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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

spent the last few days focusing on fixing some steering geometry. If you guys remember this car came with the 240sx knuckles and if you've ever done any research on that swap, its hot garbage. I spent some time adusting ackerman right off the bat and made it so it was drivable and made a small adjustment last week. My plan has always been to modify them and get all the geometry dialed to how i like it and then scan it. and make a billet version that is modular and can be tweaked in from there. Anyway. This weekends goal was to dial in the mechanical trail and some roll center correction. The 240sx knuckle on the wrong side of the car made the mechanical trail very large so the car had very very heavy steering feel. I did some measuring and made a decision. Clipped off 8º of angle off the ball joint mount. and offset the mount to where i wanted it. Designed and machined an adapter block and welded it on. came up with a quick bumpsteer kit as the knuckle needs to have the tie rod mount lowered by a good bit. didn't take good photos but the car drives SO MUCH BETTER. steering feels great. "light" (for manual steering) but centers still centers well and has good feedback. Took the wife to get ice cream last night and what a great feeling that was after a year of work.

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

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.

Got the the hood and inspection covers on. Happy

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:

I got a tradition with my dad that I took over, every time we buy a new vehicle we stop at Mc Donalds on the way back and get a milkshake. This also gives us some time to look and admire our new purchase. We will probably continue this tradition this weekend as I’ll be looking at a 2015 BMW M550D touring (almost 400hp diesel station wagon) as a new daily driver.

The first ice cream trip is a great payoff for the hard work.

I run 275/35-15 Hoosier or Avon 23x10.5-15 on all four corners. That size works pretty well and is the limit that I can run with struts and the SubtleZ body kit. If I had the SLA suspension, I would use wider wheels limited only by the body work and tire availability. I feel like 10 inch wide front wheels are perfect for these cars, but the rear could use a little more.

There is a point of diminishing returns on tire width. It varies greatly with many factors tho so no one size fits all. Its a balance of contact patch, corner weight and suspension geometry. The double a arm front will allow for a good amount of adjustment with caster, and KPI that we can't get easily with struts.

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.

This is how I feel watching some youtube channels. popularity doesn't mean skill or quality.

Very nicely done, love it! I'm on my second early 260Z so I've got a soft spot for the S30 family middle child. I do have a syncrometer, I've been tuning sidedraft Webers on-and-off for close to 15 years now. It's been some time since I've played with SUs but they're pretty simple devices comparatively. BTW, have you checked your valve lash? This is super critical to do on a fresh head. The lash can change considerably and quickly over the first few hundred miles as the valves break into their seats. I did my motor break-in while driving the car to JCCS back in 2013 and by the time I reached SLO, a cam lobe was already wiped. My best guess is that it was a result of the aggressive wipe pattern of my cam combined with a rapid reduction in lash during break-in. I'd love to pop by Pre-Stage again some time as well, I've only been once and that was on a rainy day last December. Maybe I'll even have my side mirror repainted and fresh door cards mounted by then...

Hey Leon, Thanks for the reply! Pic attached for attention - you can probably figure out which are before vs after . The interior isn't all there yet, so not sharing that mess, still troubleshooting some stuff inside. Now that the alignment is done, I'm not opposed to bringing it down your way. Still working on break-in miles (it's at 78 total), so not trying to do any LONG drives just yet, but that might be manageable. Just have to figure out timing, and tooling. I don't have an empi style vacuum tester just yet, do you? I'll also be at Cars and Coffee (Vintage Oaks) and Pre-Stage (Marin Civic Center) in September, if anyone will be there! Robert

car is officially registered and insured so i spent the weekend trying to button up a few things to make it a bit more "street friendly". did managed to put about 10 miles on it. I have a few things i need to address before racing it but it drove on the street decent. After the initial drive. did a nut and bolt check. then did like 4, did another check, and then another 6ish and everything is looking good. Got the driver mirror on. I wasn't 100% confident id like the round mirror so i designed and 3d printed an adapter to use the factory holes in the door rather than drill new holes i'd regret later. Its growing on me. I may buy a better quality mirror but the round is looking decent. Will still hook up electronic boost control but for now i just put 10psi springs in the wastegate and gave it a vacuum source. When I moved the strut towers back and inboard, i forgot to modify the hood to accept the new position of the strut tops so I designed and machined strut top spacers to push the adjuster down and hopefully clear the hood. I could make them a little thicker as i still have some ride height adjustment on the coilover but i think this will be enough. I'll go slow when closing the hood for the first time. I hooked up the hood release cable. decided to be a little fancier and routed it thru the wiper cowl instead of having the cable extend all the way across the engine bay. need to make a new handle for the cable pull as mine is MIA. Got the hood hinges cleaned up and painted black. fedex lost my order for replacement couplers to move my air filter to clear the hood tension bars so i didnt get the hood on this weekend.

