Ace L6 head bolts...maybe?

[OlderThanMe]

Well I was looking through this HUGE Ace hardware the other day and I found some bolts that look to be the identical same part as an L6 head bolt.

It's a class 8 bolt and it is black just like an L6 head bolt. Will these work?

I am currently using some 200,000 mile headbolts on my motor and am a little wary about them.

The next time I go there I'll take one of each size head bolt and check out the lengths.

Class 8 is 130,000 PSI minimum yield strength, correct?

They are at a good price too.

[1 fast z]

Here is a decent site for you to reference.

 

http://www.geocities.com/dtmcbride/home_garden/bolts.html

[johnc]

Class 8 is 130,000 PSI minimum yield strength, correct?

 

No. Typical certified Class 8.8 metric is 120Ksi. The bolts sold at consumer hardware stores are rarely certified so I would assume at least a 10% reduction in strength. Hardware store bolts are purchased from the lowest Chinese bidder.

[1 fast z]

For the price of studs, I wouldnt be messing around with any ace bolts.

[TravRMK]

If it is a 8.8, it is the same as a grade 5 bolt. If you want a grade 8 metric bolt I believe it is a 10.9.

[Pilgrim]

I've never heard of hed bolts having a mileage rating. That's a new one on me. What's the authority or reference behind that idea?

 

And I wouldn't remove any and re-insert and re-tighten them...that's asking for bolt or gasket trouble. If I needed head bolts, I'd buy Nissan - period. Of all the places to cheap out, head bolts would be the very last I'd choose.

[Careless]

I've never heard of hed bolts having a mileage rating. That's a new one on me. What's the authority or reference behind that idea?

 

And I wouldn't remove any and re-insert and re-tighten them...that's asking for bolt or gasket trouble. If I needed head bolts, I'd buy Nissan - period. Of all the places to cheap out, head bolts would be the very last I'd choose.

 

Why wouldn't you go with head studs in the first place, instead?

[Pilgrim]

Feel free to educate me - but I'm not aware of any advantages of head studs. The factory used bolts, and in 30+ years of working on cars I've never found a reason to use anything else. I'm not a racer and there's only one car I've owned that has required removing the head more than once.

 

What would be a reason TO use head studs?

[frank280zx]

Feel free to educate me - but I'm not aware of any advantages of head studs. The factory used bolts, and in 30+ years of working on cars I've never found a reason to use anything else. I'm not a racer and there's only one car I've owned that has required removing the head more than once.

 

What would be a reason TO use head studs?

 

AS ARP studs are MUCH stronger, apart from that they are reusable and dont have as much hazzard of snapping when you DO need to pull your head.

They prolly run about the same prize as a OEM nissan set..

Studs all the way for me .. then agian i am looking at removing the head for gasket issues more likely as i do run my engine hard ... if not yeah stick with what you have.. apparently it makes YOU happy however i would not go cheap and go for the studs instead!

[Xnke]

The real reason that you would want to use studs is when you have to put bolts into aluminum, and you'll be torqueing them down. Studs have less of a tendency to gall the aluminum threads, since you aren't applying a pull force plus the sliding friction of the thread engagement.

 

THAT's why you should use good quality studs in aluminum head applications.

[Careless]

My personal idea on head bolts is that when the head of the bolt bottoms out onto the washer or head mating surface, you now stress the bolt head and pull it away from the shank while you tighten the bolt, weakening the only ONE area that is gripping the bolt, or providing any sort of clamping force other than the threads against each other.

 

take a look at tightening head studs. you can tighten them to the same torque spec, but you've probably made a better effort at compressing the head gasket and seating it properly and speading load, mainly because since the nut is open ended, it can continue to be torqued further than a head bolt would, and the part that is providing most of the clamping load would be the threads. And the tighter you make them (all stretching aside), the higher the clamping load will be amongst the threads. Mainly because the threads are taking the brunt of the load, and they have more surface area than the underside of the head of a bolt, which seems to like to spread the load between threads and the bolt head.

 

If you were to tighten a head bolt, once you start to thread passed the bolt heads yield point, it will continue to stretch, and will actually lose clamping force amongst the threads. The only thing providing holding power would then be the bolt head itself, which is on it's way to being ripped off.

 

I like to think of how many rusted stud/nut combinations I've taken apart that broke in comparison to how many bolts I've taken apart, regardless of whether it's for a head fastener or not. I'm talking about various things that are just stuck, and wont move.

 

I can honestly say I've RARELY broken a stud/nut combo. Whereas a bolt... well, that's why I bought a set of bolt extractors...

 

EDIT: adding to that, there are many other reasons that I can see being the determining factor. price is just not important anymore, as I found this quote in the Corky Bell Maximum Boost book.

