Having sat in terrible Chicago traffic for 2 hours in a 1988 911 and watched the oil temp go into the red, I'll pass on air-cooled as a daily driver.
Why No Aircooled Cars?
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Good luck air cooling a turbo engine. My golf 1.8 TSI for example has oil and water cooling on the turbo itself and all throughout the engine. It yields heat in the cabin in less than a mile because the combustion heat is channelled into the turbo and its water cooling so effectively. Very little heat energy is wasted until the main thermostat opens and sends it to the radiator.
Turbos are so good these days that why not have one for most passenger car applications?
Turbos are so good these days that why not have one for most passenger car applications?
Originally Posted by ragtoplvr
Originally Posted by Passport1
Why Not Aircooled Engines?
Snip
I have experience with several VWs, older Porsches and even owned a Corvair. They never gave me any engine troubles and even kept me adequately warm during many awful Chicago winters.
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VW aircooled kept you warm in Chicago winter. What color is the sky in your world? Had to have ice scraper for inside at the ready in mild kansas winters, yes, had the heater boxes on the head pipes too.
How about cylinder 3 failures from overheating from oil cooler.
Rod
The heat in my squareback was like the breath of a large dog. Chicago winters, too. The heater tubes / system was fully functional, just not very effective.
And yes to dropping the #3 exhaust valve on I-94 while driving across Montana. Towed the car back to Chicago and put in a spare motor.
Originally Posted by Passport1
Why Not Aircooled Engines?
Snip
I have experience with several VWs, older Porsches and even owned a Corvair. They never gave me any engine troubles and even kept me adequately warm during many awful Chicago winters.
Snip
VW aircooled kept you warm in Chicago winter. What color is the sky in your world? Had to have ice scraper for inside at the ready in mild kansas winters, yes, had the heater boxes on the head pipes too.
How about cylinder 3 failures from overheating from oil cooler.
Rod
The heat in my squareback was like the breath of a large dog. Chicago winters, too. The heater tubes / system was fully functional, just not very effective.
And yes to dropping the #3 exhaust valve on I-94 while driving across Montana. Towed the car back to Chicago and put in a spare motor.
Not much love here for the idea. Of course the aircooled design has some drawbacks but none of them are insurmountable. In '69 I had a VW bug and America put a man on the moon. Imagine how much engineering has evolved since then. Improving heat for the cabin and cooling for the engine are simple fixes. Add forced air to the heaterboxes and oil coolers. Putting the engine in the stern deprived it of forced air. Moving it to the front would add greatly to the cooling.
I'm just an average mechanic, not an automotive engineer but it seems to me that if there are no more innovations on the horizon our collective future in short order will be small overpriced, poorly performing EVs.
I'm just an average mechanic, not an automotive engineer but it seems to me that if there are no more innovations on the horizon our collective future in short order will be small overpriced, poorly performing EVs.
As an owner of 2 air cooled VW's and previous owner of 2 Corvairs, I can only say, their simplicity is worth wearing a jacket. My 65 Beetle is from England and it's heater boxes will heat you out. I am not sure if they have different design internally, but they look identical to US imported ones. When everyone else is checking anti freeze, I am inside warm and cozy. When I pull the motor for a new clutch I disconnect 5 wires 2 heater control cables and 2 hoses one gas line and 4 bolts that hold the motor to the transmission. It is out and on the floor in less than 45 minutes and done by just me. I am not bragging because others are much faster at this job. I have modern water cooled cars too, but wouldn't consider to attempt doing a motor pull on one of these by myself. My VW does 75 easily and returns 30+mpg.
Modern people would burn them out pulling grades in the summer with A/C on full, and the warranty cost would be too high. They had to put red warning lights on oil and temp and other things because many people aren't interested in looking at a temp or oil pressure gauge. This was on water cooled cars. The red lights aren't even stopping some people from keeping on going.
Originally Posted by Snagglefoot
A modern emissions control system requires a consistent engine temperature to properly dial in all the parameters. A varying temperature in an air cooled engine is bad news for that.
That makes sense. I wonder if the higher cyl temps cause too much NOX?
