1970 Nissan Laurel KC30 coupe w/ SR20DET

Eric · **Posted:** Mon Jul 19, 2010 9:49 am

Now that is good info!
were can we get that 200b input?

KC30 · **Posted:** Tue Jul 20, 2010 7:50 am

Eric wrote:

what size wheels do you have? they seems to fit just under the arches?

I switched from the 14" wheels I bought it with, which also had about a 0 offset, to 15" with a highly positive offset. For the front tires, I put on 195/50R15's. They sit right where I want it.
Right now, the 14" wheels are still sitting in the rear. I'm still debating on a good tire size for the rear... The original tire size the Laurel came with was 175/80R14's. So about 25" tall and almost 7" wide. So I have considered going with the S13's stock tire size, 205/60R15's, which would be close to original height (just over 24.5") and 8" wide. The benefit with that, is that the speedometer would read pretty accurate (1.35% slower).

mattrx2 wrote:

Have you ever thought about using a MADDAT SR20 fitting kit?...Also you will be able to retain the standard SR box and im pretty sure too get the speedo hooked up u put a 200B input into the SR box and the standard speedo cable plugs into this.

I have seen the MADDAT kits, but having to ship from Australia and not being certain they fit was the first turn off. But the main reason I didn't go that route was that I wanted the S13's front suspension and power steering.
As far as the speedo issue, I may have confused people taking about going with the R32/RB20's transmission. I originally tired it for clearance...which almost worked, but decided to stick with it just on personal preference. The reasons I'm sticking with the RB20's is due to being a shorter trans (by 2") leaving me with the shifter in a better location for my preference and more clearance in the trans tunnel in the tail area of the trans (which has made it a lot easier to get in and out during test fits), that's the only difference between the two. The trans crossmember mounting is identical between the two transmissions, so installation in regards to that is not a factor. If I did choose to keep the SR's trans, I would just install the RB20's mechanical speedo output in it. I had to do that when I installed the S14's trans in the Skyline I had.
Sorry if I confused anyone talking about the two different transmissions and probably not clarifying why the RB20's was first used, nor why I choose to keep it.

mattrx2 · **Posted:** Tue Jul 20, 2010 1:46 pm

SR box into skyline, skyline box into datto

KC30 · **Posted:** Thu Jul 22, 2010 5:27 am

mattrx2 wrote:

SR box into skyline, skyline box into datto

Yeah, a little odd I know. For the Skyline, I sheered the output (main) shaft on a drag strip launch. I launched so hard, that my rear subframe twisted up enough that the front vibration dampeners hit and dented the underbody, broke them both off, and my diff dented my 4" stainless steel exhaust (which was pretty solid) very well. So when it came to a replacement, it was expensive for an RB20's 5-speed in the UK (where I lived then) compared to the SR's, and going with the SR's allowed the option for the OS Giken gear set upgrade the next time I sheered a shaft. :twisted:

But I ended up leaving the UK and couldn't take the Skyline with me back to the US before it became necessary for that upgrade... man I miss that car!
Now with the Laurel (which is a Nissan!... I once swore I'd never own a Datsun when I was a kid, keeping that word so far :lol:

) I can get the SR or RB trans for the same price in the US if this one goes. And I have no intention of putting it in conditions where it will need the OS Giken gear set upgrade. Since that doesn't matter, I just prefer the RB's for better fitment and shifter location, and decided to go with it since I got one.

KC30 · **Posted:** Sat Jul 24, 2010 7:38 am

So today, I had a goal... like I have already had a few times... to get the steering sorted and engine in! I know, deja vu!
So, first thing, steering... round two. So I finally got a steering shaft from a Gloria (Y32 body). But can use one from an R32 or 300zx as well. I shortened it and used the standard power steering knuckle. This attaches to the Laurel's steering column.
New steering shaft
So, steering finally sorted. Next the engine... to get the engine positioned right, new mounts were made. The new mounts position the engine 1 3/4" forward and almost an inch lower. They are solid mounts with urethane pads on top and bottom, then filled and coated with urethane.
Here's the mounts initial design.
And the mounts all finished up
Test fitting of the new mount
The right mount installed on the engine
And the left
Everything ready to go in

And this time, the engine's in!

Also, I got the camber bolts installed and strut height sorted as well, the camber bolts are Monroe Camber Magic ones for the S13.

Another view of the right height
Another view of the engine in
Where the engine sits in the bay
From another view
And where the shifter has ended up
Now final touches are to be worked. A custom transmission mount, using the Laurel's trans cross member, is going to be installed. The driveshaft will be made soon, and get the fuel pump installed (a Walbro 255lph external pump).

