trackend
Chief Master Sergeant
That was a stupid statement to make Paso you cannot just make sweeping remarks like that without it being you that looks the idiot I suggest you delete that very silly line and think before pressing the keys next time.
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This Twitch fellow is unfortunately a typical American, i.e. a brainwashed idiot.
This Twitch fellow is unfortunately a typical American, i.e. a brainwashed idiot.
pasoleati said:Third, Packard had to change the blueprints for their workforce was composed of typical Amis as described above whereas RR had SKILLED workforce who could think with their own brains.
I think it is true that Packard helped RR a lot in the later years in terms of producing the merlins in huge quantities. However, it is more likely that, due to the more engines produced, the less reliable the merlin became. This because it is impossible to check every engine you produce you've just got to try and get the measurement consitant.
Is there any info about a certain rpm which made the Parcard merlins run rough? I heard this from a Spitfire mk XVI pilot.
No he's not but he is a moderator here and one more ignorant statement or response and you're out of here pal - understand?!?!?You are not Twitch...
Agree Track - especially when this crap comes from a new-bee.Its all gone a bit adrift on a couple of threads recently Joe why cant guys have a discussion without it degenerating into the Yanks this or the Brits that spoils it for the rest of us, all rather daft.
Probably true - I know out of necessity that the UK was recycling as much as possible (seen photos of pots and pans being collected for the war effort). Although the alloying of materials cane be controlled, the quality of such raw materials is always a bit degraded when recycled components are used. I know Reynolds Aluminum had a problem with this in the early-mid 80s.Anyway sorry I digress swinging it back to what this thread is about I am not up on the technicalities but I have seen on a couple programs including the history channel that stated the quality of raw materials available in the US enabled manufactures to produce a higher quality engine even though the spec was the same.
You are not Twitch...
If someone here with depth of resources for a typical 'spitty' squadron, maybe they can look theirs up. However, in all fairness, mission durations between 51s and Spits would be a severe complication from a statistical POV and conclusions
Yes and no...It's not hard to keep the good stuff for airframes when it comprises 75% of the aluminium, and use the low grade stuff for seats and handles and mess tins etc.
The initial Packard modification on the Merlins were done on this engine by changing the main bearings from a copper lead alloy to a silver lead combination and featured indium plating. Indium plating had been developed by the General Motors (Pontiac Division) to prevent corrosion which was possible with lubricating oils that were used at that time. The bearing coating also improved break-in and load carrying ability of the surface. British engineering staff assigned to Packard were astonished at the suggestion but after tear down inspections on rigidly tested engines they were convinced the new design offered a decided improvement.
The real improvement Packard incorporated into the Merlin was adopting the Wright supercharger drive quill. This modification was designated the V-1650-3 and became known as the "high altitude" Merlin destined for the P-51. The ((two speed, two stage supercharger)) section of the V-1650-3 featured two separate impellers on the same shaft which were normally driven through a gear train at a speed of 6.391:1. A hydraulic gear change arrangement of oil operated clutches could be engaged by an electric solenoid to increase this ratio to 8.095:1 in high speed blower position. The high speed gear ratio of the impellers was not as great as the ratio used in the Allison but speed of the impeller alone was not the factor that increased the engine performance at altitude. The double staging of the compressed fuel/air mixture provided the boost pressure through a diffuser to the intake manifolds which increased the critical altitude of the power plant.
When the first of the Packard-built Merlins arrived in Britain, the engineers at Rolls-Royce stripped it down and were amazed to find that the production-line built Packard engine, far from being as bad as they expected it to be for component tolerances, was actually better. Up until then, R-R Merlins were hand built, every face being finished off by hand, and this time-consuming process placed great strain on the production capability of the skilled workforce involved in the manufacture of these engines. The Packard engine changed many minds, although there were still some at R-R who remained unconvinced of the quality of the American engine, produced as it was by a largely unskilled and semi-skilled female workforce. In the end, the engine's performance removed any doubts about its quality and workmanship.
Yes and no...
When you have aluminum ingot that is on the "low end" of the tolerance, it still meets specs but may have a higher level of impurities. Those impurities may come back and haunt you later on as when the "part" is subjected to environmental conditions, things like intergranular corrosion will develop more easily than if the material was at the upper end of the spec to begin with. As stated, I was involved with this in the early 80s. Several manufacturers refused to used Reynolds in their aircraft because of this...
Next, by reading the flamin manual (Air Publication 2062 A C) for the Lancaster it shows clearly that the RR Merlin XX, 22 or 24 engines were fitted with SU carbs while the Packard Merlin 28 or 38 had Bendix Stromberg pressure injected carbs.