Packard V1650-3 or -6 TBO info from manuals?

[BlitzPig_EL]

I've started looking for the USAAF/Packard maintenance schedule information on the Merlins that equipped the P51D.

The only things I have found so far are actual service manuals the detail the stripping and rebuild of the V1650. and while interesting, they are not what we need to have the "limits" on use of "breaking the wire" properly modeled.

 

The USAAF had to have a specific, and detailed policy on when a major inspection of an engine was required after using war emergency power.  After one use?  Two uses?  How many 5 minute cycles were really allowed before the engine had to be torn down?  I am absolutely NOT looking for the "Don't you do that young man!" finger shaking nanny warnings in the Pilots Notes, but the schedule used by maintenance personnel to determine when to check out an engine after WEP use was reported by the pilot in an AAR.

 

The current system in the sim just is not viable if you want to keep calling this a "simulation", as it in no way reflect the reality of how anyone's engines, Allied or Axis, were used or held up during actual combat flying. 

Edited November 3, 2018 by BlitzPig_EL

[Talon_]

 

 

 

 

Edited November 3, 2018 by Talon_

[PainGod85]

Five hours of war emergency power before the engine is dismantled and checked for damage. Oh well.

[BlitzPig_EL]

Exactly.

 

If we get 5 seconds beyond 5 minutes the engine will no doubt fail.  A gamey solution to a non-problem. 

[THERION]

I only accept modifications to engine timers, if we get the Form 1A to report and fill - otherwise it won't be realistic and too gamey.

[-=PHX=-SuperEtendard]

50 minutes ago, BlitzPig_EL said:

Exactly.

 

If we get 5 seconds beyond 5 minutes the engine will no doubt fail.  A gamey solution to a non-problem. 

The engine keeps working past the original time limit really.

With the 5 minute timer of the P-39, I ran different tests to see how long it takes to get damaged and got these results:

7:36
5:36
7:03
6:30
5:24
7:32
8:39
6:12
7:52
6:36

So if you are lucky you can get a good bit of extra time before it is damaged. I know it's still not realistic, but it's not the "surpass the timer and immediately blows up" people often talk about.

Edited November 3, 2018 by -=PHX=-SuperEtendard

[Barnacles]

4 minutes ago, -=PHX=-SuperEtendard said:

The engine keeps working past the original time limit really.

With the 5 minute timer of the P-39, I ran different tests to see how long it takes to get damaged and got these results:

7:36
5:36
7:03
6:30
5:24
7:32
8:39
6:12
7:52
6:36

So if you are lucky you can get a good bit of extra time before it is damaged. I know it's still not realistic, but it's not the "surpass the timer and immediately blows up" people often talk about.

Exactly, there is a random factor in there somewhere. It's just that in the case of a 109 the random element varies by seconds. I'd like it to be something like a small possibility of minor engine damage (small reduction in power for example) rather than the almost certain immediate critical damage to the engine. That way there would still be an incentive to obey the engine limits, but it'd be more realistic as in a life or death situation it would be worth the risk to exceed the limits, like it probably was in reality.

[-=PHX=-SuperEtendard]

2 minutes ago, 71st_AH_Barnacles said:

Exactly, there is a random factor in there somewhere. It's just that in the case of a 109 the random element varies by seconds. I'd like it to be something like a small possibility of minor engine damage (small reduction in power for example) rather than the almost certain immediate critical damage to the engine. That way there would still be an incentive to obey the engine limits, but it'd be more realistic as in a life or death situation it would be worth the risk to exceed the limits, like it probably was in reality.

Yes, the extra random factor is around up to +50%. But the 109 time limit being 1 minute, it's just extra 30 seconds which isn't a lot. I personally could have it raised to 3-5 minutes as compromise. And a modification for the P-40 to have 5 minutes at 57" as it was cleared later on for the same engine.

Edited November 3, 2018 by -=PHX=-SuperEtendard

[Kurfurst]

19 hours ago, PainGod85 said:

Five hours of war emergency power before the engine is dismantled and checked for damage. Oh well.

 

I guess the clearly stated part in the text about risking damage to the internal parts of the engine after 5 minutes of use at one time went missing. Oh well.

