Sean's '73 240z

[X64v]

So I've been meaning to do this for a while, but haven't ever really found the time to sit down and do it all at once, so I guess I'll do it in parts until I catch up to where I am today. My 240 actually started with my father, who bought the car from its original owner right about 1980. He daily drove it and auto-x'd frequently up through 1988. He kept it fairly stock, but did the usual upgrades like wider wheels/tires, bigger sway bars, stiffer drop springs (2" drop back then), urethane bushings all around, etc. (all from Motorsport Auto back when it was first starting up; we lived just around the corner). In the 2nd week of 1989, the engine developed a nasty rattle (turned out to be a broken cam spray bar), and the car was temporarily retired. Well, I was born the next week, one thing led to another, and the car never got fixed. Fast forward 15 years, I was 15, and in love with the car (even though I'd never heard it run or ridden in it or anything), so I decided to get it running again. This is as far back as I can find pictures.



I did eventually get it running in late spring '05, just a few months after I turned 16. My father decided that since I'd put so much work into it, and since it wouldn't be on the road without me, he gave it to me, and it's been my daily driver ever since.

More or less what it looked like in daily driver status:




I had gotten it running with a pair of '72 SUs. Otherwise the engine was bonestock.


So I drove it around like that for a few months, and then in late December '05/early January '06 I decided to try my hand at painting. Prepped for paint:


My makeshift spray booth (two pop up shade frames and a bunch of plastic from our new mattresses)


Primered


Painted. I had the spray pattern and settings wrong, so it came out a bit thick and rough, but overall it was better than before.


(Just water spots on the hood)


I drove it in that condition for another 11 months with nothing more than mild modifications (5 speed, cd player and speakers, etc.). That summer I got the turbo bug, and, thinking ahead, purchased and built a V3.0 Megasquirt I system. Some 338cc injectors, an n42 intake, etc. and I was on my way. Since I still had an E88 head, I had to drill the mounting holes for the FI intake, and notch the ports for the fuel injectors (it's not that big of a deal, I was able to do it without removing the head from the engine no problem).





That's all for tonight, I'll detail the turbo swap in the next update.

Edited September 5, 2015 by X64v

[X64v]

Alright, the turbo swap. I did this in June of '07. It was fairly straightforward, just collected the parts (turbo, manifold, oil pump, oil lines, etc.), pulled the oil pan and welded a bung in for the oil return, and bolted everything on. I did this mostly on summer nights way into the morning, so I have no pictures of this, but I do have pics of the engine in various states of assembly with the turbo.

 

First mock up. Note the total spaghetti dinner of wiring on the fender.

 

Just after the first test drive. J-Pipe is in the way, but all that wiring got cleaned up. Also note that the nice shiny painted manifold in the first picture isn't so shiny here. That "1200°" ceramic paint they sell at the parts store does not cut it on a turbo motor.

 

I've daily driven it in more or less that condition since June. I've done a bunch of smaller stuff like a cold air intake, 'dump pipe' exhaust (detailed here), better coil, JTR aluminum radiator (awesome product btw), etc. Another random engine shot that doesn't really fit anywhere, just taken while doing some work one day (btw the push on blue "super stock" line kicks the hell out of braided AN line in my opinion; much easier to use, super flexible, and very inexpensive).

 

I went to a track day in New Mexico in January (detailed here), and while it was a great time, I did end up beating my ringlands to hell. That's where I am today, hitching rides with my roommate to school every day, and rebuilding an F54 block in my bedroom. As long as my parts arrive in time, it should be in the car next weekend.

 

The head gasket told the tale of the death of my engine.

 

Cylinder 5

 

Cylinder 1 (2, 3, and 6 look the same as well)

 

The F54 block (out of my mother's old wrecked 280zx) freshly on the stand, ready to be worked over.

 

 

Parts removal

 

Stripped, honed, cleaned, and painted.

 

It's sitting like that at the moment, waiting for rings and rod bolts to come. I've got all the new gaskets, new timing set, new rod bearings, etc. already, and I'll be using the new water pump and turbo oil pump off the old engine.

