510revisited Posted July 21, 2019 Author Report Share Posted July 21, 2019 Well holy sh!t. I just wanted to know where i could plug in a temp sensor. I love this forum. Wish i knew about it 20 years ago when i tried to rebuild my first l20b. All jokes aside. Can you make a diagram, or send a pic showing the routing your talking about. Im very visual, and it pains me to admit im a little lost. Thanks for all the help. Quote Link to comment
510revisited Posted July 21, 2019 Author Report Share Posted July 21, 2019 Correct me if im wrong, but here is the water pump inlet. i have not touched it. Quote Link to comment
Crashtd420 Posted July 21, 2019 Report Share Posted July 21, 2019 40 minutes ago, 510revisited said: Correct me if im wrong, but here is the water pump inlet. i have not touched it. Yup that bolt is the line that should be connected to the blue plug on the intake and or the npt on the side of the thermostat housing.... I think datsunmike said it should run from the intake to a tee on the thermostat and then to the waterpump... Quote Link to comment
datzenmike Posted July 21, 2019 Report Share Posted July 21, 2019 On all Datsun 4 cylinder heads EXCEPT '75-'77 L20Bs with the U67 there is a coolant cooled/warmed intake. The U67 heads use exhaust heat to warm the intake but it's a bad idea. They can rust shut or open and bake the intake. From '78 on till they stopped making the L20B they returned to the coolant in the intake runners. ALL Datsuns even the U67 equipped had the coolant bypass on the thermostat. I'm not sure the threads are NPT, more likely metric pipe fitting. Yes that bolt is to seal up the bypass drain into the engine. You'll need some hose, two fittings, one for the thermostat, one for the intake and a Y fitting to join them. Quote Link to comment
Crashtd420 Posted July 21, 2019 Report Share Posted July 21, 2019 Sorry I keep saying npt.... probably more like bspt..... but if you have a tap you can easily and correctly change a bspt to an npt thread of the same size.... I did that with all my fittings as npt stuff is easier to find.... Quote Link to comment
510revisited Posted July 21, 2019 Author Report Share Posted July 21, 2019 1 hour ago, Crashtd420 said: Yup that bolt is the line that should be connected to the blue plug on the intake and or the npt on the side of the thermostat housing.... I think datsunmike said it should run from the intake to a tee on the thermostat and then to the waterpump... The bolt stuffed into the small section of hose sticking up vertically? Ok. Thanks for the info. That line, to thermostat housing td off to intake. 1 Quote Link to comment
datzenmike Posted July 21, 2019 Report Share Posted July 21, 2019 Yes. The L20B uses a metal line with a Y near the thermostat housing but hose will also work. Quote Link to comment
Crashtd420 Posted July 21, 2019 Report Share Posted July 21, 2019 10 minutes ago, datzenmike said: Yes. The L20B uses a metal line with a Y near the thermostat housing but hose will also work. Could he use that blue plug spot for the location of the new temp sender and then just a line connecting the thermostat to the water pump? Quote Link to comment
510revisited Posted July 25, 2019 Author Report Share Posted July 25, 2019 (edited) Pour one out for the homies. i chopped up a perfectly good 50 year old gas tank. I was gonna go with a round hole, but i would have run into the baffles, and all sorts of other issues. So i went rectangular. Gonna make the cover plate tomorrow... Pretty clean for 50 years... scratches are from my file. The blackness is from the grinder... Edited July 25, 2019 by 510revisited Quote Link to comment
Atomic Posted July 26, 2019 Report Share Posted July 26, 2019 On 7/25/2019 at 6:57 AM, 510revisited said: Pour one out for the homies. i chopped up a perfectly good 50 year old gas tank. I was gonna go with a round hole, but i would have run into the baffles, and all sorts of other issues. So i went rectangular. Gonna make the cover plate tomorrow... Pretty clean for 50 years... scratches are from my file. The blackness is from the grinder... Wow that's really clean. I had to remove a bunch of gunk and old varnish from the tank when cleaning it and prepping for E85. I used citrid acid remove the old rust and E85 to dissolve the old varnish out before applying a new one Quote Link to comment
510revisited Posted July 26, 2019 Author Report Share Posted July 26, 2019 2 hours ago, Atomic said: Wow that's really clean. I had to remove a bunch of gunk and old varnish from the tank when cleaning it and prepping for E85. I used citrid acid remove the old rust and E85 to dissolve the old varnish out before applying a new one Yeah, i was surprised too. I may run some vinegar through it when im finished. Did you line yours with any kind of sealant. Im still on the fence about lining mine.. Quote Link to comment
