Another weekend, another conundrum it seems.

This time we were flying with two indentical aircraft with different engines, but essentially the same fuel (18% oil (roughly 3% castor) and no nitro.

I was fighting the dreaded NVA bubbles on 'new' 46fx and he was having lean runs with his Enya 40 ss. I should also point out that it was around 10°c and dry.

After a while I suggested he borrow some fuel from a friend (local store bought stuff, I'd say 10% nitro and probably straight klotz from the colour)
he got a nice COOL run with his enya and a much happier engine all round.

This seems a bit counter intuitive to me, I would have thought that 10% would have overcompressed the enya and made it run hot/like a dog. Turns out the opposite is true.

IT then begs the question, is the addition of small amounts, 5% or so of nitro a way of cooling the engine and allowing more fuel to pass through the motor, without adversely affecting the C/R and timing?