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Last weekend i got the offer to run a single day of a multi day event if I wanted to shake down the car. So i scrambled all week getting a bunch of things checked off the list. a couple days getting up at 5am and working for a couple hours before work and then to 10-11pm after work but got it so i could run it. Added a front splitter. strut bar, seat belts. fuel cell bulkhead, fire extinguisher, coolant overflow, battery tie down and kill switch, tow hook, brake bias controller, some tuning changes and im sure a few more things. But i made it. My uncle and I loaded up friday evening and saturday morning drove an hour and a half to the track. Had a great time. car was an absolute trooper and didnt skip a beat. New track for me so had some getting used to the track and the car. but i did 4 sessions problem free, I didn't change a single thing all day. found one loose bolt after session 3 that i caught before it was a problem. Car performed well. Had a fairly competitive pace by the end. Anyway. huge photo dump

couple videos the wife had taken. looking over some datalogs this morning. Car never got over 201ºF in any log that I could see. I can't find a spot in a log where the oil temp even got over 200ºF. oil pressure never dipped on any turns or hard braking. Really impressed the car didn't skip a beat. For a shakedown i was pleasantly surprised. New track for me so i worked on me as a driver rather than swings at setup changes to bandaid a driver problem but my lap times where improving fairly significantly every session and was having so much fun doing it. 20260905_111217.mp4 20260905_173624.mp4

I've decided to build a detailed thread to document L-Series cylinder head flow testing and the results. Like many aspects of these engines, it's sometimes hard to know what to believe or how to interpret what you see and read. Test setup, equipment, testing methods, and just straight-up BS can all contribute to the confusion. I don't sell a product or service and have nothing to gain from the results I post, so my goal is to keep the testing unbiased and as consistent and repeatable as possible. Feel free to comment or criticize as I move through this. I'm happy for any input. First up is the equipment. I have a SuperFlow 600 converted to run the digital FlowCom directly to my laptop where I use PortFlow analyzer from Performance trends. This software sets up the test and aids in the data logging and reporting. It also compensates for Altitude, Barometric pressure, ect. So no math or reading of the old school manometers. Its super accurate and very repeatable. I built a L-Series specific test stand and replaceable cylinder bores to test the common sizes, 84mm - 240z , 86.5mm 280z, and 89mm - Big Bore. This has a considerable effect to the max flow due to bore shrouding, so its important to test on the correct size. This is the first place numbers can get "offset" If some guy is flow testing a Z head on his 4" Chevy bore, you bet the numbers will look good. More on this later. These bores are made of nylon and seal to the test stand with an o-ring. However any leakage can still occur, so the software takes a zero measurement first, and this leakage is then subtracted out automatically Next up is calibration - the bench should be calibrated on a regular basis to check for issues. You do this by bolting the supplied test plate that is matched to the machine and simply flowing it. Here you can see the plate bolted on, it has calibration flow percentages written on it to compare Ans this is the screen on the laptop, you can see the bench is within .1 percent calibration for the intake and exact for the exhaust Ill flow and document the heads I have as well as some I will borrow from friends. Some will be stock, some will be modified to various states. Ill also do some test to help point out important details. So stay tuned Thanks - monZter

09-06-2026 ATLAS Z UPDATE: Ok, so I mounted my electric panel into the car and began wiring it up. The garage is SO HOT. I had to go inside and get a fan to blow in there on me (see pic). going pretty well! about 75% done. PICS

The Video is the most detailed Rebuild of the Power Brake Booster Unit. As the 240Z family goes older, aftermarket rebuild boosters are getting harder to find. In some cases, they are impossible to find so rebuilding maybe the only solution.

08-30-2026 ATLAS Z UPDATE: Started the day with putting some cut leather on the upholstery sections that needed to be covered. Amazing my new seat covers, have managed to have a worn spot....but it's all better now. Working in tight quarters these things happen.:) Then I went ahead and bolted the seats down in then vacuumed it all up and installed the hidden toggle switch to turn on so the car will start, my theft deterrent, and wired in the brake light switch....just running the wires over to the passenger footwell.... labeled, so I can start on that soon. I finally managed to get the last piece of the end links on the steering rack off, and then wire wheeled them down really clean, and used anti-seize and installed the Moog end links for now...I will have to adjust when I am ready to align the front wheels, but for now, a lot of progress made! The whole car is about 75% done already and it's only been a year! PICS:

Have you mounted the headers to the engine while on the engine stand with the cradle in place? It will be much easier to clearance your cradle before everything is in the car.

