Datsundude123 Posted April 15, 2016 Author Report Share Posted April 15, 2016 This is from a '77 L20B with the co-joined manifolds. The threaded hole is for a vacuum fitting. PCV on right. EGR valve on extreme left just outside the picture. EGR manifold removed from intake. The two black holes distribute exhaust gasses to the two intake runners. The vacuum fitting and the PCV share the top hole into the intake. Both are under vacuum when the engine is running. EGR (exhaust gas recirculation) only happens above idle or the engine would stall. The EGR valve allows recirculation by way of a ported vacuum signal on the carb. The one with the Black cover in your picture mentioned earlier. Did you kick 'friend' in the nuts yet? Ok and my question is can I make a custom pcv with those small little pcv valves? And will the pcv valve off of a 72 l16 work on a 77 l20b? Quote Link to comment
flatcat19 Posted April 15, 2016 Report Share Posted April 15, 2016 Thing running yet? Quote Link to comment
Datsundude123 Posted April 15, 2016 Author Report Share Posted April 15, 2016 Thing running yet? Gtfo Quote Link to comment
Datsundude123 Posted April 15, 2016 Author Report Share Posted April 15, 2016 Thing running yet? You can come get it running for me! Quote Link to comment
flatcat19 Posted April 15, 2016 Report Share Posted April 15, 2016 You can't afford me. Quote Link to comment
datzenmike Posted April 15, 2016 Report Share Posted April 15, 2016 Ok and my question is can I make a custom pcv with those small little pcv valves? And will the pcv valve off of a 72 l16 work on a 77 l20b? Yes. L16 PCV will work. Plug the two bottom holes somehow, even JB weld will do and thread and screw a PCV valve in hook up the hose to the block vent. OR seal all the holes for now and get it running. Figure out the PCV later. Quote Link to comment
flatcat19 Posted April 15, 2016 Report Share Posted April 15, 2016 Break out the duct tape, bruh. Quote Link to comment
Rick-rat Posted April 15, 2016 Report Share Posted April 15, 2016 Can I make my own pcv valve like this or do I need the OEM one? You could do this, but you need to plug the 2 black holes and thread the top center hole and adapt the fitting you put threads in to the size of the PCV valve. I would use a 90 degree fitting to make it easier to connect to the crankcase breather pipe. I would like to come and help you, but you don't seem to want to listen to any ones advice This is not rocket surgery or brain science 1 Quote Link to comment
Lockleaf Posted April 15, 2016 Report Share Posted April 15, 2016 Can I make my own pcv valve like this or do I need the OEM one? Based on what Mike said, I think this would work fine. Block the two lower holes by tapping pipe threads into them and inserting some pipe plugs. Tap the upper for your pcv and I think you should be good there. But you still need the metal pipe that that pcv connects to. Quote Link to comment
Datsundude123 Posted April 15, 2016 Author Report Share Posted April 15, 2016 You could do this, but you need to plug the 2 black holes and thread the top center hole and adapt the fitting you put threads in to the size of the PCV valve. I would use a 90 degree fitting to make it easier to connect to the crankcase breather pipe. I would like to come and help you, but you don't seem to want to listen to any ones advice This is not rocket surgery or brain science I'm taking almost everyones advice ite just hard for my because a lot of the things you guys are talking about is hard for me to translate over the Internet! Quote Link to comment
Datsundude123 Posted April 15, 2016 Author Report Share Posted April 15, 2016 Based on what Mike said, I think this would work fine. Block the two lower holes by tapping pipe threads into them and inserting some pipe plugs. Tap the upper for your pcv and I think you should be good there. But you still need the metal pipe that that pcv connects to. I already have the pipe so once I get everything hooked up I'll post a picture Quote Link to comment
Datsundude123 Posted April 15, 2016 Author Report Share Posted April 15, 2016 Junk. Friend of mine here has one...runs on 2 cylinders...guess what the fix is? Another dizzy. You've shown pics of 3 different distributors through this thread. Which did you actually buy? Know which one changes diag, kind of. I haven't bought any distributor! If I were to get a distributor which one do you suggest? Quote Link to comment
Rick-rat Posted April 15, 2016 Report Share Posted April 15, 2016 I already have the pipe so once I get everything hooked up I'll post a picture If you come straight out with the PCV valve you will need a longer hose from the valve to the pipe to prevent kinking the hose and rendering your PCV useless Quote Link to comment
Datsundude123 Posted April 15, 2016 Author Report Share Posted April 15, 2016 If you come straight out with the PCV valve you will need a longer hose from the valve to the pipe to prevent kinking the hose and rendering your PCV useless Alright! I'll make sure I get a big enough hose or a 90° fitting Quote Link to comment
flatcat19 Posted April 15, 2016 Report Share Posted April 15, 2016 I haven't bought any distributor! If I were to get a distributor which one do you suggest? We don't know you need one. Let's get this thing close enough to actually diagnose if you need one or not. Quote Link to comment
Datsundude123 Posted April 15, 2016 Author Report Share Posted April 15, 2016 We don't know you need one. Let's get this thing close enough to actually diagnose if you need one or not. Ok and once I get the pcv thing done it should start right? Quote Link to comment
flatcat19 Posted April 15, 2016 Report Share Posted April 15, 2016 Are ALL the things Mike listed sealed up? The only air getting sucked in to your engine should be through the carb. Quote Link to comment
Datsundude123 Posted April 15, 2016 Author Report Share Posted April 15, 2016 Are ALL the things Mike listed sealed up? The only air getting sucked in to your engine should be through the carb. Yep it's all good! Quote Link to comment
flatcat19 Posted April 15, 2016 Report Share Posted April 15, 2016 Then you should be able to start right now. Quote Link to comment
Datsundude123 Posted April 15, 2016 Author Report Share Posted April 15, 2016 Then you should be able to start right now. I haven't hooked up the pcv yet or anything! Quote Link to comment
flatcat19 Posted April 15, 2016 Report Share Posted April 15, 2016 Plig the hole. Turn it over. Quote Link to comment
Datsundude123 Posted April 15, 2016 Author Report Share Posted April 15, 2016 Plig the hole. Turn it over. Already tried that! Didn't start yet I had everything hooked up Quote Link to comment
ddrum Posted April 15, 2016 Report Share Posted April 15, 2016 Try starting it without the pcv, meaning just tape it up "temporarily" (where the two holes are) and that will stop the huge vacuum leak which in turn should make your truck at least start :) Quote Link to comment
Datsundude123 Posted April 16, 2016 Author Report Share Posted April 16, 2016 Got em! I'll probably have to drill out the intake so it'll fit. Quote Link to comment
banzai510(hainz) Posted April 16, 2016 Report Share Posted April 16, 2016 get a L 16 intake manifold most are free as I have 4 away Quote Link to comment
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.
Note: Your post will require moderator approval before it will be visible.