Forum

[Alan R]

------------- Plus you get the use of a tool box back again ---- it's a win/win situation; a scarcity amongst the Bullet fraternity and that's the truth !! LoL ...

[Spitting Bull]

Take the PAV fittings off by all means but don't actually ditch them. Keep them safe somewhere. You'll find they'll be a bit on the expensive side if the powers that be ever decide the PAV must be re-fitted at some time in the future.

SB

[Stringers Best Mate]

Here in the UK we can rejoice & relax in the knowledge that there will never be any retrospective emissions legislation, so dump the PAV at your opportunity.

[Roeland]

agree - dump - no use - shave some weight

[Danish Dan]

Allan R writes: "It was a mechanical "scam" to fool the MoT exhaust sensor by diluting the exhaust gasses AFTER they had left the cylinder head and before they came out of the end of the silencer". I have heard this explanation many times, but always wondered. It can´t be picking up clean air, as it is attached to the other side of the carb (or at least it was on mine - before i scrapped it). So if it introduces something to the exhaust gasses, it would be a fuel/air mixture, which can´t make the exhaust gas purer? Is it so instead, that it pics up a little bit of the exhaust gas, and sends it in to the intake, thus burning some of it twice? Just a thought.

[PeteF]

Dan, the connection to the carb was to operate the valve. When you close the throttle the vacuum in the carb increases, this opens the valve in the toolbox allowing air into the exhaust header pipe. There are systems on other engines which do allow "rebreathing" of the exhaust gas into the inlet. usually on bigger diesel engines I believe.

[Presto]

Doesn't the injection of a small charge of fuel/air mix from the inlet tract into the head of the exhaust pipe act as a crude 'after-burner', to burn off residual gases in the exhausted charge?
If not what did the system in fact do?

[John R]

Digressing somewhat, I know that some submarines have diesel engines which breath their own exhaust gas plus oxygen, the advantage being that they don't have to carry an air supply, four fifths of which is non-combustible nitrogen. I would be interested to know if they can also generate enough electricity to electrolyse sufficient oxygen from seawater to supply that, too. And you could also use some of the surplus hydrogen to run a fuel cell for when you didn't want bubbles going up to the surface. And to supply drinking water!

Hey I'm in the wrong job here!

[Alan R]

Hi guys------------ please do have a look at this. Scroll down for a section relating to the Enfield.----------------------- http://en.wikipedia.org/wiki/Air_suction_valve --------------------- Now here's a thought, if we put a reed valve at the air inlet connection on the exhaust pipe and feed fuel down that air pipe we might get a pulsed-jet effect out of the exhaust pipe-----just like the Argus engine on the WW2 V1 "Flying Bomb"... Which leads nicely into this-----------------(PS Set to FULL screen and FULL volume !!!!) http://www.youtube.com/watch?v=z8Q9oAPrvZo --------------------- GRUNDA 12, here's your next Enfield project then ???------- As the late, great Fred Dibnah used to say "A nice Demon-Stration"

[Danish Dan]

Thanks Pete F for setting me straight. Then the line to the inlet was just a vacuum tube to actuate the valve in the toolbox - that makes sense. Now I don´t have to feel bad for having removed it ten years ago. And for Gerry M´s original question - you should remove it. There is af risk of it beaing erratic and leaning the mixture (so called false air) from time to time. I also remember it making an anoying noise?