This is for cheapskates (and the hard of hearing).

My attempts to balance the air flow in the twin SU’s of my car have always ended in utter frustration. I can see a difference in the height of the carb pistons before I can detect any difference in the hissing sound. It appears my ears need tuning more than my carbs. I’ve even tried to amplify the sound and shield against background noise by fitting a funnel to the end of the listening tube and holding my ear in the wide end of the funnel (made me look like the doggie in the ‘His Masters Voice’ logo). That didn’t work either.

And I wasn’t going to spend money on an instrument to do what others claim to be able to do by just listening.

So, I played around with some ideas to make my own air flow indicator – purely for fun and not expecting too much to come of it. It turned out, however, that the very first one I put together worked so well that it has now become part of my toolbox. Very sensitive, and adjustable to cater for different engine speeds.

Here are some pictures:









Key components are the tube of a dropper (cost about $1) and a little 7mm ball which I carved from a wine cork. The dropper tube is of the plastic type. These are slightly tapered (to facilitate de-moulding during the manufacturing process, I think) – an essential feature for this kind of flow indicator. The rest basically consists of some PVC tubing off-cuts and other odds and ends found around the house.

Simplesimon