Hi Martin and David, Thanks for the help. I was in a huge rush last time i posted and did not explain it at all properly. The situation is that i started this project about a year ago stripped all the accessiores, manifold, water pump etc etc. The whole block was cleaned and the manifold and rocker covers powdercoated, a new water pump, supercharger mounted and re assembled and put back in a freshly blasted and powdercoated frame. That is were it has sat under a sheet for the past year. My memory has faded on how all the systems worked that i had previously studied before removal. As i was removing the K jetronic anyway alot of the components that i removed would never be re- installed. (i do have a workshop manual also) The brass tube that you mention below is the one i was talking about and with the EFI system i dont require a cold start value or an idle speed motor (the GM throttle body i am using has one). I was addiment that that port was connected to all 6 intake ports (as i re- installed the manifold) but the reason for my question was the guy doing the supercharger pumbing for me thought that the Volov's went right through into the valley and i did not want to remove the manifold to prove my point. >The big long one with the cold start injector on the >end serves to apply engine vacuum to the oil filler, to the charcoal >cannister, and connects directly to the centre of all siz intake >ports, >so is connected to the idlespeed motor, and the cold start injector. I asked this same question some time ago (a year) and one of the responces i recieved was that the crankcase was under constant vacuum. I coulnt see how that was the case and from the responces this time i see that it is not. >I would install a non-return valve in it through so you >don't >end up pressurising the crank case too much to the point of blowing >oil >out through the main seals. However the Renault ones don't have the >vacuum feed, just the breather. The cap is clipped on and the >breather >has a catch tank that feeds back to the sump. That was my other thought. To have an alloy tank made that the oil cap breaths into and have that feeding back into the sump. The root of all my questions really was: If i have no Idle speed motor, char.canister, or cold start value, do i require this long brass tube especially if it will be under preasure most of the time and not vacuum. And if i dont have it and capp it off at the manifold what do i need to do with the small tube coming off the oil filler cap??? Capp it off or re-direct it to another source?? If i figure this out then i can move forward..... >A blow-off valve (dump valve over here) is there to vent boost when >the >throttles shut and is actuated with vacuum downstream of the >throttles. >It doesn't do anything at idle. The value i was having installed is a Bosch unit that at idle it opens to re-circutale the boost back into the intake before the throttle, been a belt driven supercharger with no magnetic clutch it will be spinning and boosting (although not much) at idle. This simply acts to reduce the load on the motor at idle so it is not permantly under boost preasure. Once the throttle opens the valve closes. When car is running i will decide on weather to fitt a dump valve depending on boost preasures. The supercharger pulley was machined to a diameter that should not over boost and on decelleration this bosch valve will open also and act simular to a dump valve. Thanks for the advice. Cheers, Nick To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/