109 e3b against spitfire II

[Crumpp]

There is no such thing as a direct injection aircraft engine in General Aviation. All fuel injection is single point injection much like the Allied designs of WWII.

If an engine has bayonet probes in all cylinders, it is not unusual to see variations in CHT readings on fuel injected engines of 100o F between cylinders, and as much as 150ø F on engines with float-type carburetors.

With the latter, an important cause of the variation is
the kind of distribution of fuel and air to the individual cylinders.

Don’t be surprised to see variations in temperature between individual cylinders where there is a probe for every cylinder. It is fairly typical to see an average 100o F variation with fuel injection, and as much as 200o F variation with a float-type carburetor. The latter (carburetor) variation tends to be greater because fuel/air distribution is not as good
as with fuel injection.

In a direct injection engine, there is almost no variation in CHT or EGT between the cylinders.

It is that temperature variation that robs a single point fuel metering system of power.

http://www.costaricaaviation.com/fli...tions_rev1.pdf