Additional Throttle return Springs???

[NTEL]

Just fitted three Weber DCNF carbs to the race car. These are each complete with a throttle return spring on a common linkage. Is there still a requirement to fit an additional spring as per the blue book?

[Carnage]

I have twin Weber 48's on mine, set out as you describe. Never had any bother.

[GreenV8S]

If you were to snip one of the springs, do all the throttles still close? If not, I'd expect a scrute to demand the extra spring.

[GC8]

The extra spring needs to be fitted on the link, surely; as opposed to on each individual throttle? Id still expect to have to fit this even if the other remaining return springs provided a degree of redundancy.

[dgb00]

Yep, you will. The scrutineers will pick it up and bk you for it. I've had long lectures about it in the past, along with threatens to not pass the car. Better to take the trouble and fit them, and it is a safety issue.

[NTEL]

Thanks for the advice chaps. Looks like I'll have to devise a way of doing it. (although, I did disconnect two of the three integral springs and one spring does operate all three carbs easily, so i suppose its a belt and braces job really)

[carl_w]

Presumably this doesn't apply for those of us with fly-by-wire throttles? I assume mine's just a rheostat.

[mat205125]

GreenV8S said:

If you were to snip one of the springs, do all the throttles still close? If not, I'd expect a scrute to demand the extra spring.

This would be the black and white letter of the rule if the scruitineer wanted to really make a point about it.

We've had similar discussions with scrutineers in the past on twin carb setups. In that instance he let us run, however insisted that we got it sorted .... Tip: When scrutineers "let you off" like this, actually go and do what you agreed to do, and they don't forget and CAN exclude you when you roll up next time.

I'd advise just fitting a spring per carb and be done with it .... A scrutineer may even pop the bonnet and think "Excellent! He read and understood that reg to the letter", and then not feel the need to detail/double check every part of the car, rather just the essentials.

[dgb00]

The point is that if for any reason the linkage should break, that all the carbs are still capable of closing. A pair of Webers jammed open once when I was driving (three pairs on the engine) - very interesting...

[TVR_owner]

Dave two springs on the linkage is what you need as a fail safe. One is acceptable if you've kept the spindle coil springs, but its not advisable.

[99hjhm]

TVR_owner said:

Dave two springs on the linkage is what you need as a fail safe. One is acceptable if you've kept the spindle coil springs, but its not advisable.

Correct.

[NTEL]

99hjhm said:

TVR_owner said:

Dave two springs on the linkage is what you need as a fail safe. One is acceptable if you've kept the spindle coil springs, but its not advisable.

Correct.

OK, Job sorted. I made a couple of brackets up from bits and pieces and fitted two return springs. Seems a bit of an over kill but should keep the bosses happy