 

In any case, 5 hours in total means 60 flights assuming that WEP was used for 5 mins on each flight. Avarage of 4 hour flights would thus give you 240 hours which was the nominal (admitted to be unrealistic by even RR, in USAAF practice they lasted about half as much on avarage) TBO for Merlins, after which complete disassembly and inspection had to be done anyways. This is the sort of assumption on operational hours engine manufacturers worked with.

 

So basically it reads 240 hours OR 5 hours of WEP logged in, whichever is sooner.

[Ehret]

It's much better to "risk damage to the engine" than a bullet to the torso! No one would be angry because of extra engine overhaul if it just saved a pilot.

The Packard V-1650s were of higher quality the RR built Merlins. To cite Günther Rall:" In the P-51 there was no oil leak, and that was just fantastic.". No wonder why considering all the manufacturing problems which plagued Germany at the time.

 

In the sim the artificial timers will have to stay if only for game-play reasons. That's why will not be getting defects by slave labor sabotages or failures due gums in the C3 fuel even if they were historical occurrences.

Edited November 4, 2018 by Ehret

[Sgt_Joch]

The Devs have said they want to move to a more realistic engine model, but I would not get my hopes up that this will happen anytime soon.

 

The only two options that I see that would be fair and practical would be:

 

1. Increase all current limits by a fixed amount, say 2x to 5x; or

 

2. Make engine limits a game option. MP servers can then decide whether to have engine limits or not.

 

Good luck though getting players to fly Russian planes on servers where F-4s can run at 1.42 100% of the time. Removing all engine limits would be the easiest way to kill MP. I would think people would have learned from the RoF debacle.

[Ehret]

25 minutes ago, Sgt_Joch said:

Good luck though getting players to fly Russian planes on servers where F-4s can run at 1.42 100% of the time. Removing all engine limits would be the easiest way to kill MP. I would think people would have learned from the RoF debacle.

 

No... it would not or... maybe it'd kill MP but in reverse. Without limits (and without detonation modelling) the Kittyhawk would be most popular VVS fighter plus handful of Airacobras.

 

Timers should go and there are other reasons than some planes seem to be handicapped by them.

There had be costs associated with extended WEP-ing, thought. Like getting rough running engine, some oil splashes on front glass, guns jamming from all those vibrations, etc. Not completely realistic maybe but neither are time based kill-switches.

Edited November 4, 2018 by Ehret

[Saburo]

39 minutes ago, Ehret said:

To cite Günther Rall:" In the P-51 there was no oil leak, and that was just fantastic.".

From the second World side,

Yasuhiko Kuroe, Japanese ace who tested captured P-51C:

..."The absence of oil leaks was surprising to most, as..."...

[Sgt_Joch]

36 minutes ago, Ehret said:

 

No... it would not or... maybe it'd kill MP but in reverse. Without limits (and without detonation modelling) the Kittyhawk would be most popular VVS fighter plus handful of Airacobras.

 

Timers should go and there are other reasons than some planes seem to be handicapped by them.

There had be costs associated with extended WEP-ing, thought. Like getting rough running engine, some oil splashes on front glass, guns jamming from all those vibrations, etc. Not completely realistic maybe but neither are time based kill-switches.

Of course the current system is completely arbitrary and unrealistic, everyone realizes that, but completely removing engine limits with the current simple engine modeling is just as unrealistic.

 

So players have two options:

1. Wait until the Devs eventually get around to implementing a more realistic system, which may never happen; or

2. Propose a simple quick fix that can be easily implemented and will resolve the worst issues even though it may be far from ideal.

 

This is not aimed at you personally, but these umpteenth threads where everyone just repeats the same thing over and over and over and over again are a colossal waste of time.

Edited November 4, 2018 by Sgt_Joch

[BlitzPig_EL]

Well, I don't see them as a waste of time with the impending launch of a large number of new aircraft that if modeled in the totally arbitrary way the engines are now, will in no way be able to perform to their real world counterparts figures.

 

If you find these threads a waste of time, simply move along and find other threads that do interest you.

