428 FE breathes Fire

[concobra]

I did not read through all the responses but I will share some thoughts

1. Over rich and retarded timing can contribute. But rare
2. Exhaust leak is more than likely the problem. This is always accompanied with a back fire. You did not write of a back fire though.
3. If you are running a holley carburetor this can occur. If the back float level is set high and you are braking hard. (That is what you are seeing when you mentioned seeing racing cars do this) The hard braking causes the fuel to slosh up against the metering block in the secondary float bowl. The fuel overwelhms the secondary circuit and spills out the booster venturies causing a super rich/flooding condition. This combined with an exhaust leak can cause your flaming issue. The fix is to simply lower the seconary floats level. I set mine about 1/4" below the sight hole. Double check your fuel curve on your plugs as this can lean out the secondary circuit.

I hope this helps

[donnieR32]

I had it running with the hood open and could CLEARLY feel exhaust escaping from that second exhaust port. Now it's a matter of figuring out the exhaust port size so I can get the correct gaskets.

[elmariachi]

Originally Posted by donnieR32

Maybe this is the culprit... this isn't the best picture, but you can sort of see the spacing.....

Sure looks like a header gasket leak on those plug wires. Your slip-fits look great so I'll bet the gaskets fix it. Be nice to get that heat and the fumes out of the engine bay too. I can highly recommend SCE Copper...8900 miles of hellish heat with cast iron heads and no leaks.

[donnieR32]

Originally Posted by elmariachi

Sure looks like a header gasket leak on those plug wires. Your slip-fits look great so I'll bet the gaskets fix it. Be nice to get that heat and the fumes out of the engine bay too. I can highly recommend SCE Copper...8900 miles of hellish heat with cast iron heads and no leaks.

My biggest dilemma is knowing the exhaust port sizes.....It's a pain in the ass to figure out online. Only way is to pull the headers, measure, then order. Remflex was nice enough to send my cardboard cut outs of all possible 428FE sizes.

[Mdman352]

Clearly all the black on the plug wires shows an exhaust leak. Call Summit and get the copper ones. have fun.