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#1 Carburretor brass tops
Posted: Mon Mar 21, 2016 4:02 pm
by Gfhug
My S2 has brass caps on the carbs not the later black plastic knurled versions. Won't pass scrutiny on a concours check, but are the brass ones common enough just to have been fitted sometime during eg engine overhaul or should I put them up for sale at an inflated price for early S1 owners to fight over?
Geoff
#2
Posted: Mon Mar 21, 2016 4:16 pm
by PeterCrespin
The latter, with a thousand pounds reserve, because Stirling Moss's shadow once fell on them through the louvres of the 3.8 donor.
Those who live by inflation shall be inflated...
#3
Posted: Mon Mar 21, 2016 4:51 pm
by Heuer
If they are original to the 3.8 they will have an 'O' stamped on the cap top. Reproductions do not have it nor do non-E-Type dampers.
#4 Brass tops
Posted: Mon Mar 21, 2016 5:11 pm
by cactusman
Had to rush out and peer at my brass tops!! All three have O stamped in the top!!
Unless you are into concourse or need the cash i would keep em as they look so much better than the plastic ones. Bit of brasso....lovely.
I have no idea how common or otherwise they are. Wise heads on here will know.
#5
Posted: Mon Mar 21, 2016 5:28 pm
by Gfhug
No, Peter, it was Norman Dewis's shadow!
Looking at Clausager's book the 'O' isn't to be seen, maybe they've been polished with Brasso too often?
#6
Posted: Mon Mar 21, 2016 5:29 pm
by Simon P
'O' for 'Original'?

#7 Carburettor tops.
Posted: Mon Mar 21, 2016 5:53 pm
by cactusman
Obviously mine had have brasso free periods then! All shiney now. Maybe a hint of Jackie Stewart's shadow but I can't be certain....lol..
Maybe the Clausager ones are copies....
#8
Posted: Mon Mar 21, 2016 6:03 pm
by Gfhug
Now we need Heuer to tell us where to find the reproductions then with the aid of a letter stamp they could be made to look pretty much like the originals (but not be fakes!)
#9
Posted: Mon Mar 21, 2016 6:52 pm
by Heuer
The "O" marked SU damper caps had their pistons reduced in length from .378" to .308". This modification allowed the carburettor pistons to lift more freely with noted improvements in acceleration. The SU part number for the modified damper cap was AUC8114. Earlier caps may be modified by machining .070" off the pistons.

#10
Posted: Tue Mar 22, 2016 7:57 am
by ALAN COCHRANE
Silly question time-do you measure the damper length with the cap attached or not?
Alan
#11
Posted: Tue Mar 22, 2016 2:15 pm
by christopher storey
Alan : I think it's the brass piston length that is referred to . The overall length of damper and cap is far more than .378 inches
#12
Posted: Tue Mar 22, 2016 2:15 pm
by Heuer
Correct.
#13
Posted: Tue Mar 22, 2016 3:59 pm
by ALAN COCHRANE
Thanks Christopher, that's what I thought. I'd check the one's on the car but there are two problems-
1. They are wrongly fitted with the black plastic tops and
2. I'm in the French Alps enjoying my second favourite pass time-skiing.
I'm assuming mine are the correct length despite them being the wrong type but I'll check them on my return.
Does anyone sell reproductions with the "O" stamped on them.
Alan
#14
Posted: Tue Mar 22, 2016 5:03 pm
by Heuer
Not as far as I am aware. The car will still run with the longer versions so unless you are going racing ..........
#15
Posted: Tue Mar 22, 2016 6:22 pm
by ALAN COCHRANE
Christopher
I've realised now that it was a very silly question. Even more so since I've had the dash pot Pistons out many times recently. I think I've had too much sun today.
I suppose you could use a grinding stone to remove the 70 thou if you could actually be bothered!
Or just make up your own reproduction with brass tops and a letter punch.