'73 240z - Project Build

[benzo]

@demo243 Yeah I know that feeling. I get frustrated but it is fun at times or get super pumped when a good result comes from the work.

 

Todd was helpful. For me Dave Rebello helped a lot and Taka from KyushaHouse and of course some Ratsun info from previous posts. It is cool to see how the car and moto folks intertwine at times. I have considered contacting Zcar garage to do a dyno tune session but for now the car is running ok but adding the AFR guage could be a huge help for me. 

 

Look forward to seeing updates.

[demo243]

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.

 

 

[demo243]

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

[demo243]

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.

[benzo]

@demo243 not sure if this matters but there is a Dorman part # 610-320 that is supposed to be a longer stud that can work for Z's and 510's at an affordable price. I was going to use these on my ZX Hubs for the 510 

[demo243]

5 hours ago, benzo said:

@demo243 not sure if this matters but there is a Dorman part # 610-320 that is supposed to be a longer stud that can work for Z's and 510's at an affordable price. I was going to use these on my ZX Hubs for the 510 

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. 

[datsunfreak]

17 hours ago, demo243 said:

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. 

 

ARP 7708 is the only way to go. 🤘

 

We always use those, and always install them with an impact gun with zero issues/failures. 

 

Pro tip with using an impact: Get 3-4 flat washers, cover them in grease, then spin on the nut. Also, we usually only get 4-5 installs out of one nut before it starts to die, so we make sure we have 4-5 nuts on hand.

 

And we recently learned this trick, stick them in the freezer for a day before you install them. This made them slide in super easy. 👌

Edited August 21 by datsunfreak

[demo243]

8 hours ago, datsunfreak said:

 

ARP 7708 is the only way to go. 🤘

 

We always use those, and always install them with an impact gun with zero issues/failures. 

 

Pro tip with using an impact: Get 3-4 flat washers, cover them in grease, then spin on the nut. Also, we usually only get 4-5 installs out of one nut before it starts to die, so we make sure we have 4-5 nuts on hand.

 

And we recently learned this trick, stick them in the freezer for a day before you install them. This made them slide in super easy. 👌

 

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). 

Edited August 22 by demo243

[iceman510]

If you use anti-seize on the threads, you can't torque to the same level.  You can exceed the yield strength of the studs when torqueing due to the lower friction.  That could be why you broke some of the weaker studs you were using.  Just FYI.  You should definitely clean that all off before torqueing the lug nuts to final torque.

 

When I worked in an assembly plant, we had a situation happen where some lubricant was left on the studs from the supplier.  The robotic lug nut installer basically started pulling the studs apart as it attempted to torque the nuts to the prescribed level and exceeded the tensile yield of the studs.

Edited August 21 by iceman510

[demo243]

1 hour ago, iceman510 said:

If you use anti-seize on the threads, you can't torque to the same level.  You can exceed the yield strength of the studs when torqueing due to the lower friction.  That could be why you broke some of the weaker studs you were using.  Just FYI.  You should definitely clean that all off before torqueing the lug nuts to final torque.

 

When I worked in an assembly plant, we had a situation happen where some lubricant was left on the studs from the supplier.  The robotic lug nut installer basically started pulling the studs apart as it attempted to torque the nuts to the prescribed level and exceeded the tensile yield of the studs.

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.

Edited August 22 by demo243

[demo243]

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. 

Edited August 22 by demo243

[benzo]

Yeah as much as I like anti seize I don't use them for everything or only when required.  From reading your past posts seems the main issue was using an impact gun to tighten the lug nuts which you have moved to using a torque wrench to do the final lockdown which is good practice. The one pic of the stud broken at the base of the threads usually tells me that stud or bolt had stretch or had been stretched from the past and finally let go. Good on you to use the ARP's as those are strong and all about safety. 👍

[datsunfreak]

16 hours ago, demo243 said:

I got one side of the fronts in but not torqued as I need someone to hold the brake to torque those down. 

 

Yeah, this is why I always use an impact gun. 😋

[demo243]

8 hours ago, benzo said:

Yeah as much as I like anti seize I don't use them for everything or only when required.  From reading your past posts seems the main issue was using an impact gun to tighten the lug nuts which you have moved to using a torque wrench to do the final lockdown which is good practice. The one pic of the stud broken at the base of the threads usually tells me that stud or bolt had stretch or had been stretched from the past and finally let go. Good on you to use the ARP's as those are strong and all about safety. 👍

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

[benzo]

@demo243 oh man same here! Seen it happen and don't want to be in that situation. 

[demo243]

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

Edited September 7 by demo243