P-40 what-if

Colin1 said:

An expensive waste of powerplants
the Griffon would be getting the best out of the airframe, the airframe would not be getting the best out of the Griffon. Airframe refinement easily kept pace with powerplant development, allowing the match-up to get the best out of each other; just dropping a cutting-edge powerplant into a mid-30s airframe would put you at a disadvantage to your enemies who've considered the aerodynamic aspects.

The Mustang I with the V-1710-39 was around 30mph faster than the P-40E with the same powerplant.

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It does immediately beg the question, if you can have a Griffon engined P-40F, why not a Griffon engined P-51A? Talk about a bat out of hell.

Markus said:

Sure, but "Vees for Victory" says 2,000 V-1710-47 were actually ordered in April 1942. That strongly indicates the engine was ready. Even if it was 100% ready, neither was the P-51B. Her production did not begin until a full year later. Plenty of time for Curtiss-Wright to improve the P-40 more than in OTL.

@Cromwell:

I disagree, the XP-40Q made 422mph at 20,000ft, not 25,000ft thus I´m convinced the Warhawk had a lot of unused potential.

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A lot of engines were ordered before they were really ready. For instance it wasn't until July of 1942, 2-3 months later that Allison decided to replace the single speed aux supercharger drive with the variable hydraulic drive on the -47. The -47 also had an intercooler as part of it's specifications at times ( the specifications were amended a number of times) but no intercooler was fitted to any flying example of the -47 or it's immediate successors.

Shortround6 said:

having one engine in flight test (or even 6 engines in flight test) is not the same as as rolling them out door a dozen a day.

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Thank you for stating that.
After all the conversation that's gone on about the V-1710-45 engine, what you stated MUST be understodd going into the conversation to begin with.

Shotrround6 said:

Allison got caught in several production problems. in Early 1939 the actual number of engines either delivered or on order was very small. Of these engines there were 5 or 6 different models, so in an attempt to squeeze some profit out of what they were making Allison had taken the approach of building a central power section and then adding accessories (gear drives, extension shafts and the like ) to this central, standard section.

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This sounds very much like the design of the Detroit 2-stroke....and who was paired with them, back when they were owned by GM?...oh yeah, Allison.
Co-ink-E-dink? Maybe. Interesting how that "thought train" seems to transition so smoothly, though...doesn't it?

Shortround6 said:

For people who say this was short sighted it is good to remember that R&D contracts are not like today. Back then the Army only paid for the successful completion of a test, if then. If a test engine blew up on the test stand the company had to supply a replacement at it's own expense. in the spring of 1939 (months after Allison had decided a 2 stage supercharger might be needed) the Army was over 900,000 dollars in arrears to Allison and weaseled out of paying this by getting Allison to forgive the debt in return for allowing Allison to export the V-1710 to France and England.

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I believe the term is "built on spec". This is exactly why there is no longer an Amercian Bantam Company in existence.


Shortround, one other thing I wanted to comment on.
In an earlier post, you touched a little on Packard's experience building large displacement engines and mentioned a 2500 cu.in. V-12 aircraft engine they made back in the 20's.
Was this the same engine as the 2500 cu.in. V-12 Marine engine they made, at around the same time?
I know 3 were included with every PT boat that hit the waves. Also, I believe Gar Wood himself ran an extremely successful boat racing campaign during the mid-late 20's and possibly the early 30's, with the "Miss US", which used a couple of those big Packard Marine V-12's, too.

...oh yes, and before I forget, there was some earlier talk about the DB engines and how/why they made so much power.
I once did a little math concerning this and found out that 2205/1475, pretty much = 1150/1710, and that 1/2" added to 5.5" 6" = 2205, when the revised combination is multiplied by 12.
Just saying.



Elvis

Shortround6 said:

A lot of engines were ordered before they were really ready. For instance it wasn't until July of 1942, 2-3 months later that Allison decided to replace the single speed aux supercharger drive with the variable hydraulic drive on the -47. The -47 also had an intercooler as part of it's specifications at times ( the specifications were amended a number of times) but no intercooler was fitted to any flying example of the -47 or it's immediate successors.

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Sorry, seems like I missed this page of the thread.
Shortround, good point, but maybe a better question to ask, is what is Markus going to do with that 8 foot space between the engine and the propeller on the "-47" engine, when he tries to install it in a P-40?
THIS, I gotta see.




Elvis

Colin1 said:

Thank you
if Curtiss hadn't realised by 1944 that the war in the ETO was raging 5,000ft higher than your XP-40Q was capable of flying at then Curtiss's interest is a what-if too far

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Please be so kind to fully quote what I wrote:

First, this is a "what if", so we assume C-W was interested. Second, if the plane can make 422mph@20ft it will be faster at a higher altitude if the engine is rated for a higher altitude. Some Allisons were some were not as the customers prefered max. performace at 20,000ft.

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Ever heard of the V-1710-117?

Elvis said:

Sorry, seems like I missed this page of the thread.
Shortround, good point, but maybe a better question to ask, is what is Markus going to do with that 8 foot space between the engine and the propeller on the "-47" engine, when he tries to install it in a P-40?
THIS, I gotta see.

Elvis

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Playing stupid I see!

