P-51D with V-1650-3 engine

[=362nd_FS=RoflSeal]

I had always thought that the P-51D had the V-1650-7, the first P-51s with the -7s being the B-15 and C-10 variants, however looking at a number of manuals mention the P-51D fitted with the -3 engine (supercharger optimized for high altitude vs the -7)

e.g.

http://www.avialogs.com/viewer/avialogs-documentviewer.php?id=3834 pg 68 specific engine flight chart

http://www.avialogs.com/viewer/avialogs-documentviewer.php?id=3964 is a post-war TO about replacing -3s and -7s with -9As on F-51Ds

 

Question I have is how many P-51Ds were fitted with the -3 engine and would it be possible as a modification (similar to La-5 and Spitfire engine modifications)

 

[DSR_A-24]

Definitely Interesting as modification.

The P-51D with the V-1650-3 is list for comparative purposes only in this chart.

[=362nd_FS=RoflSeal]

Also to note is from the 1944 pilots manual on pg55 it says 2nd set of charts apply to aircraft which have had V-1650-3 installed in service suggesting that (as I expected) P-51Ds left the factory with the -7, but for some reason, some were fitted with -3 in the field

[Solty]

Maybe no -7's were available so they fitted the old engine until proper replacement is available?

Edited January 26, 2018 by =LD=Solty

[JtD]

"Field modification kits are available to change supercharger gears, converting -7's into -3's". Manual for the P-51D.

 

Probably worth pointing out that some batches of the B&C models also had the -7 installed, not the -3. Since it can be found on the type cards, it's unlikely it was a field modification. A shortage of -7's seems unlikely.

Edited January 26, 2018 by JtD

[MiloMorai]

Initially, the P-51B and C had the Packard V-1560-3 engine rated at 1400 hp for takeoff and 1450 hp at 19,800 feet and carried four 0.50-inch machine guns with a total of 1260 rounds. There were four hundred P-51B-1-NAs and 250 P-51C-1-NTs built.

 

With the introduction of the P-51C-5-NT onto the Dallas production line and the P-51B-15-NA in the Inglewood production line, the Packard V-1560-7 engine was adopted as standard.

[=362nd_FS=RoflSeal]

I found a history of a P-51D-30NA built in 1945 and sold to RCAF in 1950.

80/130 aircraft including the aircraft in question were equiped with the -3 when this sale took place

https://www.rafmuseum.org.uk/documents/collections/X003-2338-P-51D-D-Duck.pdf

[=362nd_FS=RoflSeal]

From "List of Propellers and Governers for Service Aircraft" 1945

[MiloMorai]

I did some digging. All D a/c came from the factory with -7 engines. During overhaul the -3 could be installed if no -7 engines were available.

 

The Canadian a/c never went overseas and was produced after the war in Europe was over.

 

As Packard wasn't producing V-1650 engines anymore, engines in stock were used up. Similarly when D production began there might not have been enough-7 engines available so used excess stock of -3 engines.

 

Just more work for the devs, which could be better spent on other stuff, as the only advantage the -3 had over the -7 was over 25kft. below that the -7 was better.

[=362nd_FS=RoflSeal]

25 minutes ago, MiloMorai said:

 During overhaul the -3 could be installed if no -7 engines were available.
 

 

 

 

This is a falsehood, -3 and -7 engines were the same except for the supercharger and could be converted in the field.

 

Just more work for the devs, which could be better spent on other stuff

And we have Merlin 70 for Mk IX and DC engine for K-4, I don't see why you are reluctant on this modification when it is pretty common to have engine mods in BoBP so far.

 

I think a big reason for the 8AF limit of 72 "Hg on on 150 Octane compared to ADGB's Mustangs of 81 "Hg is due to the fact they probably used a mix fleet and just used 1 number for logistics sake.

Edited November 30, 2018 by RoflSeal

[MiloMorai]

On 11/30/2018 at 5:33 PM, RoflSeal said:

 

This is a falsehood, -3 and -7 engines were the same except for the supercharger and could be converted in the field.

 

 

 

And we have Merlin 70 for Mk IX and DC engine for K-4, I don't see why you are reluctant on this modification when it is pretty common to have engine mods in BoBP so far.

 

I think a big reason for the 8AF limit of 72 "Hg on on 150 Octane compared to ADGB's Mustangs of 81 "Hg is due to the fact they probably used a mix fleet and just used 1 number for logistics sake.

 

The Spitfire LFIX used the M66, the Spitfire HFIX used the M70. Yes the block was the same but  the HF had extended wing tips as standard. Why the HF is anyone's guess. Not that it does much but maybe because no XIV, yet.