Eric · **Posted:** Sat Jul 24, 2010 12:31 pm

Nice work! Good to see you are making such fast progress!

KC30 · **Posted:** Tue Jul 27, 2010 2:09 am

Thanks! Well, I only had this last Saturday to do the install, had to work Sunday, so no progress. I have found a shop that can do the drive shaft, so I hope to have that done for this weekend. Also, I have looked and need to rethink the rear tire size. The 14's on it now are about the same height as the front, and there isn't room for taller tires if I match the front trackwidth, which I intend to. So I'm thinking of using 205/50R15s instead of the 205/60R15s. If I fit those and rear coil overs, I should be able to achieve the stance and look I want.

Garant · **Posted:** Tue Jul 27, 2010 9:50 pm

brochure scanned by spottedlaurel

KC30 · **Posted:** Wed Jul 28, 2010 3:30 am

I LOVE that picture! And it shows the one thing I'm missing, the rear GX badge. I'll have to take that pic to the Nissan dealer and see if I can order it.

KC30 · **Posted:** Sat Jul 31, 2010 7:46 am

Well, at it again today. Making progress, feels/seems like I didn't do much, but I did get a lot accomplished. Which is good, having only one day to work on it last weekend and today this one. I'd like to and probably should work on it tomorrow... but there's a drift comp that I've been planing to see.

So, as far as today's progress:
I started with finishing getting the transmission mount sorted. I used the original trans crossmember and rotated it backwards. With the engine positioning I choose, I had to trim the crossmember a little and drill new holes for the mounting. I also added the SR's exhaust downpipe bracket.
The new trans mount The new mounting uses two of these, solid mounting. And the insert is only in the top portion and protrudes into the trans mount hole, which is larger size.
One of the mounts on the trans you can see how the bolt is installed on the other, and where the protruding part goes into.
The crossmember, you can the two new holes for the trans mounting (will be reinforced later). Also the trimmed portion and the two new bolts hold on the SR's downpipe bracket. The urethane pad with it is more padding for the mount, you'll see in a couple more pics.
The back view of the crossmemberShows the SR's downpipe bracket.
The trans crossmember installed, back view You can see the extra urethane pad goes under the trans. It just covers a small gap that the new mounts don't.
The trans crossmember installed front view.

So, trans mounting sorted. Next was getting the exhaust downpipe placement clear. The old front suspension used trailing arms. And the trailing arm mount sits right where the turbo exit pipe goes into the downpipe. So, the trailing arm mount bracket needed to be removed. As I've said, I didn't want to cut away at the body at all, but I realized I need to give on a couple of things. But I have stuck with making it all being able to be undone. As the trailing arm mounts were manufactured and then welded on, I cut the seam welds and drilled the spot welds. So the mount bracket's off and being kept if ever needed to be welded on again some day.
Turbo exit pipe and trailing arm mount bracket
The mount bracket, can kinda see how it's attached
The bracket removed, ready for a downpipe
Same thing, different view Also, you can see one of the rust spots that's through, it'll be good to get it into the desert soon and start fixing those.

So, the next project was for the fuel pump to be mounted. As it's external, I tried to get it as close to the fuel tank as possible. The closest spot was under the rear seat, driver's side. There's a nice safe area right by the fuel pipe routing. So it's mounted, but still needs to be plumbed and powered.
Fuel pump mounted

Next on the list to accomplish today was getting the engine's wire harness through the firewall for the ECU. I found a good spot on the passenger side firewall, outboard of the washer fluid tank. There was a plug with a small hole there as it was, just had to make it larger for the ECU harness.
The routing location, you can barely see the previously plugged hole that determined the location.
The ECU harness routed

The final items I finished with were getting the coolant lines connected on the back side of the engine. The power steering reservoir mounted and plumbing finished. And getting the brake booster's vacuum line connected.

That's the update for this weekend. Tomorrow I get to take pictures of other cars! I can't wait!

KC30 · **Posted:** Wed Aug 04, 2010 9:05 am

Well, even though I haven't worked on the Laurel since Saturday, some progress is being made.
Sunday I took the day off, went to the Okinawa Super Drift comp. I posted some of the 926 pics in an off-topic thread here: viewtopic.php?t=10892

It was a pretty good day, hot and it down poured for part of it. Which made it a little interesting. But there were some good cars and drivers.
There were a couple of old show cars, some ae86's, and a couple of distant cousins of my Laurel.

