RSO,


The various port timing numbers of an engine determine its behavior.

I.e. longer induction port, intake by-pass(es) and exhaust port timing (more degrees) will allow an engine to make more high RPM HP.
More modest numbers in these ports will make an engine more docile and easier to start, but lower on high-RPM power.

A longer blow-down period; the difference between the exhausts timing and the intake-bypass timing halved, if longer, will allow the engine to get more power boost ftom installing a tuned exhaust system...


Changing any of these numbers can be achieved only by machining the parts... Using a Dremel/other grinder on them, raising/dropping the sleeve, Etc..

The ignition timing in a glow engine is a function of several things; the compression ratio, the percentage of nitro in the fuel, the heat-range of the glow-plug and the load on the engine, are the less immediately changed contributing factors.


With all the above aspects considered given; the immediate control that the user has over ignition timing, is the mixture strength... Yes, the needles are the ignition timing control of the glow engine...

A leaner mixture will ignite faster and more easily than a colder, richer mixture.
Also, the flame propagation in a leaner mixture will be faster than in a richer mixture, so a leaner mixture will attain maximum combustion pressure, sooner than a richer mixture.


So, by turning the needles (both of them, each in its effective range), you are doing something that is akin to turning the distributor, in an older spark-ignition engine.

Closing the needle too far will not really cause the engine to self destruct due directly to a lack of lubrication, but rather from detonation and over-heating, caused by an over-advanced ignition (and maybe even a resultant lack of lubrication - burnt oil isn't a good lube...).

The damages to a lean-run glow engine will be alike to your car's engine after running with the distributor turned too far against its rotor's direction of rotation.