1970 Nissan Laurel KC30 coupe w/ SR20DET

KC30 · **Posted:** Sun Jun 05, 2011 3:50 pm

So I've had a little time to tinker this weekend. First here's a couple of pics of the MAF difference in the SR and the CA one I found I had installed:

As you can see, not only is the sensor different, but the SR one is slightly larger opening. So I've got an S13 SR20DET MAF coming to replace the CA one since I borrowed this.

Next, I started working on mounting the new fuel surge tank. I got it all setup, just waiting on the final install it until I get the fuel line in and installed. The best location for me to mount it is where I currently have the Walbro 255lph fuel pump, which under the rear driver's side (RHD) seat.
Just to refresh, this is where the Walbro pump is installed (the pre filter is no longer there, it was temporally installed due to debris in the fuel tank):

So I dropped the Walbro out of the way and started with a couple of initial mount brackets. I was going to use the mount brackets with the kit, but I had some clearance issues and had to come up with this using L-brackets:

Next, I needed to tie the two L-brackets together, which also gives me something to clamp the surge tank on. So I riveted a cross brace on:

And a test fit of the surge tank mount bracket on the car:

Here's the final test fit with the surge tank installed on the bracket. I also had a sheet of teflon that I picked up several years ago in Japan. So I wrapped the tank with that to prevent damage from the rivets on the bracket and minimize any vibration:

Here's the surge tank and bracket setup as it'll be used:

Here are some other less interesting pics as well:
Teflon wrapped fuel surge tank
Surge tank installed on bracket in car
Surge tank on mount bracket 1
Surge tank on mount bracket 2

KC30 · **Posted:** Tue Jun 07, 2011 7:14 pm

Today I picked up the turbo outlet pipe after the 2nd O2 bung was added. Yep, the brand new Megan racing outlet needed some modifying. The new one is on the right:

Here's an inside view:

Here it is with the 2 O2 sensors installed. For now it's the stock skinny one for the ECU and a fat one for my Apex'i TT. Down the road it will likely get a wideband O2 sensor... but there's lots of things to do before that. In the meantime this should be a good basic setup, the Apex'i TT and the same sensor is what I had in my Skyline (I miss it SO much!), and it was pretty accurate.

Here's the setup ready to go in... and yes, that is all it has for an exhaust right now! I tried to get the exhaust done before, but I couldn't get the 3" I wanted due to ground clearance. I've considered a Y-pipe with two smaller exhaust pipes running back, but the forward curve is too soon for that to work right. But I finally found a place to order 3" round to oval curved transition, then it'll be 3" equivalent oval back to behind the rear subframe, then back to 3" round, a muffler and out:

Here's the new turbo outlet installed:

Again, here are some less interesting pics:
New and old turbo outlet 1
New and old turbo outlet 2
New turbo outlet with 2nd bung, side view
New turbo outlet with 2nd bung and skinny O2 adapter

KC30 · **Posted:** Wed Jun 08, 2011 8:42 pm

Today I finished wiring in the 2nd O2 sensor, so that's ready to go. I started working on the fuel surge tank again, getting it plumbed in. I've got it in, and forgot to check the fuel level, which was near full... So yeah my stupid self got soaked with fuel.
I still have to mount the Walbro pump in it's new spot and do it's plumbing. Then do the wiring for both pumps.
Here's the fuel hose arrangement I ended up doing:

KC30 · **Posted:** Sun Jun 12, 2011 8:00 pm

Thursday night I got the surge tank fully installed, with the Walbro pump moved towards the fuel tank and both wired in. Here's a pic of the tank installed, not much to see though:

I tested it out, and surprisingly it was leaking from the electrical studs. But I was able to put on a little RTV and it's good now. I still have to upgrade the fuel lines, waiting for the parts to come in. I also won't have the SR20 MAF until tomorrow. Now that I'm able to read the AFR, it's definitely rich, I'll see what the new MAF does. But even without the correct MAF, just the new turbo outlet and fuel system... it's running MUCH better!
Since I was able to get out, I got a couple of new pics:

Eric · **Posted:** Mon Jun 13, 2011 12:50 am

Looking good! Great to see you are fixing stuff and it is actually getting better

c72c · **Posted:** Mon Jun 13, 2011 5:06 am

I like it, very much. :mrgreen:

So were you stationed in Okinawa, or were you just TDY when you picked this up? I was at the hobby shop a few times while you were doing the SR swap and someone mentioned you picked it up while you were TDY here.

Either way, nice work and great find.
You are very correct about the rust issue you mentioned near the beginning. If it had stayed much longer it would get out of control. I just got back from 4.5 months in Iraq and my trunk lid is done for, and the hood isn't much better. I hope to get mine to dry land soon.

BTW, you have pm with a few questions. :tu:

Keep up the good work.

KC30 · **Posted:** Mon Jun 13, 2011 3:57 pm

Thanks guys! I was just there temporary, I had about 1 1/2 month to get it all done.
Yeah, the rust there is vicious! I'm glad I saved it and looking forward to getting it's body restored.

KC30 · **Posted:** Mon Jun 13, 2011 8:47 pm

Today the new MAF came in. Now since I've had the second O2 sensor for the AFR, wow what a difference. The CA18 MAF that I had would closed loop idle at 10...! It would run rich and after holding constant throttle the ECU would slowly adjust to 13-14. But having the right SR MAF, it's holding 14.2-14.3 constant. It's so nice to have it running right.

