darkzebra Posted August 4, 2009 Share Posted August 4, 2009 I am modifying a non-egr N42 intake to install on my 82 280ZXT. Need to tap new PCV port on bottom of intake, since the original port is in the way of the turbo. Since the wall of the intake seems thin, is there a recommended position to tap this new port? Quote Link to comment Share on other sites More sharing options...
nismopick Posted August 4, 2009 Share Posted August 4, 2009 Position? Meaning location? About 2 inches forward (towards the throttle body). 1 Quote Link to comment Share on other sites More sharing options...
darkzebra Posted August 5, 2009 Author Share Posted August 5, 2009 OK. The new port is to be located 2" forward of the present PCV port, closer to the TB. Do I just drill and tap in the new location? Is it thick enough to get enough thread for the PCV to hold firm? Or do I need to have something welded to increase the thickness? Quote Link to comment Share on other sites More sharing options...
aarang Posted August 5, 2009 Share Posted August 5, 2009 If you are not going to use the heat shield, just drill and tap the heat shield mount boss that is in front of the PCV boss. 1/4 NPT is the tap you want. This is what I did with mine. Aaron Quote Link to comment Share on other sites More sharing options...
darkzebra Posted August 5, 2009 Author Share Posted August 5, 2009 Thanks! I don't plan on using the heat shield Quote Link to comment Share on other sites More sharing options...
Challenger Posted August 5, 2009 Share Posted August 5, 2009 Thats a pretty good idea aarang. I had my n42 on my turbo engine just to see how it looked and I noticed the heat shield mount but never thought to drill and tap it. Ill maybe do that this afternoon. Quote Link to comment Share on other sites More sharing options...
Guest Rolling Parts Posted August 6, 2009 Share Posted August 6, 2009 Thanks! I don't plan on using the heat shield I simply tapped into the cold air intake instead of the manifold. 2 reasons: That way I'm assured of having only a vent(vacuum) on the crankcase and there is no chance of an air leak behind the AFM. I tried running that nice, clean, pretty manifold without the heatshield. What happens is that the the injectors and injector wires get real hot because the turbo is right under them by less than a foot. I installed the heatshield! Quote Link to comment Share on other sites More sharing options...
aarang Posted August 6, 2009 Share Posted August 6, 2009 I cut my heat shield in half lengthways so it still shields the injectors somewhat from the radiant heat. It is also in two pieces (cut in half again) so it can be removed without removing the intake or turbo. Aaron Quote Link to comment Share on other sites More sharing options...
Administrators BRAAP Posted August 6, 2009 Administrators Share Posted August 6, 2009 I am modifying a non-egr N42 intake to install on my 82 280ZXT. Need to tap new PCV port on bottom of intake, since the original port is in the way of the turbo. Since the wall of the intake seems thin, is there a recommended position to tap this new port? Yes, There is “just†enough material in the wall thickness of the plenum floor that you can drill and tap the bottom of the plenum to relocate the PCV valve to the same location as it is on the Turbo manifold. If you have the option to build up that region where you want to locate the PCV valve by welding it, by all means do so. Here is one of my custom N-42 intakes that I drilled and tapped the bottom of the plenum for vacuum ports, (fuel pressure regulator, Brake booster, MAP signal for MS, etc). This was on my Race car for short period and now running on another HBZ members boosted L28. Quote Link to comment Share on other sites More sharing options...
Administrators BRAAP Posted August 6, 2009 Administrators Share Posted August 6, 2009 I simply tapped into the cold air intake instead of the manifold. 2 reasons: That way I'm assured of having only a vent(vacuum) on the crankcase and there is no chance of an air leak behind the AFM. So you plumbed the PCV valve itself, (the breather tube for the engine block), to a point in front of the throttle body instead of behind it where it would see vacuum? Why bother? I'll elaborate... 1) Just put a filter element on the block vent tube, serves the same purpose and gets rid of that unnecessary hose/plumbing to the cold air intake and no oily blow by being pumped through the AFM, and the rest of your intake tract! Ever notice the thick slimy oil residue on the inside of an intake manifold? That is how the rest of your intake tract, AFM, Turbo, inter-cooler if using one, will look after sometime with your crank case breathing into your cold air intake. 2) The PCV valve itself is a spring loaded valve designed for a vacuum atmosphere, i.e. intake manifold. The only portion of the intake system that experiences the vacuum a PCV valve is designed for is the air space between the throttle body butterfly and the intake valves. If plumbing your cranks case breather anywhere else, the PCV valve itself is not functioning as designed. 3) When using the PCV as it was designed, if you are concerned about the engine ingesting “false†or “un-metered†air, the OE PCV/vacuum plumbing eliminates that by allowing fresh filtered air from “behind†the AFM to be drawn in to the valve cover, (this air is metered by the AFM), and as it passes through the crank case is drawn into the bottom of the intake manifold through the calibrated PCV valve and burned in the combustion chambers. That air was measured by the AFM and the appropriate amount of fuel compensation is made by the ECU. Hope that helps Quote Link to comment Share on other sites More sharing options...
