Sean's '73 240z

[X64v]

Finally, the Z is in the body shop getting the rear end fixed. Here's a crappy cell phone pic of when I saw it yesterday:

 

 

While it's in the shop with the fuel tank out, I figured I'd bring the tank home and add a sump to fix the fuel starvation issue common in the S30 gas tanks. I got the idea for my design from this post. First I cleaned off the tank and took some measurements, then started with the design on a 12"x24" sheet of 16 gauge.

 

 

Then I cut it out. A cut-off wheel in a small angle grinder made short work of it.

 

 

The hard part was bending it up, because I have no vice, no work bench, pretty much no metal-shaping tools of any kind. I think it came out nice and decently straight, considering the tools I had to work with:

 

 

It will add 1.5 liters to the tank, giving it a new capacity of 61.5 liters (16.25 US Gallons). I should get time to weld it to the tank Friday. I drew up the dimensions real quick in Autocad for anyone who wants to copy it. All dimensions are in inches.

 

 

(I wasn't sure what the correct line style for a bend/fold line was, so I used a phantom line. If anyone knows the correct line style for this in an engineering drawing, PM me.)

[X64v]

More progress on the tank and the car. First, pics of the car from last Thursday:

 

 

 

 

 

 

Basically it's looking great. The rear floor is perfectly flat again, and the spare tire well is perfectly round again. You can't even see creases, they're just back to the way they were. It'll hopefully be done by the end of this week or so.

 

Here's where I put the sump. I drilled two 1" holes, one on either side of the internal baffle. At the bottom you can see the small vent hole at what will be the highest point of the enclosed area; I thought it'd be a good idea to vent the trapped air without letting much fuel out. I put the drain plug back in before I welded the sump on.

 

 

The sump, fully welded, leak tested, then covered with JB Weld to smooth out my ugly welds and contain any leaks that did not show up in the leak test:

 

 

I'll smooth out the fitting welds before painting as well. A whole bunch of goodies came today (all the AN fittings I need, new tail light seals, new master cylinder, etc etc) so when I finish the tank tomorrow I'll drop it and the tail light seals by the body shop.

[X64v]

All done. After I stripped off 36 years of road grime, the original paint was in pretty good shape underneath. Still I had to spray everything to make it even.

 

[X64v]

New stuff:

 

 

- Alpine iDA-X200 (DMR, no CD player)

 

- Schroth Rallye Cross ASM 4-point harness (DoT legal, also won't break your knees like a 5-point without the submarine belt will)

 

- New 7/8" master cylinder (240Z size. I'm sticking with stock calipers up front so I don't need a ZX master)

 

- SS braided line and a few -6 fittings for the new fuel tank plumbing

 

 

Too bad the car is still in the body shop. Completion is estimated at early next week.

[X64v]

I finally got it back from the shop Wednesday. I'll post up more detailed pics later, but here's a quick shot of the finished work.

 

 

It's not perfect, but considering how bad it was, I'm definitely happy with it.

 

I'll have quite a few updates over the next few days as I make a ton of changes and get all the parts I've got installed.

[X64v]

Well between having to write essays (on spring break no less ) and chasing down a nasty fuel system problem, I haven't gotten much done at all.

 

New master cylinder installed:

 

At the same time, I switched to Earl's speed bleeders all around. Now, my brakes are super mushy, worse than before. I bled the master and got lots of air out, but it's still bad. I suspect the rear bleeders aren't sealing properly, letting air in.

 

The fuel plumbing at the other end of those pretty braided lines:

 

 

I ran the return line over the top of the tank instead of around the side, and flared the emissions vapor line for a -4 AN tube nut. I had to cut the last section of the hard line out of the car to do this, so it's connected via that blue Earl's -4 push lock hose.

 

Fuel pump pigtail:

 

 

Now I'm pressed for time to fix my fueling issue, install my new stereo and harness, plumb my boost gauge, and get the car cleaned up, all tomorrow because I'm leaving for San Diego in this car Tuesday morning.

[X64v]

Finally the updates I promised. Fixed the fuel problem I was having. I ended up using a Carter P4070 by the fuel tank as a lift pump, pushing fuel up to the Walbro 255lph in the engine bay.

 

 

 

Also, I've had my new stereo and harness installed for a while.

