Originally Posted by
hsukaria
what if he's using low/no nitro and a super cold glowplug? theoretically speaking.
Originally Posted by
SrTelemaster150
Gasoline use in a spark ignition air cooled engine is limited to about 9.5:1 CR to avoid detonation. That is how they are getting gas to fire W/a glow plug. Basically what you then have is (somewhat) controlled pre-ignition.
Please read my post above & note that I specifically referenced "spark ignition".
I have no interest in discussing the ludicrous practice of trying to convert a gas engine W/an efficient CDI system into a GI gas conundrum.
What's the point? Convert to a crude inefficient glow ignition set-up to save what, 4oz of weight?
Glow ignition has its place in small airframes were there isn't room for an ignition module & the weight might be a penalty. That's a pretty small airframe & the cost of what little bit of glow fuel an engine of that size would burn would be small.
In a gas fuel GI engine, the compression ratio would have to be high because, as I also stated, the engine would be operating on "somewhat controlled pre-ignition".
Methanol on the other hand can tolerate higher compression in a CDI fired engine because it resists detonation better than pump gas.