The first head to document will be an old E88 from my 72. I used this head a long time ago worth 40DCOE triple Webbers. In typical fashion long long ago I did my best to do what I thought was right. I blended the seats to match the bowls with a grinder, and port matched the head to the intake, opening up the port about 1" in from the entrance to blend the new opening (not good). other than that, stock valves and chambers So lets flow it. Hoping to borrow a stock E88 to compare later. Some pics for referance Here are the head Specs Cylinder 2 Intake with 84mm Bore And Cylinder #2 Exhaust with 84mm Bore I then switched out the bore to 86.5mm and tested again, here is a comparison chart of the effect of only a larger bore Sorry the image is hard to read I need to figure out how to upload better resolution pics, but you can download the PowerPoint below E88_Flow_Bench_Comparison_Cyl2_84mm_vs_86.5mm_FIXED (1).pptx

Haven't been here in a while, but I had no problems getting on today. Seems fast so far. Edit: Spoke too soon. Just came back on, and got an error, and when the site finally loaded after a few refreshes it seemed slow.

That's pretty much where I've ended up the last several years. I know some people prefer a staggered setup; but I really much prefer a square setup, for tire rotation and replacement purposes. Very much enjoying this build, and the ongoing discussion in this thread! 👍👍

Nice! Back in 2009 I couldn't find a rebuilt 280z booster so I was going to buy a booster repair kit, but later figured that I might need special tools. I was able to find a rebuild shop in my city to rebuild my 280z brake booster. The shop specialized in rebuilding truck brake components.

Made some progress on the engine cradle. I should be ready to drop the engine in and mark where to attach it to the frame. I’ll be using some angle iron to sit on the frame so the cradle will be welded to that then bolted to the frame.

09-29-2026 ATLAS Z UPDATE: I mounted the plate I made to cover the hole on the side of the head with some stainless bolts I got, then I mounted up both front brake calipers, tied in the brake lines and zip tied the excess up. Then I went ahead and pulled the TC rods out, cleaned them up and painted them with some rustoleum gloss black, and wire wheeled up the washer plates and installed my new Urethane bushings. I normally would have gone with rubber, but the polys were half the price, so I will use them. While under there, I pulled out the cut off pieces that were the original sway bar end links, and installed the new ones I have had waiting. They are all rubber. Then I moved on to the drive shaft. Because of my trans layout, the factory e~brake tube going across the tunnel had to be cut out. This is fine, as the way I use the car I don't need it, and I can leave it in gear when parked. I suppose at a later date I could fashion up a cable to what is left on there to tie it back in.....I left a piece of the pipe about 1/2 long sticking out for just that. I then mounted up the drive shaft and got the bolts cinched down correctly. Then the problematic part of the day, the end links on the steering rack. Well they just didn't want to come off! It is obvious they haven't ever been adjusted, so I got one off and the other is soaking in PB Blaster! I have the end links I got from Z Car Depot ready to go, they are from MOOG. While under the car, I looked up and saw a world of polished piping so I took a pic! :D PICS:

I still have struts on all four corners. Because of this, I am limited to how much backspace I can accommodate with my wheels. All four of my wheels are 15x10 with 5.25" backspace. I run 3/8" spacers up front and none in the rear. So, a 15x10 is actually 11" wide, and a 5.25" backspace is equivalent to a -.25" offset. If you look at the steering geometry of the strut suspension, I have a fairly significant scrub radius. Having a large scrub radius causes a couple of problems. First, the tire sweeps forward and backward as it goes though the range of steering motion. This can cause the tire to contact the fender / air dam. Second, if you have sufficient caster, the tire will rise and fall significantly causing weight jacking effects. If I had the sla front suspension, I would try to adjust to fit the wheel with the most positive offset that I could get. This would minimize scrub radius and maximize control arm length. You will get less weight jacking as you turn the steering wheel, and the wheel will rotate about a point closer to the center of the contact patch.

Picked up a drill press on marketplace and started drilling into this thicker metal for the engine brace. Got the two pieces that will connect to the engine mounts drilled and bolted up to the engine to try and figure out the angles to attach it to the brace. I made some marks and will cut it and drill it next weekend. We got a lot of rain so I spent most of my time trying to adjust the front suspension. I got one of these wheel fitment things a few months ago and it was saying I needed some negative off wheels to fit I so started adjusting the track width to get it close to a normal offset. Lots of adjusting the toe/traction/camber arms but I think I got it in a better spot. I’ll start shopping for wheels later this year. I have a set that will work temporarily, but are narrower than what I want.