Author Topic: RAF report on Tempest vs Typhoon, Spit 14, P-51-B, FW-190, Bf-109G, (Read 3928 times)

Crumpp · « **Reply #45 on:** December 11, 2004, 10:02:23 PM »

You were wrong Milo. You claimed only FW-190A3's were derated.

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Now tell me what was inferior about the 91PN fuel.

What did the USAAF normally use? 100 octane right?

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I asked for examples but to bad your overly inflated ego got in the way Crumpp.

BS lets call a spade a spade, Milo. You follow me around like a lapdog nipping at your heals. Every thread you contradict anything I say. And your wrong. Anyone can do a BBS search and see. Your tiresome Milo.

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It was common practice and allowed the Force to use up inferior grade Aviation fuel without damaging rated engines."

Did you read the P38 POH? What does it say about damaging the engine when using 91N?

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Derating: e.g. the Pilot Mnaul for the P-38H, J and L has an engine chart showing lower limits when operating with grade 91 fuel. So, derating did happen in the States too though in this case there were no mechanical changes, just lower MAP limits.

Take a wild guess why you have to use lower MAP? Because you will damage the motor if you used normal MAP, Maybe?

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So considering your claim the 801 was a finicky engine, one can expect a variation in their state of 'tune'.

Yes you can expect some variation as with any engine. The best results come from a factory trained mechanic. Why do you think the engine came as a power egg? Cowling, prop, and motor bolted on as one piece. When it came time for rebuild it was simply swapped out by the Geschwader and the motor sent to depot level maintenance. Sort of like NASCAR.

EB-104 was a rated motor. It developed about 100 Hp less than a Luftwaffe motor simply due to USAVgas.
Additionally EB-104 was weighted wrong so it climbed much better than a service FW-190 but because of the Hp did not go as fast on the deck.

Crumpp

KurfÃ¼rst · « **Reply #46 on:** December 12, 2004, 05:18:20 AM »

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Originally posted by Crumpp
This same report used to be up on a noted Spitfire website. It was removed from that sight and I can't help but wonder if it was not done so because they realized this.

`So many more good examples of such 'filtering' of information on that site, Crumpp.

Angus · « **Reply #47 on:** December 12, 2004, 11:43:52 AM »

Ummm...which site?
Can you post URL?

Anyway, if they had something that was false or full of errors, I can not see why not to remove it.

Am explanation would be better though.

Crumpp · « **Reply #48 on:** December 12, 2004, 12:10:00 PM »

Mike Williams Spitfire site.

Crumpp

Angus · « **Reply #49 on:** December 12, 2004, 06:28:43 PM »

Ok.
What was removed?
I am in the dark here.
Oh, the URL?

Crumpp · « **Reply #50 on:** December 12, 2004, 07:42:44 PM »

Roger the URL. This report was up on his website for a few weeks. It was suddenly removed.

Why, I don't know.

Crumpp

MiloMorai · « **Reply #51 on:** December 12, 2004, 08:57:28 PM »

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Originally posted by Kurfürst
"In service the Tempest was raised to 11 lbs, 2850 rpm, then possibly to 13 lbs."

Sources and references ?

Flying Officer Ronald Dennis, a NZer with 56 Sqd RAF.

"All our a/c were fitted with Rotol airscrews when the maximum rpm were increased from 3850 from 3700 and the boost to 13lb from 11lb."

This being mid 1944 during the V-1 terror bombings.

There is also Roland Beamont using 150PN fuel during this time and achieving 415mph IAS @ 500ft. His Wing then using 150PN fuel.

MiloMorai · « **Reply #52 on:** December 12, 2004, 10:19:53 PM »

The P-38 was NOT derated as the 190A-3 was. The P-38 was restricted to what boost it could use with a lower, NOT inferior, PN fuel. The A-3 was derated because of reliability problems. When a higher PN fuel was available the Allisons could use it.

There is a definate difference in 'derated' and 'restricted'. You do have a real problem understanding the difference Crumpp.

quote: EB-104 was a rated motor. It developed about 100 Hp less than a Luftwaffe motor simply due to USAVgas.

So American 100PN fuel was not as good as German C3, 95PN, fuel. OK.

Crumpp · « **Reply #53 on:** December 12, 2004, 10:58:53 PM »

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The P-38 was NOT derated as the 190A-3 was. The P-38 was restricted to what boost it could use with a lower, NOT inferior, PN fuel. The A-3 was derated because of reliability problems. When a higher PN fuel was available the Allisons could use it.

Nice bait and switch Milo. Show me where I claim the P 38F in that trial is derated?

The P 38 could be de rated to run 91N fuel.

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So American 100PN fuel was not as good as German C3, 95PN, fuel. OK.

Ask Mr Goodwrench. It's not about better, it's about different. C3 had a very high lead, aromatic, and iso-parafin content. Go run unleaded gas in an engine designed for leaded gas and see what happens to your valves. Had that problem with my Harley in Europe because of their gasoline. Call a Harley dealer and ask for an unleaded conversion kit, they will sell you one. I needed additives to even run it and it did not perform as well. Guys a lot smarter than you on WWII aircraft engines have looked at that curve, the composition of C3, and agree on the cause why the Hp was off.

Crumpp

MiloMorai · « **Reply #54 on:** December 12, 2004, 11:36:40 PM »

About derating

quote: Was nice enough to chime in as well correcting Milo.

quote: Take a wild guess why you have to use lower MAP? Because you will damage the motor if you used normal MAP, Maybe?

Here you are saying the P-38 was derated. Has nothing to do with the P-38 trial.

You still are confused about derated and restricted. Why am I not surprised?

I don't need a conversion kit as me scoot came from the factory already setup to run on unleaded fuel.

Hogs have been using unleaded fuel for years.

Purzel · « **Reply #55 on:** December 13, 2004, 04:26:28 AM »

Why don't you two marry?

Angus · « **Reply #56 on:** December 13, 2004, 05:09:00 AM »

I think they are

MiloMorai · « **Reply #57 on:** December 13, 2004, 05:12:41 AM »

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Originally posted by Angus
I think they are

That is not nice Angus.

And here I was going to suggest that Crumpp go visit you, so that your fertilzer bill could be lowered.

Crumpp · « **Reply #58 on:** December 13, 2004, 06:32:26 AM »

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Here you are saying the P-38 was derated. Has nothing to do with the P-38 trial.

Your Splitting hairs, Milo.

It was no longer rated to use higher manifold pressures. That is de-rating and de-rating is restricting.

All engines are different since you seem to have forgotten in your eagerness to find fault.

Sometimes it's as simple as don't move the throttle past this point. Others it requires some tinkering and work on the motor.

My Harley had to have the valves replaced to run unleaded gas without additives.

Crumpp

MiloMorai · « **Reply #59 on:** December 13, 2004, 06:54:03 AM »

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Originally posted by Crumpp
Your Splitting hairs, Milo.

You would think so. You do have problems with your choice of words.

It was no longer rated to use higher manifold pressures. That is de-rating and de-rating is restricting.

It is an operational restriction since when a higher PN fuel was available it could use it, unlike the Fw which was derated due to reliability problems and could not increase its boost pressure. When the reliabilty problem had been fixed, the derating was lifted.

Crumpp