Engine choices for P-51 mustang ?

[Snautzer01]

Drag racing is immensely pleasing to engine builders, beause it involves going faster starting from an absolute speed of zero. See my previous post.

If somoene starts a drag racing series where the clock only STARTS once you pass the 400mph boundary, aerodynamics people will start to get phone calls... (we already did this experiment, and it has been agreed that we will call it "war".)

But it will be fun. Not the life saving war winning kind off fun. Its a 1930 designed deathtrap going into insane speeds and power like in the good old booz running times. Nothing to do with aeroplanes. It does it think gives a very slight inside in how the crews would tinker with their machines to get a mile extra. Or so i want to believe. Did they?

 

[Deleted member 68059]

But it will be fun. Not the life saving war winning kind off fun. Its a 1930 designed deathtrap going into insane speeds and power like in the good old booz running times. Nothing to do with aeroplanes. It does it think gives a very slight inside in how the crews would tinker with their machines to get a mile extra. Or so i want to believe. Did they?

Sadly (or not... I`m not sure sometimes) I missed proceedings by three quarters of a century. But I was told by the son of one Battle of Britain pilot (would have to go look up the squadron, but Lionel Goddard was the pilots name), that many in his squadron (which did unusually well) had a load of engine mechanics who had been motorcycle racing people in peacetime. He claims that they did lots of little bits on their pilots Merlins, like cutting the valve seats into three angles instead of one, and so on.

However, this is not something I`m in any position to prove.

 

[Snautzer01]

To bad too much time is now gone to research. I would have been minimal i think but in the pilots head could have made a difference. And if realley succesfull it would have gone through the lines i am sure.

 

[Howard Gibson]

The Sabres impact on the air war was minimal. The Typhoon and Tempest each shot down about 250 aircraft which in the overall scheme of things isn't much. The monthly totals for the Tempest are:
June 44 3
July 44 V-1 duty
August 44 V-1 duty
September 44 6
October 44 4
November 44 6
December 44 39
January 45 47
February 45 30
March 45 35
April 45 66
May 45 28
From this Website: Victories
It isn't until December 44 that the Tempest starts to have any effect.
As for the V-1 it may surprise some that the Merlin shot down more V-1s than the Saber. The combined totals of the Mosquito and Mustang alone exceed the Tempests score. In addition, Spitfire IX s also shot down some V-1s although I can't find the numbers for that.

The Hawker Typhoon's primary job after D-Day was ground attack. At low altitude, it was faster than a P-47, and more heavily armed. The Tempest's job was low altitude air superiority. There were not a whole lot of German aircraft left to shoot at. Neither the Typhoon or the Tempest were good at high altitude bomber escort.

 

[Deleted member 68059]

The Tempest was not terribly favoured by the engine people for operations against V1`s because the engine didnt stand up to the emergency boosting measures which were sucessfully taken on the Merlin`s of the Mustangs and Mosquitos etc flying RR product.

When they tried over-boosting it, it blew up. They coudlnt get the Sabre over +11lbs boost, while Mustangs and Mosquitos were getting +25lbs
and Mosquitos with Merlin-25`s additionally on Nitrous.

The modified Mustangs were MUCH faster at sea level than the Tempests, even the Spitfires were better than Tempests below 2000ft-ish.

Despite all that, the fact is the original data shows the Tempest made a very significant contribution and was very active. I suspect this must be put down to
the extremely heavy armament, and the Sabre (despite its flaws) being at its best low down.

Not really surprising about the V1. Typhoons were on ground attack with 2nd TAF. Squadrons converted to the Tempest V as follows:-

3 - March 1944
486 - April 1944
56 - June 1944
501 - July 1944
80 - Aug 1944
274 - Aug 1944

All bar 501 moved to the Continent at the end of Sept 1944

 

[Deleted member 68059]

Results of specially prepared aircraft to intercept V1s.

 

[VA5124]

Me: I need a 2000HP engine.

P&W: Oh no, we are not willing and/or able to copy the Napier Sabre, and solve all the problems with sleeve valves. Woe is us!