A modern emissions control system requires a consistent engine temperature to properly dial in all the parameters. A varying temperature in an air cooled engine is bad news for that.
That makes sense. I wonder if the higher cyl temps cause too much NOX?
Because traffic. Vehicles should work in any environment that is common on public roads, not constantly risk overheating. Stating some certain combo with an air cooled engine that was hard to overheat, does not make that configuration what most consumers demand for various reasons.
Let's just go back to two strokes because simpler is better, except for emissions.
The US ever rising fuel economy mandates make air cooled engines impossible. Soon they will also make all ICE cooled engines impossible too, unless the rest of the vehicle is made of tin foil and you ride lying down to reduce the drag coefficient, or so small that you can't stand being sardined inside.
They didn't add water cooling for no reason, seems like you just want a complete education about the evolution of the modern ICE engine?
Let's just go back to two strokes because simpler is better, except for emissions.
The US ever rising fuel economy mandates make air cooled engines impossible. Soon they will also make all ICE cooled engines impossible too, unless the rest of the vehicle is made of tin foil and you ride lying down to reduce the drag coefficient, or so small that you can't stand being sardined inside.
They didn't add water cooling for no reason, seems like you just want a complete education about the evolution of the modern ICE engine?
Good question, I was wondering this myself recently.
Also, why no carburetors on vehicles anymore? They seem so simple, and cheaper than fuel/direct injection to maintain, repair and build.
While we're at it, is there any way to attach a manual hand crank to the front of my Lexus?
This push-button starting feels rinky-dink and I'm worried something will soon break.
Also, why no carburetors on vehicles anymore? They seem so simple, and cheaper than fuel/direct injection to maintain, repair and build.
While we're at it, is there any way to attach a manual hand crank to the front of my Lexus?
This push-button starting feels rinky-dink and I'm worried something will soon break.
Originally Posted by BMWTurboDzl
Originally Posted by Snagglefoot
A modern emissions control system requires a consistent engine temperature to properly dial in all the parameters. A varying temperature in an air cooled engine is bad news for that.
^^^^^ This
Agreed EPA does not allow air cooled cars,
Hot = NOX
Originally Posted by Snagglefoot
A modern emissions control system requires a consistent engine temperature to properly dial in all the parameters. A varying temperature in an air cooled engine is bad news for that.
^^^^^ This
Agreed EPA does not allow air cooled cars,
Hot = NOX
Supposedly next year's Euro emissions standards won't allow an air-cooled Harley Sportster into the country. The USA can still have them, though. It will be a sad day for me if Harley ever stopped making their best bike, the Sportster.
With the amount of power people want these days, emissions and the available space in an engine bay for the air to actually cool the engine, it doesn't seem like its going to make a comeback anytime soon.
Deutz has some air-cooled Diesel engines
http://www.deutz.co.za/mining-and-industrial-engines/912w
Quote
Air-cooled 3-, 4-, 5- and 6-cylinder in-line engines
DEUTZ-two-stage combustion
Advanced injection and combustion system
PTOs via gear, flywheel and v-belt pulley
High torque at low speed
Modular system with single cylinder arrangement and high degree of parts commonality
Customized component system with many different peripheral parts
Extremely compact design
Cold-starting ability even under extreme climatic conditions
http://www.deutz.co.za/mining-and-industrial-engines/912w
Quote
Air-cooled 3-, 4-, 5- and 6-cylinder in-line engines
DEUTZ-two-stage combustion
Advanced injection and combustion system
PTOs via gear, flywheel and v-belt pulley
High torque at low speed
Modular system with single cylinder arrangement and high degree of parts commonality
Customized component system with many different peripheral parts
Extremely compact design
Cold-starting ability even under extreme climatic conditions
Originally Posted by Cujet
Originally Posted by Ws6
Because a liquid-cooled engine can be properly designed to be MUCH more efficient, as the coolant can be routed to "hot spots", etc.
Maybe, maybe not. Air cooled engines may run with cylinder head temperatures as high as 500 deg F. This means less combustion energy is wasted into the cooling system. Aircraft engines are air cooled and have been able to match the thermal efficiency of a Prius engine for the last 70 years.
