xsamis

Good afternoon everyone!

EDIT: i am editing this threat to make it way shorter now that times have changed and new advancements have been made:

I'm making this thread to put a whole bunch of things that I have learned from this thread but mainly by just doing it.

The reason why I'm making this thread is to help someone out so they don't have to spend thousands on mistakes. I've been through about 7-8 motors so far so I've made a lot of mistakes lol. First off ill address the main motor building then other information below: PS: sorry for the spelling and grammar errors I was using talk to text.

You can build a block in your garage the "cheap way" and you can build one the "Expensive way"
Cheap way: Tear the block down yourself, make sure the block is in good health and use a ball hone to hone the cylinders. You can get stock bore pistons and plop them in. Rods/pistons/crank need to be balanced. Put the block back together and you have a 700+ WHP capable monster

Expensive way: Send the block to CSS for block support and get the copper ring grooves put in

The parts you should use on both builds:

OEM bearings (best imo)
ARP stud kit
soho 625+ head studs or L19 at the very least
eagle rods, wiesco pistons. (Carrillo rods if your going expensive route)
leave the heads alone, cams dont help
OEM rod bearings
dynosty or oem head gaskets (cheaper then dynosty)

Thats it.

The second thing is that the clearances on the motor are extremely tight and I would probably loosen the clearances but if they are too loose then the motor won’t work correctly. The VVEL motors need a certain oil pressure for them to work. If you are running into timing codes and everything else checks out, meaning the crankshaft and camshaft position sensors are fine and the teeth on the flywheel are fine then chances are that your cam phasers are bad or you have the oil gallery gaskets leaking.

Cam phasers can also get stuck. There's a thread by Jim Wolf tech that shows how small of a difference they look but the car will run terribly and think its out of time. There are pictures for it and they released a PDF showing the correct position and one that has failed.

Fifth gear is usually what kills these motors. There's a lot of strain while the car is in fifth gear and you’re at WOT.

A closed deck block alone does nothing for the head lift. The current solutions (that dont really work) are: ARP 625+, top fuel hoop from soho, CSS copper ring, Dynosty headgaskets


Ring gap: The ring gap is based off many factors, follow the instructions that Weisco gives you to determine your ring gap. I usually do it on the looser side, especially if you’re gonna push the car and the car is going to get hot. One of the issues that nobody really talks about with a VQ is when you're boosted the rings are way too tight and the piston will actually crack at the groove where the piston rings sit, from the rings getting too tight due to the extreme heat.

The heads are just heads if they work fine but the one thing you have to be worried about is when you take off the VVEL motor that you need a position it back into the right spot. How you do this is you grab an angle gauge, set it on top of the VVEL cam, move the cam until it says 5.5° and then line up the VVEL motor with the holes on the VVEL cam. I know they say not to take off the VVEL motor or else you need to replace it but it is almost impossible to put the gasket maker on the back of the VVEL motor and have a clean contact with it without it getting everywhere.

Then you can then use Z1’s scan tool, which I find is easiest, to get the sensors within range. If not then you can go to the factory service manual and there is a box underneath the battery where you can scratch off some of the insulation on the wires and use a gauge to find how many volts are going through. There's a whole process for this in the factory service manual.

For a gasket maker I would only use the Nissan factory gasket maker. It works really well and it is relatively cheap if you buy the big tube that goes into a caulk gun.

One issue that isn’t talked about on this form is that when you replace the main stud kit with ARP studs they are torque down to 65 foot pounds which is more than the OEM main stud kit. You need to make sure that this gets re-measured so that you can know exactly where and how much clearance you have. On the crankshaft there are numbers and letters that you can go on the Z1 website or the factory service manual that tell you how thick the camshaft is and what type of bearing you need for that thickness. You then take that and the measurement that you take from the main housing journal and that will tell you which bearings to use. There are also codes on the block that tell you what the OEM Clearances are for the main journal bearings. Once everything is together it’s just a simple bolt on process. Make sure you follow all of the instructions on how and what pattern to bolt them in and each main stud has stages of torque you need them to get to. If you have new piston rings you want to make sure that the cylinder is honed. Also you wanna make sure that the cylinder isn’t scored or out of round which I mentioned above. Do not forget to balance out the assembly.

