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View Full Version : To Developers: New engine settings for Merlin III at +12 lbs


Kwiatek
02-23-2011, 12:32 PM
When Cliffs of Dover is coming i wonder if 1C has detailed info about new engine settings for Spitfire MK1 +12 lbs with Melin III engine which was intruduced since using 100 octan fuel in engine Merlin III.

With lower octan fuel Merlin III maximum power was + 6 1/2 lbs. I found that most avaliable data claim that after using 100 Octan fuel Merlin III settings were +12 lbs - emergency power and +6 1/2 lbs for climbing power (nominal power) which isnt true.

I just put here document which show which engine settings were used in Merlin III at 100 Octan fuel :

http://i53.tinypic.com/r0p095.jpg

As we see such engine settings are similar to these one in Merlin XII using in Spitfire MK II.

So we should have for Merlin III engine at 100 octan fuel:

- emergency power ( take off) - +12 lbs
- climb power ( rated power) - + 9lbs
- crusing powe - +7 lbs

I think it is important information regarding Spitfire performacne expecially climb and maximum speed at different engine settings.

At spitfireperformacne site we have climb rate for Spitfire MK1 at 6 1/2 lbs 2600RPM :

http://www.spitfireperformance.com/n3171.html

We see that climb rate was 2810 ft/min - 2900 ft/min at low level ( 14-14.5 m/s).

So if we take new engine settings with 100 Octan fuel for climb power at 9 lbs 2850 RMP - climb rate would me much better - ab. 3000-3100 ft/min ( 15-15.5 m/s) and with emergency power at +12 lbs 3000 RPM it would be much more higher.

Being in the topic of engine settings and WW2 fighters planes performacne i just wonder if 1C has detailed info about BOB fighters performance and engine settings to make correct FM and performacne of these planes.

I know that these topic is not simple easy beacuse there are many various information about performance of these planes expecially Bf 109 E and Spitfire MK1.

I wonder also about engine settings for Db601A and 601Aa for 1940 year ( BoB era). There are also various information about maximum allowed ATA - some claim that Ata was restricted for only 1.3 Ata when full emergency power for DB 601 A was 1.42Ata ( 1.45 Ata for 601Aa).

I hope some from 1C would read these topic.

=GI=Joel
02-23-2011, 09:14 PM
Just spoke to Oleg:grin:
He said no problem. He will hold back on the release day to get this implemented for you. Oh and thanks for bring it to his attention.:grin:

JG53Frankyboy
02-23-2011, 09:33 PM
i strongly belive the Maddox team is full aware of this site
http://www.fourthfightergroup.com/eagles/spittest.html :D

so, if not at least the Spitfire Mk.II in CoD will have the 12lb/sq.in. boost, i would be very surprised !!
And there will be 3 flyable Mk.I versions too..

41Sqn_Banks
02-23-2011, 10:32 PM
Well, Kwiatek is not only talking about +12 boost. The document indicates that a Merlin III with 100 octane fuel has the same engine power (look at the mentions hp rating and compare with that of a Merlin XII here (http://www.spitfireperformance.com/spitfire-II.html)) and limitations as a Merlin XII.

However this document (http://www.spitfireperformance.com/dowding.pdf) doesn't support this. It states that 3.000 rpm and any boost over 6 1/4 is only allowed for 5 min for a Merlin II/III. "Climbing" power is by definition allowed for 30min or 1 hour. See the contradiction?

The main difference between a Merlin III and XII is the of 70/30% water/glycol coolant which allowed the higher power and limits of the Merlin XII. Maybe this engine was operated at with that coolant?

Kwiatek can you give some more information about the document? What is about and what is on the other 39 pages?

WTE_Galway
02-23-2011, 10:44 PM
Well 9 lb boost when climbing would make a substantial difference over 6.5 lb.

Biggs
02-23-2011, 11:38 PM
And there will be 3 flyable Mk.I versions too..

3?

I thought it was just the mkI (de havilland 2-pitch) and the mkI (Rotol constant speed)

JG53Frankyboy
02-24-2011, 12:40 AM
3?

I thought it was just the mkI (de havilland 2-pitch) and the mkI (Rotol constant speed)

some video of the last Kiev gameshow showed 3 Mk.I and the Mk.II
also 2 Hurricane Mk.I .
Also 109E-3 and -3/B.

swiss
02-24-2011, 02:32 AM
Just spoke to Oleg:grin:
He said no problem. He will hold back on the release day to get this implemented for you. Oh and thanks for bring it to his attention.:grin:

ROFLMAO! :grin:

Good one.

Kwiatek
02-24-2011, 07:12 PM
Just spoke to Oleg:grin:
He said no problem. He will hold back on the release day to get this implemented for you. Oh and thanks for bring it to his attention.:grin:

Well maby you should also speak with Oleg about slats in 109 and 110 so he could implement it before relase :P