pre-dated this application... and in the 2.0 litre they were Porsche design, but on the 1.7 and 1.8 they were identical to the VW "Type IV" engine.

In any case, the 912E had, oh, about 91 HP if memory serves? Not a lot, for sure, but the 912E of 1976 apparently drove quite nicely.


You're right. It appears that either Porsche or VW had warmed the Type IV up to 86 bhp for the 912E, probably sacrificing durability in the process.
Porsche did build at least a brace of flat six Vanagons, allegedly for use as chase cars in continental testing but probably more because the wrenches knew that it could be done and would be fun to do and the factory would have had some engines laying around.
A not uncommon swap would be a Subaru into a Wasserboxer. You'll see these for sale from time to time. Even a 2.2 Subie makes more power than a VW Wasserboxer ever dreamed of.
 
Originally Posted by Elkins45
I may have overlooked it, but I didn't see anyone mention transmission cooling. Most people have automatic transmissions these days and (at least for trucks) I've never seen one that didn't use the radiator system for cooling. There would need to be a more robust passive cooling mechanism added to hold down transmission temperatures.


It can be done, But requires a big cooler & alot of air flow. Some early aluminum GM Powerglide transmissions didn't have a cooler circuit at all. They had huge intake holes in the bellhousing & a fan welded to the torque converter. Powerglide equipped Corvairs were similar in design.
 
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