Jeff G 78

Don't run EFI. Get yourself a set of SU's. The EFI will make for a very slow race car and will not like any engine mods. Since you are in GA, contact a friend of mine that lives near Atlanta. He has endurance raced Datsuns and has a huge stash of parts. He has since given up on Datsuns and switched to BMW's since they simply are no longer competitive in ChampCar or WRL. LeMons is possible with a Z, but you will still be slow. PM me for his contact info. My biggest issue with running a Z is that you will have more money in it than most other cars and if it gets wrecked, you will not find a cheap shell to rebuild it. I built mine when they were cheap, but after a decade or so, the Z prices had gone through the roof and it was very risky to race it. If you start with a car you already own, plan on spending at least $8k to get it on the track. I had way more than that in mine and I had 30 years worth of Datsun hoarding before I started my build. My car was done as cheap as possible!

That's when Ford switched over from SAE to Metric. They designed the all-new modular engine family with all metric dimensions and fasteners, but they installed it in carryover and mildly refreshed vehicles which were still all SAE. The F150, Econoline, Mustang, and Continental all used the Modular engine family in SAE-based platforms. It really sucked to work on them and it was several years later before all of the platforms were refreshed. As for tools, @dutchzcarguy, are your socket sets still 1/4", 3/8", and 1/2" drive or are they the metric equivalent? I'm pretty sure that ALL machining in the US is still 100% SAE. No matter what the drawings state, everything is converted to SAE for the actual fabrication.

I believe we finished 102nd out of 120. We did not want a DNF so it was all worth it.

I bought my 260Z out of a barn and turned it into an endurance racer over the course of 11 weeks. We had a list of a few hundred things to do before it was finished and we had very little time to get it all done. The night before we left for the race, we had everything crossed off the to-do list except for one item and it came back to bite us in the arse. The first time the car moved under its own power in 20 years was onto the trailer for a 24 hour road race. Six hours into the race, the R180 diff grenaded due to a lack of oil which was the one thing we never got to on the list. The race was over 200 miles away from my house where I had a spare R180, but I'd lose 8 hours just in travel time plus the repair time. My dad lived only one hour away and I still had a lot of Z parts stored there including a R200. The problem was that I had no R200 mustache bar at his place. Again, I did have one hanging on the wall at my house which did me no good at the time. I sent a teammate to my dad's house to retrieve the R200 diff and I got busy pulling the failed R180 from the car. It was 40°, raining and now getting dark. We had the car on an open trailer as the once grass paddock was now 4" deep mud after days and days of steady rain. Once the R200 was on site, we took measurements of the R180 and R200 and made a drawing on an old cardboard box of how we would have to modify the R180 mustache bar to fit an R200 diff. We then walked around the paddock looking for scrap steel and somebody with a welder. By now, it was 1am and a teammate managed to find a guy with a welding truck at the track. We had him weld spacer blocks on either side of the mustache bar to get the depth correct and then weld a plate across the spacers. Once we had that done, we transfer punched the original holes to the new plate. Once we had reference marks, we cut the original center section out of the mustache bar. Finally, we measured over from the punch marks to get the new hole positions since the R200 studs are not in the same left/right location as the R180 studs. Once Marked, we drilled the new holes. This was by far the worst part of the job. The R200 studs are M14, so the holes had to be 5/8" if I remember correctly. Drilling through the spring steel that the welder had proved all but impossible. He burned up drill bit after drill bit. No matter how small the pilot holes, the steel was destroying his bits. After about an hour of drilling, we had a really ugly, but perfectly fitting R200 mustache bar. We fitted the newly fabricated bar and differential and we got back on track at 8am after working all night. We finished the last four hours of the race. The fabricated bar worked perfectly and we actually left it in place for the next race before we swapped a real bar into the car.

I didn't mount the hoses when I deleted the rail. I might have used a zip tie or two so they wouldn't flop around, but they are not that long or heavy, so they stay in place pretty well. After running the original rail with an electric pump, I saw no benefit in having a return. It actually ran better dead headed, so when I went to rubber, there was no point in rigging up a return. The rail has a loop built-in to make the flow and pressure equal to both carbs when there is a return. The hoses don't have that, so any return would likely make the flow uneven between the two carbs. The car ran perfectly with no return, so why try to fix what isn't broken?

Yes

Agreed and it's a 10 minute job that is completely reversible. I came up with the idea for this mod and did the install during a pit stop in a race. It took less than 2 minutes and the car was back on track. It was the first time in years that the car ran right. We completed the last 8 hours of the race and climbed from 36th place to 9th place after the fix.

