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Fuel injected from the MkV onwards I believe. Not sure which Merlin Mk that was though.

I'm not convinced the Merlin had conventional fuel injection. The later examples had Bendix-Stromburg or SU carburetters injecting fuel direct to the supercharger.
http://www.spitfiresociety.demon.co.uk/engines.htm

I'm sure Ozzy will sort this one out.

Thanks to Doug asking this question I finally found the answer to something that's always puzzled me. Why do the Merlin & Griffon rotate in opposite directions?

From my previous link: Quote:

Interesting, now I shall have to find that site and see if I can find out more about the Merlin and fuel injection because it did mention the date 1943 when the Merlin was fuel injected.

Cheers...Happy Landings...Doug

Doug trust me NO FUEL INJECTION ON MERLINS!!!! Dr. Oz knows about these things being slightly Merlin-Mad 8) 8) 8)

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Question - and on this I know nothing - would the carburettor injection have been on the RR Merlins or would the Packard Merlins have had "true" fuel injection?

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Can you be more specific.  This seems to contradict your previous statement of "NO FUEL INJECTION ON MERLINS!!!!".  Not knowing a lot about engines I must admit to being thoroughly confused.

The Packard Merlin is also known as the Packard  V-1650.  According to this article it was manufactured in different models from the -1 to -25 :
http://www.unlimitedexcitement.com/Pride%20of%20Pay%20n%20Pak/Rolls-Royce%20Merl...
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It also says this further down the page: Quote:


On this page is a list of all major models of the Merlin. http://www.spitfireart.com/merlin_engines.html From what it says the first Packard-built version was the V-1650-1 & based on the Merlin XX.  The Packard-built Merlin 66 is the V-1650-7. Quote:

I think the confusion here is between direct fuel-injection used on the DB 601/605 where the fuel is injected straight into the cylinders & the carburettor injection system as used on later Merlins. I still don't know if any versions of the Merlin/V-1650 had a proper direct fuel injection system.

Note: A carburettor mixes air with the fuel before it enters the cylinders.

Gentlemen:   

So what year, what aircraft and what was the first true fuel injected engine that entered RAF service?

Cheers...Happy Landings...Doug

Only a guess but I suspect it was the RR Welland fitted to the Gloster Meteor F.1. Entered service with No 616 Sqdn in May 1944. http://www.enginehistory.org/r-r_w2b.htm

PS. Of course, most rotary engines have no carburettor so they could be said to be fuel-injected.

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Indeed. From what I can make out supercharged variants used the carb injected systems like the later Merlins. Napier Sabre was fitted with the Hobson injection-type carburettor developed during WWI. http://www.localhistory.scit.wlv.ac.uk/Museum/Transport/planes/hobsons/hobson01....

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Griffon 62 (Mk21 and 46) had a Rolls Royce fuel injection system as did the 88 (MkXIV? 21 and 47), the 89 (Mk22) and all thereafter (mostly Mk21 and 46/47). Everything else seems to have an injection carburettor of some kind, mostly a Bendix-Stromburg.
Rolls Royce claimed that the carburettor was better than direct fuel injection because of the drop in temperature caused by the air passing the venturi in the carburettor, thus giving better combustion, or something like that. I’ll leave it up to you technical folk to give the proper explanation on that one.

Interesting reply's folks. 

I would think the Allied aircraft operating in the Pacific Theater of operations would really welcome the fuel injected engine because of the type of weather they flew in.

I am not up on military aircraft or commercial jets to much but I would think most of the aircraft operated by Japan in the Pacific Theater were probably fuel injected but please correct me if I am wrong.

The last "Dak" Douglas DC3, C47 we lost in the Royal Canadian Air Force was due to carburetor icing and spun in on a Search and Rescue mission taking all the crews lives.

I picked up carburetor icing on the DC3s several times, always when training a new pilot and they learned real quick how fast they could run out of rudder, how heavy that rudder was and how quick that old bitch would roll.    "(not that I ever let it get that far)" 

Oh the days of flying the aircraft with "carburetor heat", the proper use of "RPM" and "Manifold Pressure", a good Flight Engineer are nearly done.
A good co-ordinated crew always had something to do.

AND:

Then some dam fool put a suck and blow thing on an aircraft and left off the props.      

Took all the fun out of flying they did. 

