New vacuum gauge

[alanworland]

Sometime ago I made inlet manifolds for my sidevalve and these accommodate a pair of the original carburetors. This seems to work well enough giving unfathomable horsepower!
However I connected the manifold stubs together with a small ID pipe with a 'T' take off for a vacuum gauge which results in a pulsing gauge needle - it wrecked the gauge.
I picked up another gauge at an autojumble to replace the busted one but I am planning on fitting some sort of damper/chamber in the pipework before the gauge in an effort to smooth out the pulses, has anyone gone this route or is there a better way?
High accuracy is not required, I just don't want to wreck another gauge!



Alan

[Declan_Burns]

Alan,
When I did the testing with the PCV valve on the MG, I had the same issue with the needle wanting do go into orbit. Just stick a cigarette filter in the tubing as a damper and the problem is solved and the needle us steady. You can find them everywhere for free - even on the side of the road
Regards
Declan

[Monty-4]

Interesting, I have a vacuum gauge that is connected to a manifold/carb spacer on one side of a twin carb setup - no pulsing whatsoever. Perhaps it is more exposed to the turbulence when plugged directly to the manifold?

[alanworland]

Thanks for your replies, don't really understand why it should pulse and did consider just connecting it up to just one pair of cylinders but as both intake stubs are tapped it seemed a good idea to tap off of both?
I shall get hold of the nearest cigarette filter and give it a try! Not really bothered if it makes the gauge sluggish as long as it stops it getting broke.

Alan

[RobThomas]

Jet out of the carb of an old Fiat etc. Tiny little drilling in it removes the pulsing. I just shove it down the vac hose after filing it down to fit.