I'd like to share some of my improvenets. I2F inspired me to make this reed valve thing.
I decided to try a little thing to improve crankcase vacuum in my car. The rest is in the pictures, I can share my technical drawings if anyone needs them.

Machined from polyamide - good stuff, pretty cheap and from what I'm told nice to turn


60x3 aluminium alloy pipe


valve from a 2-stroke scooter










Obviously I could only test it without any load on the engine. This is at idle. It's hard to say how it behaves while actually driving under some load and I didn't have enought time to feel any differences. At the very least it does no harm so I'll keep using it



As for the exhaust - I always had problems with the crossbox/swan neck joint leaking after a short time, so my 2CV was always a bit noisy and tried to poison me if I closed the windows. I know there are cast "full" exhaust clamps, but they're not available anywhere near me and they are very expensive. This is a solid fix for 1/3-1/4 of their price.
This is how it was supposed to look like:


This is how it actually looks because the turner didn't have the appropriate tool:




Cut in half and pulled together with an ordinary cheap clamp, it fits just right, the car is now much quieter:

like

like x2

although you need a small hole in the lower side of the reed valve housing to let the oil that condenses above the valve to drain back, the original had this IIRC the drain hole was 3mm

EDIT ah its not a replacement to go in the tower its an in the breather pipe one

Thanks, guys. Yes, it goes in the rubber tube. Any excess of oil will either be blown through to the air filter housing or drip back the tube to the filler neck. And some small amount should help seal the valve.

Very neat I like it.

Saurus,
looks as though your R&D department has gone into overdrive, to bring out two nice developments so close together.
Out of interest, what reading does the manometer show at high rpm?

It is possible to test crankcase vacuum on the road.
All you need to do is to make the connecting tube long enough to mount the manometer inside the car, ideally on the passenger side so that they can check what's happening with the engine under load at 3,750 rpm, which corresponds to peak torque.

Btw, I have reservations about the claims of an increase in power with a new breather.
The BMEP of a 2CV engine is likely to be in the range of 8.5 to 10.5 bar; 850 to 1050 kPa; 125 to 150 lbf/in2.
http://en.wikipedia.org/wiki/Mean_effective_pressure
50mm water gauge corresponds to less than 0.1 lbf/in2 vacuum, so it's difficult to see how that could have any significant effect on the power output as it's so small compared to the average pressure above the pistons during each cycle.

ken

Are you making some of these to sell?

Would the new "valve part" fit inside the old breather?

No, it would not be practical. There's a cross section illustration of the original 'reniflard' somewhere which would show you why.

The water goes a tiny bit higher. Which is interesting, because when I made one 2 months ago it used to climb noticeably until low-mid revs and reached around 55 cm water height. I gave that one to a friend who had problems with occasional LOADS of smoke on startup and his problem is now gone.



I might just try that. This was a quick test I could perform all by myself.



Here the manometer indicates just abowe 0,04 bar. For me it's more about preventing oil leaks at the camshaft oil deflector or the head oil return tubes. But it's worth listening in to see if I can hear anything different in the way my engine runs.

@Russell:
Well, I haven't planned on it... maybe if I had to make a few at once, one is just too much driving around for materials, machining etc.

@subarupete:
No, for the reasons knightley pointed out.