Old - Punk Technology Filter Restriction Guage/Decoker - edlithgow

Found a case of dialysis tubing sets dumped in a nearby field with some domestic junk. I'd guess someone on home dialysis died/was hospitalised and this was a house clearance.

I put a couple of #22 needles with about a 70 degree bend in them through a washer built up from inner-tube rubber under the air cleaner hold down butterfly.

The passenger side (blue) one runs into a bottle of fridge melt***er (I would normally use aircon condensate but its seasonally unavailable. Might have to distill for a while). The bottle breathes through an inline filter (referred to as a transducer filter in the dialysis literature IIRC). Dunno the specs of this filter but you can blow air through it.


The idea here is that this will suck water so over time it will come to indicate/record the maximum negative pressure generated within the air filter. At the same time it should do some decoking, adjustable by the frequency and amount of topping up.

The driver (red set) side is intended to serve as a real time manometer visible through the windscreen while driving and showing the current filter restriction. The set is bit short so I might have to join two together. The tape is unlikely to hold in the rain (dry season now) and there are likely to be ram or venturi effects causing errors, though these could be checked by disconnecting from the air cleaner.


If I can find or make a hole I might move this inside, but since its mostly for initial evaluation I may just drop it.


I thought of adding potassium permangenate to make the water level easier to see, but decided not to in case it got into the engine.

Not sure when I'll next be driving the car, but when I do I'll let y'all know why it doesn't work.

Bet you can hardly wait, eh?

Alternatively, you could tell me why it won't work now.

Edited by edlithgow on 01/01/2018 at 10:43

Old - Punk Technology Filter Restriction Guage/Decoker - edlithgow

Well, it either didn't work, or there's very little airfilter restriction.

Passenger side hardly budged when revved to about 3000 rpm. (didn't want to rev it higher than that without any load) and the driver side meniscus rose less than an inch revving the engine to climb a steep mountain road.

I suppose the narrow needle (perhaps narrowed futher by being bent through 70 degrees or so) could be damping out low-pressure transients.

I'll try adding extra filter restriction next time I drive it.

Old - Punk Technology Filter Restriction Guage/Decoker - edlithgow

I wrapped 4 layers of paper handtowel (continuous roll, no perforations) around the air filter and Lo, it sucks! (and that's a GOOD thing here)

Seems to be at about 4.5 inches. Don't need that much so I'll take about half the layers off next and see how that goes

The attempt at a manometer visible while driving sucked air, so I shut it off. I THINK this is perhaps because the dialysis tubing is a complex shape with that filter chamber thing in it.

A straight tube might work better.

Old - Punk Technology Filter Restriction Guage/Decoker - edlithgow


Trying to get a picture of the piston top down the plug hole. I used a small Christmas light style 12V incandescent bulb for illumination and an autofocus camera, which probably isn't the best setup.

LED Christmas lights (maybe the innards of one of those novelty illuminated balloons) or maybe a laser or a pen torch, and a manual focus camera might be better.

Nevertheless, I THINK it looked cleaner, though the p-icture isn't very clear. I don't have a comparable "before" picture, but given that it was running on, and I could scrape carbon off the piston top with a chopstick, I think it was probably coked.

So some circumstantial evidence that the decoker has done something.


Ask Honest John

Value my car