 

For a cylinder head, I'll actually be re-using my E88. Before you dismiss this as stupid, hear me out. It's the '73 model E88, which means it's got the large 48.7cc chambers. On an L28 with dished turbo pistons and a standard fiber head gasket, that puts me at 7.9:1 SCR, which will be just fine for making more power off boost for daily driving, as well as being low enough to handle the boost. The valves are 2mm smaller each than a P90, but I figure turning the boost up a pound or two would take care of that no problem. It's already been rebuilt and in great shape, so my cost on that is $0.

 

That's it for tonight, we're up to date. I'll post more pics of the engine and swap as it gets assembled and installed.

[X64v]

A small update. The engine, totally stripped and disconnected, ready to be removed.

 

...And engine out!

 

I'm still waiting on rod bolts to finish the motor, and plus I've been too busy with school to make any significant progress on assembly anyway. I should have everything ready to go in by next weekend though.

[X64v]

The last of my parts arrived today (rod bolts, couldn't do anything without them), so I got straight to work this evening. Sorry for the crappy pictures this time, had to borrow my roommate's camera.

 

Pistons are in!!!!! (stock turbo dished)

 

Bottom end is all done.

 

I'll finish getting the cylinder head cleaned up tonight, and get it on and get the timing chain set up. Tomorrow morning I'll finish cleaning the front cover and oil pan, and then it's ready to go in (hopefully tomorrow afternoon).

[X64v]

Lots of updates for today. I'll start with what I did yesterday (Saturday).

Finished building the engine on the stand. Timing components assembled.


Front cover, water/oil pump, oil pan, and valve cover on.


The giant engine hoist from the rental place a block down. It looks like it could lift the entire car. Clutch looks the same as before, but it's hiding a 6 puck sprung disk from clutchnet.


With a helping hand from my father, the engine went in without much trouble at all.


And that was it for last night. Got up and assembled the engine this morning, but don't have any pictures during, just after.

Just back from the first test drive.






I'm really happy with its first run. No water or fuel leaks, and just a small oil leak on the right front corner of the oil pan. The engine has lots of torque (much more than I was used to with the L24). The new clutch disk isn't broken in yet, but so far I really like it. The sprung center really makes smooth shifting easy. This is the clutch disk I'm using.

I was tired of having oil all over my engine, and I wanted the ring-sealing benefits of pulling a vacuum in the engine block, so I decided to set my pcv system back up. Instead of drilling and tapping a hole in the underside of the intake manifold, there was a hole I had plugged in the underside of my '82 zx n/a throttle body which was the perfect size to take a 1/4" npt tap, and after the butterfly so it would be under manifold vacuum.



And installed on the engine.


Also, I owe a big thanks to Clifton for the turbo pistons and the recommendation on the clutch disk.

Edit: One final note, replacing the pilot bushing in the end of the crankshaft made a HUGE difference in the feel of the transmission while shifting. Remember how it felt to replace the warn out (or non-existent) bushings in the shifter? Well imagine that again. The whole thing feels so much tighter and crisper, I'm surprised it's just from a new pilot bushing.

Edited September 5, 2015 by X64v

[X64v]

All three or four of you who actually follow this thread are probably wondering why I haven't posted any updates lately. Well, about a month ago, I got rear ended on my way home from school. The damage:

 

 

 

According to my friends, the damage looks worse in person. There were no physical human injuries, but I've been super bummed out about it, and the z is a little worse for wear. No suspension or drive train damage, thank god, and the tail lights are intact, but the hatch is jammed shut, and the fuel tank leaks above 3/4 full. I'm going to get an estimate in a few days.

 

In other news, I also blew a head gasket at cylinder 4 the other night. I was also pinging all the way back to 20 degrees spark advance at 7psi, so I have an abnormal problem causing excessive ping. I think it's my cylinder head; it's designed for an 83mm bore, not an 86mm bore, and the edge of the chamber is pretty sharp. When I replace the gasket next weekend I'm going to radius the edge of the combustion chambers to take away the hot spot, and we'll see if that fixes it.