Sorry, I forgot to say WHY it worked. The steel rail is bolted directly to the head, which is only a few inches from the exhaust ports. The heat was trasferring through the steel bracket directly into the rail where it would heat the fuel. By going all rubber, the only heat was radiant which is much easier to combat. As for fuel, we ran 93 pump gas. At a typical race, we'd go through 7 gallons per hour or 150+ gallons in a 24 hour race. We'd send somebody to the nearest gas station every four hours to buy 6 jugs of fuel. Some tracks had close-by stations but most were quite a ways away. I think we always had summer blend. The latest race we did was late October. Most were mid-summer.

In my case, I tried every possible combination of things I could think of over a several year period. I deadheaded it first with the mechanical pump and then with an electric pump. Deadheading did improve it somewhat on my car, but not enough. Mine would run great for 30 minutes in a race and then start to fall on its face at high RPM and get progressively worse until it wouldn't pull at all aver about 4000 RPM. When I'd pit for fuel, it would refuse to restart and I killed several starters over a number of races. The electric pump didn't help until I dropped it down below the tank height as shown above. I also immediately opened the hood at pit-in to reduce the heat soak from the cherry red exhaust. Those two things would usually allow it to restart after refueling. When I clamped the return, it would run longer and better as long as the ambient temp wasn't really hot. In one 25 hour race, it ran like crap in the 85F daylight and then ran great from sunset until it got hot again around 10am. Lap times are normally much slower in the pitch black, but we turned our fastest laps around 3am when the temps were lowest. Ditching the fuel rail along with the other mods made my car run great even in 90+ temps in race conditions. I sold the car before I was able to do any A-B-A testing to see if I could undo any of the mods. I had a huge multi-layer heat shield plus additional bowl shields and the back of the hood was propped-up 2 inches.

Try this simple test. Buy about 4 feet of fuel hose and a T fitting to bypass the fuel rail entirely. Run a hose from the fuel pump output to a T fitting at the front carb and then run hoses from the T to the two carb inlets. Finally, clamp off the return line with needle nose vice grips so it doesn't drip what's left in the rail. I had terrible vapor lock issues with my race car and this mod solved the problem after I tried every other possible fix. Prior to ditching the rail, I also ran an electric fuel pump at the tank mounted on a drop bracket so it was gravity fed from the tank. Ethanol fuel doesn't like being "pulled". By being gravity fed, the pump could "push" the fuel to the front of the car. This helped get the car started hot, but did nothing to fix the vapor lock while on the track. Different carbs did nothing, shielding the heck out of the exhaust did nothing, eliminating the return line helped a bit, but not enough.

My Stompers all came with foam and rubber. I think I ran rubber on most of them.

C'mon Cliff, everybody knows that you don't put rubber tires on front and foam tires on the back of a Stomper! 🤣 I had the same '81 Toyota Pickup Stomper, but mine was red.

Thick one looks like the crank pulley washer.

I haven't gotten to look for it yet. I might have time tomorrow. I can't remember where I stored it. I saw it after the move to AZ, I just haven't seen it lately. I'm sure it's somewhere that made sense at the time. 🙂

I always add a ground or two just to be sure.

If my ZX cam is good, it's yours. The spray bar went away with the introduction of the N47, yet there are a few with that combination. I might even have a set of block off plates. It's been so long, I can't remember for sure. Yes, the GT350R engine sounds incredible at it's 8250 RPM redline. In that video, I purposely didn't upshift in several places around the track where a higher gear would be faster, but it was more fun to scream it. That day was close to 100F and we ran the cars all day like that. Grattan Raceway is a fun track. I prefer others around the country, but every track is unique and is special in its own way.

Do you have a N47 head with a spray bar? If so, that's a pretty rare, but not unheard of. I have a very early N47 in my car with a factory spray bar. I've thrown away a bunch of stock cams. I might even have a spare from a ZX motor that's internally oiled. I can look around and see what it is. If you want it, I can give it to a co-worker who lives in South Tempe. Here is video of me driving a GT350R with "only" 526HP on a race track with a journalist in the passenger seat.

Sounds exactly like my journey 15 or so years ago. I was right where @ckurtz2 is at and I too swapped the original cam back in just to be sure the rest of the EFI was operating correctly. It immediately ran great and I never looked back. The cam went into my other Z which I sold last fall. If I wanted to get more performance now, I'd ditch the L Jet and go with something better. SU's are getting dumb expensive, so I'd likely go triple Webers or stand alone EFI. The reality is that I'm pretty immune to power, so I'll likely live with the low power I have. I've spent the last 27+ years working on performance cars and no matter what power they make, you get used to it after a while. The last one I worked on was the GT500 at 760HP. No amount of power I put in the Datsun will make it feel fast after the Shelby, so I won't bother.

