Barefootdan

Thanks @Zed Head! I've updated for a little more info but even I need to sit down and remember whats been done over the last few years 😅 I originally copied description from my Facebook post which severely limited me on how much I could write

Life is always full of surprises. Unfortunately for me, that means the Rotsun is up for sale. Definitely not a restoration build, so please take that into thought. But alot of hard work and help from many members here has lead to a beautifully fun car to drive on the weekends. Feel free to ask any questions! I have posted an ad in the forum's classifieds for pricing details.

View Advert 1975 Datsun "Rotsun" 280z 1975 Datsun 280z Started as a "Rotsun" build, only three rust spots remain, all fairly small and in easy locations, pics attached. Floorplan rust removed and resealed. Engine was built with flat top pistons, N42 head that was rebuilt, new timing chain, bearings, rings, etc. 6-2 headers and Z story exhaust. Triple Mikuni PH44 carbs tuned with a wideband gauge. Starts and runs excellently. 5 speed swap from the 280zx. New clutch and resurfaced flywheel. All rubbers have been replaced including fuel lines, coolant lines, and full poly bushings. Aluminum radiator with dual fans. New fuel pump and cleaned up fuel tank. Koni Yellow struts with Zcar springs. Konig wheels with Toyo R888R tires. Apex engineering rear control arms. Skillard door cards and trim bits. Engine wiring harness fully redone with a new fuse box. Interior has new carpet, new dash cover, Sparco Sprint seats and Sparco mounts, OMP harnesses, T3 Tuning Harness bar. Open for trades as well. Recently ran this at an HPDE event to shake down. Passed NASA inspection and had no issues other than minor annoyances fixed at the track during 4 sessions. Offered by: Barefootdan Date 10/02/2024 Price $17,500 Category Cars for Sale Year 1975 Model 280z Vehicle Identification Number (VIN)  

Finally made time to take the Z to the track. What an exciting day. Made it 30 minutes to the track, four 20 minute sessions of track driving, and 30 minutes of driving home without any issues!! I have a list of new tasks to dial in since the first shakedown, but looking forward to spending more time driving the Z before summer hits!

Wow its been 5 months since my last update! I have been slow to work on the Z as I have moved to a new home in Phoenix and it has been a very hot summer. Lately I have been able to get some time to work on the interior. I was never satisfied with the molded carpet kit I originally installed. Probably user error since it was my first kit but it felt very bulky and didn't lay nice. I eventually reached out to Chester and Herod for a carpet set. The gentleman I spoke to was very nice and had my carpet shipped out the following week. This is a loop pile style that I think fits the Z much better than the cut pile. Fitment was stellar and I had no issues installing and gluing down the individual pieces. While everything was out of the car, I decided to finally address my seats and ordered up a set of Sparco Sprints with mounts and OMP harnesses. I am looking into taking the Z to a NASA track day so this made my seat style an easy choice to meet safety requirements. Overall I am very happy with how the interior turned out. It is a comfortable place to be. One piece I completely forgot to pick up was the door sill covers. I recall my original covers being glued down vinyl. And I played around with the idea of ordering new ones or making my own. But I decided to paint the sills first to see how it looked, then decide on what to do. I am pleased with the satin black look. It blends in just fine and I think the pressed circles provide a nice "race" look as well. Lastly, I was able to pick up a close ratio 5 speed transmission out of an '82 zx from a friend who is doing a small block chevy swap. It was a direct swap and the extra 5th feels great. Rowing through the gears without bogging feels GREAT. Thats all for now, happy drives ahead!

That is a good solution @Racer X....that requires more work

Thanks Zed Head. I think I was misunderstanding the NASA CCR rules for running a catch can. Now that I am rereading, it sounds like it just needs to terminate within a can, but the can itself can be vented. I just assumed it needed to be a sealed system. I am running triple mikuni carbs so running a sealed system was causing a headache.

Bumping a super other thread to life. But I'm in the process of building a catch can setup for my Z that needs to be sealed to conform to NASA regulations. I was planning to do crankcase and valve cover to a two port can. But the above option looks like a possibility as well perhaps?

I ran one on mine when I redid my wiring. Definitely not intended for theft as I labeled my switch FUEL But I do enjoy having it. I also want to look into inertia switches in case of a crash and I am unable to shut off my fuel manually.

Thanks @inline6 This is super helpful. In post #295 you can see the approach I took which is a bit different. First note being the idle mixture screws were turned out 2-2.5 turns which is double your recommendation. I will need to see where I landed at and if I need to change my pilots. Is there a reason why 2 turns out is too much? I was able to get my AFR gauge temporarily installed enough to check my idle AFR. I'm glad I picked this up because I was LEAN. At idle I was in the 17s. It makes sense now, but I assumed that I would be rich just because I smelt fuel. But looking back now, running lean can have poor combustion where not all the fuel is vaporized. Wasn't able to drive the car since its been raining all day so that'll be for another day. In the meantime I'll check my idle mixture screws and adjust my pilots if needed.

I picked up an AEM wideband to help with the tuning of the Mikuni's. Before I start blindly doing my own process, curious to see what the order of operations should be. My thought is idle, cruising, then WOT pulls. Thoughts?

Yep, its still the 4 speed and original diff from when I got it. Its possible the previous owner swapped something out as I don't think it was the original motor to begin with. Yesterday I softened up the suspension further and took it out for another cruise. I'm learning to trust it more and more each time. It is definitely a conversation piece! First time getting gas under its own power and already had a talk with a gentlemen who owned one in his college days.

I'll give that a shot. I think it also has something to do with the needle placement on the gauge itself. As soon as I start moving it jumps to about 20mph. Might need to reseat it in the correct spot.

Definitely. Its an easy test to do and would help diagnose the issue.

Got around to getting some new tires on the Z and took it out for a cruise around the block...this time without the constant worry of the dry rot tires leaving me stranded! It handles so much better and drives way smoother, who would've thought No overheating issues, solid oil pressure and voltage. The Koni struts need some additional adjustments to get the ride where I want it. One thing that I need to fix is the speedometer reading. It is reading nearly double what my actual speed is. Tested it with some neighborhood radar readings to get a baseline. I looked up the issue but most people are off by a few mph's due to tire size, diff ratio, etc. But I am way off, double or nearly so. Any thoughts on whats going on here?

I believe its mainly to show the valves seating tightly. I wont google either just to add to the fun

I’m liking that fire extinguisher and mount! Which did you go with?

Surprised the mechanic let you/showed you this method. At least this explains the low compression numbers. If you can, do the test again with all spark plugs removed and throttle wide open. You'll get better results 🙂

are those numbers dry or wet? hot or cold? throttle fully open? Seems low, but at least consistent

Also while doing the compression test, I’d like to see the valve cover off and some shots of the valve train. Perhaps there is something out of wack

Are these heads prone to cracking? Perhaps there’s a hairline crack in the #4 chamber.

I thought the video was entertaining. Leno puts out great videos for the car community and I don't expect him to be an expert in every possible chassis there is. While his collection is expansive, he is always open to learning from what I've seen. He asks lots of engaging questions and really enthusiastic about the program.

Thanks! I'm going to save this for when I need my hatch replaced. Been looking for months now with no luck.

Yep! Thats the thought process for making these. Hopefully by using a larger radius during the first half of the pulley, it will give a somewhat noticeable increase in throttle modulation off idle. Then, it ramps down quickly for high throttle inputs.