So, back to the little progress. I test fitted the original radiator, and it won't work. So I should have a 300zx radiator in the next day or so for it.
Also, the original drive shaft was too long, so I got it with the S13's larger UC knuckle and input grafted on the front of it. That way the driveline's weakest point should be the tail end of the driveshaft. The safest place I think. Here's a pic of it, not too exciting: New Driveshaft setup

Eric · **Posted:** Wed Aug 04, 2010 10:46 am

now i can see the difference in gearboxes. with the sr20 gearbox i am using i cannot bolt the original trans mount back to the chassis like yours. i must use some sort of spacer to mount it.

you are making good progress again!

ill have my holiadys in two weeks, cant wait to get working on my c30 again.

KC30 · **Posted:** Tue Aug 10, 2010 9:46 am

Eric wrote:

now i can see the difference in gearboxes. with the sr20 gearbox i am using i cannot bolt the original trans mount back to the chassis like yours. i must use some sort of spacer to mount it.

Yeah, I was looking at it today and noticed that if I had the SR trans in it wouldn't be able to fit as well as the RB's.
And today I got the driveshaft installed, fits perfectly! I was sweating that I somehow screwed up the length I gave for it to be made at. Even though I checked over and over again, I was still paranoid. It's the Laurel's drive shaft with the 180SX's U-joint and trans stub shaft. Here's pics:
Driveshaft installed 1
Driveshaft installed 2
Though it'll stay this way for shipping and getting the car home, I intend to put a driveshaft loop in for safety is a u-joint fails. Like I said before, the front U-Joint knuckle is stronger than the rear, so the rear should go first if something happens, safer than the front failing.

So, other things since last time, I got the brakes bleed now. I started working the fuel system. I've got the fuel pressure/feed connected in the engine bay with the filter needed for an SR. I have to cut the line by the pump and connect it. I started checking out the return fuel line routing, and came across something a little odd. It looks like the tank and car were designed to have a fuel return line... almost like it was available with fuel injection. At first I saw the tank....
Fuel tank and lines, top is capped off
I thought, wow, there's two lines already, the top one being capped off. So I'm wondering why it would be setup like it was for fuel injection... but then think it must have been something someone else did, and had the tank modified. But then I started following the fuel feed line, and everywhere theres a slotted clip in line clamp, it's got a second open spot for another line... Then I get to the wheel well where the line goes through and I find this as well:
Fuel line through wheel well with second spot
Yep, there's a factory routing plug with the second spot for a fuel line. So it's certain that this was designed for a second line. The KC30 Laurel was only available with the G18 and G20 engines. So being as my G18 obviously doesn't use it I have wondered if the G20 does.

Anyways, I honestly didn't have time to ponder that puzzle, because I have been faced with a more difficult one. And that's the radiator. The radiator that was in the Laurel was not the factory original one (could tell where it was mounted). Which wouldn't be too much of an issue, except that the outlet on the passenger side now has a power steering hose routed through there and won't work. I have the 180SX donor car's radiator and grab it, too tall. I think, maybe the 300ZX radiator fits better, it's a commonly used one for tight spaces. But, come to find out... it's WAY too tall! So I get my measurements and go searching for a radiator. I find one in a Mazda Familia, that measurement wise was right at the limits and looked ideal. So I picked it up, but I didn't see that the drain cock at the bottom sticks out 1/2" and didn't include that in the measurement. The result is, the hood would hit it. So, back to square one. But I did find out news of a radiator shop here that I will try to see tomorrow. Then I should be able to get the ports moved to where I need them on the radiator that was in the Laurel (which is brass and 2 core).

Edited to update with better photo of fuel lines from tank

Eric · **Posted:** Tue Aug 10, 2010 12:47 pm

nice to see you are making everything easier for me

I think i will go for the rb20 gearbox as well, i lik ethe way you fitted the gearbox on the original mount, and how it sits way high in the transmission tunnel.

weird thing about the fuellines though, maybe datsun had plans for a different engine but they never got that far.

will you be using a swirlpot ar anything like that in the fuelling system? or fill up the tank with foam to prevent the fuel from slapping etc?

i ahve been looking at radiators too, i had the original radiator in it but the in and outlet are on the wrong side. stock s13 or s14 radiator is way to big. let me know what you find out

datsunboy · **Posted:** Tue Aug 10, 2010 1:40 pm

na, the second fuel line probably wasnt for fuel injection.
a lot of 510's came with a return line installed to the carby.....dont know why.
they just had this little return fitting on the side of the carb......maybe it was some sort of emmisions thing? I dunno.
a lot of 510's didnt have the return line also (all L16 engines), so I dont know why they chose to have or not to have the return on different cars?

