Last year I posted a message to the list seeking advice on why I was getting
oil based fumes in the cabin of my '72 TR6. No exhaust smoke was evident
but after driving the beast for a while I would get out of it smelling like
an oily rag.
Advice was shortcoming and I noted someone else post a similar request some
months later with, once again, little response. Well I've been chipping
away at the problem and the following applies to my situation. These
factors may or may not apply to others.
Factor 1 - ensure all your firewall holes are plugged - no rocket science
here. Also helps to quieten the beast.
Factor 2 - ensure your exhaust pipes terminate far enough outside the rear
valance so that the suction effect caused by the Kamm tail is reduced. Poor
sealing of the boot/trunk lid will allow the fumes to be sucked inside.
Factor 3 - resolve any engine/gearbox/OD oil leaks. Hah! I hear you say
these LBCs leak oil everywhere. So they might but try to minimise the leaks
because the oil will burn on the exhaust pipe.
Factor 4 - Worn valve guides play a major part. If your guides are getting
tired there is a good chance that oil are being sucked into the combustion
chambers or the exhaust ports. I had my head replaced with a reconditioned
PI head and this has dramatically reduced cabin fumes.
Factor 5 - Worn rings mean burnt oil but this is very evident by oil smoke
after a long period of idling or after deceleration. This is not as
insidious as the quite fumes that people may get.
I can safely say that attention to the detail above has resulted in no fumes
in my LBC.
John '72 TR6
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