You have no idea what you're talking about. Letting an engine run hotter does not mean less combustion energy is wasted, it just means more stress on the engine. On the contrary you want a controlled temperature to maximize a lean fuel ratio.
Aircraft engines are only air cooled for two reasons. One, there's a massive amount of air to do that. Two, they care about simplicity in failure modes and maintenance more than efficiency.
"Thermal efficiency" is a completely nonsensical concept. Neither has a method of turning waste heat into power.
If you maintain a consistent temperature then you can optimize the fuel mix ratio and the timing. Either way a colder cylinder air temperature pre-compression, is denser, and the compression ratio determines the power, while hotter would just cause a retarded timing detriment if the engine can adjust instead of knocking.
No, no, no. It's nonsense. There are emissions regulations and the only way combustion "energy" serves any useful purpose is if you add weight for an extraction system that can convert it into either propulsion force or battery charge, either adding weight when the criteria for an airplane is keeping weight down.
Thermal efficiency of a prius engine? You have no idea what you're talking about. None. Heat is not directly converted into power, it's just not applicable. The only similarity is for both to run in an optimal power curve RPM for efficiency, airplanes being optimized for their cruising speed.
Everything you suggested, is ridiculous.
Originally Posted by Ws6
Because a liquid-cooled engine can be properly designed to be MUCH more efficient, as the coolant can be routed to "hot spots", etc.
Maybe, maybe not. Air cooled engines may run with cylinder head temperatures as high as 500 deg F. This means less combustion energy is wasted into the cooling system. Aircraft engines are air cooled and have been able to match the thermal efficiency of a Prius engine for the last 70 years.
You have no idea what you're talking about. Letting an engine run hotter does not mean less combustion energy is wasted, it just means more stress on the engine. On the contrary you want a controlled temperature to maximize a lean fuel ratio.
Aircraft engines are only air cooled for two reasons. One, there's a massive amount of air to do that. Two, they care about simplicity in failure modes and maintenance more than efficiency.
"Thermal efficiency" is a completely nonsensical concept. Neither has a method of turning waste heat into power.
If you maintain a consistent temperature then you can optimize the fuel mix ratio and the timing. Either way a colder cylinder air temperature pre-compression, is denser, and the compression ratio determines the power, while hotter would just cause a retarded timing detriment if the engine can adjust instead of knocking.
No, no, no. It's nonsense. There are emissions regulations and the only way combustion "energy" serves any useful purpose is if you add weight for an extraction system that can convert it into either propulsion force or battery charge, either adding weight when the criteria for an airplane is keeping weight down.
Thermal efficiency of a prius engine? You have no idea what you're talking about. None. Heat is not directly converted into power, it's just not applicable. The only similarity is for both to run in an optimal power curve RPM for efficiency, airplanes being optimized for their cruising speed.
Everything you suggested, is ridiculous.
Put a air-cooled engine in Phoenix traffic and this is guarantee for failure.
Originally Posted by SubLGT
Deutz has some air-cooled Diesel engines
Deutz made (quiet) aircooled diesels engines for decades, their modern engines are water cooled.
Ducted aircooled engines are not easier to work on, the ducting has to be removed to do any repairs....mind you, the modern water cooled engine is much harder to work on than older engines....so much stuff to remove to get at what needs to be done. I own more aircooled engines than water cooled, ducted and not. Oh, and they are not water cooled engines, but indirectly air cooled, direct water cooled are plumbed into an external water supply.
Deutz has some air-cooled Diesel engines
Deutz made (quiet) aircooled diesels engines for decades, their modern engines are water cooled.
Ducted aircooled engines are not easier to work on, the ducting has to be removed to do any repairs....mind you, the modern water cooled engine is much harder to work on than older engines....so much stuff to remove to get at what needs to be done. I own more aircooled engines than water cooled, ducted and not. Oh, and they are not water cooled engines, but indirectly air cooled, direct water cooled are plumbed into an external water supply.
Come here to Colorado on I70 at Vail pass at 11,000ft, get stuck in traffic and you will find out very fast why.
Originally Posted by Dave9
Air cooling Everything you suggested said:I stand corrected, aircraft engines are not my world. I
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