demo243

Still kicking! Had to get something out of the corner of the garage so I pushed her out. Best proof of road worthiness I have right now.... Transmission still sounds like shit... maybe worse? Or maybe Im just getting used to the Z which is much quieter in every aspect... Funny how different of a car this is then the Z. The Z is such a cruiser and this is just a beast - close upright seating position; quick reving, quick steering; loud and obnoxious; the list keeps going.... Still a freaking blast to drive though!

Car successfully made it out to Lime Rock and back! Really did great after a few last minute adjustments. I wanted to roll it out there on the TBT wheels with the Fallen 660s since it just looks so much more bad ass... but I started loading gear in and went to push it back in the garage and the exhaust hung up on the lip... raised the rear end a half inch, but ultimately decided it was a better idea to throw my shoulder/storage season wheels on there as they give me another half inch of height. The Mass Pike is constantly under construction or paving and I was a bit worried about dragging flanges the whole way. Camp set up! Ultimately very glad I raised the rear end and swapped wheels - the Pike was BRUTAL! but we survived. The car did great as I said and even got 22mpg with my 6 pack of carbs. It was a really good test of the carbs as well with no issues. Luckily avoided most the traffic but did sit in a little bit on the way home. What ever radiator is in this car works! 85 degrees out stopped in traffic after 2 hrs of driving and it still sits right below 180 degrees. I must be sucker for punishment though... came home Sunday and on Monday I swapped the wheels back out for the 660s and dropped the rear end again and took her out to run a few errands. Saw this new Z parked out front and had to swing back around to snap a photo at the local dealer. Just another hard parked grocery getter

Noticing the missing out was pretty eye opening! Loosing a wheel is probably one of my biggest fears…

With a little further digging - mostly for piece of mind - I found this ARP torque chart https://arpinstructions.com/generaltorque.html ARP GENERAL TORQUE RECOMMENDATIONS Listed below are the general torque recommendations for bulk 5-packs and engine/accessory fasteners. Recommended torque is equal to 75% of the fastener's yield strength. Simply read down to the correct fastener size, then across to find the torque value for your application. Always use ARP Ultra-Torque® and follow the instructions below to ensure the correct preload is created. Recommended Torque to Achieve Optimum Preload (Clamping Force) Using ARP Ultra-Torque® Fastener Assembly lubricant* Note: For those using Newton/meters as a torquing reference, you must multiply the appropriate ft./lbs. factor by 1.356 Fastener Diameter Fastener Tensile Strength 170,000 / 180,000 (PSI) ( 1,171 Nmm2 ) 190,000 / 200,000 (PSI) ( 1,300 Nmm2 ) 220,000 (PSI) ( 1,515 Nmm2 ) TORQUE* ( Ft. / Lbs. ) PRELOAD ( Lbs. ) TORQUE* ( Ft. / Lbs. ) PRELOAD ( Lbs. ) TORQUE* ( Ft. / Lbs. ) PRELOAD ( Lbs. ) 1/4″ 12 3,492 14 3,967 16 4,442 5/16″ 24 5,805 28 6,588 32 7,371 3/8″ 45 8,622 50 9,782 55 10,942 7/16″ 70 11,880 80 13,470 90 15,060 1/2″ 110 16,391 125 18,515 140 20,639 9/16″ 160 21,220 180 23,944 200 26,668 5/8″ 210 26,372 240 29,756 270 33,140 6 mm 11 3,359 13 3,814 15 4,269 8 mm 24 5,801 28 6,581 32 7,361 10 mm 54 9,970 62 11,305 70 12,640 11 mm 72 12,184 82 13,961 92 15,738 12 mm 98 14,472 112 16,949 125 19,425 14 mm N/A N/A 184 22,771 205 25,730 16 mm N/A N/A 244 29,664 272 33,519 The 100-7708 Wheels studs are 190,000 psi rated which puts them at a recommended torque of 112 ft/lbs for maximum hold. This spec is at 75% of the yield strength of the stud so I can hold higher torque then that. With a 25% reduction for the anti-seize I used on the rears that takes 112 down to 84 - right where I torqued them to, so I should still be well within the yield strength of the studs. As mentioned I will be going back and cleaning off the the studs and lugs to ensure proper torque is achieved. Looking at the Permatex site it does specifically say " Not for wheel stud or lug use" --- Whoops! Big mistake on my part.

