Weber Anti-Vibration Mounting Spacers

[Gopherit]

Got a problem in this area - like leaks from the carb/manifold interface?
Worth checking the mounting spacers that hold the o-rings. I am going through a +2 that is new to me, but is somewhat tatty and has been worked on by "experts" and non experts (the servo for instance has been mounted in the nose and the front intake blanked off).

When I took the carbs off I found the spacers were worn/corroded through in several places on 2 of the 4 spacers - see the attached pic of the worst one. Although this wasn't obvious from the outside the potential problems are not just leaks - you will notice that the inner diameter next to the holes has flattened out as the metal has disappeared. This is where I had the o-ring pop out when trying to set the ignition (that's another story as the dizzy advance curve was incorrect!

I'm now going to Misabs, as favoured by Rohan, although personally I don't like the fact that their ID is bigger and therefore creates an obvious step - but they are, I think, safer.

Paul R

[MickG]

Hi Paul,
I have found the same corrosion as you and replaced with original items available from QED.
http://qedmotorsport.co.uk/qed-shop/lotus-twin-cam/carb-ancillaries

Regards Mick G

[Pistacchio sprint 72]

They exist both in alloy and plastic!

[types26/36]

They exist both in alloy and plastic!

Plastic, Alloy, rubber....I've tried them all and still prefer the originals

[Jeff@Jae]

That spacer damage is usually the result of someone in the past over tightening the mountings (no float) and crushing the O rings solid.

[rgh0]

If your seeking power the best spacers are the ones from the last HC Excel which had a venturi shape built into them. They suit a 45 DCOE bore and dyno tests we have done show about a 3 hp improvement at the back wheels on a racing twin cam versus the plain spacers.

As I have said before the bonded versions (Misab spacers) guarantee the O-rings don't get sucked in and potentially jam the throttle open if the adjustment is wrong. I have only seen them in 45DCOE size so they leave a gap if used on a 40DCOE but in a road car that is not critical I believe and most competition twin cams use 45DCOE's.

The hole problem in the standard spacers are common as the metal between the 2 O-rings is very thin even when new.

cheers
Rohan

[Pistacchio sprint 72]

What is hc excel?

[richardcox_lotus]

Rohan is referring to the Lotus Excel with the HC (high compression) version of the 2.2 ltr engine, used in the SE version of the car.