A couple of questions reguarding Mixture, Boost & Pitch

[GunnyHighway]

Mixture Rich and weak (I understand it works on the carburetor), but: Rich in what?...Air?...Weak in what?...Air?

What are the "Boost cut out" and "Slow running cut out"?: Is it related to a turbo-compressor?... how does it work, what does it do to the engine?...Is there a more modern term for it?

Is the variable pitch of the screw can be related to gears in a car?...Fine = 1rst gear?....Coarse = 5th gear?

thank you for your help.

[Roblex]

Mixture is easily answered....don't touch it. There is no reason to alter the mixture unless you are a long way from home with very little fuel. Even then you would be unlikely to want to weaken the mixture as that would mean you would have to fly home at very low revs and throttle so would be a sitting duck if an enemy sees you.

Slow Running Cutout is for forcing the engines to stop when you are about to despawn. Some people just switch off the magnetos or just despawn without stopping the engines.

Boost Cutout Override, or BCO, is a confusing name for what most people simply call 'Boost'. The strange name comes from the fact that what you are actually doing is bypassing the safety mechanism that stops your engine running at a power level that will damage your engine if done for too long.

[ATAG_Dave]

Mixture Rich and weak (I understand it works on the carburetor), but: Rich in what?...Air?...Weak in what?...Air?

What are the "Boost cut out" and "Slow running cut out"?: Is it related to a turbo-compressor?... how does it work, what does it do to the engine?...Is there a more modern term for it?

Is the variable pitch of the screw can be related to gears in a car?...Fine = 1rst gear?....Coarse = 5th gear?

thank you for your help.

Rich = rich in fuel. weak = lean in fuel. As Roblex said you really dont want to be touching that (RAF fighters at least)

your analogy re pitch and car gears is broadly correct

Good luck :thumbsup:

[Baffin]

Mixture Rich and weak (I understand it works on the carburetor), but: Rich in what?...Air?...Weak in what?...Air?

What are the "Boost cut out" and "Slow running cut out"?: Is it related to a turbo-compressor?... how does it work, what does it do to the engine?...Is there a more modern term for it?

Is the variable pitch of the screw can be related to gears in a car?...Fine = 1rst gear?....Coarse = 5th gear?

thank you for your help.

1. Weak = Lean. Less fuel per unit of air. Burns hotter... Burns pistons ...may save fuel. Best left set to auto-rich in CLoD for all conditions.

2. Boost Cutout = Properly called boost cutout override (BCO). The Merlin engines automatically implement a boost cutout feature to prevent excessive pressure in the intake system. BCO (Throttle full forward through the red "gate") bypasses that protection and permits pressure up to the capacity of the supercharger. High pressure=heat=stress=failure.

3. Slow running cutout is the normal way to shut down a Merlin engine. First, the fuel cock from the tank is closed, then after about a minute (1 second in our simulator), the engine will start to run slow as it starves out. At this point, the pilot pulls and holds the Slow Run Cutout ring to stop the fuel/air mixture from flowing into the cylinders, preventing detonation due to the lean mixture. This quickly kills the engine. Finally, the magnetos are deenergized to complete engine shutdown.

4. Your simile is correct. Coarse pitch = high gear or overdrive. Fine pitch is low gear, with infinite settings in between if equipped with the ROTOL CSP. Only two gears are available with the older two speed props. :lecture:

[Roblex]

Sorry, I forgot to answer the 'Pitch' part of your question. I am going to answer specifically for RAF fighters as you asked about BCO which the LW don't have. This is my own take but others may quibble over the details.

Yes, it is like gears but think of 100% pitch as being something like 2nd or 3rd gear rather than 1st gear. It takes a while to get moving but eventually it starts giving you good torque for climbing and unlike first gear you could actually stay in that gear for while but you wont get full speed and it is stressing the engine.

Pitch 75-80% is like 4th gear. It will allow you to reach cruising speed and accelerate when needed but the fuel consumption is not optimal and take-off and steep climbs would be harder.

Pitch 50% is like 5th gear. It allows you to cruise efficiently but does not increase the top speed much and it wont accelerate very well.
Also bear in mind that a setting that does not accelerate well does not decelerate well either so this could make dogfighting more difficult.