Sounds a lot like when I tried the performance cam in mine 15 years ago. I was getting around 11 and it ran like crap. Like I mentioned a few posts back, I'd clean contacts in the connectors and then check resistance on each wire to see if the harness has an issue. You never know if it got pinched at some point and has broken strands that are barely flowing current. You can clean plugs, but for a few bucks each, I wouldn't try. I've hit them with a torch to burn off oil and gas and then wire brush them clean. I used to do that all the time on my old 2-stroke dirt bike plugs when they would foul.

17 years for me. How many here used to be on Carl's IZCC server? I think I joined that about 24 years ago. It was quite a different experience. We'd get the daily traffic and then reply via email and responses would post in the next day's edition (sort of...) There was no way to get immediate help on a topic.

I shipped my Z when I moved from Michigan to Arizona last year. It was a corporate move, so they paid to ship two vehicles in an open hauler, but I had to do the Z on my own. I got a quote from the same transport company figuring that I might get a break since they were already taking two. The quote came back around $1800 for an open carrier. I then requested a quote through U Ship and got a dozen or so transport company responses. Most were around $1100, but because of my situation, none were going to work. Enclosed transport was around $1600. The best any could do was a one week pickup window and an even bigger delivery window. I was leaving on a specific date from MI, so I would have to back up the pickup at least a week before my departure. I also had rented a 30 yard dumpster to clear out anything I couldn't take to AZ and that happened to be blocking the driveway until a few days before my move. I was forced to go with the same transport company that my other cars were using. They gave me a specific date and a few hour window for pickup with about a week window for delivery. When my cars arrived (open carrier), they were filthy, but mostly intact. The side mirror broke off along the route, but to be fair, it was weak and just broke from being shaken, not from being struck. If you request a quote from U Ship, I highly recommend using a throw away email address. You will get dozens of emails immediately and they will keep coming for a few weeks. We ship cars every single day at work via Reliable Carriers and I can say that paying more does not mean better care or reduced chance of damage. It all comes down to the individual driver, the position on the truck, and luck. If your car goes on the back of the truck, it could get unloaded and reloaded several times along the way. Each time they move it brings damage risk. If it's on the bottom deck, it could get dripped on from the car above, and so on.

The cam in question sat on my shelf from 2006 until 2013 when I put it in my SU carbed L28 race car. I loved the cam in that engine. It pulled strong up to 7,000 RPM. It was a night and day difference between how it ran with the EFI and the SU's. I still have the EFI car with a stock cam and it runs just fine. It just didn't like the duration of the cam and the low vacuum that came with it. Speaking of which, what is your vacuum reading at idle? Your last post tells me that there is a problem with the connector and/or wiring between the dropping resistor and injectors. You went from #1 not firing to #5 not firing. If I recall correctly, there are two resistors. One for 1-3 and the other for 4-6. Somebody correct me if I'm wrong. It has been a decade or two since I did any work on a EFI Z. The fact that you went from 1 to 5 is a bit odd since they are on different resistors (if I remembered right). Use DeOxit on both sides of the dropping resistor connection and then take resistance measurements from one end to the other for each wire going between the dropping resistors and the injectors.

The injectors are batch fired, so the order of the injector plugs doesn't matter. I can't remember if you said if you tried swapping the injector wiring between injectors #1 and #2, but if not, that's the next thing I'd try. If the issue follows the plug, you know it's a wiring issue in the injector harness. If the problem stays in cylinder #1, you can rule out the fuel system since you already changed the injector. At that point, you can start looking elsewhere. Assuming the issue stays in #1, I'd recheck the cylinder itself next. If you have a reasonably decent air compressor, go to Harbor Freight and buy their cheapo leakdown checker. It's similar to a compression gauge, but you put compressed air into the cylinder rather than using the starter to build pressure. With the piston at TDC, you add pressure and listen for air leakage. It can leak from several places and each tells you what's wrong. If you hear air in the airbox, you have a leaky intake valve. Air from the exhaust is a leaky exhaust valve. Leakage out of the adjacent spark plug hole or if the coolant in the radiator bubbles, it points to a bad head gasket. Finally, air coming out the timing chain cavity means the rings aren't sealing. The tester itself has gauges on it that tell you the percentage of leakage. Less is better and under 10% is good. Again, cylinder to cylinder variation will tell you if #1 is unlike the others. If the fuel injector test and leakdown don't give you the answer, then I'm at a bit of a loss without more details. Good luck and let us know.

Let me read through the thread and see if I can offer anything.

I had a similar problem 10 years ago in my race car. The +12V wire from the ignition was gone (a teammate inadvertently removed the wire while cleaning up the harness), so it wasn't charging. After a lot of head scratching before we figured out that several feet of the wire was missing from the middle of the harness, we ran a new wire from the ignition on to the alternator and it charged fine again. The wiring diagram (available online) will show you the color of the wire and the end connections. Do a continuity test from one end to the other and see if the wire itself is bad. Worst case, run a new wire.