Edited November 4, 2018 by BlitzPig_EL

[Sgt_Joch]

2 minutes ago, BlitzPig_EL said:

Well, I don't see them as a waste of time with the impending launch of a large number of new aircraft that if modeled in the totally arbitrary way the engines are now, will in no way be able to perform to their real world counterparts figures.

 

 

Well yes they will be modeled in the same arbitrary way. That should be obvious by now.

[czech693]

I don't interpret that section of the manual to say you can run WEP for five hours total before breaking down the engine.  It would never take that kind of use.  To me it says if you use WEP, log it, report it, and the crew chief has to inspect the engine for damage.  Then after five hours of "total" operating use after the incident where WEP was use, the engine must be broken down.

[Talon_]

3 minutes ago, czech693 said:

I don't interpret that section of the manual to say you can run WEP for five hours total before breaking down the engine.  It would never take that kind of use.

 

You would have to be an idiot to interpret it that way considering the Merlin 66 on only maximum continuous will empty the internal and external tanks of any aircraft that used it in half that time.

[Chief_Mouser]

3 minutes ago, czech693 said:

I don't interpret that section of the manual to say you can run WEP for five hours total before breaking down the engine.  It would never take that kind of use.  To me it says if you use WEP, log it, report it, and the crew chief has to inspect the engine for damage.  Then after five hours of "total" operating use after the incident where WEP was use, the engine must be broken down.

 

That would be almost every escort mission that resulted in a combat then. Five hours WEP seems a lot, but five hours engine run time would mean rebuilding the engine almost every day.

[Legioneod]

I've posted a pretty good solution to our engine modeling problem. It still has limits but it's better than what we currently have. I'l try to find it and copy it here.

 

Edited November 4, 2018 by Legioneod

[MiloMorai]

10 hours ago, Ehret said:

It's much better to "risk damage to the engine" than a bullet to the torso! No one would be angry because of extra engine overhaul if it just saved a pilot.

The Packard V-1650s were of higher quality the RR built Merlins. To cite Günther Rall:" In the P-51 there was no oil leak, and that was just fantastic.". No wonder why considering all the manufacturing problems which plagued Germany at the time.

 

In the sim the artificial timers will have to stay if only for game-play reasons. That's why will not be getting defects by slave labor sabotages or failures due gums in the C3 fuel even if they were historical occurrences.

 

What do you mean by higher quality?

[Ehret]

34 minutes ago, MiloMorai said:

What do you mean by higher quality?

 

Better machining and bearings thus no leaks, better alloys in parts of the engine, better QC.

There are notes by Germans and Japanese that manufacturing quality of the captured P-51s were superior to their own planes. That includes other equipment found in the Mustang like radios.

 

Soviets said the same about the LendLease P-40/P-39.

Edited November 4, 2018 by Ehret

[MiloMorai]

Better machining of what? Bearings cause oil leaks? What better alloys for what parts?

[Ehret]

1 hour ago, MiloMorai said:

Better machining of what? Bearings cause oil leaks? What better alloys for what parts?

 

Yes! Poor bearings can cause leaks - just ask the DB how they liked the change to sleeve from ball bearings.

 

About the V-1650; from: " The initial Packard modifications to this engine changed the main crankshaft bearings from a copper-lead alloy to a silver-lead combination and featured indium plating. "

 

For machining it could be better in the US for the time for everything I guess... Machining tools were in short supply in the Nazi Germany; when they were plundering countries they took everything including tools. Shouldn't be the case if things weren't problematic, right?

 

Then we have: "As the war progressed, the use of slave labour increased massively." Getting bombed hadn't helped, either.

Edited November 5, 2018 by Ehret

[BlitzPig_EL]

Packard simplified some aspects of the Merlin to speed production.

 

Anyone that has ever worked on a Rolls Royce automobile will understand this.  If a particular component can be properly affixed by 4 fasteners, Rolls Royce will use 18 fasteners, three of which will be of different sizes (each) and be in locations that will require the removal of at least two other equally complex components to get to.

 

Ask me how I know.

Edited November 5, 2018 by BlitzPig_EL

[mumbojumbo]

9 hours ago, Ehret said:

 

Better machining and bearings thus no leaks, better alloys in parts of the engine, better QC.

