Vacuum delay valves

[SlowRider]

Recently commented to an independant garage that the Chim had a flat spot around 3,000 rpm. They fitted a vacuum delay valve saying the V8s need them.

Is this right? Seems odd that the car would have managed perfectly well for 4 years without one.

Cheers
SR

[simpo two]

Vacuum advance is the norm, surely - perhaps the gadget you mention counteracts this to some extent. I'll be interested to see what others say.

[GreenV8S]

They normally have this fitted from new but it is often removed subsequently because it can cause problems. There have been various discussions about this, for example www.pistonheads.com/gassing/topic.asp?t=43166&f=11&h=0&hw=vacuum

Removing it doesn't normally cause engine running problems, has the problem gone away now they have fitted the valve?

Cheers,
Peter Humphries (and a green V8S)