Atomic Posted July 26, 2019 Report Share Posted July 26, 2019 2 hours ago, 510revisited said: Yeah, i was surprised too. I may run some vinegar through it when im finished. Did you line yours with any kind of sealant. Im still on the fence about lining mine.. Yeah I used por15. Tho I was too slow when sloshing it around the tank and didn't mix it properly. So it gooped up in one corner quite bad and I had to scrape some off. So just make sure to mix it really well before pouring in and then slosh it around quickly and pour the rest away. It will start to cure and expand like a sponge and after a 92 hours it's rock solid and almost impossible to remove. Haven't tested with E85 yet tho. Quote Link to comment
510revisited Posted July 27, 2019 Author Report Share Posted July 27, 2019 21 hours ago, Atomic said: Yeah I used por15. Tho I was too slow when sloshing it around the tank and didn't mix it properly. So it gooped up in one corner quite bad and I had to scrape some off. So just make sure to mix it really well before pouring in and then slosh it around quickly and pour the rest away. It will start to cure and expand like a sponge and after a 92 hours it's rock solid and almost impossible to remove. Haven't tested with E85 yet tho. What did you use to cap off the holes on the tank when you did seal it? More specifically the filler neck? Quote Link to comment
Atomic Posted July 28, 2019 Report Share Posted July 28, 2019 18 hours ago, 510revisited said: What did you use to cap off the holes on the tank when you did seal it? More specifically the filler neck? I used aluminum tape, seemed to work really well. Just make sure to cover the hole in one pass to avoid leakages, the sides can be then patched with smaller pieces etc. Or if there is a larger hole and not wide enough tape I made couple of runs criss cross at the fuel sender hole Quote Link to comment
510revisited Posted July 29, 2019 Author Report Share Posted July 29, 2019 (edited) Got a lot done yesterday. Finished the cover plate for the tank. Well mostly. I'm debating putting a curve on it so it will hug the tank. At least in theory. Installed the an fittings for the feed/return lines. They are close to each other and I'm wondering if that is ok... managed to build 2 hardline for the tank area. Another hard line from pump to hard line at tank. Flared all the ends wrong, caught myself, and redid all the ends without building new lines. Took a bunch of pics, then promptly (unbeknownst to me) destroyed my phone. So here are all the pics I have fro. The new phone. Everything is still in mockup stage.. but here is and idea. Oh and I may have to move the pump. But no one reads the ends, so no one will know!!!! 🤣 Oh, and I removed the old fuel lines. Which MAY come up for sale. Edited July 29, 2019 by 510revisited Quote Link to comment
510revisited Posted August 3, 2019 Author Report Share Posted August 3, 2019 (edited) I'm contemplating how to do the radiator, coolant bypass that was mentioned a few posts back. I'm curious, for those in the know (datzenmike) what diameter is the hose for the bypass. I'm thinking of doing an aluminum tube that I can bend my self... Edited August 4, 2019 by 510revisited Quote Link to comment
510revisited Posted August 10, 2019 Author Report Share Posted August 10, 2019 Does any one know the stock size of the radiator hose that goes from the intake port to the thermostat housing port? Quote Link to comment
510revisited Posted August 18, 2019 Author Report Share Posted August 18, 2019 I came up on this today.. Pulled it off a 73 620. The block was an l18. When I pulled the valve cover I was shocked at how CLEAN everything was.. so clean I figured the whole thing was gonna be clean. But alas, here is the underside... Here's where it gets weird/funny. My dumb ass forgot my phone so I couldn't get any pics of the block. But I can say this, number one and four pistons i could move inside the cylinder left to right, by hand. Tons of slop. There were 3 different pistons. One with a dish, one with valve clearance from a valve, one good, and one that had the indents for the valve from factory. I managed to come up with the smog intake as well. no pics of that. I'm so impressed with how CLEAN this head is, I'm gonna send it to a shop and have it checked out. Everything looks good by my eye minus some dings and dents on the cam towers, and bolts. Plan is to put a bigger cam in it. But only the next size up from stock. Nothing wild. I'm playing with the idea of port and polish. We'll see about that. This is what all this will be replacing. The dreaded, craptastic w5? whatever the smog head is. No more round ports to square port manifold!!! Dont judge. This is the first time I've taken my valve cover off. 1 Quote Link to comment
