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1985 z31 300zx ls swap


Mikepad3

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Hi I'm new to this whole forum thing,  but I decided I would do one to share my ls swap into my z31.  I am a college student majoring in engineering and I work part time at a structural steel fabrication factory.  I have been around cars, dirtbikes, drag cars and anything with a motor my whole life.  Partly due to my dad being a Automotive instructor who literally eats, sleeps, and breathes cars and his father before him was also a Automotive instructor and is the same way(aka my grandpa).  So I have acquired a lot of information from them and I also took my dads two year course in high school so I'm pretty efficient on general car knowledge and working on them(third in state skills USA automotive written no big deal also competed in Ford AAA state contest.).  Anyways I am new to nissans I have worked on some but only newer 2000 plus models so I am extremely new to 80s nissan technology and aftermarket.  I was originally looking for a junker 70's or 80's GM car to swap this engine into but the z31 was cheap and was also in decent condition. It has very little rust and the interior is clean.  The car was originally a vg30e non turbo with a FS5W71C 5 speed in it.  The engine's timing belt had slipped and bent some valves due to the car being an interference engine.  Anyways I decided the Z31 was going to be a better platform for my 5.3 which is the motor out of my 2001 Chevy silverado.  I had it because I put a new motor in my truck awhile ago.  It was an engine I built myself bored it over 40 and put flat top pistons in it.  Anyways so I know the last 3 years history of the 5.3 I'm putting in my z31.  The engine has 240,000 miles but it still ran like a beast when I pulled it from my truck I just decided I would rebuild my daily driver motor first so it won't die on me while I am pouring all my money into this project.  Being a college student this build is going to be on a tight budget.

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I have already started and pulled the motor and transmission.  I was very surprised on how easy it was to pull the engine and tranny out.  I assumed it was going to be a pain, but in reality I have pulled small block chevys out of trucks that have fought me harder than this thing did.  This was only the second time I have ever pulled a motor without a lift and even with out the lift this was an easy removal.  I am now figuring out how spoiled I have become without my dads arsenal of automotive tools and equipment and instant advice.  I was on the automotive gravy train before; having unlimited access to the schools equipment like tire machines, parts washers (which I would kill for now), alignment machine, brake lathe, anything you name it.  And my dad also has a huge shop with a lift and nameless tools and spare parts.  Now I only have a limited amount of tools and it SUCKS.

 

Here is some pics of the car

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Edited by Mikepad3
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The motor Im putting in is a 5.3 lm7.  It is bone stock and has a wopping 240,000 miles.  I am putting the Edelbrock 28457K msd carburetor kit.  Which comes with the intake for the carb, msd computer and the harness.  I was going to try and do fuel injection, but I am on a budget and this will be easier to wire and just simpler all around and did I mention cheaper.  I am going to use a Edelbrock 750 cfm I already have it but it has been sitting around for awhile so I will probably need to rebuild it.  I should be able to use the factory fuel lines and fuel pump but I will have to put a pressure regulator on the line to get my 6 psi.  Also a negative con to the carb swap is there is gonna have to be a hole in the hood also probably crap mileage but I don't care.

 

Here is a pic of the motor 

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I have started prepping the motor for my first test fit. I have been doing some research and I read another guy thread on a z31 ls swap and he said he had to use an f body oil pan and block hugger headers which I have already ordered.  I have not ordered the oil pan yet because I am doing more research into my options.  If anyone is even reading this and know what others have done or maybe yourself about oil pan clearance that would be cool if you could let me know.  Right now I am contemplating maybe doing some hackery and sawing the bottom of the truck oil pan and welding it back on.  My only concern with this besides the obvious sketchiness is, I don't know if this is going to interfere with my pan baffle and pickup tube.  I will have to investigate this week.  

 

Anyways I started cleaning some of the 15 years of gunk of this engine and installed a knock sensor delete plate while I am waiting on the headers to come in this weak. I just don't want to sped 300 dollars on a freakin oil pan and pickup tube.  So I plan to search craigslist and local contacts a little bit before I jump into the oil pan. 

