Jorgen
A spot of research suggests that an octane molecule is about 0.5 nano metres is diameter (0.5e-9 metres), and I suspect that a hole size roughly 10x that would let them through, suggesting a 5nm size to retain petrol vapour. 1nm =3D 0.001 microns. I don't know what size would be needed to retain petrol as a liquid, since that would be governed by its surface tension - experiment would seem to be the best approach!
I don't know if Toyota have changed the fuel cap design on the 120 series, but on my 80 there are two vents:
#1, in the cap, is spring loaded (rubber seal) to prevent over-pressure escaping but will allow air in once a small degree of vacuum has formed.
#2, somewhere underneath, is the over-pressure vent.
Do they do it differently on the 120?
Christopher Bell
Devon, UK
1996 1HD-FT
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Hi Folks,
=A0
Does anybody know=A0how many microns=A0the largest round
Ventilation hole can be in a Petrol Cap without the fuel getting out?
=A0
Regards Jorgen
KDJ120=A0 UK
=A0
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