Aviation’s Largest Piston Engine (2016)
tested.com
tested.com
Speaking as a full time engine mechanic for a small chain of midwestern repair stores, this is the death-knell of every heavily customized car. Heck, 3/4ths of the engineering for a Dodge Hellcat or Mustang cobra is just to keep the thing cool enough that the driver isnt chased out of the cockpit. You cant idle them the same way you idle a Toyota...they'll burn up.
the Dodge Viper is another perfect example of engine displacement gone wild. The intercooler and radiator are massive, but the additional cylinders and their size means the V-10 motor has 10 cylinders firing onto a 90-degree crankshaft, which means it has an uneven firing interval for two of the ten cylinders. it makes the idle rougher than a garbage truck, and very prone to overheat with a 220 degree camshaft.
Edit:
For something like a race-car that's trying to minimize weight/power loss by running the minimum radiator/fan necessary and depending on airflow from movement (or rely on the fact that you're only running 1/4mi at a time) I can understand. Still, that's a cooling system sizing issue, not a cam or crank issue. A street going vehicle isn't going to have a cooling system that's sized within a hair of inadequate like that. Power output (and heat generated) at/near idle should be fairly constant regardless of cam and if it's not the higher power output cam profiles will probably have lower power output at/near idle (this depends a lot on the engine, some engines force you to choose where you want your power, some are hard to throw "too much cam" at). No matter how you cut it only so much air can get passed a closed throttle and that amount of air only corresponds to a certain amount of fuel, that puts an upper bound on heat generated at idle. I can see how adding forced induction could significantly affect heat generated at idle but even then, if everything is sized properly it shouldn't be much of an issue.
This place is really turning into Reddit where you get down-voted for questioning anyone who sounds knowledgeable.
Or any air cooled car ever made. But the reality is that in a lot of designs, idling will test the effectiveness of the cooling system more than driving the car at speed. (Adding power only exacerbates such a problem. The OP completely fails to understand this)
It's much less of a problem than it used to be, with lots of cars including electric fans to help out the radiator, but it used to be standard to see a warning in the owner's manual about temperatures increasing in slow traffic or at idle.
Are there still any being built? I thought the 911 was the last holdout until they also switched to water cooling.
"with lots of cars including electric fans to help out the radiator,"
I had that fan breaking once in my Miata and temperatures went into the red really quickly in LA rush hour.
> I had that fan breaking once in my Miata and temperatures went into the red really quickly in LA rush hour.
No doubt. Once you train yourself to hear that fan, you realize how much the car depends on it.
The new stuff is technologically stunning, of course.
Is the extra width and weight the Miata has gained over the years down to changing safety standards? I guess on the bright side, in 2019 they're adding a little power.
To me the new model has lost all of its appeal. It's way too mainstream. The only interesting thing left is the rear wheel drive.
Powerful motors will sometimes run well enough at speed but overheat at idle. For example, after receiving an upgrade like a camshaft with more radical timings.
One key point: you can increase the size of a radiator or oil cooler but that helps a lot more when the vehicle is actually moving.
Put another way, one does those mods to increase power output. Not all of the increased power is used to turn the wheels, a lot of it is turned to heat (just like a stock engine). More power, more heat, more cooling is required.
VTEC, yo. In in the 1940s no less.
There's tons of tech that was well understood for WW2 aviation that finds its way back into land transportation given enough time. Adding water and alcohol blends to the intake charge to reduce temperature and prevent detonation, ABS, Fuel injection, probably other stuff as well.
As comparison an early generation single spool turbojet has pretty much one moving part.
Nowadays there might be two or three spools and moving vanes and a thrust reverser.
But aviation would never have been possible for the masses with piston engines.
The Avro Lancastrian was a passenger variant of the Lanc and developed into the large bodied Avro York that had the range to replace a few of the old flying boat routes. Some lasted into the 60s on commercial routes.
The Lockheed Constellation had four 18 cyl radials, and being pressurised survived in commercial service even longer.
Neither had a turboprop variant.
Mass aviation was going to happen anyway whether the DH Comet arrived or not. It would have looked rather different, and perhaps not quite as endemic as now, but definitely mass aviation as we know it. Jets just hastened the process, and came at just the right time.
64 years ago today a KLM Constellation crashed at Shannon in Ireland, it was carrying 56 people. That's miniscule and was only sustainable with fares that the 1%ers of the era could afford. A Norwegian 737Max on a thin Atlantic route today carries 186 and that is considered borderline small.
Incidentally the Constellation did have a turboprop variant but Lockheed and GE had a disagreement and it went ahead with pistons instead as the Starliner. Few people even remember that aircraft now because of the 707.
Jets certainly helped the growth in size, and grew the market faster than it could have without. The market was already there and growing. Prop aircraft would have grown too had there been no jet engines, though I doubt we'd have got to 300+ capacity - but who knows?
On seating. The DH Comet had a smaller passenger capacity than the Super Constellation, which was upto 110 depending on seating configuration, though usually a bit less. The 707 had 140 when first introduced. For the 1.5% - 2%ers then?