KC30 · **Posted:** Thu Jun 16, 2011 5:13 pm

Argh... So I thought everything was running right... Until I hit about half a tank, it started running very lean! Max'd out the gauge at twenty and could start hearing the surge tank pump. So something's wrong in the main tank. Starting to wonder if the pickup in the tank broke, because it started doing it after a few months of doing fine.

john · **Posted:** Thu Jun 16, 2011 7:51 pm

KC30 wrote:

I tested it out, and surprisingly it was leaking from the electrical studs. But I was able to put on a little RTV and it's good now.

I'm pretty sure that gasoline slowly dissolves RTV... :shock:

KC30 · **Posted:** Mon Jun 20, 2011 4:45 pm

datsunfreak wrote:

I'm pretty sure that gasoline slowly dissolves RTV... :shock:

I should have clarified on that post, it's not regular RTV I put on. It was a sealant made for petroleum resistance. So it shouldn't leak again... Fingers crossed.

KC30 · **Posted:** Mon Jul 11, 2011 7:56 pm

So, this last weekend I finally got the Laurel back on the lift to change the fuel lines between the surge tank and the engine. It now has 5/16 feed and return lines. Next is to do the lines to the fuel tank and between the tanks.
Here's a pic right after it was on the lift, you can see the surge tank (white, on the middle right side) and the rear coil overs.

djlotus · **Posted:** Thu Jul 14, 2011 10:39 pm

I'm enjoying this build. The car looks great.

KC30 · **Posted:** Mon Jul 18, 2011 8:14 pm

Well, this last weekend I got the Laurel out for a drive in the nearby mountains, very nice drive... and VERY loud! I need exhaust! Anyways, I've been having some odd issue with the headlights dimming at WOT/high RPMs. Also, on occasion at idle the volts drop to 11. The volts are constant through the high rpms, but I have to wonder about the amps. So I'm going to be doing an alternator upgrade. I'll be putting the Nissan Quest's 125A on the SR20. Should prevent any issues.

KC30 · **Posted:** Tue Jul 19, 2011 7:39 pm

Ok, so someone mentioned the possibility if the old 1970 headlight relay being the source of my headlights dimming at WOT/high RPMs. So I'm exploring that possibility, and seeing the old fashioned relay, I wouldn't be surprised it it's unable to handle the forces the new SR gives the ride.
In the meantime, I'm still working the alternator upgrade. The new Nissan Quest 125A one showed up today. Just waiting on the new linkage for the upper mount/adjustment to put it in. Here's a couple of comparison pics:

KC30 · **Posted:** Wed Jul 20, 2011 6:11 pm

I started the first part of the alternator upgrade/swap. I drilled out the two lower mount holes on the Nissan Quest alternator. They needed to fit the 10mm bolt from the SR. I mounted that on and checked the stock belt fitment, looks good. Now it's just waiting for the upper mounting linkage.

KC30 · **Posted:** Mon Jul 25, 2011 3:54 pm

Today the last of the parts for the new alternator upper mount linkage showed up. So I finished the install. The pics aren't the greatest, it's a tight area to fit a camera into.

It's started up fine and seems to be good on power.

KC30 · **Posted:** Sat Jul 30, 2011 8:31 am

So I've been running the new alternator for a week, and it's made a huge difference that I didn't expect. As some may know, I'd have an issue with the engine running lean on occasion. In trying to sort it out, I've added a fuel surge tank with a second pump, replaced fuel lines, and still the engine would run lean/start stuttering once the tank got near 1/2. This was something that started a few months ago, I originally noticed it when it was at about 1/4 of a tank. But that was a new change since I originally had it running/shipped with hardly any fuel. Even more recent after all the changes to try to sort it out, it was starting to run lean randomly even with a full tank. I was last attempting to find a way to install an in-tank pump or change tanks.
Now, in deciding to upgrade the alternator while trying to sort out an odd electrical issue, I didn't expect to find what seems to be the source of my fuel issue. Since I've replaced the alternator the engine hasn't has any readings of running lean and so far I've been able to drive it down to 1/4 of a tank. My old alternator was always reading good volts, but as I was wondering about, it seems that the amps were low.

Now I've been frustrated with dim instrument lights and seen something about upgrading to LEDs. So I ordered them and did that yesterday, what a difference! It seems like I had the original lights in there as well, with the old Toshiba script on them:

Here's a view of what it looks like now, finally some actual light. Before, the brights indicator was hardly even visible, now it's very noticeable.

Jhale034 · **Joined:** Tue May 24, 2011 4:34 pm **Posts:** 3

What pump are you using to feed the surge tank?

Those LEDs look great! Love the green OEM look, with added brightness!

KC30 · **Posted:** Fri Aug 05, 2011 11:52 pm

For the feed fuel pump, I'm running the external Walbro 255lph that I had prior to installing it. I found some test specs that show it should be flowing 310-320lph since it doesn't have to provide pressure.

The LEDs were definitely a nice update, I wish I had a before pic showing how dim the old bulbs were.

1970 Nissan Laurel KC30 coupe w/ SR20DET

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