Skypilot,

Actually, I've designed just such a device. I tried it, a bug surfaced and am making a change. This will be used on a Norvel .15 and yes, a turbo plug will be used. This eliminates the possibility that the threads of a conventional plug might interfere with the results.

Two contra-pistons have been made, one with a trumpet shaped head for glow and one flat for use as a diesel. But in fact, both will be tried on both fuels to explore all possibilities.

I've been getting hints that compression changes affect the needles of glow opposite to that of diesel. If this can be established as fact, this might explain much when we have problems with our engines.

This experiment is going to get serious and will require a scientific approach to carry it out. Working on that now.

Some variables to consider.

Glow fuel content, as in nitro.
Diesel fuel content. Ether, kero, oil, Amsoil percentages. This is a biggie.
Plug heat ranges/brands.

A hundred combinations to fool with, record, mull over, conclusions to be drawn.

Fun AND work.

But that Enya. That must be new, I haven't kept up.

And hey, thanks for the tip on getting a diesel to smoke. I wonder if there might be an additive that would enhance the effect. I remember blowing a head gasket on my Corolla many years ago. Spectacular.

Say, would a bit of water added to our fuel help? Hurt? Do ANY thing?