08-14-2026 ATLAS Z UPDATE/. Plastics 4 Performance has sent the final draft for my polycarbonate rear hatch "glass" for my approval. It is ready for production! The vents are to give the car an even more open air feel, which is what I want with this build. should look pretty cool. 8/32 bolts will be around the edge with a thin rubber layer between it and the lip on the hatch. Ferrari uses the vents for engine heat.....I used them because I like the look and as I said the open air feel.......no glass at all looks too unfinished to my eye. PICS:

A few pictures from the last time the engine was out

The front plate mid plate set-up was way easier than regular motor mounts. I originally used stock mounts, but switched to the motor plates when I decided to make it purely a track car. The front plate is 1/4" aluminum and sandwiches between the water pump and timing cover. The rear plate is .090" steel and sandwiches between the block and bell housing. The front plate on mine attached to tabs welded to tubes at the front strut towers. The mid plate is attached to two tabs welded to the frame. I use a regular rubber transmission mount. You can buy front and mid plates for the SBF that have the water pump and bell housing bolt patterns already machined. The plates come with a lot of extra material that allow you to trim to fit about anything.

Finally had the time to head south and pick up the replacement transmission and enjoy a cup of coffee while we were at it. And what better way to pick up a transmission for the broken one in your Z then with said Z! 😂 All jokes aside she still drives fine except for a worn out syngro on second gear and a missing fifth gear. The replacement gearbox is a >80’s FS5W71B 5-speed from a 280ZX that’s been in storage for a long time. I’ll be ordering some new seals and transmission oil before switching out the gearboxes for some peace of mind.

I love my front plate/mid plate mounts. It opens up lots of room under the engine and stiffens the front structure. The downside is that you hear and feel everything from the drive line.

work has been to busy, small update. Headlight bucket has been welded in and planished. Everything is starting to look alot better and starting to feel like an actual car again, not just pieces.

I drove the car about 3/4 of a mile around the block.... tune needs a lot of work (obviously), tires had a slight rub and it rattled a bit but was so exciting and such a relief after a year of hard work. Got the rest of the windows in as well. Wife offered to polish all the trim so I gave her some supplies and let her scrub away. also added a couple interior shots.

For anyone who's swapped or planning to a BMW S50B32, I have two special, exclusive engine covers to sell. A = usd$250 shipped B = usd$350 shipped

Got an Accusump for the Z, and made a mounting bracket for it. I’m going to have another plate on the front side to weld on some angle iron for the oil cooler to mount on. Added a pressure sensor so I can read the Accusump oil pressure with the engine oil pressure so I can see when it’s charging and discharging. the bottom bolts are just to hold the clamps and it’ll sit up slightly higher when it’s tightened up.

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! 👍👍

08-23-2026 ATLAS Z UPDATE. Today was another tough one. 4+ hours in getting the clutch master cylinder rod screwed in to the custom clevis on the pedal arm and then everything bolted back up, adjusted and set up. VERY hard for me to get in there, and I am old, so it is a ball breaker. I knew it would be and put it off for months, today I did it. I managed to get the trim piece I mentioned yesterday painted silver and then after the clutch, I tackled the next issue. I don't know how, but there is no bar from the brake pedal arm to the switch so the brake lights will come on and go off. So, I simply took some sheet metal, bent and hammered a 90 and then with a sharpie and my angle grinder cut and formed a piece that I am bolting to he brake arm, that will stick out and push the brake light switch closed when the pedal is released. I drilled 2 holes through the arm and this sheet metal bracket It's hanging up painted and will be install with 2 1/4X20 bolts and nuts. After it was done it was time to relax a bit with a couple Coors and look around, I taped one of my atlas emblems to the front corner of the hood. I don't know If I will use it there or not, I can either paint it flat black to contrast on the gloss powder coat, paint it datsun metallic blue like the engine compartment, or I don't know, any ideas?

