Simple.....you can get methanol to flame in the pipes if retard your ignition point....Or even big overlap on the exhaust side w/ nitro....

BTDT,
there was this new TA/FC here in town being started for the first time.
The owner/driver wanted to make a couple of shakedown burnouts in the parking lot.
We don't know who put the fuel system together, but the crew chief goes to lite the motor. It wouldn't fire the first 2 tries.
3rd time is the charm and a huuuuuuuuuge flame shoots and stays out the right header. I mean huuuuuuuuuge and long lasting!
When it happened, we were all
but then later, we were

You may want to forge those pistons if you run nitro.

No No I wont be running nitro anytime soon , I was just dreaming before thinking . Which is something I do quite often.

I don't think a cast piston or rod is a great idea running on pop.

RE: Nitro flames at idle. Its the reverse of what you think. I can get two foot flames at idle when I lean the barrel valve. We run our car on 90% and it won't show flames until about 200' due to being rich at idle and at the hit of the throttle. Having a cackle car set up for flames and running that car in competition are two different animals.
Dave Hough