Shit… you are right. I totally spaced and forgot about that…. Which means I definitely over torqued those Z car depot studs. Damn in trying to save the threads in setting the studs I’ve done more harm. Either way- 65 ft lbs is in my opinion to low to run with big super sticky tires… Ive got the back 8 ARPs in and torqued them to 85… so I’m close to ARPs recommended max torque when you factor in the anti seize factor. I got one side of the fronts in but not torqued as I need someone to hold the brake to torque those down. I guess I’ll be going back with some good brake cleaner and cleaning off those threads! Thanks for catching that! This is what I love about forums and why I wish more people were still active on them.

Thanks! If they give me trouble I’ll try that freezer trick. My plan is to get them started with the impact and then finish with a rachet/torque wrench. Hoping ~85ft/lbs should get them seated- TBD…. I’ve got two of those lisle stud installers. One I snagged for the first round of studs and the other I got with the spindle pin tool (RIP to the rest of that tool…) I was using some anti seeze on the threads and a spare lug (I’ve got 20 and only need 16).

I read about those- at this point not worried about the affordable option but the strongest option. Also wanted something long for peace of mind and more thread engagement. ARPs should be the answer to that. Seems they have max torque for the m12x1.5 at 98 ft/lbs. Giving me plenty of freedom with my usual 70-75 ft/lb lug torque. I order 100-7708 per a number of recommendations. Knurl size matches what came out of the hubs.

Well in good news I passed safety inspection! Time to drop it back down. I also spent hours hunting down stud replacements- I noticed on Z car depots website they say street use only and 65ft/lbs max lug torque… so yea definitely doing away with them. I looked into the nismo 240sx studs and other replacements with the intent of keeping my 12x1.25 muteki lugs… eventually though I just decided to get the strongest and ordered up some ARPs and some new muteki 1.5 lugs. I’ll keep the other ones for the 510.

Some more work on the Z this week for the few that are following. Dropped some 32.5 Pilots in the HSR carbs (bumped up from the 27.5s) - Was hoping for a some more turn on the air screws and maybe a slightly leaner cruise in return, maybe a little more response/less hesitation on roll on on the highway. Don't really notice any change... gained a 1/8 of turn on the air screw. Maybe slightly better roll on on the highway... That's it for HSR tuning for now. Next step is to replace the needle jet- but not up for that right now... maybe next year... Carbs are running solid enough Im just going to cruise them now. I tried to grab some good video, but disappointed in the sound. Will try and grab some more in the coming weeks. Working on the e-brake to hopefully pass inspection... its close... tbd. Got refused inspection today since the front plate was zip tied on and the car too low... Raised it up 1.5" today so hopefully that will be good enough... Also noticed I was missing a stud/lug! This was my biggest fear using the bearing stud installer instead of a press... I must have over torqued them when installing. Sheared off right after the knurls. While raising the car up I found out I sheared a second one! I am pretty religious about torquing the wheel lugs to 70ft/lbs so I am assuming both are due to install using the impact... I had two spare so I replaced both. Im probably going to order a bunch more, and replace the other 3 on each rear hub just to be safe. These are from Z Car Depot... The fronts I was definitely more careful with since I was more worried about the cast hub cracking... but Im still a bit nervous about them too. In other frustrations. I had impassively ordered the 1320 muffler way back on Black Friday last year. I didn't do my research first to realize how big the canister is... I was hoping I could just trim the pipe and use a clamp to instal it- at least short term - but its just too long. I can take it to the local exhaust shop and they should be able to trim and weld it... but its still a big canister that barely clears the fender and tire well... I do like that larger 2.5" tips though. With that said Im afraid of what the exhaust shop will want to weld it up... and the canister is still really big. Thinking I might order up the Z-Story one that is smaller and "should" clamp right up... it does have 2" tips though. TBD

Yea not enough travel on the BC coils as they sit. Need to either extend them or as someone said above - drop the top hat and support the bottom with a jack.