What i did for my bearings is i actually measured them with a dial bore gauge and Nissans recommendation was WAY too tight. I would recommend buying a dial bore gauge and finding the exact measurement because the recomendation from nissan cost me a motor. Bearings were too tight and one of them spun

I have also found that when you were changing your galley gaskets that it is best to use Allen style bolts instead of the OEM Phillips. You can torque them to spec. I use Loctite on them just to make sure they stay in place. Another thing I would look at is your tensioner if your tensioner is clicked out 7-8 clicks and your previous motor overheated, The chain might be stretched. This is only if your re-using tensioners and chains.

Now let’s talk about oil, this is what killed my first motor. I used to use purple power and while purple power is great it doesn’t work great for our motors. It gets burnt up, our motors run hot. I have also used mobile1 which has done the same exact thing. The one brand that I have had a lot of success with is Amsoil. They are a little bit more expensive but they are hands-down the best oil to use In my opinion for this particular car. Regarding oil coolers: 34 row is a little bit of overkill unless your F/I. If your in a very hot climate i would look at a 34 row as well. The 20 row works just fine for a N/A car. Track applications N/A i would still use a 34 row.

Regarding clutches: my favorite clutch is a Z speed clutch: I have used South Bends and I’ve had bad luck with them. Make sure that all the hardware is exactly the same. If you have one bolt that is different It can throw the assembly out of balance and you’re gonna have issues with your clutch. Also you want to change out the CSC. I use the reinforcing CNC. I have had the kind where it relocated the CSC outside but that has failed on me as well due to the pivot arm getting stuck. Also some turbo kits dont work with the CSC delete kit.

Regarding fuel lines the CJM return kit is amazing. That's the only fuel system that I would be willing to put in my car. Fuel pumps I would say the hellcat fuel pump or a Walbro 450 compatible with 85 which is called a Walbro 485.
The injectors: Injector dynamics or just stick with stock. If you’re going to boost the car: ID1050’s or for E85 N/A: GTR injectors or ID650/750’s.
Install a fuel pump relay also.

Regarding turbo kits: My favorite turbo kits and what I think the Z really likes is a single big turbo.
Twin turbo kits have a lot of torque and torque kills these motors. If you plan on sticking with a stock block just get a single turbo kit.

Rear mount vs Top/Mid:
Rear mounts have a lot of lag.
Mid/Top mounts, not so much.

Regarding Journal bearing versus ball bearing I know everybody loves ball bearing turbos but the journal bearing is a lot more forgiving. I had a ball bearing turbo in the beginning and it blew up due to coolant entering the oil from the head lift. I had to rebuild the turbo entirely which cost as much if not more than just buying a new turbo.

My journal bearing also went through the whole head lift issue on the next motor i had but didn’t blow up. Journal bearings have more room for oil to cool the turbo. If a ball bearing turbo fails you have to stop the car and get it towed. If a journal bearing fails you can drive it home.


For my N/A guys: The best mods in my opinion are to have ISR long tube headers as they don’t break the bank and the fast intentions exhaust or a Tomei depending on your budget.

Regarding tires or wheels: The R888R by toyo are the best for traction but they cost a lot and get worn down quickly.. Michelin pilot sport4s are also very good tires that dont wear down as quick.
Wheels: stock touring/Nismo wheels OR te37’s are the only wheel i would use. The weight on any other wheel is too much. You can use Enkie rpf1’s but those are an 18in so you would need a little bit of a thicker tire to make the car look aesthetically pleasing.

Tire size: I’ve tried different tire sizes. The best in my opinion is 305 in the rear and 265 in the front. The car still handles like a beast and it has enough traction. I would also get the SPL rear camber arms if your car has spacers or is lowered.

When it comes to coil overs the best IMO are the V3‘s by KW. Anything else I would not spend my money on. I would rather get KONI shocks and some type of springs, probably white line or Swift. The problem with coil overs is that eventually you’re gonna have to rebuild them. KW’s have a lifetime warranty. If you’re in an area that has a lot of salt the KW also cover salt damage in the warante.

Breaks: The best rotors in my opinion of the Z1 two piece rotors. When it comes to the pads: Project MU if your N/A
F/I: I would look at endless pads.

I think I’ve covered almost everything here. The factory service manual is very helpful.


Coolant: I would run the Nissan OEM blue coolant. Everything else is garbage. I also would not run redline transmission fluid in my transmission. The OEM Nissan transmission fluid is amazing and it shifts in my opinion way better than the red line at hot or cold temperatures.

Also if you don’t like stability control, you can take it off by pulling the fuse. It is right underneath where those three fake buttons are on the armrest.