 

Also, my oil pan has been leaking like mad, with no end in sight, so I'm finally going to do something about it. Instead of battling with the thin stamped flanges on these damn things like everyone does, I'm going to have a 3/8" thick flange made up, cut the flange off a spare pan, and weld the new flange on. This way I'll have a nice big flat sealing surface that can actually be torqued a little without warping. Here's the design so far:

 

 

A buddy of mine is going to cut it on a waterjet. I'll run a test piece out of thin scrap to check fitment, then I'll have two flanges cut (one for him, one for me). If they fit and work well, I may consider cutting more up to sell. After that, I'll also post up the dimensions and Solidworks/AutoCad files for whoever wants to cut their own.

 

Almost forgot, I also threw on a 'Turbo' valve cover that I got for free (thanks Dan!) and got my 1g DSM B.O.V. on. I really like the sound of it, just a nice psshhhh on shifts.

[X64v]

I haven't updated this in a while. My biggest change has been my fueling system. I got rid of my 338cc barbed injectors for some 400cc o-ring injectors fed via a new pallnet fuel rail.

 

The last picture of the old setup

 

The new hardware

 

Installed

 

 

 

These injectors are a million times quieter than the others I had in before. I'm pretty sure it's because these are high-z injectors, while my old ones were low-z, so these don't snap open as hard. Also, I LOVE the Pallnet rail. Beautifully machined, top quality mounting hardware, and it sealed perfectly on the first try, no leaks, no resealing. It was worth every penny I paid and every minute I waited while it was on order. A piece of advice on seals: unless you have them already, just spend the $20 on his hybrid seal kit (if that's what you need). I needed the hybrid kit (14mm o-ring uppers, and stock datsun lowers), and it took me a few days, trips to three different parts stores, an online order, and over $20 to put them together. $20 seems a lot for the seals, but I would have saved money on gas and shipping if I would have bought his hybrid kit in the first place.

 

When I order the -AN fittings for my cylinder head coolant rerouting stuff, I'll order -AN fittings for the fuel rail as well. I'm bring a P-79 back down from Phoenix tomorrow, which I'll be rebuilding, probably sending the cam out for a regrind, and modifying the coolant flow. I'll have pictures of the bypass ports for the #5 and #6 cylinders pretty soon here. It's going to be a pretty cool little modification. I'll detail the theory behind it a little more as I actually do it.

 

Also, I've pretty much quelled my pinging problem by switching back to a 160 degree T-stat and pulling a little more timing. When I get the P-79 head on, we'll see what it does as far as ping.

 

A random picture of three Datsuns in the bays. Front to back: My 240, a kick ass 510 with a KA24de, and speedgato's 240.

[X64v]

I've got my cooling re-routing ports drilled. The theory behind them can be found in this thread.

 

 

 

 

See my posts in the aforementioned thread about drilling them, positioning, etc.

 

Hopefully this weekend I'll get all the valves out of this head and start removing the step in the exhaust runners.

[X64v]

Head is completely disassembled, and I got the exhaust ports smoothed out.

 

Porting in my bedroom

 

The cast-in step where the aluminum behind the valve seat dumps into the steel liner

 

Removed. It's now a nice gradual radius all the way through to the steel liner, which should flow nicely. The liner is also radiused nicely; I can see how these flow just as well as the square ports, even though they're smaller.

[X64v]

I felt like doing more work on the head, so I unshrouded all the valves. There really was tons of material to be taken out of the cambers that was totally blocking flow. For this (and the step-radiusing above) I used a sanding drum on a Dremel, 1/4" for the exhaust ports, 1/2" for the valve unshrouding.

 

Stock exhaust shrouding (all valves at about .490" lift). The smallest clearance between the head and the valve is about .060"

 

Unshrouded exhaust. The smallest clearence is now about .110", almost double from stock. It really is a huge difference.

 

Stock intake

 

Unshrouded intake

 

I owe thanks to BRAAP for his informative posts about removing the step in the exhaust ports and unshrouding the valves. If it wasn't for those posts, I probably wouldn't have done the carving I did.

[X64v]

I dropped the head off at the machine shop today to be hot tanked, have its valve seats recut, valves and guides and springs checked, made flat, etc etc, so that should be done in a few weeks and ready to go.