 

Here is an update on the engine

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My basic plan is as follows

 

Transmission =

 

    turbo 400 or 350 but most likely 400.  I plan on finding one on craigslist or from local contacts.  I'll most likely have to rebuild             the tranny, but I'm hoping I can buy one from someone I know that knows it works so I won't have to spend the money on                 rebuilding it and I can put money into other parts of the build.  I am no matter what going to put a full manual valve body in it             because they are awesome.  I wanted to stick to a manual transmission, but that was going to cost to much and the th400 will be       an easier install I won't have to worry about all the intricacies of that comes with a manual.

 

Motor mounts=

 

     I plan on fabricating these myself since I have access to unlimited scrap plate, pipe, tube, beams, and really any kind of steel            from my job.  I plan on just building a solid mount I think it will be fine. 

 

Front accessory drive= 

      

     I plan on using a stock f body front drive except for the AC.  I might use a corvette front drive as it will be about the same price          and will give me even more clearance.  We will see how it goes.  I hoping I can fab all the ac and power steering brackets myself      which I should be able to just copy aftermarket parts designs and I will have access to cnc plasma cutters at work so I should be        able to make some badass parts.  For the power steering I also should be able to hook a camaro power steering pump to the            z31 rack and pinion taking out the line and getting the right line with the right fitting crimped on by oreillys.  Hopefully that all              works out

 

Cooling=

 

     I am hoping the z31 radiator will work but I have a good feeling it won't I will also have to making custom cooling hoses shouldn't      be a big deal just money right (sarcasm which I use a lot sorry if this forum is hard to read).

 

Trans Mount and drive shaft=

 

     I will probably have to do some firewall massaging to get the TH400 to fit.  Do any of you guys know how they fit in the z31?

     I plan on fabbing my own trans mount might try to be creative and even put some kind of rubber dampening, but probably not.  

 

     For the drive shaft I should just have to cut it to the right length and then weld it back together with the right yoke on it and enjoy        the wicked drive shaft vibration I will have.  I don't know yet I might have someone else but I'm guessing not because I am too          cheap.

 

Fuel, ignition throttle

 

    I am using the edlebrock ls carb conversion kit like I said before and should be able to use the stock fuel system.  The carb kit 

    also runs the ignition so as long as I can get the power to it I'm good there.  It looks like also my stock throttle cable with reach my     carb perfectly.

 

Exhaust=

 

    For exhaust I bought some cheapo block hugger headers off of ebay and I'm hoping they will work.  Then I will fab some exhaust 

    pipes from there.

 

Electrical and everything else=  

 

    I will figure it out when I get there.

 

 

              

 

 

 

 

 

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hey man, you can check out my 530ZX build on the Chevy Gen III / IV sub forum and I believe nismokid's turbo ls build is on this subforum, and there are also a couple of threads on ls1tech.  As for mine, i did use the fbody oil pan with the fbody dipstick, pickup and windage tray and it clears perfectly with the crossmember and the dirty dingo engine mounts that nismokid helped get developed. 

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  • 2 weeks later...
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I just saw this thread.  :oops:  As jshapaka stated you can use his or my build thread for reference. I tested several oil pan options and the Fbody pan was the best fit. The truck pans work if you modify it but you'll lose oil capacity. The LS2 C6 pan kinda works but you'd need to modify the firewall to make room for the transmission bellhousing(I'd add this pan to the list of DO NOT FIT.)The GTO, C5, Autokraft, Trailblazer SS & SSR oil pans DO NOT FIT. If you'd like to take the guess work out of the engine mounts you can get the direct bolt in Dirty Dingo mounts which allow 3 inches of adjustment. At only 150$ they make life much easier. I'd buy them even if I didn't Co-develop them. As for the radiator the factory radiator or the Champion 3 row work just fine. To fit the TH400 or TH350 you'll need to massage the transmission tunnel with a BFH( Big F*cking Hammer). I highly recommend if you're going to solid mount the engine to also solid mount your transmission. You'll quickly find out what'll flex the hard way if you mix and match solid & rubber/poly mounts( It won't be the chassis. It'll be your transmission).  If your dead set on having power steering use the gm power steering pump then have custom lines made at a hydraulic line shop( I.E. Taylor Made). I personally have no problem steering my Z31 without power steering. For my last recommendation I'd weld vbands on those headers for ease of installation while helping with clearance. I hope this post helps you with your build. Nice car man B) . Oh here's a link showing My Vic Jr test fitting. The EFI and Carb  Vic Jr intakes are basically the same design, only difference is the injector holes being drilled out.