 

[edited]

 

A -3 D adds nothing to the game and is worse at altitudes under 25kft

 

Come up with some numbers for -3 engined Ds. and I might change my mind if the devs can work it into their large workload.

 

If the blocks were the same then it shouldn't matter what the boost. Did HF IXs use 25lb boost? American Ds flew much longer distances than RAF IVs. I would say that the Americans used the lower boost because of the distances they flew and the extra boost if used put extra strain on the engine. Would you like to fly 3, 4, 500 miles with a dodgy engine?

Edited December 1, 2018 by SYN_Haashashin
False claim

[Bremspropeller]

19 hours ago, RoflSeal said:

This is a falsehood, -3 and -7 engines were the same except for the supercharger and could be converted in the field.

 

It's not a falsehood per sé.

If the installation of the kit takes more time than just changing the engine*, then it might be more viable to change the engine as a whole and do the conversion in the shop, rather than doing it on the line. Thus, you're pullng off a -7 and you're instaling a different -3 that may or may not have been a -7 some time ago.

The core-difference is just a different SC gearing and a different plackard on the engine.

___

* And the kit-instalition might require pulling the engine in the first place.

Edited December 1, 2018 by Bremspropeller

[=362nd_FS=RoflSeal]

On 11/30/2018 at 10:39 PM, MiloMorai said:

 

but  the HF had extended wing tips as standard. 

 

HF Mk IXe did not have extended wingtips, those were only ever present on Mk VI, VII and HF Mk VIII

 

Quote

 

Come up with some numbers for -3 engined Ds. and I might change my mind if the devs can work it into their large workload.

Why do you try to lead me astray with this baseless statement when numbers clearly don't matter to the devs. (Bf-109K-4 DC engine, I-16 canopy, C.202 20mm gunpods, LaGG-3 23 mm, IL-2 1942 with 37mm).  What I do know is that it was prevalent enough to be included in manuals and other documentation. 150 Octane we know was used, but you don't see it mentioned in P-51D or Spitfire Mk IX pilot's manuals.

 

Quote

If the blocks were the same then it shouldn't matter what the boost. Did HF IXs use 25lb boost? American Ds flew much longer distances than RAF IVs. I would say that the Americans used the lower boost because of the distances they flew and the extra boost if used put extra strain on the engine. Would you like to fly 3, 4, 500 miles with a dodgy engine?

Merlin 70s were cleared to +25 lbs boost according to documents in Jan 1945. Again asking for numbers is irrelevant when we are already getting rare stuff (I'll add D-9 with EZ-42 on top of the list above).

RAF Mustang IVs did long range missions such as escorting strikes into Norway and fighter sweeps over the continent in addition to their anti-diver role

 

Quote

A -3 D adds nothing to the game and is worse at altitudes under 25kft

The -3 performs better then the -7 between 12,000 ft and 21,000 ft and above 28,500ft. according to the Tactical Planning Characteristics & Performance Chart.

Judging the current K-4 vs P-47 matchup on KOTA, a lot of engagements start at 15k to 20k ft

Edited December 2, 2018 by RoflSeal

[Rattlesnake]

On 12/1/2018 at 2:41 PM, RoflSeal said:

HF Mk IXe did not have extended wingtips, those were only ever present on Mk VI, VII and HF Mk VIII

 

Why do you try to lead me astray with this baseless statement when numbers clearly don't matter to the devs. (Bf-109K-4 DC engine, I-16 canopy, C.202 20mm gunpods, LaGG-3 23 mm, IL-2 1942 with 37mm).  What I do know is that it was prevalent enough to be included in manuals and other documentation. 150 Octane we know was used, but you don't see it mentioned in P-51D or Spitfire Mk IX pilot's manuals.

 

Merlin 70s were cleared to +25 lbs boost according to documents in Jan 1945. Again asking for numbers is irrelevant when we are already getting rare stuff (I'll add D-9 with EZ-42 on top of the list above).

RAF Mustang IVs did long range missions such as escorting strikes into Norway and fighter sweeps over the continent in addition to their anti-diver role

 

The -3 performs better then the -7 between 12,000 ft and 21,000 ft and above 28,500ft. according to the Tactical Planning Characteristics & Performance Chart.

Judging the current K-4 vs P-47 matchup on KOTA, a lot of engagements start at 15k to 20k ft

Aaaaaannnnnd the K-4 got the 1.98 ATA option, so we get the full menu of available  mod options as well.