Ford could do it though remember the flathead v8 was one of the best . If pratt says no you have ford bulid it

 

[GrauGeist]

Ford's 49A was a good engine, but it's output (torque and horsepower) was limited by the block's design.

Once they transitioned to an OHV design, their power output jumped by leaps and bounds.

 

[buffnut453]

Folks, hate to say it but there's some trollish behaviour happening here. A statement was made about squeezing a Sabre into a P-51. Several others then explained why that was not possible. Since then there's been no engagement on the actual topic, just the occasional short post that doesn't respond to any other posts and merely seeks to stir the pot.

I'm not playing this game any more. However, I do thank all the positive contributors ( D Deleted member 68059 et al) for your comments which I found valuable.

 

[Hardrada55]

http://www.enginehistory.org/members/articles/Packard1923-1939.pdf

Hard to say, appears that the 5A was a bit of a mystery with dubious evidence of it ever being produced in anything other than a couple of prototypes.

Going by the 4A, it looks archaic, no better than a Hispano-Suiza 12Y, inlet and outlet ports on the same side of the head. Hopeless.

5A might have been a lot better, who knows, but if it was, odd than it just dissapeared. One suspects upon testing it fell far short of the specs and
was dropped, as is usually the case will all such "vanished engines".

I think Packard made 14,000 marine versions of this "vanished engine". They had transmissions with reverse gears and water cooled exhaust manifolds attached which made them much heavier than any airplane engine. https://www.pt-boat.com/packard/packard.html

 

[rinkol]

VK-107s? a russian v-12 it still would be better than the 1710

Wasn't reliable during the war.

 

[drgondog]

Why becuase theres a big difference between 1250hp and over 2000hp Ive said it before and I'll say it again the Aillson was the worse engine we made during the war .

I had to go back a ways to look at your commentary. From my perspective comments like this point to a.) intentional trolling to stir up a cloud of fetilizer, or b.) kind of Tourette's (sp?) syndrome or Asperger in which 'stuff' just flows out of your head and you blurt nonsense - kinda like a.), but not intentional.

Whatever it is, your toolbox of knowledge and relevant facts is pretty small to engage thoughtfully with several members on this forum- at least anything associated with WWII airframes, engines, strengths and weaknesses.

Are you here to teach, or learn?

 

[Spindash64]

setting aside the issue of "shoehorning", it's not even that the Allison was a bad engine. It's just that the Merlin was being modified to create a two staged supercharging design at around this time frame, meaning that the RAF happened to have Mustangs and Merlin 60 series at around the same time. For a single stage engine, the V-1710 was actually quite solid: yes, it suffered in power output at higher altitudes, but below 10,000ft, the power output was comparable to, or even better than, other liquid cooled V-12s. It could also run smoothly at extremely low rpms, making it suitable for long distance, low altitude reconnaissance missions, and ideal for "rhubarb" missions over occupied France to destroy trains, communications, or anything else not nailed down. And of course, the engine was also famous for being able to keep running even with multiple cylinders damaged, incredibly unusually for an inline engine

People also seem to forget that the US had tried already to create a "hyper engine" program for a liquid cooled engine that gave at least 1hp per cubic inch of displacement. The Allison wasn't even a participant, yet it still ended up being the only engine of the bunch to have reliability worth a damn.

Quite honestly, you weren't going to find another 2 stage equipped engine that could be fit into a small cross section. And make no mistake, this system gives a LOT of extra power compared to a single stage system. The maximum allowable manifold pressure, all other things equal, is almost directly proportional to the maximum power. And a 2 stage supercharger not only can cool the charge air enough to allow a higher safe manifold pressure, but cooling the charge also allows it to be compressed further. While some of the later war USN aircraft eventually staged using dual stage systems, this was also at the point where Water Injection had become standard issue, which fulfills a similar purpose. The Germans didn't even HAVE a functional 2 stage supercharged engine. Neither did the Russians or Italians.

The ONLY other engine that could have given the mustang potentially better performance than the Merlin without forcing a major redesign was the Rolls Royce Griffon, and even then, the Merlin still holds up admirably.

