Watercooled Jabiru 2200

[onetrack]

Nev, the old Inter truck engines needed heaps of fuel to keep the valves cool. They were built for the American market, where "gas" was dirt cheap, and fuel consumption didn't matter.

I hauled around a Cat D6 dozer behind the Inter, coupled to an old ex-WW2 tank-carrier trailer. The prime mover weighed 4.5 tons, the trailer weighed 8 tons, and the D6 weighed 18 tons, so all-up, about 30.5 tons (31 tonnes).

 

If you look at the old trucking photos from the 1950's and early 1960's, when petrol trucks outnumbered diesels, you'll see every petrol truck has a fuel drum rack behind the cabin.

My Inter fuel drum rack held 3 x 44 gallon (200 litre) drums, and you needed those 3 drums for long distance work. The factory fuel tank was only 31 U.S. gallons (118 litres), they must have had servos close together in the U.S.!

Of course, there was also the fact that truck gearing was low in those days, all trucks were limited to 80kmh (50mph), and the fines for exceeding 80kmh in a truck were quite severe.

[Bell Driver]

Thanks to all.

[Bruce Tuncks]

Old k sounds correct to me. Biggles was often damaging the cooling system of aircraft he was attacking. A glycol leak would lead to an engine failure. So an air-cooled engine would be tougher in a battle, but those engines were bulkier and higher-drag so of course they would use more fuel.

[facthunter]

They are not higher drag if cowled properly. FW 190 and Sea Fury for example. Each were the fastest piston engined planes at the time. Beaufighters also..Older single row without even a townend ring, early 30's, maybe. Liquid cooled motors all had protruding radiators bar a few experimental racers. and problems on the ground in the tropics with overheating. and problems with coolant leaks.. In line motors tend to be heavier as well due longer crankshafts and heavier crankcases. A radial is particularly well suited for aircraft in so much as the crankpin is not heavily loaded when power is on . It's loaded more at High RPM and throttle closed .Nev

[skippydiesel]

They are not higher drag if cowled properly. FW 190 and Sea Fury for example. Each were the fastest piston engined planes at the time. Beaufighters also..Older single row without even a townend ring, early 30's, maybe. Liquid cooled motors all had protruding radiators bar a few experimental racers. and problems on the ground in the tropics with overheating. and problems with coolant leaks.. In line motors tend to be heavier as well due longer crankshafts and heavier crankcases. A radial is particularly well suited for aircraft in so much as the crankpin is not heavily loaded when power is on . It's loaded more at High RPM and throttle closed .Nev

 

Are you sure Nev ? - check out the DH Hornet

[Bruce Tuncks]

Nev has convinced me about the FW190. So why was the Boomerang so tubby?

[onetrack]

The Boomerang design was derived in haste from the Wirraway, with a much larger engine in the Boomerang. The financial and qualified personnel limitations of early WW2 made it necessary for Wackett to dredge up as much as possible of currently-available materials, designs and structures, using less-than-desirable numbers of design people, to produce a fighter as fast as possible, and within tight financial restrictions.

 

It's interesting that Friedrich W. "Fred" David, an Austrian Jew who arrived in Australia as a refugee from Nazi Germany (and who was registered as an alien, and who had to report to Police weekly), was a particularly clever aircraft designer, who had worked for the Nazis on Heinkel designs - and he had also done design work for Mitsubishi and Aichi Aircraft Co. He had major input into the Boomerang design.

 

David's major design contributions to the Japanese military aircraft companies resulted in the Mitsubishi A5M Claude fighter and the Aichi D3A Type 99 Val dive-bomber.

It's unfortunate that Davids crowning effort, late in WW2, resulted in the CAC-15 - an outstanding aircraft that was scrapped simply because it was designed as the jet age arrived, and it was obsolete as soon as it was ready to enter production.

[facthunter]

Other way around. ( I think) The boomerang came first and was slow and underpowered . They made a lot more Wirraways some later converted into the Ceres cropduster. A bloke I knew well got killed in a Wirraway. Another crashed in a Ceres at night dusting Cotton. They had a bit of a bad habit of dropping a wing in a turn. There's very few boomerangs about, most being restored the hard way. Nev

[skippydiesel]

Are you sure Nev ? - check out the DH Hornet

So Nev, have you checked out the DH Hornet ??

[kgwilson]

Air cooled aero engines especially horizontally opposed engines are 1, Low revving for direct drive, 2, lighter than liquid cooled alternatives and 3, less complex with no pipes radiators etc. Radials have all the cylinders in the direct airflow so there is no advantage trying to liquid cool them. The Merlins and BMWs of wartime aircraft were fantastic with huge power but heavy, complex and expensive. A Rotax spinning at 5000 rpm without water cooled heads would be complete failure. There would just be insufficient airflow from the reduced drive prop to dissipate the heat. It is only 1.3 litres also, producing only 20 HP less that the Jabiru 3.3 litre 6 cylinder engine albeit for short periods.

