Special oil filler Necks

[andrea70]

Interesting to discover that early 911 SR/ST and 914/6 GT had different special oil filler necks ( the ones with Preschona valve attachment):

my Nos early 911's item: (normal dimension) - VIN 901 107 640 03



914/6 GT large dimension (thanks to wonderfoul Armando Serrano's Pelican 3d) - VIN 914 207 035 71



You'll find the large dimension hole on 911 only with the later Preschona valve type (typically on 2.5ST or RSR)

The good question is why different codes for 911 1968-1970 and for 916/6GT 1970.....

[andrea70]

thanks to dear friend Frank i have the reply!

for 911 it exists 2 types of early filler neck: one normal ( as mine) for rally/ short races, and one large (that he has) for long run races.

the difference between 911 and 914/6 necks lies in the angles of the tubes, because of course the 2 oil tanks are different!

thanks again Frank!

[mike curnow]

My 2 cents.
The smaller of the two has been around since the 911R, which was used for long and short races. The larger came on all the RSR cars from 1973 to 1975 along with a larger oil tank.The larger tank was good for better cooling, since it held more oil, and the bigger mouth was good just in general. The 914-6 GT, which I have never had, was used again for long and short races and I suspect the large opening was used for convenience and quick refills.

Mike Curnow