510revisited Posted September 9, 2019 Author Report Share Posted September 9, 2019 (edited) One step closer. Managed to knock most of this out. Still plan to smooth it all out more, but I'm no machine. Ok, well maybe a little. I used a cone shaped die grinder bit in a drill for most of the shaving. I squared it off with a square die grinder bit in a drill press. At the moment its loosely bolted down. Still need to die grind the bridge off in the intake, still need to make a gasket for between the adapter and intake. Still need to make a line from intake to thermostat to lower radiator housing. Need to make a return line. May need to reroute the existing new line into a new direction.. pretty close though. I am starting to see the light at the end of the tunnel. Lots to do, but slowly checking shit off. For those in the know, a question... I need to weld, clamp a bung onto my exhaust for an o2 sensor. Since my exhaust is all fd up anyhow, I need to redo things. I was contemplating making a single piece "downpipe" from manifold flange to exhaust. Instead of 4 into 2 into 2 into 1 it would be 4 into 1 into 1. Down pipe from flanges on would be one. Any issue with such setup? Here's the existing setup. Discuss amongst yourself's Edited September 9, 2019 by 510revisited 1 Quote Link to comment
510revisited Posted October 6, 2019 Author Report Share Posted October 6, 2019 (edited) Knocked out a big portion of the project today. Managed to bend all the fuel lines under the hood. Well most of them. Still need to run a full length return. I'm contemplating insulating the lines where they are near heat. Maybe that's overkill, you guys tell me.. I need to know which way the motor torques when it moves. I'm not sure my fuel hose from back side of motor to the firewall is long enough to flex. I know its gonna go left or right... The tube ends. Not perfect, but who cares. I did install the temp sensor into the t housing. A guy on YouTube, which I've mentioned before, installed his temp sensor in his t housing. It ran too. Not saying drove, but ran. So I think ALL of you guys were right. Just saying. I plan to tap all the remaining holes in the housing with 1/4 npt and plug. Minus one for a bypass to lower end. It's getting closer. I can see the light. Only thing left is everything else. Edited October 6, 2019 by 510revisited 2 Quote Link to comment
510revisited Posted October 12, 2019 Author Report Share Posted October 12, 2019 The light is getting brighter... Doing my best to keep the tube from touching the body. 1 Quote Link to comment
510revisited Posted November 11, 2019 Author Report Share Posted November 11, 2019 Bolted all the fuel lines down for the final time. Tightened all the hose clamps down. Installed the a.n. bulkhead fittings for the pass through to the tank. After posting this second pic, I may redo the hard lines. They kinda look like crap. They were my first time running lines. But they are in and tight. I plan to seam seal the aluminum bulkhead plate. All holes are painted. I need to add a few hard lines and soft lines in the engine bay. Heat wrapped the hard lines that run near the exhaust. Torqued the t housing, and the intake manifold adapter down for the final time. So all in all got a bunch of stuff checked off. Left to do, more or less: exhaust redone for an o2 sensor and to swap in a 5 speed. Wire the efi. Wire the bluetooth dizzy. And some small misc things. Swap in 240z seats. Need to build some sort of mount for the touch screen. Got a BIG win. Figured out my fuel level sending unit works!! Just a bad ground... all in all a good day.. 1 Quote Link to comment
510revisited Posted December 1, 2019 Author Report Share Posted December 1, 2019 (edited) Update. Only days away from firing off for the first time... I've repainted, and reinstalled the fuel tank. Buttoned up the bulkhead i made on said tank. Reinstalled the vent lines. I've purchased and installed a air cleaner. It fits, but just barely. I will make a final decision on it after i run it a bit, obviously so I can tell if it hits when the motor torques. I'm waiting on an o2 bung clamp on kit. Idea is I'm gonna get it running, drive it a wee bit (more like a lot o bit in reality) then take it down to a muffler shop and have the entire exhaust redone... need to wire the sniper. 4 wires. Need to wire and setup the bluetooth dizzy. 3 wires. Adjusted the valves, changed the oil, and filter. Refilled the radiator. I'm hoping by next weekend. MAYBE. I am curious, how does one post a vid. I'm gonna film the whole startup thing... Edited December 1, 2019 by 510revisited Pics Quote Link to comment
Crashtd420 Posted December 1, 2019 Report Share Posted December 1, 2019 Cant wait to see it run..... As far as I know on the video YouTube was fairly easy and it links itself.... Goodluck.... Quote Link to comment
510revisited Posted December 1, 2019 Author Report Share Posted December 1, 2019 5 hours ago, Crashtd420 said: Cant wait to see it run..... As far as I know on the video YouTube was fairly easy and it links itself.... Well I meant for here.. but I see what you mean. I can just link it here... right before im ready to fire off im gonna wire that dizzy. I think that's where I'm gonna need some of your expertise. I still have your number, and plan to be blowing up your phone soon. Quote Link to comment
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