 

It would seem that the Rotax is about the optimum size for liquid cooling. Any larger and the weight penalty would likely counteract the additional power available. I know there are a few V8s in AG aircraft but there are few large liquid cooled engines in modern aircraft.

[facthunter]

I am aware of the DH Hornet .. What point are you making? Nev

[facthunter]

The limit of aircooling is above a certain HP for capacity (power density) or having more than one exhaust valve in each cylinder..(usually with the high HP/Litre being exceeded also.).. The actual figure varies but is around 70 HP/Litre. give or take a fair bit

Race car style engines are not good in aircraft unless for a special purpose (competition) and /or complexity ,cost hard to service, inspect.and relatively short service life can be acceptable. They have several things in common including weight constraints.. ALL suitable aero engines are built light, as that's what designers want.. After all they build the actual structure as light as possible so why add a heavier than needed engine if there's a choice?. Once you go for lightness all parts are shaved down to where they are just strong enough to do the job RELIABLY for the design life of the engine. They should also have a certain amount of overspeeding/ overstressing built into the formula but not that much or it's got a weight problem. Nev

[skippydiesel]

I am aware of the DH Hornet .. What point are you making? Nev

 

Just this:

 

Air cooled - Your quote "FW 190 and Sea Fury for example. Each were the fastest piston engined planes at the time. Beaufighters also. "

Wikipedia

 

Fucke-Wolf FW 190 1941-1945

Max air speed 352 knots

Range 540 Nm

Climb 3,000 ft/min

 

Hawker Sea Fury 1945 - 1955

Max air speed 400 knots

Range 904 Nm

Climb 4,320 ft/min

 

Bristol Beufighter 1940- 1960

Max air speed 289 knots

Range 1,520 Nm

Climb 1.600 ft/min

 

Liquid cooled;

 

DH Mosquito 1940-1950

Max air speed 361 knots

Range 1,100 Nm

Climb 2,800 ft/min

 

DH Hornet 1944-1956

Max air speed 413 knots

Range 1,290 Nm

Climb 5,000 ft/min

 

I chucked in the Mosquito to compare with your Beaufighter.

 

I think you will agree, that the liquid cooled Hornet leaves the air cooled competitors coughing in its exhaust wake by, a good margin.

[Yenn]

I think I see why Nev was unsure as to what you were saying. There are two DH Hornets, the old Hornet Moth and the wartime Hornet, which was very similar to a Mosquito and I think only about 15 were built.

I met an old bloke a few years ago who flew one in the war. Bombing in a Norwegian Fiord.

[onetrack]

Other way around. ( I think) The boomerang came first and was slow and underpowered

Not according to the all-knowing Wikipedia, Nev. They say the Wirraway came first.

 

In late 1941, Lawrence Wackett, Manager and Chief Designer of CAC, began examining the possibility of designing and building a new domestically-designed fighter aircraft.

The main challenge to this ambition was the fact that fighter aircraft had never been manufactured before in Australia; according to aviation author Rene J. Francillon, many experts considered that the licensed manufacture of a complete fighter aircraft would be beyond the capabilities of Australia's industry at that time.

Wackett quickly made the decision to use elements of aircraft which were already being produced in Australia. Only two military aircraft were in production at the time: the CAC Wirraway, based on the North American NA-16, and the Bristol Beaufort bomber.

[facthunter]

The Hornet is a major redesign of the Wooden mosquito built mainly for Carrier work. Most Mosquito pilots don't know much about it. It's really a new plane and pretty trick with a super slim wing section and contra rotating props etc. It came into the show near the end of the war. I don't believe the liquid cooling is the reason it goes well by itself. The Merlin is used by the brits because it was the best engine THEY had..Overall analysis of comparable engines make that point frequently . Nev

[facthunter]

' OT I'm basing my "I think" on my experience of seeing them( when I was Very young) flying LOW off Newcastle baths during the war and I saw very few (if any) Boomerangs and plenty of Wirraways post war then Sea Fury's. I doubt either plane stood a chance against anything the Japs had.. I know some parts are in common from rebuild information of one in Australia.. It's very likely "WE"couldn't get a decent engine for the boomerangs. They had the same problem with the Wackett trainer . Had to use the 165 HP Warner Super Scarab. (I think). WIKI probably has it right. Nev

[skippydiesel]

I think I see why Nev was unsure as to what you were saying. There are two DH Hornets, the old Hornet Moth and the wartime Hornet, which was very similar to a Mosquito and I think only about 15 were built.

I met an old bloke a few years ago who flew one in the war. Bombing in a Norwegian Fiord.

 

Nooo I dont think so - petty sure they were too late to see service in WW2 - Malaya perhaps. Not many were build but a lot more than 15 (Wikipedia say 383). There was a a carrier version & a land version. Fairly sure there was a contingent based at Bankstown.

They had comparable performance to the erly jet aircraft - better TO, climb and range only being bested at high altitude speed.