Return spring Ver. 2 - moved it back between carbs 4 and 5; utilized the stock throttle cable mount for the return spring. Verdict is- it’s better. Seems to function just as well but has a lighter and better pedal feel. Also a bit cleaner and tighter to the set up. The spring does bend around the back portion of the “wheel” at wide open but I don’t see a real issue with that. Now I just need to play around with the upper mount bracket and clean it up or tweak it.

Quick and dirty- but proof of concept is there. Here is my initial bandaid fix to the rev hang issue- I want to move it further back - between 4 and 5 I think - and want to clean it up. But overall it helped. There is still a slight occasional hang between 1,500 and 2,000 rpm but much better and easier to drive when it hangs. Downfall is the pedal is definitely stiffer. After some more reading it does sound like many Moto guys use a push /pull dual cable set up. And V performance does mention the potential need for an external return spring. This was just what I had on hand and could grab quick from Orielly. I have another split clamp lever coming and will play around some more. Car felt really good today- makes me even question about playing with the pilots - but I still think a slightly richer pilot with more turns out on the air screw will help… just need to decide if I want to try 30s or 32.5s….

Played around a little bit more this evening. I have a very minimal amount of adjust at the slide mount- so played with that and the idle adjuster. Tried to lube the needle bearings, but really no access to them… I can try by putting the front end up and hoping the lube drips down. Still thinking of ideas… but ultimately thinking I may eventually need to make another throttle shaft with a couple extra degrees offset between the slide mount and return spring hole angles. I could potentially try to add an additional return spring… but that seems over kill and I don’t have much room either… Just gonna keep driving it for now. Still trying to decide if it try 30 or 32.5 pilots… should probably try both… thinking I might go 32.5s first though if they are better with no issues then I can skip the 30s and save myself $30. TBD

@benzo thanks! It’s been a fun albeit frustrating process! Ive been lucky with my carb dealings in the past- first time Todd from Wolf Creek had my PHH 44s dial from the rebuild for my L20b; literally didn’t change anything other then set the pilot screws. Second time I snagged the jetting info from @Duke for the same Mikunis on my KA. For these I got an idea of where I should be from MikuniOZ and one of the Triumph Moto guys- and luckily they got me close! I think I’m only 1 or 2 pilot changes from being done- and honestly could just run it as it is! AFR gauge really makes it easy to see what the carbs are doing. I’m using that mostly, but I am using plug checks for the pilot air screw balance. I have played with them a little to even out the carbs.

Updates! The biggest being I figured out what is causing my Rev/Idle Hang issue! Long story short - it is mechanical. Ive been chasing a vacuum leak that wasn't there - not a bad thing, since I cleaned up some other things dealing with that. It seems that with little/no throttle I am not engaging the return spring enough to close the slide - this could be due to a few things... Friction on the throttle shaft from a mis alignment; either due to the rubber mounts or the support brace I am using- or could be a miss measurement on my part of the spacing between the slide mount and the return spring/accel pump offset. Im going to try lubing the needle bearing that the shaft rotates on first and see if that helps. Click below for the video of the rev hang issue. I also swapped rubber mounts, I initially missed that there is a new style and old style. The new style has an oval outlet to the manifold, vs the old style with a round outlet. The old style round outlet better matches the manifold so I went with that. Still need to port match the manifold at some point... but Im not chasing those minute gains at this moment. Finally- I swapped to a 27.5 pilot, up from the 25. This had minor effect, but also a big change. At idle it bought me about an 1/8th turn on the airscrew. Its worth mentioning now that the air screw on these carbs makes a BIG difference! Essentially you can run practically what ever pilot you want and fix it with the air screw! Car has run great on 20, 22.5, 25, and now 27.5! But the air screw really effects your low/no throttle cruise and it seems the leaner you get turns out the leaner your cruise is. For example with the 22.5 pilot I was 1 turn out for and idle AFR of 14.5ish... but at low/no throttle cruise around town I was around 12 AFR! With the 27.5 at 1 1/8 - 1 1/4 turn out I am at 14.5-15 at idle and 13-14 around town cruise. Back on track - this bump to the 27.5 also seems to make a BIG difference on the highway "roll-on" ie 5th gear cruise to accelerate - much less of a stumble or super lean condition. With all that said I think I'm going to jump from 27.5 to 32.5 to see how that changes things. All other jets - needle, needle jet, and main seem to be good. On a more annoying note I seem to have developed a squeal in the rear end somewhere - likely due to the coil overs being so low. It seems to be only on acceleration - so I am thinking a u joint in one of the half shafts or maybe drive shaft.... tbd

