Removing ZX9 air valves
locodude - 22/5/03 at 09:40 PM
Hi Guys
I notice that a few of you have removed the ugly secondary air induction set-up from your engines. Is it just a matter of junking all the external
gubbins or do the reed valves need junking/blocking off too? Can't see a reason for having it on a car that will only ever be visibly smoke
tested at m.o.t. time.
benedict - 22/5/03 at 11:10 PM
Just block 'em off.
The reed valves are to stop gasses coming out that way, so if you block the top holes in the cam cover it doesn't matter if they're there or
not.
If you do take them out, you'll see 2 small chambers in each err "housing", one under each valve. Each chamber has a small hole which
goes down to the head. I've blocked these holes off. While I had the cam-cover off, I actually tapped them to m6 (or whatever fitted) and
threadlocked some studding in there.
The other alternative is to just leave them open to the air (or pipe in filtered air) to get lots of popping and banging on the overrun and nice big
stabs of flame at night. 
I did this for a while and think it's slightly damaged the tops of my exhaust headers so have blocked them now.
Cheers,
Ben
MK9R - 23/5/03 at 06:29 AM
I have connected them together with the original pipes and inserted a small air filter. I should now get the nice poping and banging that Ben
described, but it should quieten the rattling noise downthat you get if you leave them totally open.
Jasper - 23/5/03 at 10:15 AM
Done the same as MK9R, I couldn't believe how much noise comes from them, and I want it as quiet as possible for track days.
benedict - 23/5/03 at 12:12 PM
quote:
Originally posted by Jasper
Done the same as MK9R, I couldn't believe how much noise comes from them, and I want it as quiet as possible for track days.
In that case
I'd block them off completely in the rocker cover. I'm sure on mine that this is the quietest as if you leave them open to the air (even
filtered) then noise still comes through.
Also to elaborate slightly on my earlier post, I'm currently blaming the burning fuel in the exhaust for some melting/damage to the very top of
the collector pipes where they join the head. This definately wasn't there when they were new and hasn't got any worse since I blocked the
air-bleeds. Can't say for 100% definate though.
Having said that, burning fuel in the exhaust can only shorten the life of the wadding in the silencer.
Cheers,
Ben
locodude - 23/5/03 at 05:40 PM
Cheers guys. I wondered what the hell the noise was when I took the pipes off, it sounded like the engine was full of marbles, only the reed valves
opening and closing but sheesh, what a racket!
Jon Ison - 23/5/03 at 06:05 PM
remind you of anything that then Chris ???
"sounds like a bag of marbles" 
locodude - 23/5/03 at 10:04 PM
quote:
remind you of anything that then Chris ???
"sounds like a bag of marbles"
Yes, a bag of marbles!