http://z31performance.com/showthread.php?25250-LSX-Vic-Jr-Intake-Manifold-amp-Aaron-elbow-Z31-test-fitting

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  • 4 months later...
  • 3 months later...

Sorry for the hiatus I have been busy with school,work, and life.  So the moral of the story is I stopped working on the car and it became a shop ornament for a very long time.  But thankfully I am back to working on it after almost a year.  So enough BS since my last post this is where I am at.

 

 

If you do this swap you will need an ls1 camaro oil pan or dry sump system but dry sump is costly

 

 

 

 

a picture of the oil pan on the motor below

 

 

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Edited by Mikepad3
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After getting the oil pan installed on the motor I started doing engine bay cleanup.  I took out everything I wasn't going to use like wiring, ac stuff, manual trans stuff and etc.  

 

After removing all of the excess the engine bay looks much more inviting for the ls

I also borrowed a th400 shell to use for a transmission mock up 

 

 

Before and after pics shown here 

 

 

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Edited by Mikepad3
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So the next step was dropping the motor and trans in and see if they were going to fit.  The motor was installed using a trolley crane (A beam attached to my shops ceiling with a chain hoist that slides) and a motor tilt installer.  The motor sits perfect in the car.  I only had to do a little fire wall manipulation to get it to fit.  I actually ended up cutting a piece out of the fire wall for clearance and it ends up I probably didn't need to do that.  

 

I have also purchased a th350 with a shift kit and a 3200 stall off craigslist for the transmission.  The guy I bought it from said it had low miles and I believe it( So hopefully this tranny doesn't come back to bit me)

 

Really the only issue with the motor placement is the carb is going to sit a little above the hood line so I will have to have a cowl hood. 

 

 

 

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I plan to keep you guys updated more frequently, I actually have a great deal of work done to the car, but I still have to find the time to post all the details and pics. I have been working pretty hardcore on the car for the last few weeks and have bought and installed many parts and can't wait to share my progress when I find the time.

 

 

 

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After installing the motor and confirming it was going to fit with no clearance issues I started fabricating motor mounts out of the old Nissan motor mounts.

 

 

(For reference ls motor has an ls1 camaro oil pan, block hugger headers and a th350 attached to it.  So any others trying this should note the ls motor will fit in the car and honestly its not a bad fit and with the right equipment is really not that hard to install.  The only thing you have to be cautious about is the heads on the motor are near the brake lines on the fire wall so you have to be careful to not damage them.) 

 

 

As I have mentioned before I fabricated motor plates with 3 inches of travel.

 

From there I just centered the old Nissan mount on the motor plates because miraculously the old vg30e motor is about as wide as the 5.3 ls so the mounts only needed to be modified a little bit.  Its almost like this car was designed for the ls.

 

So I then tacked up the mounts to the desired location and welded them up 

 

here are some pics of the mounts in post-51623-0-18284400-1481184884_thumb.jpgpost-51623-0-07645800-1481184892_thumb.jpg

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After installing the motor mounts I started working on fabricating a trans mount 

 

The Th350 already had a rubber mount on it so i decided to make use of it.  Although Nismokid has a good point about the mixture of solid and poly mounts can damage the transmission I have already fabricated the mount so I'm just going to see what happens I can always re-manufacture the mount. 

 

The mount was made from the old Nissan mount and 2 inch pipe 

 

It actually turned out nice my redneck engineering and fabrication skills are unmatched 

 

here are some pics

 

 

 

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Edited by Mikepad3
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