Markus said:

Please be so kind to fully quote what I wrote

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Markus said:

First, this is a "what if", so we assume C-W was interested. Second, if the plane can make 422mph@20ft it will be faster at a higher altitude iif the engine is rated for a higher altitude. Some Allisons were some were not as the customers prefered max. performace at 20,000ft. Third, IIRC the P-51B was not that available at first. All went to the UK for some time, resulting in complaints from the Med for example.

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Thank you
if Curtiss hadn't realised by 1944 that the war in the ETO was raging 5,000ft higher than your XP-40Q was capable of flying at then Curtiss's interest is a what-if too far

Colin1 said:

Thank you
if Curtiss hadn't realised by 1944 that the war in the ETO was raging 5,000ft higher than your XP-40Q was capable of flying at then Curtiss's interest is a what-if too far

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Ok, I get it you don´t get the concept of a "what if".

Elvis said:

I believe the term is "built on spec". This is exactly why there is no longer an Amercian Bantam Company in existence.

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I am not sure it is the same thing. My understanding on "built on spec" is that the buyer either puts out a specification and invites proposals/prototypes or a company builds an Item it believes the buyer will want/need even if no specification has been issued. In Allison's case there were signed contracts detailing how much money was to be paid for what item and level of performance. As in engine model "X" will produce 1000hp at 3000rpm for "Y" number of hours. Fail to meet the conditions and the Army didn't have to pay.

Elvis said:

Shortround, one other thing I wanted to comment on.
In an earlier post, you touched a little on Packard's experience building large displacement engines and mentioned a 2500 cu.in. V-12 aircraft engine they made back in the 20's.
Was this the same engine as the 2500 cu.in. V-12 Marine engine they made, at around the same time?
I know 3 were included with every PT boat that hit the waves. Also, I believe Gar Wood himself ran an extremely successful boat racing campaign during the mid-late 20's and possibly the early 30's, with the "Miss US", which used a couple of those big Packard Marine V-12's, too.

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Yes it was the same engine. It differed from the Allison and most other WW II V-12s in that each each cylinder was separate rather than using a common cylinder block for each bank. They were surrounded by a common sheet metal water jacket however so this is not apparent when looking at the engine.

Markus said:

Ok, I get it you don´t get the concept of a "what if"

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Yes, I do
but you stepped outside the bounds of the what-if (which is hardly illegal), furnishing us with some data on the XP-40Q appended with an opinion on the 'hawk fighter as a result of that data:

Markus said:

I disagree, the XP-40Q made 422mph at 20,000ft, not 25,000ft thus I´m convinced the Warhawk had a lot of unused potential.

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There is very likely some credence in your claim to unused potential, I just don't think Curtiss-Wright by that stage were inclined to try that hard to achieve it; to get from 422mph to 437mph (simply to match the P-51D on level flight speed), they would need to do something else to the XP-40Q.

My first port of call (in my uninformed opinion as a non-aerodynamicist) would be to adopt a conventional main undercarriage; I do not believe that getting from 400mph to 422mph is anywhere near as difficult as getting from 422mph to 437mph.

The next best thing to catch a V-1650-equipped P-51 is probably a V-1650-equipped XP-40Q and when we've finally secured one of those and nailed the speed @ altitude issue, we can start working on how we're going to defeat the P-51 on range.

This wasn't going to happen, the high minds at Curtiss-Wright were elsewhere.

Colin1 said:

There is very likely some credence in your claim to unused potential, I just don't think Curtiss-Wright by that stage were inclined to try that hard to achieve it; to get from 422mph to 437mph (simply to match the P-51D on level flight speed), they would need to do something else to the XP-40Q.

This wasn't going to happen, the high minds at Curtiss-Wright were elsewhere.

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True, very true. In OTL C-W concentrated on replacing the P-40 with the XP-53/XP-60 whose prototypes had the following engines: XIV-1430, V-1650-1(two speed), V-1650-3(two-stage), V-1710-75(turbo), XV-2200 and R-2800. Than there were the XP-62 with an R-3350 begun in 1941, the XF14C again with an R-3350 and the XP-55.

But in an ATL C-W could have cancelled some of these planes and thus freed engineers to work on the P-40. IMO the XP-55 and -62 would have been logical candidates as they were supposed to be bombers interceptors. And between 1939 and 1942 no such thing as a German B-17 had been seen by anyone. Same goes for the Japanese.

Shortround6 said:

I am not sure it is the same thing. My understanding on "built on spec" is that the buyer either puts out a specification and invites proposals/prototypes or a company builds an Item it believes the buyer will want/need even if no specification has been issued. In Allison's case there were signed contracts detailing how much money was to be paid for what item and level of performance. As in engine model "X" will produce 1000hp at 3000rpm for "Y" number of hours. Fail to meet the conditions and the Army didn't have to pay.



Yes it was the same engine. It differed from the Allison and most other WW II V-12s in that each each cylinder was separate rather than using a common cylinder block for each bank. They were surrounded by a common sheet metal water jacket however so this is not apparent when looking at the engine.

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Spec stands for speculation or more properly "Speculative Investment". The most common example is buying an empty lot in a new suburb and putting a house on it.

For the purpose of the what if, he's implying that Allison anticipate the need better than the War Department would and spending their own money on development.