Okay will stop rambling on and try to keep on topic. 

Cheers...Happy Landings...Doug

Thanks for another site Doug. 

Cheers...Happy Landings...Doug

I was never an 'engine man' but this fascinates me. I've never seen carburettor icing mentioned in relation to aircraft powered by the Merlin. I read somewhere that the butterfly on Merlin carburettors was automatically heated by engine oil to prevent icing. I don't know which carbs this applied to & can't find any reference to it on the WWW. If it's true I have to wonder why this idea isn't common practice now.

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I'm sure they did.  http://en.wikipedia.org/wiki/Rolls-Royce_Merlin
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German manufacturers were/are noted for their precision & also pioneered the use of diesel engines in aircraft. These would have been fuel-injected so the technology would have been available for petrol engines. http://www.casa.gov.au/fsa/2003/nov/58.pdf
(Not so long ago diesel fuel would have been liable to freeze in the tank in sub-zero conditions without winter additives. I've never heard of petrol freezing.)

PS. It's a long time since I worked on them but if I remember correctly the carburettor on the Gipsy Major engine is automatically heated from the engine exhaust. Our Tiger Moths had no carb heat control in the cockpit.

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That's a common fallacy Doug. The Merlin was basically a new design* intended as a stop-gap to fill the void between the Vulture and the Kestrel. The Griffon was not a development of the Merlin as many seem to think but the derated production version of the R-type engine used on the S6 seaplanes. http://www.solarnavigator.net/aviation_and_space_travel/rolls_royce_merlin_engin...

*PS. I think the Merlin was developed from a much earlier RR engine but can't find any details right now.

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No no, Doug. You're getting all confused. The Merlin (PV12) was designed several years after the "R" type engine that powered the Supermarine S6 racing seaplanes. The Schneider Trophy seaplanes were never named Spitfire although there was a later seaplane version of the Spit. The Griffon (not the Merlin) was a development of the "R" engine.
http://www.sciencemuseum.org.uk/on-line/flight/flight/s6b.asp
http://www.sciencemuseum.org.uk/on-line/flight/flighten/r.asp

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http://www.spitfiresociety.demon.co.uk/engines.htm

Okay now I see it...computers are so wonderful...it is great to have this information at your fingertips as long as you can remember where it is.  LOL   

Cheers...Happy Landings...Doug

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Okay, so the design got changed after a German airplane with a British engine came over...

There is one on eBay at the moment. They've put it as a Type 500 but I think they mean 50

Starting price was 16,500 quid! It did need an overhaul and work done to it.
A fully rebuilt and zero-timed 66 would cost me 45,000 quid. It is why that'll be the last part of Binky to get! I've just got a Rotol 4 bladed hub on the way however

Don't forget Doug that the Meteor spins in the opposite direction to a Merlin (not sure why as tanks aren't really my thing).
A fully servicable Meteor tank engine will cost you 5000 quid.

I keep blubbing everytime I think about the scrapped Spits
The Meteor actually rotates the opposite direction to the Merlin. I've never found out why, tis one of the GREAT mysteries... Any tank experts out there?
I think the warbird fraternity are now reaching the point with some engines where they actually need to do short production runs of new ones. Merlins, Griffons and several Soviet engines are urgently needed along with several German ones.
The question is of course cost. I know for instance that the Yak (1 or 3 can't remember which) being rebuilt in Russia at the moment is having an Allison lump thrown in. The new run of FW-190s don't have the original type engine either. For authenticity parts are needed....

Gentlemen:

Had a little time on my hands so tried to do some research to find out if any World War Two Bombers were ever fitted with Counter Rotating Props or had engines that could turn opposite to each other.

I looked at the Avro Lancaster, the Avro Lincoln which came out at the end of the war but never saw World War Two service from what I read, the Avro Shackleton which had Griffon Engines with Counter Rotating Props and the American built Boeing Washingtons (B29s).

I might be a bit off topic but I did find some interesting information on the fuel injection/carburetor system used on the Griffon Engine on the Avro Shackleton.

The reason I am so curious about these engines is I do not understand why they did not have the engines on the port side turn opposite to the engines on the starboard side of the aircraft or vice versa.
It would have made more sense and made for much easier control of the aircraft on takeoff and landing or if battle damage/engine failure occured.