Pilots loved them - supposedly very nice handling characteristics.

Although they come from the same stable, look very much like a scaled down Mosquito, they were in fact a ground up new design (obviously heavily influenced by the Mossy).

Not a single flying example survives of this end stage development of the piston fighter aircraft.

If I had the dosh, I would commission a replica, made with modern materials, tandem two seater and using a couple of turbo props.

For my money - the best looking piston fighter ever.

 

I respect Nevs encyclopedic knowledge to hihly, to belive he did not know that I was putting up an aircraft of similar era and much higher performance than his air cooled jobs.

 

The Hornet is a major redesign of the Wooden mosquito built mainly for Carrier work. Most Mosquito pilots don't know much about it. It's really a new plane and pretty trick with a super slim wing section and contra rotating props etc. It came into the show near the end of the war. I don't believe the liquid cooling is the reason it goes well by itself. The Merlin is used by the brits because it was the best engine THEY had..Overall analysis of comparable engines make that point frequently . Nev

 

Hi Nev: see above for some of my response.

 

Further - I think the carrier version was in the minority but would not swear to it.

 

As for liquid cooling - little doubt, in my plebeian brain, that the low frontal area & close cowling of the engines, only achievable with liquid cooling, would have contributed greatly to this aircraft astonishing performance.

[Bruce Tuncks]

Wow the fw 190 was good. There is a story about how the pommy minister for munitions wept when he saw the fw 190 performance figures since he knew that they were much cheaper ( about 1/3 i think ) than the spitfire.

[facthunter]

Another very successful air cooled fighter is the Mitsubishi model"0". Liquid cooled motors must also have Radiators which have to be taken into account for drag and weight ,reliability under attack and low /high temp operations.eg High altitudes and deserts .Some well designed cowls can add thrust. The higher the temps you are dealing with the more likely that process will work... I would not like to think of the pressure cap the engines would need above say 30,000 feet. Boiling point of coolant depends on pressure above one atmosphere already to elevate the boiling point to a good efficiency. You have to increase the diff pressure to maintain the desired absolute pressure. Nev

[skippydiesel]

Nev, in general, what are the operational altitudes for civilian internal combustion engine aircraft.

I ask because understand that above about 18,000 ft, pressurised oxygen mask & a pressure suit start to become necessary OR alternatively cabin pressurisation .

If this is correct, the need for specially adapted cooling systems above 30,000 ft for most such aircraft, will become moot. (Super Constellation had a 24,000 ft efficiency ceiling)

Not saying that military aircraft and some civilian aircraft may not be capable of sustained altitude above this, bit is it the norm?

[facthunter]

Mosquitoes with the right superchargers went above 30,000 ft for Photo reconnaissance trips. The "Consolidated Liberator was a high flyer(P&W R1830's with turbochargers). plane itself unpressurised. Pressurisation will not include anything to do with the engines or some cargo lockers. It's mainly cabin area and in some big Russian freighter Jets only the cockpit. area is pressurised. .Ignition systems have to be pressurised Coils on each cylinder and low tension magnetos to prevent electrical leakage of high voltage current. Your OAT at those levels can be about minus 45 degrees C or lower..

Most pressurised Piston aircraft have multi speed superchargers. You manually change the gears on the way up (and down).

Oxygen is required to be available at FL100 here and FL120 in some other countries .This covers the failure and unpressurised situation. The oxymask usually mixes the oxygen with some air but you can select 100%. which is not considered too good for you if you do it for long periods.. Nev

[Bruce Tuncks]

Skippy, people have climbed mount everest (25,000 ft ) without oxygen.

At the start of ww2, they were ferrying GI's to Europe at 14,000 ft. They had lots of smokers in those days.

Anyway, some got into difficulties after hours at 14,000 ft so the Americans lowered the legal height without oxygen to 12,000 ft.

Of course here in Australia, like embarrassing yokels, we have gone for 10,000 ft.

On a good gliding day, 15,000 ft agl is not unusual in Australia. In Alice Springs, ( gliding strip is 2,400 asl ) this means over 17,000 ft.

Personally, I used oxygen up there in an attempt to stay smarter.

[facthunter]

I think Everest is above 27,000ft Most are in trouble over 24,000 without oxygen. Lower if you are older, smoke or unfit. You can be conditioned to varying extents if you train at high altitudes where the red blood cells increase with time. Your fingernails go blue is one indication, but your performance can deteriorate with you thinking you are OK till you start writing and you can hardly read it. This can be done in a decompression chamber and is part of most pilot's training before they fly/operate pressurised aircraft.. Slow loss of pressurisation can cause loss of consciousness of the crew..if a cabin altitude warning is not acted on The highest Ive operated without using it was FL175 . I was young fit and had it available though..Nev

[Bruce Tuncks]

Highest I've been to without oxygen ( but with it available ) was 19,000 ft. But I was young and fit and a non-smoker. We used to make fun of this smoking guy who got headaches over 14,000 ft.