 

 

 

 

A word of caution in regards to the blue Aeroquip Push-Lock hose. It's wonderful for oil and water lines, but it doesn't hold up well at all to gasoline. It fades and cracks and gets kinda stiff; no leaks, but still no bueno. I called up the guys at Earl's Store #1, they said it's not a defect or a bad batch of hose, it just simply doesn't like street fuel.

 

The bottom hose served as a fuel rail feed line for about 9 months carying 91 octane pump gas, the top hose is just as old but unused:

 

 

Also made a video while testing my pumps just for fun, to see how the camera worked at night, how well it picked up sound, etc. Nothing amazing, just a spirited run through some out-of-the-way desert roads. I wasn't pushing the car at all, only driving at perhaps 5 or 6/10ths.

 

http://www.youtube.com/watch?v=fUmhNmQuZx4

[X64v]

I needed to get my wideband back in to tune for the change in fuel pressure. Instead of just taking 30 minutes to put it in like it was, I ended up spending the entire weekend redoing the Megasquirt wiring in the engine bay (it needed to be done anyways, and I had everything on hand).

 

12 circuit terminal block (McMaster, $3.98) mounted on the left-hand frame rail:

 

 

Injector harness all nice and pretty:

 

 

Pretty much finished:

 

 

From left to right: 1-2 +12v; 3,4 injector ground pass-throughs; 5,6 IAT and CLT pass-throughs; 7-12 chassis ground.

 

I should have gone with a terminal block years ago, when I first installed Megasquirt. It makes the wiring neat, secure, organized, and out-of-the-way.

[X64v]

A few months ago, I snagged a used Dezod same-sided intercooler for $40 plus shipping, basically a freakin steal. This weekend I finally got around to installing it (a week after I show the car at MSA, but oh well).

 

All the blue silicone couplers and T-bolt clamps are from Silicone Intakes. Good quality stuff, fits very well, and pretty much the best prices I've ever seen. The piping is 2.25" aluminized steel exhaust tubing covered in VHT wrinkle paint.

 

 

With a combination of silicone bends and mandrel bends, I didn't have to make a single cut in the core support:

 

 

(Ignore the vacuum line and temporary coil mounting, with finals week here I haven't had time to do them properly)

 

 

With my 1G DSM BOV set up recirculating, it's now almost totally silent. This means no more BOV wars with the WRXs around campus, but on the freeway it's much nicer not having to listen to the thing venting like mad under mid throttle acceleration, and I don't have to worry about a separate filter for it. I'm very happy with the set up so far, the thing pulls much harder than it did before (after re-tuning, obviously).

[X64v]

I have some not-so-great news. As lots of you know, I blew a head gasket big time when my dizzy came loose at 12psi (see thread here). The only change I've had since then is that the motor has been blowing a little oil out the valve cover, where it never did before. It's been getting worse so I ran a compression test today. The results:

 

1-130

2-130

3-80

4-130

5-125

6-130

 

So #3 is dead. This makes sense looking back at the head gasket, where #3 is the only cylinder where the gasket didn't blow, thereby subjecting it to the full force of detonation at 35+ degrees of timing at 12psi boost and 190 degree intake temps. This really sucks because the compression numbers of the other holes are damn near perfect.

 

Now I have a huge decision to make. If I stay with the L28, I can either go with forged pistons so this doesn't happen again and keep building this turbo motor, or ditch the turbo and build a hot street 3.0L N/A L28 (which even in its fastest trim will always be slower than what I have now, but probably much more reliable). If I do a motor swap, I have a range of options, but all have their problems: I have a free complete VQ45 in good running condition, but an adapter plate to run a manual tranny is $$$$. I'd most like a VQ35, but I don't have the fab tools or 220v mig needed to modify the crossmember or build my own engine/tranny mounts. I'd also like an LS1 (which is now practically a bolt-in), but the cost is pretty prohibitive. I'm very averse to a traditional iron block SBC because of the weight and low powerband/redline.

 

So as you all can see, I'm in a bit of a pickle here. My budget really doesn't top $3k for a complete motor swap, and I'm definitely not putting that much into an L motor (more like $1500 or so). For any option but keeping the turbo, I'll be able to sell the turbo, intercooler set up, and a few other things to make some money back. If you have any suggestions or think I'm overlooking something, feel free to PM me. Otherwise I'll be thinking this over very well the next couple of days/weeks.