For the above reasons my general advice would be to take off with 100% then after climbing out reduce the pitch to 75-80% or maybe 50% if you are settled into a long cruise and may need to conserve fuel. In a dogfight you may want to use 75% or even 100% (as long as you watch your temperatures) so you can accelerate , decelerate and climb well. In a long dive reduce the pitch to get best speed and stop the revs going too high (think of descending a long straight hill with no worries about speed limits).
When preparing to land, once you have slowed down to below 200mph, go to 100% pitch as this allows you better control of your speed ie maximum braking from the propellor drag and also quicker response if you need to add some more speed to avoid a stall or to abandon the landing and go around again.

Really though, in a car you don't think of gears in terms of 'In this situation I use this gear', you change the gear to keep the engine revs in the optimal rev range. You could slow down to 30 and stay in 5th gear but you change down because the revs are too low and the engine starts to struggle with gentle hills and wont accelerate. Similarly you could cruise at 50 in 3rd gear but you change up because the engine is running too fast and you might damage it if you keep it there. An airplane is slightly different from a car as you really aim to pretty much leave the throttle in one position and adjust the pitch to bring the revs to its optimal setting which for a merlin engine is around 2650-2750 (unless trying to save fuel or cool the engine at the expense of performance in which case you go for lower rpm)

I struggled for a while when I first started using full CEM settings in CLOD because some people would give advice in terms of 'Boost' and some in terms of 'RPM' and some in terms of 'Throttle%' and some in 'Pitch%' and I could not tie it all together :-| I hope this helps give you a basis for you to make your decisions on pitch & RPM.

[Baffin]

A final note:

The above discussions underscore the two main methods of using the Cliffs of Dover Simulator. One is a fantastic flight game with lots of fun at every turn in a competitive gaming environment. The other is a visually compelling simulation of actual WWII combat in an historical setting. In either case, the CLoD program is not perfect. Gamers must deal with mostly full realism settings, while vicarious Battle of Britain fighter jocks must accept the compromises necessary for an entertaining experience on an affordable PC.

Why say all of this? Because if you want to simulate historical military operations, you need to do some study of the actual manuals that the BoB pilots used for guidance. There will be no mention of "Rads 40%" or "prop 75%", etc., simply because these are not settings used at the time. Instead, you must figure out that GENERALLY the prop controls engine RPMs and the throttle controls engine intake manifold pressure, accurately called "Boost" pressure in the RAF Fighters. Purists will not even display the digital control data box on the screen. It's more difficult to learn, but once you figure it out, its no more difficult to fly than the computer provided digital numbers.

That being said, using all the digital input sources available in the game may be just what you're looking for. You spend less time babysitting a cranky engine design so you can concentrate on inflight tactics and techniques for blasting the bad guys. You don't really have to study anything because, as I think you know, there is a ton of good advice out there for getting your score up if that's what interests you. There's also a lot of good and bad opinion...

So, my recommendation is to figure out how you want to employ the CLoD software and see which works for you. Many of us combine elements of the two in order to attain our individual goals. You should feel free to do the same.
:flying2:

[Osprey]

I think this will all confuse the lad. It's not like car gears at all, and % is a nonsense hangover from the old game, why are people still using that? :recon:

Simply:
RAF types in the BOB used a Constant Speed Prop. This means that regardless of airspeed and engine power the RPM of your engine will remain constant. This is quite different from variable pitch (which is actually like a gearbox, a 'variomatic' gearbox) because that just sets prop pitch angle, so if you are going faster, the prop rotates faster and the RPM of the engine is higher. But this is in some of the German types in COD so won't worry about that.

Boost is power controlled with the throttle lever. The Merlin was restricted to 6.25lbs @ sea level to prevent shortening the engine life. Pilots could override this with the BCO, termed 'pulling the tit', and achieve 12lbs @ sea level (boost gauge only goes up to 8lbs). None of this changes the RPM (controlled by your pitch lever) but it will affect your speed. As you gain altitude the boost pressure falls off because the air is thinner, the drop from 12lbs starts at around 11,000ft for the Merlin, and by the time you reach 18,000ft it will give no benefit at all - this is the Full Throttle Height (FTH) of the machine, 6.25lbs.

Just use 3000 RPM for takeoff, 2600 for climbing and fighting, and 2200 to save fuel. You won't go much wrong with those whilst you learn the limits.

If you want further advice give me a shout, happy to talk you through it on Teamspeak, contact details in sig.