 

In the meantime, I picked up the materials for my new exhaust today. 10 feet of 3" aluminized steel pipe, and two 6" radius 3" mandrel U-bends. It's going to be 3" starting at the turbo (I'll make a 2.25" to 3" expander cone), with no muffler, and no bend greater than about a 45-50 degree angle. I'll get some pictures as I cut and weld it all up, it really is pretty massive. In Arizona the cops won't bother you if you're running a turbo without a muffler, the turbo keeps it quiet enough. I've heard a turbo is a legal muffler here, but I'll have to look into that some more.

[X64v]

I got my exhaust finished yesterday. Took about 10 hours of work to get everything tucked up and fitted the way I wanted. All bends are 6" radius mandrel.

 

Home-made 2.5" to 3" adapter

 

Downpipe section

 

Downpipe snaking around the tranny and floor pan

 

 

 

I kept it tucked up and against the floor pan so it wouldn't scrape on any but the largest speedbumps, and I can get the driveshaft and tranny out without removing it (I think)

 

Not using a muffler allowed me to use two ~45 degree bends instead of 90 degree bends (nevermind that fuel line, it's out of the way now)

 

I couldn't have done nearly as good a job without total access to a lift (the owner of the shop I work at is a great guy).

 

This is by far my favorite exhaust I've ever run. It's much quieter than a dump pipe, but flows pretty much just as well. If you lean over the engine with the hood open while it's running, all you can hear is the fan, valves, and faint sound of the clicking injectors, otherwise it's dead silent. Of course, out back it "sounds like a speedboat" as speedgato put it. Driving on the street it's totally mild, not obnoxious at all; I could easily listen to my stereo (once I get it back in) or have a conversation with a passenger, no problem. On the freeway with the windows down (240 style a/c), the engine is just barely audible at a 70mph cruise, and not audible at all at an 85mph cruise. If you give it some gas but don't get the wastegate open, you get a nice medium growl. Get on boost to pass someone (enough to open the wastegate), and the exhaust just screams like open headers; it's the perfect exhaust in my opinion.

 

In other news, the machine shop is 95% done with my head, they're just waiting on valve springs (medium stiffness ordered from Rebello). I'll have lots of pictures when it comes home Monday or Tuesday.

[X64v]

Cylinder head is done. I didn't take tons of pictures, we all know what a finished cylinder head looks like.

 

The guides and valves were all perfect, all the seats were cut (looked to me like 4 and 5 angle cuts), .009" was taken off the block mating surface to make it perfectly flat (the very front around the timing cover was all that wouldn't cut, the rest was much straighter than that). The manifold mating surface around the #1 exhaust port and the water outlet was really badly corroded and pitted. They took .100" off the surface, but it was still bad enough to not seal, so they welded up the pitted area and then surfaced it again. There's still a pit here and there, but it'll seal just fine now. The new valve springs came up at 110lbs seat pressure, seemingly about half-way in between stock springs and springs strong enough to require new retainers (these use the stock retainers). Dave Rebello says these are good to .500" lift, which is more cam than I'll ever run on this motor.

 

A few pictures

 

(The marks above 1 and 2 are finger print smudges)

 

 

 

I have some other things that will require my financial attention these next couple of weeks, but after that I'll get this head on, get the coolant lines routed, and get a few other things done I've been planning.

 

By the way, if anyone needs machine work done for any motor in the Tucson area, take your business to Machine Works on Stone and Elm. They're a great shop, very competent and knowledgeable, and have great prices to boot. All the work done to this head ran me $255 out the door.

[X64v]

Having my stereo in the stock radio location was really a pain to install/remove. Since I had to take it out anyways (and didn't want to put it back), I moved it to the tranny tunnel. I used one of these, and it worked out really well.

 

To secure the stereo, one just bends the tabs on the little metal bracket that comes with your stereo.

 

It's very secure, there was no reason to use every single screw hole. The tunnel curves in such a way that one can't use the holes in the lower right corner anyways, but it doesn't rattle at all set up this way.