KC30 · **Posted:** Wed Aug 11, 2010 8:53 am

datsunboy wrote:

na, the second fuel line probably wasnt for fuel injection.
a lot of 510's came with a return line installed to the carby.....dont know why.
they just had this little return fitting on the side of the carb......maybe it was some sort of emmisions thing? I dunno.
a lot of 510's didnt have the return line also (all L16 engines), so I dont know why they chose to have or not to have the return on different cars?

Thanks for that info! At least the option of a fuel return from the carb makes since.

So today was to continue the fuel and cooling systems. To start with, I checked around on radiators... and thought about either the route of using a performance three core radiator for the Toyota Starlet Turbo (EP91) or getting a custom made one. But both are options I don't have the time to wait on. So going off some info a friend gave me, I took the radiator that was in the Laurel to a radiator shop and having them change the outlets.
So I'll see soon I hope.

As far as the fuel system, I started plumbing the fuel pump... here's a pic of a not so great attempt:
First attempt to plumb fuel pump
As far as what fuel system intended, I plan to use a surge tank down the road, but for now it's just using as is for the most part. The only change, after opening the fuel line, I found it full of debris. So dirt or whatever in the tank and line became a concern. So I blew out the line from the engine to where I cut it. So that part is cleaned out, now I still have concern from the cut to the tank. So, for now I intend to install a second fuel filter right before the fuel pump. Something that may actually remain in the long run, doesn't hurt after all.

The last part was just cleaning up the engine bay. Pulling out the old coil and the electric fan relays that were added when the radiator was once swapped. Here's a not so interesting pic of the engine area:
Engine bay
I covered all the exposed old engine wiring and it's all ready to be finished.

Lastly, I figured I'd throw a couple of other pics in. First another view of the trans, with the new driveshaft and the original speedo connected:
Trans-shaft-speedo
Next the interior:
The new shifter in the interior
I test fitted the center console with the new shifter location. I'll be able to just install it about 2 inches back from the original location, and it'll look like it belongs there. The forward cut out was where an aftermarket cassette tape deck was installed once. I'm hoping to use the spot for a few gages to monitor the SR without changing the original instrument cluster. The best part is that I won't have to change the shifter cut out at all. I'll be getting a short-throw shifter down the road, which will make it even nicer, but will work as is for now. Also, I'm planning to install the original wood shifter with the 4-speed markings.

KC30 · **Posted:** Thu Aug 12, 2010 8:28 pm

Well, there was another day of good progress. In the morning I picked up the radiator, already done and an outstanding job!
I'd forgotten to take pictures of the radiator before the modifications, so I'll try to describe them properly. The radiator has been modified to sit in the Laurel opposite of the way it used to.
Radiator new front side
Radiator new back side
So, the way it used to sit, the tank cap was on the passenger side. If you look at the "new front side", it used to face the engine and the bottom outlet used to be on the lower left, and was a straight outlet. The upper outlet used to be on the upper right, and was a 90* outlet. There also used to be a temp sensor and drain cock of the lower half of the right tank. All that was removed and capped off and now faces the front of the Laurel. To help out with picturing this I've got a picture with the changes marked:
Radiator marked the way it used to be
The radiator used to have mounts in the vehicle that made it sit about 1 1/2" higher than it needs to. So I removed the mounts and cleaned up the front area for the radiator to go in.
Radiator mounting area
Next to get the radiator sitting a little lower so it sits in the path of all available air and better with the fan location, I made low profile bottom mounts. They are urethane pads with a urethane snub for the radiator to set on:
Radiator lower mounting
For the top mounting, it's a simple bracket and urethane pad setup:
Radiator upper mounting
Radiator mounted in finally
Next was the tank lines and fan. I still have to get the upper line installed:
Radiator lower line spacing
Radiator upper line spacing
Radiator fan installed
Radiator lower line installed

Getting as far as I could on that, I decided to get the turbo to intake piping done up. For those that don't know, to get the Laurel driving and shipped, I'm running without intercooler for now. So I installed the usual S13's pipe over the radiator and it fits good:
Turbo to intake plumbing
It does clear the fan despite how the picture looks. The only part left is the hose to the throttle body.

I also worked on the fuel system a little bit. Sorting out the fuel filter mounts. I used R33 fuel filter brackets for this:
Engine feed fuel filter installed
Fuel pump fuel filter bracket installed
For those that didn't catch, I decided to install a second filter prior to the fuel pump due to debris found in the line when I opened it.

KC30 · **Posted:** Mon Aug 16, 2010 7:12 am

So, since the last update, I have been chasing wires. I'm trying to sort out all the wiring so that it will be ready to start by Monday. (Start only, still have to get the throttle cable ran)

So, I used the great, fabulous internet, and it took hours of searching to get the info I needed. But I pieced together the info from about 4-5 sources and have a good wiring idea that should work out. I'll find out when I turn the key and the ECU smokes (did that once on my Skyline)!