Hi All, I have been restomodding my very first Z (early 260), and probably did things way out of order. Got the car (rusty, needed work, half disassembled but told the engine would run, gas tank in the hatch, no airbox, etc) and it went straight into body and motor work/build. I wish I had gotten it running first, to appreciate how it ran and handled, but the rust gave me pause, so I went the full resto route first. All that said, this is not my first engine build, but my first L series and first car with carbs. Now that it's done, I need to work out what's keeping it from running better. The motor is a frankensteined together L28 (F54 block, N47 head), roughly 9.2:1 CR based on (Priddy - Cometic) head gasket and (flat top) piston combo. Steve Bonk stage 1 cam, stock hitachi/SU carbs (rebuilt with SM needles and rebuild kit from ZTherapy), cleaned up balance tube with N36 intake manifolds. Early 280zx close ratio 5sp trans,3.9 R200 rear end, stock (l28 appropriate) clutch/flywheel combo. The shop that did the body/resto work dropped the motor in, and got it running, but it I'm pretty sure it should be running a lot differently (read: better). It's idling around 5-600 rpms, lumpy, and feels pretty underpowered considering it's a light car with a modded L28. Did the break in drive in which I didn't take it over 5k RPMs, ran it decently hard with solid acceleration and engine braking across gears to seal the rings, did the oil first oil change, and all that jazz. This is where you come in - I'm hoping that someone here who knows the L series is up for a half day of walking me through confirming that the (mechanical) timing is set right (the easy part, I've done this with my other cars but appreciate a second set of eyes), then wants to help me make sure I don't do anything stupid trying to set the idle and balance the carbs. Looking to learn from one of you gurus so I'm not messing up a fresh motor in a fresh car. Anyone in the Bay Area want to come to Novato and help me out in exchange for beer, lunch, and the opportunity to mock me while you help me learn this motor? Thanks in advance! Robert

$170 is a lot less than I would have guessed for shipping something that size across the ocean. I've paid half that or more for shoebox-sized boxes from Japan.

I got curious so i did this layout to approximate scale. It's not 100% accurate, but it gives you an idea of how our car sits in the world. Autos& Vehicles

Works great for me today! No issues and everything was quick to load.

https://i.imgur.com/SKO8gwQ.jpeg soldering connector did nothing, tail fuse still gets hot. i swapped pins on white connector, dome fuse is now park tail. you can really tell what is the hot fuse, color has changed

well, you could look it all up on their website plstics4performance. The hatch glass actually isn't flat, it has a crown to it. It isn't just plexiglass. it is Polycarbonate, with a special hardened coating, and the vents and everything are a custom deal. I wanted it professionally done. I waited for you to volunteer to do it for me, but you never did, so.... Yes it is made in England. Cheers.

Started working on the cradle this weekend. Laine’s design was a good starting point, had to change some of the angles to work around the apex subframe bracing, but it looks like the 1-1/2” square tubing will work. I’ve got it tacked together now to test fit. I need to do some more measurements and figure out the where to put the vertical part and the correct angle. Hopefully get it wrapped up next weekend and then test fit the motor the following weekend.

That is just beautiful. As great as always to see your posts.

how much of a "notch" would your cradle need to sit down? maybe notch it and attach it to the those apex supports aswell as the frame?

Well bit of a bummer this weekend, I made a mock up of the engine cradle out of cardboard and it doesn’t fit, the extra bracing on the Apex track attack kit interferes. I made a mock up using 1-1/2” instead of 2” and it might work, still a little tight. I’m going to try and make it with the 1-1/2” and change the geometry a little, hopefully it’ll work. Since no fab/metal shops were open over the weekend to get the 1-1/2” tubing I decided to make a bracket to mount my clearview remote filter. I’ll get it painted and re-mount it. Not sure this will be its final location, but I’m happy the way it came out.

Big update on aesthetics. Got the whole front put together. Made a "crash" bar out of chromoly the support the front valance and fenders. It wraps around the front and the valance "rest" on it for support. Went a little extra because I know in the future im going to build a splitter and having a solid place for mounting will be needed. Front and rear glass is back in. will polish the quarter windows and put the side glass in this week. Fitted the fiberglass 240z bumper (had to do some trimming and fitting). need to make a more permanent center brackets. just wiped up some simple aluminum bars to hold it in place. Then i'll spray it a satin or semigloss black i think. I'll experiment. I don't think it would look good orange but maybe. Finished up the wiring to the back of the car. The PDM really simplifies the amount of wires. Added a few extras for future modifications/add ons. All the lights and electronics are working. Slowly working on the tune. it starts and free revs nicely. I plan on trying to get it registered and insured this week so i can start getting it finished up Then for the first time, under its own power. Drove it outside, took some photos and drove it back in. very exciting. Seeing it sitting in the sun, all the work I have into it and to be extremely happy with it. I'm proud of this one.