 

The wiring is just barely visible here. I ran it all under the driver's seat, and through the center console.

 

It clears my leg just fine, I don't even brush up against it while on the gas. (Please excuse all the dust, hehe)

 

This stereo is going out, though, so I'll be buying a new one in the near future here. I'm going to get another Blaupunkt, but this time it won't have a CD player, just an SD card slot (I just loaded my CDs up with mp3s anyways, this will save me CDs).

 

 

My new meats.

 

They're Kumho v700 Victoracers, 225/50/ZR15. They have about 40% life left on them, not bad for free tires. They're going on the Sportmax XXR 15x8s I'm ordering next week.

 

 

I've got all the gaskets I need to get my new cylinder head on, and Friday night I ordered an ARP Head Stud Kit ($150 shipped on eBay), a manifold stud kit, and all the -6 AN lines I need for my fuel lines and coolant re-routing. The new head will go on next weekend.

[X64v]

My new cylinder head is now on the car. I stayed up all night (literally, 8pm to 6am) Monday night/Tuesday morning to get it done in between days at work. Swapping over the valve train took quite a bit longer than I thought it would (I re-used my previous cam, rockers, lash caps, and adjusters). Good news, I haven't heard any ping yet. I'm at 25 degrees at 7psi at the moment, so I'll get out and get the tune dialed in this weekend. Anyways, on to the pictures.

 

It's like a pile of aluminum treasure.

 

-6 AN fittings installed. I used pipe dope on all the pipe threads to seal them up.

 

 

 

Where/how broke college students get to do their work.

 

A forest of ARP head studs ($150 shipped on eBay). They're wonderful to work with.

 

The bare aluminum is a bit over-exposed, but otherwise I really like this picture. (Yes, I checked my wipe pattern, those lobes are not running off the ends of the lash pads).

 

The coolant bypass lines. The hose running from the T connects to the metal Y pipe where the original carb heater line used to join in with the cabin heater return. I'll get a better picture of that tomorrow.

 

 

The engine is running great so far. I had to enrich my entire fuel map by 8% to return my AFRs to normal; I would assume that means this head flows 8% more air, which would mean 8% more power. I haven't gotten a chance to really beat on it yet, so I don't know how well the coolant bypass lines are working yet, I'll get a better feel for it this weekend.

 

 

I also got my wheels in, tires mounted, and them all on the car. I'll take some decent pictures tomorrow after work (weather permitting), but here's a teaser:

[X64v]

A day late, but here they are. All pics were taken on the University of Arizona campus.

 

 

 

 

 

 

 

Disclamer: My roommate post-edited these just a touch. If you see it in person, it has a big scratch down the driver's side door. All other body work defects are as pictured.

 

 

This wheel and tire combo weighs in at 40 pounds even, 5 pounds lighter than my old combo. I really, really like these Victoracers; going from a street radial to a D.O.T. slick is like going from a golf cart to a shifter cart. The sidewalls are super stiff, and I have all the traction I can use and more on the street. They do follow every little rut in the road (and go wherever they want if there are no ruts), but it's not too bothersome.

 

The quality on these wheels so far has been just fine, definitely more than you'd expect for $350 shipped off eBay. There are no flaws in the spoke finish or lip polish. For anyone who wants to know exactly what wheels they are, they're XXR 513 wheels, 15x8, 0 offset, 3.5" front space, 4.5" back space, wrapped in Kumho Victoracer V700 225/50ZR15 tires. There's about 3/8" clearance between the tire and the lower spring perch on all four corners (stock perches with drop springs), and they do not rub on the fender (though I had already rolled the rear fender lip).

[X64v]

The Z got some new shoes today, since I'd already corded my used Victoracers (two of which are now the base to an end table in my living room). I chose the Yokohama AVS ES100, 225/50/R15 (V-rated). A few quick pictures, along with better pictures of my wheels.