[X64v]

Alright, after talking to some people, crunching some numbers, and thinking things through, I've decided to go LSx/T56. It's always been my dream swap, and I think I'm in just the right situation to make it happen. I'll be buying a second car ('89-'92 Mercedes-Benz 190e 2.6) as a daily driver in July; as soon as I do, I will be parting out everything engine-related except the radiator, Megasquirt, and wideband. If any of you want to 'reserve' any of my engine parts you see in this thread, feel free to PM me and you can have first chance at it when I tear things down in July. The intercooler/piping/BOV/exhaust/fuel rail are spoken for, the rest is fair game. Unless someone wants the entire long block, I'll be completely parting out the motor as well, so reserving specific pieces (head studs, e.g.) is fine.

 

What's more interesting is I will not be using the LSx electronics; I've been so happy with my Megasquirt set-up and my tuning abilities that I'm going to use it on the new motor. I'll be re-reading Moby's LSx/MS write-up and doing my own research to figure out how I'd like to tackle that. I'm fine with batch fire injection and wasted-spark ignition, and I really enjoy tinkering with Megasquirt, so this will be fun.

 

Sorry for two picture-less posts in a row. This thread may go dark for a couple of weeks, but then I'll have lots to post about once I start buying/selling parts and getting things ready.

[X64v]

Well, I can never make a decision without changing my mind a few times, and this is no exception. After talking to some people and getting a better idea of what the machine work is going to cost, I've decided to stay with my L28et. I'll be using 89mm forged pistons, running a knocksense module, and redoing my crank trigger set up. This way, there will be no more dizzy to come loose, no pinging undetected by the knock sensor, and any pinging that does occur won't destroy my ring lands. I'll be changing lots of other stuff while I'm at it, ceramic coating a few things, porting a few other things, etc. I'll post up lots of pictures as I start work on it.

[X64v]

Back at it.

 

(Sorry for the over-exposed pics, forgot to change the exposure correction back to zero.)

New work area:

 

In place, on jack stands:

 

Final engine bay pic, before some decent changes get made:

 

Four hours and lots of dilly-dallying later:

 

On the to-do list:

 

Scrub engine bay clean

Clean up factory engine bay harness

Weld up antenna hole

Remove crossmember, relocate LCA pickup points

Figure out how to mount/use the VQ35 cam sensors I have as crank and/or cam sensors

Spend more money than I should

Break down motor, send various parts to machine shop/ceramic coating/wherever

 

Since I now have a cushy daily driver, the Z is going to be moving in a more raw direction than before, for use on nice days/autox/track only. FG dash, no HVAC, stiffer/more modified suspension, etc. I'd like to shed 100lbs and make some useful changes while I'm at it. I also doubt I'll paint it in the next 5+ years. I'll keep the bodywork straight, but who cares about paint when it's just your fast car?

[X64v]

Engine bay, sans engine:

 

Some more progress tonight, started ripping out the HVAC:

 

About 17lbs of stuff just here:

 

The heater core and air box + cables are on their way out soon.

[X64v]

Engine is back from the machine shop. I decided forged pistons really weren't worth the money at this point in time, the Nissan head gaskets are still working well as fuses, and my tuning is pretty much spot on. So, I grabbed a set of ITM 86.5mm turbo pistons new w/rings for cheap off eBay. The engine should get dropped back in this weekend, so I'll post up details/pics as it happens. For now:

 

Mmmm, fresh machine work

 

Polished crank/rod journals (mains and rods still std/std after 200k miles)

 

The ARP forest, again

[X64v]

Engine mostly assembled

 

 

Since the dizzy drive end of the oil pump shaft is unsupported without the dizzy, I took a second to remove it. It was wonderful installing the oil pump + drive without having to give a thought to gear orientation.

 

 

I'm using 3000gt coil packs, to the underside of which I have glued BIP373s. All wired up...

 

 

...and mounted to the valve cover

 

 

It's not apparent in the picture, but the aluminum stand-offs I used keep the coil pack around 2-3mm off the valve cover. Mounting hardware used:

 

 

I used some sealant on the back side of the holes to hopefully keep them from weeping, and threadlocker + split washers so they don't vibrate out and create mayhem.

 

[X64v]

I finally decided on using a 6-1 pattern in the forward face of the flywheel, based on my specific needs (ease of sensor placement, accuracy, ease of machine work, etc). I did it myself with a friend's HF drill press; not all that hard to do if you just work slowly and carefully.