There are notes by Germans and Japanese that manufacturing quality of the captured P-51s were superior to their own planes. That includes other equipment found in the Mustang like radios.

 

Soviets said the same about the LendLease P-40/P-39.

That's the second or third remark about manufacturing quality of Packard merlin, but not a direct comparison between rr merlin and Packard merlin. More likely a comparison between Packard and homare.

 

Most things I've read on this state that the Packard was identical to a rr, if they favoured different materials then that may be more of a supply/standards issue. 

[MiloMorai]

11 hours ago, Ehret said:

 

Yes! Poor bearings can cause leaks - just ask the DB how they liked the change to sleeve from ball bearings.

 

About the V-1650; from: " The initial Packard modifications to this engine changed the main crankshaft bearings from a copper-lead alloy to a silver-lead combination and featured indium plating. "

 

For machining it could be better in the US for the time for everything I guess... Machining tools were in short supply in the Nazi Germany; when they were plundering countries they took everything including tools. Shouldn't be the case if things weren't problematic, right?

 

Then we have: "As the war progressed, the use of slave labour increased massively." Getting bombed hadn't helped, either.

 

It would be poor seals as bearings are supposed to ooze oil.

 

What has German manufacturing have to do with Packard and RR Merlins?

8 hours ago, BlitzPig_EL said:

Packard simplified some aspects of the Merlin to speed production.

 

Anyone that has ever worked on a Rolls Royce automobile will understand this.  If a particular component can be properly affixed by 4 fasteners, Rolls Royce will use 18 fasteners, three of which will be of different sizes (each) and be in locations that will require the removal of at least two other equally complex components to get to.

 

Ask me how I know.

 

That is not just a RR auto problem these days.

[BlitzPig_EL]

I'm not talking about modern RR cars, I only work on vintage automobiles.  I agree that modern cars are far more complex, but they are also far far more reliable.  But, enough of this little derail.

[MiloMorai]

What is a Packard V-1650-6

[Ehret]

2 hours ago, MiloMorai said:

What has German manufacturing have to do with Packard and RR Merlins?

 

In the WW2 timeline? Everything. It affected arms race and performance. I just answered questions how it was possible that captured P-51Ds were considered of better quality by German and Japanese than their own equipment. Indeed, there were reasons for that. For the time it was very good thing to had stuff manufactured in the North America.

 

5 hours ago, Tarks91 said:

Most things I've read on this state that the Packard was identical to a rr, if they favoured different materials then that may be more of a supply/standards issue. 

 

There are some remarks that the materials choice was to increase reliability and make the engine more robust. After all, the P-51Ds had to fly multi-hours sorties over the enemy territory. Everything on just one engine; it would be very weird if changes made were of no consequence.

Edited November 5, 2018 by Ehret

[Sgt_Joch]

There was an interesting article about the problems Packard faced in manufacturing the Merlin to U.S. standards. Basically, Rolls Royce handbuilt their engines while Packard wanted to mass produce them. However, both sides adapted which resulted in a better product. By 44-45, I doubt there was any real difference  between a Packard Merlin and the RR original:

 

Quote

Engineers at Packard soon discovered that Rolls-Royce did not design the Merlin for mass-production. The manufacturing tolerances were much looser than Packard’s standards. This was because Rolls-Royce had never implemented mass-production techniques to their assembly lines. Rather, they employed highly-trained “fitters” to assemble the engines. The fitters filed or otherwise massaged individual parts to achieve a precise fit. They even tightened critical bolts by trained feel, rather than with calibrated torque wrenches. In effect, each Rolls-Royce-manufactured Merlin was a hand-built engine that reflected the company’s traditions of premium quality and craftsmanship.

While Rolls-Royce’s manufacturing techniques churned out very high quality engines, they simply didn’t jibe with Packard’s way of doing things (or Ford in Manchester for that matter). In his book “Not Much of An Engineer”, Rolls-Royce engineer Sir Stanley Hooker recalls his introduction to the matter with Ford:

“One day their Chief Engineer appeared in Lovesey’s office, which I was then sharing, and said, ‘You know, we can’t make the Merlin to these drawings.’

I replied loftily, ‘I suppose that is because the drawing tolerances are too difficult for you, and you can’t achieve the accuracy.’

‘On the contrary’ he replied, ‘the tolerances are far too wide for us.’ We make motor cars far more accurately than this. Every part on our car engines has to be interchangeable with the same part on any other engine, and hence all parts have to be made with extreme accuracy, far closer than you use. That is the only way we can achieve mass-production.’”

Like Ford, Packard was obligated to redraw all of the Merlin blueprints to satisfy their own manufacturing requirements. This effort took the better part of a year to complete and was closely coordinated with Rolls-Royce emissaries in Detroit. During the time that Packard was gearing up for production, Rolls-Royce was making continuous improvements to the Merlin based on feedback from the front lines. These updates also had to be incorporated into Packard’s operation. This continual two-way exchange of data took a heavy toll on the men tasked to manage it. Of the two original Rolls-Royce liaisons at Packard, one died during his tenure in Detroit and the other perished soon after his return to England.

Packard’s licensing agreement prevented them from implementing any changes to the design of the Merlin without approval from Rolls-Royce. There was an understandable need to maintain compatibility and consistent performance among the engines regardless of where they were manufactured. While Rolls-Royce engineers were typically attentive to suggestions from their manufacturing partners, any accepted design changes were applied across all production lines.

One area where the Americans contributed to the greatness of the Merlin was the crankshaft bearings. US aircraft engine manufacturers had determined that a silver-lead alloy with indium plating provided long wear and exceptional corrosion resistance. Thankfully, German engineers who evaluated captured American engines falsely deduced that the indium was merely an impurity. Packard shared the secret bearing formula with Rolls-Royce who incorporated it into the Merlin.

The Merlin became somewhat further Americanized by the components that were attached to Packard-built units. Carburetors, magnetos, spark plugs, and similar items were sourced through American vendors and sub-contractors, although they were still manufactured to British specifications.

To maintain compatibility, Packard did not convert any of the bolts, nuts, and studs to SAE dimensions. Rather, they were obligated to use fasteners with Whitworth threads, as specified by Rolls-Royce. Whitworth-form hardware proved impossible to source within the US, so Packard eventually produced all of the necessary fasteners in-house.

The first Packard-built Merlins emerged in August of 1941. As would be expected, there were a few teething problems such as excessive cylinder blow-by and oil leakage. Most historians agree that Packard and Rolls-Royce tackled the issues with a high degree of cooperation. The US-built engines soon performed on par with their English doppelgangers. Packard would ultimately manufacture 55,000 of the 150,000 Merlins that were built.

 

https://www.tested.com/art/makers/492418-packard-merlin-how-detroit-mass-produced-britains-hand-built-powerhouse/

[MiloMorai]

Packard - 55,523

Manchester - 30,428

Glasgow - 23,675 set a record of 100 engines in one day

Crewe - 26.065

Derby - 32,377

 

Ehret, Lancasters, as did Mosquitoes, flew many hours over Germany. Granted it was with more than one engine.

 

[Ehret]

59 minutes ago, MiloMorai said:

Ehret, Lancasters, as did Mosquitoes, flew many hours over Germany. Granted it was with more than one engine.

 

That one engine had to endure rapid changes of settings and G-loads, too. It would be surprising if those weren't taken into account. But I will not insist; it's just the enemies were impressed and considered P-51s to be better built and equipped than their own fighters. Should be really enough of praise.

 

Sorry, but couldn't resist...

"Thankfully, German engineers who evaluated captured American engines falsely deduced that the indium was merely an impurity. Packard shared the secret bearing formula with Rolls-Royce who incorporated it into the Merlin."

 

That's fine example of German engineering for ya! ?

Edited November 5, 2018 by Ehret

[JtD]

Actually, that's a fine example of easy it is to have a biased point of view. It's very demanding to always understand better solutions when they come from a different school of thought.

 

Germans put a lot of thought into their bearings and went long ways to remove any impurities from their silver-lead alloys. It's very understandable that folks trained to look at an issue in a very particular way cannot see the forest for the trees.