 

[drgondog]

setting aside the issue of "shoehorning", it's not even that the Allison was a bad engine. It's just that the Merlin was being modified to create a two staged supercharging design at around this time frame, meaning that the RAF happened to have Mustangs and Merlin 60 series at around the same time. For a single stage engine, the V-1710 was actually quite solid: yes, it suffered in power output at higher altitudes, but below 10,000ft, the power output was comparable to, or even better than, other liquid cooled V-12s. It could also run smoothly at extremely low rpms, making it suitable for long distance, low altitude reconnaissance missions, and ideal for "rhubarb" missions over occupied France to destroy trains, communications, or anything else not nailed down. And of course, the engine was also famous for being able to keep running even with multiple cylinders damaged, incredibly unusually for an inline engine

People also seem to forget that the US had tried already to create a "hyper engine" program for a liquid cooled engine that gave at least 1hp per cubic inch of displacement. The Allison wasn't even a participant, yet it still ended up being the only engine of the bunch to have reliability worth a damn.

Quite honestly, you weren't going to find another 2 stage equipped engine that could be fit into a small cross section. And make no mistake, this system gives a LOT of extra power compared to a single stage system. The maximum allowable manifold pressure, all other things equal, is almost directly proportional to the maximum power. And a 2 stage supercharger not only can cool the charge air enough to allow a higher safe manifold pressure, but cooling the charge also allows it to be compressed further. While some of the later war USN aircraft eventually staged using dual stage systems, this was also at the point where Water Injection had become standard issue, which fulfills a similar purpose. The Germans didn't even HAVE a functional 2 stage supercharged engine. Neither did the Russians or Italians.

The ONLY other engine that could have given the mustang potentially better performance than the Merlin without forcing a major redesign was the Rolls Royce Griffon, and even then, the Merlin still holds up admirably.

The Griffon installation required a major airframe mod to the Mustang, namely moving the wing forward to maintain cg limits. NA did a layout per D-12007 dated 8-8-42.

 

[Deleted member 68059]

The Griffon installation required a major airframe mod to the Mustang, namely moving the wing forward to maintain cg limits. NA did a layout per D-12007 dated 8-8-42.

Personally I think the Griffon would have been a retrograde step, the Mustang was already heavy (until the "H" version) and its biggest
strength was the range and speed through clean aerodynamics etc, stick in a Griffon and you`ll definetly lose fuel economy through
weight increase and probable bulges and CG compensation.

The Griffon spitfire was a brutal interceptor, probably the most lethal late war fighter in figher-fighter use, but it also had abysmal
range.

A good thing it didnt happen I think, I dont think you can beat a P-51-H with a 100 series Merlin - thats pretty much the ultimate WW2 fighter
for air-air usage, in my view.

 

[Reluctant Poster]

And of course, the engine was also famous for being able to keep running even with multiple cylinders damaged, incredibly unusually for an inline engine

I have never seen any evidence of this

 

[Deleted member 68059]

I have never seen any evidence of this

On that note, I`ve never seen any real documented evidence that ANY engine could do it for anything more than a few minuites on the way home just before landing.

 

[drgondog]

I have never seen any evidence of this

I have - for both the Merlin and the Allison. Not common, but not at long distances from friendly airfield. One such Occurance was Scout Force - Experimental based out of Steeple Morden landed successfully near Nantes on September 3, 1944 after being hit by 20mm flak while letting down in foul weather over France returning to base. P-51D-5 WRbarW, 44-13349

 

[Admiral Beez]

No, definitely not a better option. It had lower power output than the Allison and it was not produced by either the USA or Britain, so, bad idea. The Mustang would have been slower and had poorer performance with an engine that no one wanted.

This makes me wonder how the Arsenal VG-33 would have done with a Merlin engine in the proposed VG-40 variant. Or for that matter, the VG-50 proposed to be powered by the Allison V-1710-39.

 

[Reluctant Poster]

I have - for both the Merlin and the Allison. Not common, but not at long distances from friendly airfield. One such Occurance was Scout Force - Experimental based out of Steeple Morden landed successfully near Nantes on September 3, 1944 after being hit by 20mm flak while letting down in foul weather over France returning to base. P-51D-5 WRbarW, 44-13349

As a matter of curiosity how far did it travel? Did it lose oil?