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  #41  
Old 05-24-2012, 12:52 PM
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He has to cling to this, its all he has.
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  #42  
Old 05-24-2012, 04:11 PM
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Originally Posted by Crumpp View Post
No I think they tore up a lot of engines. In fact, I think it was to the point the Operations and Maintenance Chiefs expressed enough concern for Dowding to do something about it.
Dowding states that the the EBCO allows for 12lb boost for 5mins. I know you love the RR Merlin but would you really have us believe that this could be done with 87 octane fuel?

Last edited by Seadog; 05-24-2012 at 05:51 PM.
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  #43  
Old 05-24-2012, 05:00 PM
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A override for take-off is linked to extra rich mixture to preventing detonation.
Exactly. It was used to test the engine at altitude during service maintenance.

THAT IS WHY YOU HAVE PILOT ANECDOTES OF FLYING AT +16 LBS ON 87 OCTANE!

If they tested the engine to 10.5lbs then a low engineering safety factor of 1.6 yields 16.8lbs. That pilot who did that was extremely lucky his engine did not destroy itself from detonation.

Quote:
AIR MINISTRY
Air Publication 129
Revised November 1937
Royal Air Force
FLYING TRAINING MANUAL
Part I - LANDPLANES
Chap. II
Aero-engine speeds and boost pressures
66. (vi).(c). Aircraft should not be flow at the maximum conditions for level flight except in emergency, or when special operational conditions necessitate it.
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  #44  
Old 05-24-2012, 05:10 PM
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Originally Posted by Crumpp View Post

THAT IS WHY YOU HAVE PILOT ANECDOTES OF FLYING AT +16 LBS ON 87 OCTANE!
Where? Source please.

Last edited by fruitbat; 05-24-2012 at 05:18 PM.
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  #45  
Old 05-24-2012, 05:55 PM
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Originally Posted by Crumpp View Post
Exactly. It was used to test the engine at altitude during service maintenance.

THAT IS WHY YOU HAVE PILOT ANECDOTES OF FLYING AT +16 LBS ON 87 OCTANE!

If they tested the engine to 10.5lbs then a low engineering safety factor of 1.6 yields 16.8lbs. That pilot who did that was extremely lucky his engine did not destroy itself from detonation.

Weeeeeeeeeeeeee boooom...!

That's the sound of Crump's credibility cratering...

16lb boost with 87 octane...

Crump an RAF fanboy...who knew?
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  #46  
Old 05-24-2012, 06:35 PM
41Sqn_Banks 41Sqn_Banks is offline
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Originally Posted by Crumpp View Post
Exactly. It was used to test the engine at altitude during service maintenance.
As said: There is no "override" for Merlin II/III engines. There is no device for extra rich mixture for take-off. There is only a cut-out to disable the boost control. But this was not used for take-off, as maximum take-off boost is the regular rated boost of +6.25.

Quote:
THAT IS WHY YOU HAVE PILOT ANECDOTES OF FLYING AT +16 LBS ON 87 OCTANE!
Great, show us the anecdote.

Quote:
If they tested the engine to 10.5lbs then a low engineering safety factor of 1.6 yields 16.8lbs.
Once again you forgot atmospheric pressure in your calculation.
10.5lbs (+ 15.0) is 100%
16.0lbs (+ 15.0) is 121,56%
This is only a factor of 1.2; a factor of 1.6 would be +25.8lbs (+ 15.0).

Quote:
Quote:
AIR MINISTRY
Air Publication 129
Revised November 1937
Royal Air Force
FLYING TRAINING MANUAL
Part I - LANDPLANES
Chap. II
Aero-engine speeds and boost pressures
66. (vi).(c). Aircraft should not be flow at the maximum conditions for level flight except in emergency, or when special operational conditions necessitate it.
Exactly. Only in emergency or special operational conditions the aircraft is flow at the "maximum rpm/boost for level flight" (later called "all out") limits and not above.
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  #47  
Old 05-24-2012, 07:22 PM
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There is no device for extra rich mixture for take-off.
Read the description in AP129.
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  #48  
Old 05-24-2012, 07:34 PM
Seadog Seadog is offline
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Originally Posted by Crumpp View Post
Exactly. It was used to test the engine at altitude during service maintenance.

THAT IS WHY YOU HAVE PILOT ANECDOTES OF FLYING AT +16 LBS ON 87 OCTANE!

If they tested the engine to 10.5lbs then a low engineering safety factor of 1.6 yields 16.8lbs. That pilot who did that was extremely lucky his engine did not destroy itself from detonation.
This is the most hilarious post I've ever read anywhere bar none

I just can't believe that anyone could post something like this...even Kurfurst can't possibly agree with this!

The Me109e was limited to ~6lb boost with 87 octane fuel, and even late war with 100 octane the 109 could never pull more than ~12lb boost (even Kurfurst only claims ~14lbs), yet RAF fanboy Crumpp believes that the RR Merlin was so superior, in 1940, that it could pull 16lb boost with 87 octane fuel no less! And if it could pull 16lb boost with 87 octane and escape destruction, then 12lb boost would be no problem...

Next Crump will be asking for an 18lb mod for the 100 octane RAF fighters...

Crumpp's faith in UK technology seems to know no bounds...
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  #49  
Old 05-24-2012, 07:37 PM
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Once again you forgot atmospheric pressure in your calculation.
OOPS. Of course the British have to be different. Not any better, just different from everyone else in the world.

MAP - Manifold Absolute Pressure and it does not mean Manifold AIR pressure.

Good, I was thinking 1.6 is pushing it for the odds of somebody attempting it and surviving.

1.2 makes his story more credible, still very lucky but definately more credible that he was able to push it to +16lbs momentarily on 87 Octane.
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  #50  
Old 05-24-2012, 07:39 PM
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Originally Posted by Crumpp View Post
OOPS. Of course the British have to be different. Not any better, just different from everyone else in the world.

MAP - Manifold Absolute Pressure and it does not mean Manifold AIR pressure.

Good, I was thinking 1.6 is pushing it for the odds of somebody attempting it and surviving.

1.2 makes his story more credible, still very lucky but definately more credible that he was able to push it to +16lbs momentarily on 87 Octane.
"credible" ....
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