Complex Engine Management / Oil on window ?

[reflected]

As soon as I turn on the engine temperature effects, my engine dies no matter what. I can't fly any of the Spitfires above 160-180 mph.

even if the oil and rad temps are ok. Not to mentino that as soon as I set the prop to fine pitch it overrevs the engine which dies. Inconcievable...

[tintifaxl]

One thing I notices: On your screen shot the prop pitch is all the way down, so the engines struggles at low rpm to drive the prop thus overheating it quickly.

[jrg]

here is a nice video about the overreving problem (it's beacause of the time needed for the blades to reach the new angle) :

http://www.youtube.com/watch?v=psYL7...112BDB5C43E0E3

As tintifaxl said check that your mixture lever is on the rich position (the lean position is for high alt cruise)
Move the throttle very slowly to avoid overreving and keep the boost needle below +4.
Avoid negative G.

[Ivan Fooker]

Prop Pitch
As we already have a very interesdting thread here, would it be possible to sort the prop pitch out here?

In theoretics i would say the prop pitch is similar to a gear in a car.
But i still dint find an effective way to use it properly in a Bf109.
So could someone explain when should i why set the prop pitch to what position.
I read the manualö and the few line about the prop pitch ,nevertheless i am sure this can´t be all.

[BlackbusheFlyer]

It is like a gear change, capable of biting more air as the air thins with altitude. Typically you reduce prop speed shortly after takeoff in the climb, recommend bringing it back to around 2,600RPM. As you reach cruise altitude you can then bring it back to around 2,300-2,400. In combat I believe most pilots set their RPM to 2,600 prior to entering combat.. slaming it forward will mean that you run the risk of over-revving the prop in a combat dive.

When diving, keep an eye on your RPM, normal practice is to make sure you reduce your manifold pressure (or boost) even in an accelerated dive to manage the prop.

[jrg]

Hi Ivan, check this link: http://www.shockwaveproductions.com/store/solo/bf109/ scroll down the page to find the engine limitations characteristics (they're for the 109e-4 but ok for the E-3).


There is 3 kinds of designs: Fixed pitch propeller, constant speed propeller, and variable pitch propeller.

- In the first one the blades of the propeller have a fixed angle, so increasing speed or throttle increase RPM. (eg some spits, the Tiger Moth)

- The CSP: (eg: some spits)
With a constant speed propeller the CSU (constant speed unit) adjust the angle of the blades in order to keep a certain RPM, if your speed increase or decrease or if you change the throttle position, the blades angles will be automatically adjusted by the mechanism to keep the rpm at the determined speed (I simplify, if you want more explanations don't bother to ask). So for example if you set your rpm to 3000, the rpm will not change with your speed (simplified again^^).

- The VPP: (eg. the 109)
In a variable pitch propeller (yes the CSP is also a variable pitch prop, but here there is no CSU, I hope I'm not too confusing, tell me if needed. The bf109 uses a VPP) you adjust directly the angle of the blades, the rpm will stay constant only if your speed and the throttle settings are stable (and i think altitude too). If you accelerate, the rpm will increase, because the angle of the blades will not adjust itself, (imagine that you are blowing with differents strenghts onto a small windmill like the ones for children) so you have to reduce the lever (which in fact increase the angle of the blades) to reduce rpm. If you are slowing down, you must reduce the angle (pushing the lever) to keep your desired RPM, wheras a CSP (constant speed propeller) will adjust the angle to maintain the same RPM on it's own.

The settings for cruise dive, military power (see the link) are a combination of RPM and Manifold pressure/Boost (the gauge in ATA). Thoses settings are defined by the manufacturer of the engine as the best settings for the purpose. For example if you want the max power see the charts and set your MP to 1.3ata and your rpm at 2400. Increasing the rpm in this case above 2400rpm will only shorten engine life and reduce speed and acceleration, because 2400 is already the best combination for this task.

Don't think too mutch about cars because the comparison can be confusing, yes gears in cars and propeller pitch in aviation serves the same function (make an efficient use of the engine), but they work differenly, in the car you have only 5gears maybe, but in the plane you can adjust rpm with a full range between 0 to 2400 for the 109 (above 2500 is like the redline in your car.)

When you dive the procedure in the 109 was to throttle down and reduce the prop pitch at minimum, (see the manual in the il2 COD folder) take care of the temps, they could drop sharply.

Generally speking, a variable pitch prop is used to find the best thrust to drag ratio, because a propeller cause a lot of drag (i should say a huge amount of drag).

Finally if you don't have complete tables of performances for a plane try at least to find the max admissible rpm (besst power) on a document or internet and use the procedure described below to find a suitable cruise setting combination:

For cruising adjust the throttle to attain your desired speed (eg 200mph) and then reduce the rpm until you can no longer maintain this speed, the lowest rpm at which you can maintain the desired speed will be the best setting. When reducing rpm (if your manifold pressure is not on max but on a reasonable setting for cruise) your plane will accelerate, this is because the thrust to drag ratio will be better, so in order to keep the speed at eg. 200mph you will have to reduce the throttle. Once the trhrottle is reduced repeat the operations as long as you can maintain your desired speed. Here you see what's the use of the prop pitch = making the best use of the engine power, reducing consumption and wear that's great don't you think! .

A last thing, the normal procedure is to increase rpm before increasing throttle, and to reduce throttle before decreasing rpm. This is to avoid detonations in the engine.

[klem]

Originally Posted by Derinahon

Can anyone give similar advice for the Hurricane? Oil and water temps, plus optimum RPM and prop pitch? I'm just getting into CEM and I can't figure out how to keep the engine happy. At anything other than level flight I normally get black smoke and red flame pouring from the engine. I can adjust prop pitch and throttle to calm it, but I'm just guessing really!

