That reminds me....At DCS we were helping one owner having engine problems and when they stepped on the gas the whole top of the air cleaner would compress. (I'm taking an inch of movment) Naturally it was just a plugged air filter. But that makes me think there is more vacuum pulled by the air filter box and the orifice hose adds nothing since it's volume is Nil. A normal setup would have a vent on one side of the engine and the PCV valve pulling vacuum on the other side. Maybe our passenger side valve cover could be machined to install a PCV valve in it and then you really would have PCV. --- In dmcnews@xxxxxxxxxxxxxxx, "Dave Swingle" <swingle_dmc@...> wrote: > > It doesn't take much if the engine is tight. If you have anything > coming out of the hose going to the filter box the top (clean) side > of the filter will be oily. The only car I've seen with blow-by gas > coming out of the tube to the filter box had a cracked piston. I > haven't tested this, but I'll bet on a normal engine you'll actually > feel a slight vacuum on that hose, it's to provide filtered > replacement air for the air going into the engine thru the other > line, so you don't pull a vacuum on the crankcase. > > There isn't much vacuum in side the filter box, it's supposed to be > open to the outside air - the only vacuum there would be caused by > the obstruction of the air filter itself. > > I do find it interesting that there is apparently no PCV "valve" in > the system like you find on "normal" engines. Unless there is one > inside the filler cap that I don't know about. I've never cut one > open to see. > > Dave S > ------------------------------------ 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/dmcnewsYahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/dmcnews/join (Yahoo! ID required) <*> To change settings via email: mailto:dmcnews-digest@xxxxxxxxxxxxxxx mailto:dmcnews-fullfeatured@xxxxxxxxxxxxxxx <*> 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/