Guest Rolling Parts Posted August 6, 2009 Share Posted August 6, 2009 Sorry for the confusion. I hoped that my post implied removal (not re-installing) the bulky PCV. As aarang said, a small unobtrusive tap can be used instead. Quote Link to comment Share on other sites More sharing options...
Administrators BRAAP Posted August 6, 2009 Administrators Share Posted August 6, 2009 Sorry for the confusion.I hoped that my post implied removal (not re-installing) the bulky PCV. As aarang said, a small unobtrusive tap can be used instead. Ah.. gotchya.. Quote Link to comment Share on other sites More sharing options...
darkzebra Posted August 7, 2009 Author Share Posted August 7, 2009 I do plan on retaining the PCV valve so I will tap the heatshield mount boss. I did not plan on installing the heatshield, neither on running the cooling fan for the injectors. Instead, I intend to jet-coat the exhaust manifold, and also wrap it. Would this compensate enough so that the injectors would not overheat? Also, I notice a protrusion inside each runner at the injector end - one of the screws for the injector holder. Should I grind this down? Quote Link to comment Share on other sites More sharing options...
DuoWing Posted August 7, 2009 Share Posted August 7, 2009 I just did this a few weeks ago. I just tried to match up really closely where to put the PCV on my N42 egr-less intake. I was trying to do a 90* fitting, but that still was against the turbo. So I just drilled a new spot for the PCV and used some pipe thread sealer. There's enough material as mentioned, although I did notice that spot for the heatshield. I agree with what others have said. It may not look as nice, but run the heatshield as it will help. Not to mention with the N42 there is no webbing to help dissipate heat under and out from the sides of the manifold. I just painted my heat shield with manifold paint. Looks nice. Also just use a 1/4" NPT pipe plug for the old PCV spot. Quote Link to comment Share on other sites More sharing options...
Guest Rolling Parts Posted August 7, 2009 Share Posted August 7, 2009 I intend to jet-coat the exhaust manifold, and also wrap it. Would this compensate enough so that the injectors would not overheat? That's a lot of cost and work and still does not address the turbo heat on shutdown. Removing the fan and heat shield are a double-whammy for increasing heat soak on the injectors and rail. I hope it will work for you. I tried the super clean look but soon discovered that Nissan had a reason for simple fixes for a problem.... Quote Link to comment Share on other sites More sharing options...
Challenger Posted August 7, 2009 Share Posted August 7, 2009 I do plan on retaining the PCV valve so I will tap the heatshield mount boss. I did not plan on installing the heatshield, neither on running the cooling fan for the injectors. Instead, I intend to jet-coat the exhaust manifold, and also wrap it. Would this compensate enough so that the injectors would not overheat? Also, I notice a protrusion inside each runner at the injector end - one of the screws for the injector holder. Should I grind this down? Well as for the coating and wrapping, I believe it was hughdogz that did this and he cracked his manifold it got so hot. Ill search for the post to confirm my memory. Also those protrusions can be ground smooth, I cant see any reason it would harm performance and the screw hole doesnt break through. Quote Link to comment Share on other sites More sharing options...
darkzebra Posted August 7, 2009 Author Share Posted August 7, 2009 I'm sure Nissan had a good reason for the fan and webbing, so if I have to keep the heatshield then I will. Talk about the work - it ain't easy being 60 and arthritis and all, and using a damn file on the N42. And it seems the real fun now begins - my engine is in a running car, I did not plan on taking it out, and it seems real difficult to switch the intake and exhaust without taking it to a shop. Quote Link to comment Share on other sites More sharing options...
Challenger Posted August 7, 2009 Share Posted August 7, 2009 Its not that bad. Do you have a chiltons? Quote Link to comment Share on other sites More sharing options...
darkzebra Posted August 7, 2009 Author Share Posted August 7, 2009 I have a Nissan Service Manual and a Haynes. I have removed the J-Pipe but can't get to the 4 bolts on the underside of the heat-shield. Quote Link to comment Share on other sites More sharing options...
Challenger Posted August 7, 2009 Share Posted August 7, 2009 Those four bolts below the heat shield that go into the head dont "hold" the manifold on they just "hold" it on. If you remove the 4 bolts on the top of the manifold, two in the middle one on each end, make sure all the fuel lines and vacume lines are detached the manifold will pull strait up off the engine. The bolts you mentioned only wedge the manifold onto the engine, loosening only makes it easier to pull off. It will feel like its impossible to pull off but it is possible. I actually used an engine hoist an a junkyard to pull it off it was on there so tight. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.