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Old Jul 10, 2002 | 04:25 PM
  #1  
Iroc87's Avatar
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From: tornado alley USA
PCV questions

Couple questions
1 Anyone know were I can get a PCV with an AN fitting? (link if ya got one)
2 What size is the PCV fitting on the intake (looks like 3/8 npt to me) anyone know for sure?
TIA
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Old Jul 11, 2002 | 05:47 AM
  #2  
ede's Avatar
ede
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From: Jackson County
last pvc i looked at was fitted to a barb on the tbi, might help if you said what engine you wanted to know about
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Old Jul 11, 2002 | 09:46 AM
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If you want your engine to run like a POS Mitsubishi, just go ahead and slap any old PCV valve on there - just as long as it looks pretty.

If you CARE about how it runs, you'd better get the correct one for your engine. PCV valves are not simply sold by size. The internal pintle design, vacuum spring, and seating spring are all calibrated to maintain a given flow rate at a given vacuum. I used to work for a Textron company that manufactured PCV valve pintles, and part of the QC process was not simply a dimensional check, but statistical flow testing on a flow bench, with the springs and calibrated test housing in place. Tolerances were less than 1.5 SCFM at maximum flow and less than 0.3 SCFM at the high vacuum position.

Get the wrong valve installed, and you'll have idle and EGR issues, MAP errors, etc. I bought a Fram replacement PCV valve as part of a tune-up that was either mislabeled or poorly made, and chased a set of problems around a TBI engine for a week. A replacement AC valve solved all the issues, after trying a new MAP, EGR, cleaning the TB and IAC, setting minimum air, TPS, timing, checking the ignition, checking plug gaps and wires (again), etc. Needless to say, I was pissed, but learned my lesson. Just trying to save you from the same problems.
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Old Jul 11, 2002 | 11:14 AM
  #4  
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From: tornado alley USA
explanation

Perhaps a little more explanation is in order
What I'm trying to do is put a hard line from the PCV to the intake (it's a TPI BTW) no performance improvement, it just looks better IMO, than the rubber tube. I saw this done in Hot Rod several years ago, so I'm looking for a PCV cover that has an AN fitting on it, (I've looked at the suppliers, that cater to the hot rod crowd, and can't find it, it maybe discontinued) and the size of the hole in the intake to know what AN fitting to use. If I can't find the cover with the fitting, I guess I'll just leave it stock, or put a braided sleeve and some fake AN fittings with hose clamps on it. So if any one can help I would appreciate it.
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Old Jul 12, 2002 | 01:32 AM
  #5  
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From: Somewhere around the South Side of Chicago just crusin' in one of the Niteriders
Car: 92RS 25th Anniv./88 IROC Z28 Vert
Engine: 305 TBI w/Tpi Air / 305 TPI
Transmission: 700r4/700r4
Axle/Gears: Posi
So if I have a LG4 carbed Quadrojet and I want to replace the PCV what should I look for or ask for at the parts store that will make my car run the same or better?
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