 

 

The arrow points up at TDC, and that tic mark on the 2 o'clock hole denotes the sensor's position (again, relative to when the motor is at TDC). Note that this will create a trigger angle of 90 degrees, give or take depending on exact sensor placement. It was easy to measure/mark precisely where the holes needed to be by using the fact that there are 120 teeth on the ring gear. Some careful work with a dial caliper and I was able to be sure the marks were right on the money. I made sure the hole depths were plus/minus .001" of eachother (to ensure the material removed from each hole was of equal weight), then drilled an identical hole (size, depth, radial position) where the 'missing tooth' would be, but on the opposite face of the flywheel, to keep it in balance while still providing the 6-1 pattern the computer needs.

 

 

The sensor threads in to this super-fine-pitch (M12x1.0) nut tack-welded onto the engine backing plate.

 

 

Also happened to get the engine back in the car. The flash on my camera is harsh, I swear my valve cover/engine bay isn't that dirty...

 

[X64v]

A 35mm brass core plug makes the nicest dizzy block-off I've seen anyone else do, so obviously I followed suit.

 

 

I screwed the sensor all the way in, then backed it out 1.25 turns for a 1.25mm (.050") air gap. This is definitely small enough, I just hope there's not enough run-out on the forward face of the flywheel for contact (I seriously doubt it).

 

 

I have really grown fond of the NGK spark plug wires I've been using. They're inexpensive, seem to be built well, and don't give me any interference problems with MS. Of course they'd have been a quite horrible fit for my coil packs as they were, but couple this Taylor dizzy terminal kit with a couple hours of swearing and some careful cutting, and now they're perfect.

 

 

 

The only two that touch are 2+6, but I added some heat shrink tubing there for some extra protection. I'm a bit worried to see how the amount of EMI changes with the changes in legnth (and therefore resistance). I think they were all somewhere in the 5.xk ohm range at original length. Now, the four shorter ones are ~1.8k ohms, and 2/6 are 2.7k/2.9k ohms, respectively.

 

A couple random things that don't have a specific place or pictures:

 

- I switched from a 6 puck sprung clutch disk to a 4 puck solid disk. It was noticeably lighter. I'm told by some that I won't notice much of a driveability difference between the two, and told by others that the 4 puck solid will be hell on the street. We'll see.

 

- I bought a Powerforce damper (the cheaper one) since the elastomer on my old stock one had seen better days. Just like everyone else's, mine mic'd a couple thousandths of interference. I just heated the bore of the damper up well and it eventually went on, though I had the advantage of having the engine on the stand so I could hit it squarely. It wasn't that big of a deal, and I feel more comfortable knowing it's on there solidly and isn't gonna damage the keyway moving around. So far, I'd buy one again, though hopefully I won't have to.

[X64v]

I've had the car running since Sunday night (10/18). I've got about 125 miles on the motor at the moment. Everything works perfectly. No oil/water/vacuum/exhaust leaks, and my crank trigger and coil packs are working absolutely beautifully (see here). My trigger angle guess was close, it came out to 84°.

 

So far zero interference issues with the shortened wires. The 4-puck disk is definitely a bit harder to drive with (grabs much more aggressively, chatters more), but totally livable, especially for a weekend car. I don't know if the chatter increase is affected by the fact that it's a solid center, but I can say that having a solid center hasn't changed shifting ease/difficulty AT ALL, it's no harder to make a smooth shift with the solid center than with the sprung center.

 

Some overall pics and such, since it's finished and clean:

 

 

 

 

(Top block: Spark A, Spark B, Spark C) (Bottom block: left two are + (dinky black wire in top left is power from tach), right two are ground)

 

 

 

The -10 Aeroquip hose I'm using for the valve cover breather doesn't like making that sharp of a bend off a straight hose end, as you can see by the partial kink (I overestimated the distance it had to travel). I'll be getting a 45° hose end next time I place an order somewhere.

 

That ZX coolant inlet housing is 1/2" NPT, if anyone's wondering. Also, if anyone ever wants specific/close-up pics of anything on my car, feel free to PM me with your requests, I'd be more than happy to snap a few for you.

[X64v]

Forgot to post the battery hold-down strap I made. Took something like a 2000ish Maxima or Altima bracket and bent it to fit.

 

 

 

Also, I've started selling off my turbo stuff; I'm going N/A. I'll detail the elaborate plan soon but here's the first piece of the puzzle: