Erich Hartmann's Bf109K

[Nick Hector]

Originally Posted by gaupe75

C3 and B4 is the fuel type, C3 is 100 oktan and B4 is 87 oktan. B4 was more often marked with 87, instead of B4.

Respectfully, I disagree with you slightly: C3 is usually given as 96 Octane. Additionally, for Michael/Knusel's interest J2 octane triangle denotes Kerosene for Me262 jet engines.

[Nick Hector]

Originally Posted by knusel

Can you tell me what "C3 triangles" are ?

Michael,
have a look at a photo or profile of (for the purposes of example) the left side of a Messerschmitt 109.

If you are looking at an Me109E, G or K, you should see a little painted yellow/orange/reddish orange triangle high up on the fuselage side. Typically just a above the fuselage code number and above left of the balkenkreuz. On an F, it will be on the side of the cockpit. This is the plane's octane level/fuel-type triangle.

(Unless you are looking at a photo where it has been overpainted for camouflage purposes of course...)

Inside that number will be any of the following: B4 or 87, 96 or C3, or 100.
As stated elsewhere: B4 is code for 87 Octane and C3 is code for 96 Octane but sometimes, as demonstrated, just the octane level was painted there.
It was intended to tell the mechanics and ground personnel what fuel the aeroplane should be serviced with.

Hope that helps. If you have trouble finding what I am referring to, we can perhaps decide on a book that both you and I have in our collections and I can then refer you to a specific page with an illustration that shows a good view of what we are talking about here.

Nick

[Denniss]

C3 was specified as 100 Oktan per german testing method. Allied testing method was different and usually gives 96-97 octane rating.
Fuel composition was changed several times but AFAIR retained the 100 Oktan rating.
I would be interested to know of a possible use of fuel triangles with 96 instead of 100.
http://falkeeins.blogspot.de/2009/12...3n-weisse.html

[Nick Hector]

Originally Posted by Denniss

C3 was specified as 100 Oktan per german testing method. Allied testing method was different and usually gives 96-97 octane rating.
Fuel composition was changed several times but AFAIR retained the 100 Oktan rating.
I would be interested to know of a possible use of fuel triangles with 96 instead of 100.
http://falkeeins.blogspot.de/2009/12...3n-weisse.html

Interesting, Denniss. This could explain some discrepancies I have seen....

[gaupe75]

Originally Posted by Nick Hector

Respectfully, I disagree with you slightly: C3 is usually given as 96 Octane. Additionally, for Michael/Knusel's interest J2 octane triangle denotes Kerosene for Me262 jet engines.

European method of octane rating is RON and american is MON.
https://en.wikipedia.org/wiki/Octane_rating

As Germany had to create most of their fuel synthetically, they had problems creating the same premium fuel as the allies, and that's where the allies were able to get a edge on the germans.

On jet-engines, the fuel is more like diesel and kerosene, which were a lot easier to produce. This was also a reason for getting jets into production.

[Kutscha]

Denniss

[Nick Hector]

Nice one, Kutscha

[gaupe75]

Originally Posted by Kutscha

Denniss

Also shows the origin of the Gallandpanzer

[knusel]

...is a "Gallandpanzer" some form of armour plate ?

Michael

[Juha]

It is the armoured glass behind pilot's head.

Juha