Guest KEINsm Posted October 8, 2003 Share Posted October 8, 2003 Yesterday I replaced my airfilter with an K&N drop-in for the first time since my ownership (only a couple weeks). It's an early '71 240Z with the stock SU carbs and orange airbox. What I found in the airbox was a pretty thick layer of black oily soot and the filter itself had dark amber oil on it. What is wrong with my car? Is it the carb oil leaking out? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 8, 2003 Share Posted October 8, 2003 The PCV (crankcase vent) goes to the stock airbox. If your engine has a lot of miles it probably has a lot of blowby which is venting through the PCV to the airbox. You'll always have some residue from this, but it sounds like you've got a lot. You don't have a hookup for that PCV hose on the K&N filters. I used the stock hose off the PCV which is located on the front driver's side of the block and rerouted that to a catch can right next to the radiator support. If you really want to get spiffy you can use one of the vacuum lines off the intake and route that to the catch can as well, so you still have some vacuum pulling pressure out of the block. Also the hose from the valve cover won't have anywhere to connect to. You can get a small K&N filter for the valve cover, or you can buy a longer length of hose and route that to a catch can too. BTW--cut out the stock air horns around the mounting bolts and bolt them up inside the K&N filters. That's supposedly good for a few hp. Jon Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 8, 2003 Share Posted October 8, 2003 Oops, I just realized that by drop in you mean the new filter fits in the stock airbox. Nevermind all of the hose rerouting crap. Your Z sounds fairly normal, just sucking engine vapors and oil through the PCV into the airbox. Maybe a little tired from the sound of it. Jon Quote Link to comment Share on other sites More sharing options...
Guest KEINsm Posted October 9, 2003 Share Posted October 9, 2003 Yup, I was actually talking about the drop-in filter not the one's where I have to buy the "custom" assembly units. My car is about to hit 170k miles on the original engine with no rebuild history. It gave me no problems on a 500 mile trip from NorCal to SoCal so I am not worrying about it dying on me any time soon. Thanks for the pipe re-routing tips. I'll keep it saved for future reference. Now that you mentioned that this conditon is "normal" I want to do something to prevent the blowby from clogging up my airfilter again. Would you have pictures of your catchcan setup? Seems like a very good idea. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 9, 2003 Share Posted October 9, 2003 Nope don't have any pics, sorry. You can get a catch can from any racing outlet, Summit, Jegs, Pegasus, Racer Wholesale, etc. Just an aluminum container basically. For a long time I ran the PCV into an old 1 quart plastic oil bottle (hose straight into the hole) and a big hole in the top so that it didn't blow the hose out of the bottle. Anything to keep it from falling straight on the ground. I suppose the amount of oil in the air cleaner would also depend on when the last filter change was done and if the PO cleaned all the oil out then too. Clean it out and keep an eye on it. If it quickly gets a puddle of oil in it then you may have a problem. Jon Quote Link to comment Share on other sites More sharing options...
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