C3 Yates on AU2

[JamieA]

Did you have the V8sc camshaft in it also?

Those Camshafts are very ordinary down low, and probably not suitable for street driving. Those cams will cause that sort of popping and missfiring <2500 rpm...

On the V8sc I was playing with, we had many airbox fires, but generally it was when the car was at low RPM and had reasonable amounts of throttle, such as being on the pit speed limiter.

The driver used to make the fire go out by turning the limiter off and giving it a rev, and sucking the fire into the engine... Seemed to work ok, but a few other teams had the fire get out of control, so you cetainly wouldnt be the first.

With standard camshaft, and lower injectors, it shouldnt be a problem like that.

I really dont think that wasted spark had any influence on the fire. Having one coil fire into cylinder with the exhaust valve open, and exhaust gasses in the cylinder shouldnt cause that type of issue.

-Jamie

[Sean]

What/whose manifold is it? A local guy here did/does carbon trumpets for many teams, he may have a plug.

[Blu302]

The camshaft was aftermarket, suited to the original GT40P heads, intake and exhaust. The change from hydraulic to solid lifters increased the overlap markedly.

I'm not sure of the manifold maker, but it came 2nd hand from Cragsted in Brisbane.

I'm going to rebuild the engine with aluminium/non-fire supporting trumpets and possibly mount the injectors after the butterflies if there is enough room.

[Holmz]

Once you get a fire on the outside of the trumpets then I doubt that the alloy would do much better than the CF with the injectors spraying and the all that air available.

You should be right with the injectors down low.
If you keep the trumpets in an airbox then I think that could also help to limit the flames, but there are also stories of airbox fires with high injection.
The other benefit is that the air is filtered and likely cooler and more dense air if you duct it in from outside the engine bay.

[Blu302]

I was part way to making an enclosed airbox for it all. I had already dropped the radiator 75mm to allow for over the radiator air flow. During testing, the air temp was around 25-30DegC. When stopped/idling they shot to 75+DegC. Never seemed to bother it otherwise.