Oil filter assy on XJS etc !

Hello Richard and all others,

finally I have rebuilt my original E Type with new pistons and liners, all valves etc... = the really big thing!!! The XJR-S engine had a failure and I could send it back and get back my money...

Now my E Type V12 Roadster is still at my mechanic - we are converting the car to 6 Weber carbs with the "sausage" style foam air filters from Ramflo.
I have tried to follow all experts advices: lowering the engine (engine mountings), putting shims to the hood to gain clearance and AIR under the bonnet. I have changed the "poor working" retard vacuum unit from E Type V12 and fit the advance vacuum unit form XJ-S H.E. together with the DAB113HE distributor conversion kit from SNG Barratt. But the car still missfires sometimes when starting and accelerating. And today happened what I hope would never happen: one carb missfired and its foam air filter fired!! My mechanic immediately could extinguish the fire and we cannot understand how the foam air filter material is NOT fire resistant or incombustible!!!!! Now my mechanic will fit an air mesh filter made of 2 or 3 coatings or layers of a colander or sieve metal material that filters the air, but cannot catch fire. (I hope you understand my english...)
My mechanic wants me to ask the experts or people with experience in Weber V12 conversion how to avoid the miss firing: should we try even more ignition advance? Because at around 30 degrees of advance the missfiring never happens, but so much advance is not normal. Change spark plugs, try with another distributor cap and rotor, even other spark leads? Please give me ideas or advice.
This was a shock for me.....
Thank you and best regards from Valencia
Carlos