As a result, 'Pep" 100/150 was being supplied to all fighter groups by March 1945.
That is the timeframe I have on 100/150 grade beginning to see general service. Not in the summer of 1944.
I do not remember that inquiry about Operation Diver. If you are in contact with Crump ask him the date of my letter/email of reply. It will help me find out what sources I used. As I do not recall the inquiry it is likely the information credited to me was snipped by me from some other source/report. I handle thousands of inquiries yearly and this one does not appear to be in my saved file.
I spoke with Dr Stolle as well on the phone and reminded him of the conversation. It was not an email but rather in person just before we went to lunch several years ago. He does not know me as Crumpp, BTW. I don't know what the P47 has to do with anything either.
Hey Timras! That is exactly where I am getting my information. If we look, "Pep" was approved by
March 1945Lets include the next paragraph from page 218:
As a result, “Pep” 100/150 was being supplied to all fighter groups by March. However, contrary to Technical Services findings, fighter groups reported that while sparking plug life was prolonged, valve adjustment had simultaneously become a problem, checks having to be made every third or fourth mission instead of the usual 50 hours. Opinions differed but the most likely reason was thought to be valve seat inserts burning out leading to diminishing valve clearance and loss of power. Enthusiasm for the new fuel waned quickly and in the same month some units requested a return to 100/130. As the old grade had been largely replaced by 100/150, supply was difficult. By April the position with “Pep” was so critical that a valve check was advised after every 25 hours of flight. In the middle of that month a message to Wright Field requested valve seat inserts on V-1650 engines be made of stelite or other suitable material with corrosion resistant properties. It was found that there was additive separation when fed to the engine, forming hydrobromic acid which attacked the valve seats. In May the British had made a decision to supply 100/150 containing less ethylene dibromide as additional spark plug maintenance was preferred to short engine life, a decision with which the 8th Air Force concurred.
I would say this a large gray area.
In summary the 8th USAAF appears to have used it for short periods of time but kept having technical difficulties.
They most certainly intended to change over completely.
First difficulty is the plugs fouling and lead deposits which they solved. The solution however turned out to be another problem.
Obviously, 100/130-grade fuel was used concurrently.
IIRC the original order dated July 44 directed that all stocks of 100/130-grade are to be used up before the conversion to 100/150 grade. The intention was to phase it out of the supply system.
When the units did use up there stocks and converted to 100/150 grade unforseen problems occurred a shortage of 100/130-grade occurred on the switchback.
Make sense?
All the best,
Crumpp