 

 

 

 

 

 

These things grip. Hard. I had been losing traction when boost hit in 1st gear with the old Victoracers (~12,000 miles, 0 tread depth), even with a passenger in the car and a full tank of gas. These don't lose traction, they hook. I'm sure brand-new Victoracers would beat these, but that shows how close these are in performance, even at 2/3 the price and a much higher treadwear rating. So far they're very quiet, don't tram-rail (the Victoracers tram-railed horribly), and give a much nicer ride. Not that these things are important to me, but if I can get the same performance with these tires on the track with a nicer ride off the track, that's fine with me, I'm no masochist.

 

We'll see how these tires do at the Auto-X tomorrow, but so far, they get an A+.

[X64v]

They performed very well at the Auto-X today. I had a bit more sidewall flex than with my Victoracers (obviously), but wasn't noticeable in anything but the tightest 180 degree U-turns. Straight line grip is tremendous for a street tire, and they were very controllable and forgiving in the corners, still providing more cornering force than the warn-down Victoracers. I stand by my A+ for these tires.

[X64v]

Alright, so I've been running the 25-year-old Suspension Techniques drop springs my dad originally put on the car in the early '80s. I didn't know the spring rates, and wasn't aware of any way of calculating them, save for removing them and using a press/scale. That is, until I found this handy calculator. According to it (and a few others to which I compared the results), I had 125lb/in springs in front, and 160lb/in in back. These numbers were far too wimpy for my taste; they simply would not do. The 'obvious' solution would be coil-overs, but as a full-time college student, I'll have neither the time nor the money to do so for a few years yet. So, I did some looking around to find what was available in the stock spring diameter, and ended up ordering two 200lb/in Tokico springs made for the 280z rears from John Coffey (www.betamotorsports.com). They need to be cut for ride height, but that's 20 seconds with a cut off wheel, and it ups the spring rate anyways. I used those for my new rears, and moved my old rear springs up front.

 

One of the new Tokico springs next to an old rear (new front) spring. The sharpie line on the red spring is my cut line.

 

I needed to alter my rear ride height anyways, so this was the perfect oppertunity to do so. I was at 6" all around (rocker outboard of pinch weld). After cutting all the springs (front and rear) to account for the differences in ride height and spring rate, I ended up with 5 7/8" up front and 6 1/2" in back, which is perfect, because once I get the rear end fixed, I'll put the spare tire, carpet, and speaker box back in, which will give me around 6 3/8" rear ride height. After cutting, I ended up with 215lb/in spring rates in the back and 200lb/in spring rates in front; not too bad for stock size springs. I didn't take any pictures of the process, it's just a spring change.

 

 

I'm also in the process of setting up megasquirt to run wasted spark coils via a hall sensor and magents in the crank pully (not through the ford edis module and 36-1 wheel). I'll detail that as I continue building it, but here's the hall sensor, since I have it built. [EDIT: I wasn't very happy with the original sensor/wiring, so I made a new one, and changed the picture below to reflect that.]

 

[X64v]

More progress on the crank trigger set up. I've actually had it together and working, but for reason's I'll detail later I'm back on the VR dizzy for now. These are the magnets I used. First, for positioning the magnets, I used the six evenly-spaced threaded holes in the front of the ZX crank pulley (you can see them in one of the pics above). I took button-head allen screws, locked a jam nut up against the head (with red locktite to be sure), then drilled out the hex to ~.005" greater than the diameter of the magnet. The magnets are held in with JB Weld to be sure they stay.

 

 

 

The nice thing about setting it up like this instead of using allen-head cap screws is that I can fasten/remove them with a 12-point 10mm socket, instead of vice grips or the like.

 

Below is my original mounting bracket for the sensor. It's 1.25" x .125" steel (just leftovers from another project). Turns out that this one wasn't stiff enough, as at about 4500rpm it flexed enough for one of the magnets to come in contact with the sensor, completely annihilating it (on the way to school, no less, forcing me to walk the rest of the way to class). Bear with the weld splatter, I only have access to flux core.

 

 

To reinforce it, I used some 1/4" solid square stock. I also added some 5/16" x 2" roll pins through which to route the wires so they can't get caught in the fan.

 

 

Most of the ideas and hardware I got from this thread. I won't be detailing software settings or how to wire the MS board in this thread. If you're doing something similar you can PM me about the details or check out the hardware/software manuals at msextra.com.