Finally swapped the sticky rubber back on and took her for a cruise this morning before it got too hot. Thought about a couple of the local cars and coffees but decided to just drive it. Sticky rubber is a 45 series instead of a 50 so the car dropped 1/2” and definitely scraped the exhaust again. Obligatory 7Eleven shot

Progress! Bumped the needle clips up to the mid spot with out much change… Went back and bumped em up one more - slightly leaner. Big change! Highway cruise is now a solid 14. Mid throttle is solid 13 and WOT down in the 12s. Town cruise is still a little rich but no big deal… could probably tune em a bit more - but not quite ready to throw money at jets and needles just for the sake of trying… Also golf cart mirror definitely works! Still would like to see a bit more behind me- but that due to the Sparco seats sitting slightly higher and I don’t want to drop the mirror lower. Wide angle is great! Can see the blind spots though the quarter windows.

That’s the plan

Few minor updates- Ditched the 5 panel wink mirror- it works really well in the 510- but in the Z it ends up to low and too close to the driver, and really only 1 or 2 of the mirrors work. So trying something different- channeling my inner golfer with this convex golf cart mirror- so much more visibility, we’ll see what it’s like on the road. Then I picked up some new rubber carb mounts- in doing some digging around for tuning advice I realized there are two versions - the new version is an ovalized port and an old version with a round port. Going to try the old style round port since it matches the manifold better. Of course nothing is simple… went to pull them off and the spacer was stuck to it… so I just ordered another set of spacers. On hold for mounts till those show up. Of course when ever I take something apart I find another issue…. Really disliking this header and manifold…. Looks like there is contact between the number 1 port and almost at the number 5 port… so the manifold will have to come off again … And just for good measure at least they still look awesome!

I don’t disagree but that requires me to go buy a bat 🤣 and I would still have to raise it up. but definitely in the potential tool box.

that’s pretty sweet but a tough pill to swallow when I probably only need it one more time… unless I find myself another 510 or 610 and can somehow con the mrs into letting me buy it 🤣

Definitely one of the issues I’m fighting- meant to do it before my coilover install… but forgot… now it’s too low to get a good angle. Got the camber slammed on the Z right now so I’m good, but when I put the sticky rubber back on it might be to wide and I’ll need to try again. 510 was much easier to roll.

Props on doing that road trip solo! Amazing how many good people are out there and how an old Datsun can bring them together. Gotta ask about rolling those 260z fender- how? I tried with a roller on my 240z with no luck! Rear fenders are so thick it wasn’t making a dent - quite literally! Ended up stripping out the adjustment screw on the roller

That seems like a STEAL!

Swapped back to my “baseline” settings- 142.5 main and 22.5 pilot. Car is better all over - so leaner pilot and a richer main were the wrong way. I mentioned the leaner pilot being better before- atleast by smell- but the 22.5 is more reactive off the line. Less the 1 turn out says to go richer so going to try that way. And hope that more turns out (leaner) is better. Still have the rev hang issue so need to keep hunting for a vacuum leak. Might try some nicer clamps for the flange adapters. Ordered up some 25 pilots and 140 mains but probably won’t be till after the holiday that I get to try them. Worth mentioning the change in rail mount seems to be good. Cooler temps, and allows me to remove the carbs for jet changes without dealing with the fuel lines. Clunkier on the car then on the bench but definitely doable. zip tie for safety