Yesterday I used it to get started, I made the relay setup with fuses and started running wires. Something that has added time is that I am also relocating the battery to the trunk. Mainly due to lack of space because of the SR's intake and the coolant overflow tank I'm adding. I got the ECU harness relay setup and neutral switch wired. I got the power (positive) side of the wiring ran from the trunk to the engine bay. I started working on the RH side wiring (Starter, Oil Press, Alt) and found I'd forgotten to mark the wires during the engine removal, so I had to hunt down the oil pressure switch and starter signal on the Laurel's harness. Found those and wired to the new components. I then started on the alternator and hit a road block I didn't think/know about. The old alternator uses an external voltage regulator... The new one is internal. I found this out when I looked at the connector's markings on the old alternator and found it marked F & N, which I haven't seen before now. I started ohms checking wires and got results I didn't expect. So last night again on the internet, and found out how to disconnect the old voltage regulator and jumper it for the dash gen light signal.

So today, I spent the morning collecting needed parts and I corrected the Alternator wiring and kept running wiring I was still working on. I wired in the ground (negative) side to the trunk for the battery as well.

Here are some diagrams showing the wiring into the KC30 Laurel and a couple of pics of the voltage regulator connector jumper. I have to say, that the source ideas for drawings and info are by no means mine. I hope that after I have this swap done that I will have time to redo the drawings and list all the various sources, without their help it would have taken me forever to figure out the wiring. The ECU harness relay wiring did not work as shown on this link
ECU harness relay wiring DID NOT WORK (front engine bay connectors)
RH side wiring (minus Alternator)
Alternator wiring
External Voltage Regulator and connector (already disco'd and jumpered)
Voltage Regulator Connector jumpered for Dash Gen Light

Edited to say that the ECU harness relays wired as above did not work.

KC30 · **Posted:** Tue Aug 17, 2010 9:30 am

So, today I installed the upper radiator hose and added some fluid. I also finished the wiring and installed the second fuel filter just prior to the fuel pump.
Here's a link to the picture of the new fuel pump with filter setup
So, I figured everything's in, give starting it a shot... Here's the pics of the ECU and Key, ready to go:
Getting ready to start ECU
Getting ready to start key
And so I gave it a shot, starter turns... and that's it. I listened, but didn't hear the Fuel Pump kick on and we've checked and there's no spark. My instinct is telling me the ECU didn't turn on. But, I ran out of time and will have to try to figure it out tomorrow. I know I'm going to take out the Fuel Pump relay (which has the ECU tell it when to turn on) and run it off the original fuel pump power so that I can start narrowing things down.

KC30 · **Posted:** Wed Aug 18, 2010 4:56 am

Today I started where I left off... engine not starting and trying to figure out wiring. So I started by undoing what I had done for relays, re-looking at all the diagrams and re-evaling some of the wiring. So, I started with the fuel pump, the KC30's wiring harness has been unchanged and used a fuel pump for the carb, so I decided to wire it off the existing fuel pump control. So just wired the 20A fuse and power to the pump off the existing power on the KC30 harness (green wire). Next, I re-looked at all the two relays left... and found that the Nissan relays have a picture of the relay working on top (which I used for reference), but that unlike most relays I've seen before, the picture doesn't correspond with the pin locations... So I had them wired incorrectly. So I rewired the relays, plugged it all in, ECU showed power... go to start, still nothing. Again I looked at all the gathered info I had, and I noticed that it was split on if you should use a relay or not for the ignition, coil and sensor wire's power. So, I took the relay out and wired them directly to the fused power from the switch "on" position, supplied by the old coil wire.
I go to start it, thinking here it goes again, it's not going to start and I'll be utterly confused... Turn the key, watching the timing light for sign of spark, expecting nothing... And then light and a loud noise... Scared the crap out of me, it started! Finally!!!!

So, here's the new ECU harness wiring diagram updated to reflect the new setup:
New ECU Harness wiring/relay setup

Also, here's the engine starting!!!!! I love the sound of it, in this it's actually running exit pipe only (no down pipe) and the sound you'll hear in the first part is the shop fan. This is actually the 3rd start. Like said above, didn't expect the 1st on, and the 2nd I was just too excited to think of recording it!
KC30 Laurel with SR20DET starts!

Now I just have a few things to do to get it on the road. I have to fill the diff with oil, new throttle cable is in, but need to install pedal (kinda important) and install the down pipe. Once that's done, it's time for a test drive!

1970 Nissan Laurel KC30 coupe w/ SR20DET

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