Alright, finally got some time to make some more progress. The engine is mostly disassembled, and I have mics and a bore gauge coming to measure clearances. I am planning on a stock engine, with the oil fixes, and a bigger turbo. I am not concerned with making a ton of power; anything will be better than the stock L24, and I just want it to not blow up immediately. I am new to engine work, and have a couple of questions: 1. Does anyone have any recommendations for what size oil restrictors to use? Enjuku sells oil gallery restrictors in 0.9, 1.1, 1.3, and 1.5 mm. 2. I have googled RB25 specs for rod and piston bearing clearances, but does anyone have a trusted source that they recommend? Thanks for all the help! I have read through the site and watched a couple of rebuild videos, but I'm still not 100%, and I don't want to make a stupid mistake.

You want to do mine next?

Its been an exhausting month of hard work getting the chassis in Epoxy to move it back home before the end of the month. Here is the process. 1.) strip all factory sound deadening/undercoating with a scraper, heat gun, wire brush. 2.) clean any residue with paint stripper and after-wash solvent. 3.) strip original paint from body with Citri-Strip paint stripper - again clean with after-wash 4.) remove interior tar paper with dry ice and liquid nitrogen. 5.) wash and clean entire body with Mastercoat metal prep - phosphoric acid rust neutralizer https://nomorerust.com/collections/metal-prep-rust-remover-products 6.) sandblast all seams and overlop joints. 7.) brush Mastercoat rust sealer primer into all seams and nooks https://nomorerust.com/products/mastercoat-ultimate-permanent-rust-sealer-silver-primer-original-sprayable-slim-quart 8.) lightly blast the floor pans with white aluminum oxide until white metal 9) brush 3 coats of Mastercoat rust sealer primer on to floors 10) blast the internal frame chambers clean and blow out any sand 11) spray the internal cavities ( rocker panels, rear fenders, rear internal quarter, and front internal cowl area with Matercoat using a 18 inch long extended tip spray gun https://paascheairbrush.com/collections/extension-spray-guns?shop_consented_scopes=email%3Averified+openid+pay%3Asession_token+profile+shop%3Aaccount_uuid&shop_sign_in=true using a 360 degree spray tip to coat all surfaces 12) sand the entire body removing any Mastercoat not reaming in pits or detents 13) sand the entire external body shell and underside with 180 grit and clean with wax and grease remover 14) lightly blast entire body inside and out until perfectly clean and lightly textured to promote adheision - holding the blast nozzle 12 to 15 inches away at 60psi with white aluminum oxide 15) hours blowing out the remaining grit 16) again using 360 degree long extension spray gun, paint all internal cavities and under sides with DPLV Epoxy Primer 17) Spray entire body inside, outside, underside with 2 coats of Epoxy Ridiculous amount of hours https://www.youtube.com/watch?v=y-kogRrJYJU

It's a "little" thing, but progress.

I finally had some time this weekend to work on the Z again and finish off some of the little things that where nagging me. I finished my DIY door card project and got them installed in the car. I must say that they turned out pretty good. The only finishing piece would be to add the wood trim back in but I would have to make one myself. A few weeks ago I managed to pic up a set of Euro taillights from an original Dutch 260z that where in excellent condition. So with the remaining time I had that day I quickly switched them out. Yesterday there was a small all Nissan/Datsun meet I attended which gave me the opportunity to compare my Z with others and do up some inspiration for future modifications. Afterwards I finally had the time to take some proper pictures of the car (with the car not half apart) and cruise along the dikes. WhatsApp Video 2026-07-13 at 09.15.40.mp4

im not happy voltage drops on this thing. best would be new fuse box re-route wiper and lights. i might try easy re-pin cause common, dome and lights uses same source. if that fuse box connector is some how the issue. on dome light i have not much draw, swap dome and light pins on end of connector

you ever weighed this? I always thought a Z with a k series would have a great balance.

It was messy, but axles are put back together. Overall pretty easy with the correct parts, probably spent more time cleaning up all the grease 😂.