With temperature effects my engine likely wouldn't last very long

We have a problem because the Hurricane (and Spitfire) mixture outputs are reversed to what they should be.
Engine Start:
Set mixture to RICH in cockpit.
Be aware that currently the mixture selection is reversed in the cockpit, RICH = WEAK and vice versa. On the DH prop Hurricane move the mixture lever all the way forward until it is fixed when it will be all the way back. On the Rotol Hurricane, closing the Throttle also closes the Mixture to RICH, which is what it should do on both Hurris. But remember RICH is in fact LEAN atm so with the Rotol move the throttle forward to just clear the START label then move the mixture up to just behind it, thats as RICH as you'll get without over-opening the throttle for startup. When running, handle the Rotol Hurri throttle opening carefully, moving the mixture lever forward behind the advancing throttle as much as engine running will allow. This should all go away once the problem has been fixed. See
http://forum.1cpublishing.eu/showpos...70&postcount=5

Temps for takeoff:
Oil temp: min 15'C
Coolant temp: min 60'C (according to Pilots notes)

Open Radiator until you are in a position to manage the engine temp with it (70C - 90C, max 105C)

Takeoff prop is usually 3000 rpm, max boost. Climbout around 2600 with boost reduced around 4lbs. Combat in the region of 2600-2800. Cruise anywhere from 2000-2400, typically boost 0. These are from memory of the pilots notes but they should help.

[Rattlehead]

I'm also getting that shaking syndrome in the 109. It's an intermittent but permanent shaking and sometimes it eases off and sometimes it's really bad.

The only way I can make it stop is running the engine at full throttle. The prop pitch doesn't seem to matter. I've tried all settings of prop pitch but the shaking remains.
Radiator and oil radiator are open; sometimes I close the engine radiator a little but nothing I do seems to stop the shaking, except again if I run the aircraft at full throttle. Temperatures are normal. It's wierd.

I also have an info box open that shows engine damage, but according to the game I have no engine damage. (?)

[skouras]

Originally Posted by jrg

Hi Ivan, check this link: http://www.shockwaveproductions.com/store/solo/bf109/ scroll down the page to find the engine limitations characteristics (they're for the 109e-4 but ok for the E-3).


There is 3 kinds of designs: Fixed pitch propeller, constant speed propeller, and variable pitch propeller.

- In the first one the blades of the propeller have a fixed angle, so increasing speed or throttle increase RPM. (eg some spits, the Tiger Moth)

- The CSP: (eg: some spits)
With a constant speed propeller the CSU (constant speed unit) adjust the angle of the blades in order to keep a certain RPM, if your speed increase or decrease or if you change the throttle position, the blades angles will be automatically adjusted by the mechanism to keep the rpm at the determined speed (I simplify, if you want more explanations don't bother to ask). So for example if you set your rpm to 3000, the rpm will not change with your speed (simplified again^^).

- The VPP: (eg. the 109)
In a variable pitch propeller (yes the CSP is also a variable pitch prop, but here there is no CSU, I hope I'm not too confusing, tell me if needed. The bf109 uses a VPP) you adjust directly the angle of the blades, the rpm will stay constant only if your speed and the throttle settings are stable (and i think altitude too). If you accelerate, the rpm will increase, because the angle of the blades will not adjust itself, (imagine that you are blowing with differents strenghts onto a small windmill like the ones for children) so you have to reduce the lever (which in fact increase the angle of the blades) to reduce rpm. If you are slowing down, you must reduce the angle (pushing the lever) to keep your desired RPM, wheras a CSP (constant speed propeller) will adjust the angle to maintain the same RPM on it's own.

The settings for cruise dive, military power (see the link) are a combination of RPM and Manifold pressure/Boost (the gauge in ATA). Thoses settings are defined by the manufacturer of the engine as the best settings for the purpose. For example if you want the max power see the charts and set your MP to 1.3ata and your rpm at 2400. Increasing the rpm in this case above 2400rpm will only shorten engine life and reduce speed and acceleration, because 2400 is already the best combination for this task.

Don't think too mutch about cars because the comparison can be confusing, yes gears in cars and propeller pitch in aviation serves the same function (make an efficient use of the engine), but they work differenly, in the car you have only 5gears maybe, but in the plane you can adjust rpm with a full range between 0 to 2400 for the 109 (above 2500 is like the redline in your car.)

When you dive the procedure in the 109 was to throttle down and reduce the prop pitch at minimum, (see the manual in the il2 COD folder) take care of the temps, they could drop sharply.

Generally speking, a variable pitch prop is used to find the best thrust to drag ratio, because a propeller cause a lot of drag (i should say a huge amount of drag).

Finally if you don't have complete tables of performances for a plane try at least to find the max admissible rpm (besst power) on a document or internet and use the procedure described below to find a suitable cruise setting combination:

For cruising adjust the throttle to attain your desired speed (eg 200mph) and then reduce the rpm until you can no longer maintain this speed, the lowest rpm at which you can maintain the desired speed will be the best setting. When reducing rpm (if your manifold pressure is not on max but on a reasonable setting for cruise) your plane will accelerate, this is because the thrust to drag ratio will be better, so in order to keep the speed at eg. 200mph you will have to reduce the throttle. Once the trhrottle is reduced repeat the operations as long as you can maintain your desired speed. Here you see what's the use of the prop pitch = making the best use of the engine power, reducing consumption and wear that's great don't you think! .

A last thing, the normal procedure is to increase rpm before increasing throttle, and to reduce throttle before decreasing rpm. This is to avoid detonations in the engine.

excellent
exactly what i have in mind

[jrg]

This is strange Rattlehead, I've noticed some vibrations too with the 109, it seems bounded by a bad engine management but I'm not sure. I say that because since I take care of my engine, the plane dosen't shake as mutch.