It is also interesting to note I believe on many light post war twin engine aircraft both engines still turn in the same direction.

I am sure that even on the "C130" four engined Herc the engines all turn the same way.

Now this does not make any sense to me in this day and age and all comments are most welcome.

Cheers...Happy Landings...Doug

I think the PR variants supplied to the RAF had the original engines actually Doug. I seem to recall from reading the Adrian Warburton biography that the reason he liked the P-38 so much for PR stuff was it didn't swing on take-off.

ozzy72 wrote on Dec 11^th, 2006 at 2:28pm:

I should have said the ones supplied for evaluation purposes in the early days of WWII. The high torque on take-off was one reason it was rejected. The lack of turbochargers was another. http://www.channel4.com/history/microsites/H/history/a-b/battletwo10a.html

PS. It was the RAF that named it Lightning.

http://en.wikipedia.org/wiki/Counter-rotating_propellers

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I suspect it would have been just after take-off. The Lanc was a remarkable aeroplane but I reckon it would take a very skilled pilot to control a heavily loaded 4-engined type if it lost an engine during the actual take-off run. Most RAF bomber pilots didn't have the time to become highly skilled.

Aye, mechanical fuel injection. A lot of the German planes such as the 109 had it

ozzy72 wrote on Nov 13^th, 2006 at 4:21am:

Why? because you get 5 gears in reverse and one forward if your engine turns the wrong way

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Reason #2 is that the original Klimov usually has been demilitarized by placing a cocked grenade between the valve heads... You can't remove the cannon from the engine. There is only one left that still has the original engine (and the centerline cannon)

Also there are a few Yak-11s that have been converted to Yak-3s (it's the same plane but whitout a few meters of wingspan and a radial)

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CR props = extra gearbox = power loss + added complexity

Only reason why the NK-12 is the only CR engine still in production is that it doesn't need a gearbox to change the turning direction, it uses a bunch of internal splitters instead... When the thing is off you can turn both props the same direction.

Spitfire we're talking about paired engines rotating in opposite directions not contra-rotating props

On the subject of counter rotating props and the C130, the new A400M is certainly going to have them...(work experience at Airbus pays off )

.mic

A common misconception is that the P-38 had counter-rotating props to eliminate the hazards that appear when a "critical engine" fails. That is not the case. With the P-38, the propellers both rotate outward at the top, which makes BOTH engines "critical engines". From what I've read, the only reason Kelly Johnson settled on the  final setup was that it made a more stable weapons platform, which is the only reason the plane existed.

A "critical engine" failure is only a problem when the wing is at a high angle of attack (aircraft going slow with the nose up), and the engines are at high RPM/power. The propeller blade angles are equal relative to each other, but not to the relative wind. The descending blade is at a higher relative pitch and takes a bigger "bite" out of the air than the ascending blade, so at a high angle of attack, the thrust of each propeller is asymmetrical.

When viewed from the pilot's seat, the standard for rotation in the U.S. is clockwise. On a plane with identical engines, the descending blade on the left engine is inboard, and the descending blade on the right engine is outboard. If the right engine fails, the tendency to yaw and roll is lessened because the centerline of the thrust provided by the left engine at full power is closer to the centerline of the aircraft. If however the left ("Critical") engine fails, the centerline of thrust from the right engine at full power is outboard of the engine, and the yawing moment is much larger. An unwary pilot may not be able to recover from the resulting roll to the left in time if it happens close to the ground, like during take-off.

If the engines counter-rotate inward at the top, neither engine is critical. If they counter-rotate outward at the top ~which the P-38's did~ BOTH engines are critical. Adding the engine's tremendous torque to the equation made things even worse. Many young, inexperienced crews were lost in that manner.

That this made things more dangerous for the crews was of concern, but there was a different mentality during the war. Hagar mentioned having an engine failure on take-off. In the Pacific, bomb and fuel loads were calculated without regard to the possibility of an engine failure on take-off. If you lost an engine before you rotated, you ran off the end of the runway and crashed. If you lost an engine shortly after take-off, you better drop your ordinance, because with still full fuel tanks, less than full power on all engines could not keep you aloft. It was understood that crews would be lost, but there was a job to do, and they took the risk in order to put as much steel on target as possible and finish the war.

Eddy Current
Pilot and Airframe & Powerplant Mechanic