A turboprop constellation variant was prototyped but never produced commercially. The were none in service. I think the US Navy might have ended up with a couple for trials too.
At least over here, the last significant price drop was after 2000 or so with Ryanair etc. with 737:s and A320:s. Probably a new business model in other ways as well. Single aisle, two reliable high bypass engines. There were still DC-9 derivatives flying around but no more really.
I bet you could calculate maintenance man hour per kilowatt hour for all sorts of engines.
Even the old manual flight control operations without computers meant the amount of work hours per flight was big - meaning for an ordinary worker it would not be possible.
The number of moving parts and the complexity of the piston engine compared to a gas turbine is significant.
When you think about the effort to concoct the compounds for the air war, and drop them on cities, with no guidance like lasers or anything, and then you look at the sheer tonnage dropped, and how indiscriminate it really was, you wonder how aerial bombardment is at all distinguishable from chemical weapons.
It really is chemical warfare by another name. The only real difference being the explosive burning. Clean up was still a similar problem, since, as with shells, munitions would hit but not detonate. Couple this with such indiscriminate bombings that cities were engulfed in fire storms, and I think it's splitting hairs, for the most part.
People were so mentally numbed and damaged by the carnage of the first world war, that the second world war was put on track by the leadership that had survived the carnage.
But looking at engines like this, and knowing that they ran on leaded AvGas, and knowing that leaded mechanization was the norm, you wonder if the psychotic leadership was actually an expression of lead poisoning from environmental factors. Just like all those crime curves that trend according to leaded gasoline bans, what if front line WWI veterans were driven psychotic by frontline exposure to heavy metals through exhaust fumes?
I beg your pardon? IIRC is a poor excuse when a ten seconds Wiki search proves you wrong.
He was a frontline lieutenant.
It's super bad if some bad guy destroys innocent lives with chemical weapons, but totally fine if we drone strike them. Doesn't make much sense, although in this crazy world things aren't as black and white as we'd like.
I see the argument that it ultimately doesn't make much difference how a vast bunch of civilians end up indiscriminately dead, but the people who actually experienced it seem to think differently.
There's obviously a
difference because
people differentiate.
Ask most people choose between burning their face off with a chemical or fire, and they'll likely choose fire, but getting your face burned off is categorically bad. Why distinguish.
That, much more than it was punishingly cruel, in excess of death and dismemberment by other means.
They say, yeah, it's okay to zip a supersonic bullet through soft tissue such that it shreds with cavitation, and smash it through bone that splinters and explodes, so people lose whole limbs. And that's okay. It's like a deer hunt.
But hey, you don't hunt animals by mutilating their lings with bug spray. That's no fair. You wouldn't consume an elk carcass tainted with persistent organic pollutants. No fair. We can't even bury our dead.
But, you know what? You aren't going to bury your dead, when they're incinerated by high explosives.
And hey, what's fair about war at all? What's fair about several hundred planes unloading kilotons of conventional munitions, indiscriminately, to break an apparatus of geopolitics.
Gee, unfair, undignified, unsportsmanlike, in the pain, injury and slow death (leaving a contaminated corpse) department.
When you piece those explicit details together, the real problem is that it deals a degree of harm to the perception of gallantry, duty and honor of service. It's pretty much impossible to pat a chemical burn on the back, and say "there, there, thanks for defending the country" but, you can still pull that off, when sharing the room with an amputee that lost a limb to ballistics.
Exchanging chemical weapons for aerial bombardment exhibits "differences" but nothing that makes me say "wow, one is okay, and the other isn't."
Both are essentially equally bad, and neither is remotely good, or an improvement over the other.
People have their preferences, but in the same way that they rationalize the side effect of rampant smog and pollution as bad, but millions of fatal car accidents as normal, and a calculated risk.
The real choice being put on the table though, is: Would you choose between an air war that includes both regular explosions and chemical attacks, or just a regular air war only?
At that point, the choice becomes more rational. We say: "Hmmm, well, at least I can take some of the destruction out of the equation. I get to make one kind of misery go away. I can choose X = A as an alternative to X = (A + B + C). A never goes away, and nothing can be done about that, but at least I don't have to think about B and C anymore."
So, it's not about incediaries and high explosives being okay. Or aerial bombardment being different, and better. It's just that they can't be taken off the table, under any circumstances, no matter whatever else gets negotiated. I guess it's just a fundamental characteristic of destruction, that if destroying things is on the table, the basics of destruction get to keep their scalar qualities. You can limit the method of destruction but not the quantity.
So why are chemical weapons banned? Well the talking heads like to say “they don’t work, they’re just as likely to blow back on your own troops, they’re cruel.” Really though, they do work on non-combatants. Intentionally targeting non-combatants is what’s actually illegal and discouraged. Dropping bombs to destroy a city or AA batttery while knowing that you’ll massacre civilians is seen as tacitly kosher, but just gassing the populace to the exclusion of armed manpower and armaments is very much a taboo. At least, legally and officially, although countries find ways to skirt that with defoliants, pyrophorics, nuclear weapons, etc.