Underbonnet foil

[Simpatico]

I'm stripping and repairing a couple of Elite bonnets.... and have a couple of queries about the tin foil layer.

1. Is it essential? 2 out of three of my bonnets have it, but the one that doesn't looks original..
2. Is it anything special conductivity-wise or just aluminium Bacofoil?
3. Does it have to be "earthed" to the chassis (there is a wire connected to the bonnet grille bolt, but how does that connecr to the foil?

[Lotus-e-Clan]

It helps stop HT radio interference and prevents electrostatic damage to the ignition amp etc (hence the earth).

... and as a secondary effect maybe it serves to dissipate heat evenly (esp from the exhaust side) which may otherwise damage the bonnet finish under extreme operational circumstances?

[Simpatico]

Ii goes under the standard bonnet foam (which I bought a few of cheaply in the recent factory sale, only to see SJ sportscars lowered theirs to the sale price, doh!)

I didn't immediately think of aluminium as a good electrical conductor, but Wikipedia says it is physics was never a key skill

[chrisw2811]

Aluminium is not necessarily the best conductor but for its density it it is pretty good, which is why a lot of high voltage overhead power lines and railway power distribution lines are made of aluminium. The radio ground plane under the headlining of my Excel is bacofoil and seems to work fine.

[Simpatico]

Bacofoil it is then, or turkey roast if budget permits