"Head bolts are an accountants decision. Head studs are an engineers decision"

 

and as for price not being important. I say that because head bolts from OEM suppliers are good quality, but about +/- 60 dollars than a good set of ARP or Tomei stud kits.

 

You can get them for way cheaper though. probably even half of what the better stud kits will cost you.

 

ARP and Kameari make stud kits for the Datto' L6 I think.

[Guest TeamNissan]

Feel free to educate me - but I'm not aware of any advantages of head studs. The factory used bolts, and in 30+ years of working on cars I've never found a reason to use anything else. I'm not a racer and there's only one car I've owned that has required removing the head more than once.

 

What would be a reason TO use head studs?

 

In 30 years you never heard or people running forced induction/hi comp/nos studding their motor because its much stronger? There are a slew of reasons too as previously listed.

 

I think maybe here we are more accustomed to removing our heads multiple times because most of us push our L series motors way passed stock tolerances. The head gasket being one of the weakest points on a L series leads to taking that head off enough times to warrant studs, besides the strength advantages.

[Careless]

The real reason that you would want to use studs is when you have to put bolts into aluminum, and you'll be torqueing them down. Studs have less of a tendency to gall the aluminum threads, since you aren't applying a pull force plus the sliding friction of the thread engagement.

 

THAT's why you should use good quality studs in aluminum head applications.

 

Yep, once you reach a point where the head of the bolt cannot be seated any further, if the bolt does not yield, the part of the bolt that is not seated into the block's iron threads will probably start to spin first, which would essentially "run over" the aluminum threads in the head, until the head of the bolt decides to break free.

 

[m4xwellmurd3r]

hmm, after reading all this, i think i'll stud my engine when i overhaul it XP

it's not a performance engine, but i see why you'd stud it.

[Careless]

hmm, after reading all this, i think i'll stud my engine when i overhaul it XP

it's not a performance engine, but i see why you'd stud it.

 

the higher in power you go, the more of a no-brainer it becomes. You could get twice the factory rated output on most engines with OEM head bolts, but why take the chance if you spend the money to get there?

 

A few things to remember are

 

1) torque in steps. 2 to 4 steps, Ideally. 3 if you like odd numbers. 5 if you have the time to do so (make time).

 

2) ALWAYS use proper 10W-30 or 30W weight oil, or even better, the provided assembly lube. dry threads have create more friction, thus more resistance, thus making the torque wrench FEEL like it's working against more fastening torque than it actually is. If you don't use the provided assembly lube, you better be good at calculating what the resistance and final torque rating must be in comparison to the fastener's provided instructions (or... dont even try to and just do it the proper way), as they're read with proper assembly lube. You can buy the assembly lube in 25ml and 50ml bottles direct from your ARP distributor, which is better than the small sample-pack that they supply you with. Mostly because engine assembly can take several tries. Don't lube once and never again. Always put enough to cover all threads.

 

3) Re-torque once the engine is run in for a while, or after the break in period. Metal needs to go through heat cycles to relax itself. If you have to take the cam off to do so... so what? it's part of engine building. Either do it before a head gasket problem occurs, or do it when the head gasket problem occurs anyway... I'd rest knowing I've done the former.

 

4) make sure your torque wrench is within proper spec. Don't go by the supplied spec sheet, there are various ways to calibrate your device. and make sure you always relieve the spring tension in the torque wrench when it's not being used. they will settle and provide inaccurate readings if they are tightened all the time (that's how torque wrenches work, they use an internal spring, and they settle over time if always taught).

 

ummmm, anyone have anything else to add? or should we move this to another thread or something?I guess it sorta does coincide with not using cheap bolts from the hardware store too... right?

[OlderThanMe]

Wow...What a threadjack...

 

Anyway the ACE bolts have "8" stamped on them. Not "8.8" so I guess that means the're the equivalent of a 10.9 on the US system.

 

For $40 that doesn't seem bad for a street motor. Some of us have VERY limited funds since there is a good majority of colege students here and we don't have access to buy head studs for 3-4X that price especially when building a V8 for the car(can't justify studs).

The motor the head bolts are for doesn't eat head gaskets and never will. Mild 10.2:1 N/A L26 making MAYBE 160 horsepower on a good day.

Its probably on it's last head gasket before getting scrapped for the V8 anyway.

Better IMO than getting head bolts at a JY for $10 in used unknown condition that may be compromised already.

[Guest TeamNissan]

Ya, was kind of a jack lol, sorry for my part of it.

 

If they are rated to handle the task I would have no prob testing the idea out. I'm the definition of she string budget ala john deer paint and being forced to do every single tedious thing myself. I even followed suite on your coil over idea as it was the cheapest most effect method I could find.

[Xnke]

as for using ACE hardware bolts, forget the grading scale. ALL internally wrenching fasteners are grade 5 minumum, if they are of any account. Grade 8 internally wrenching fasteners are *MOST LIKELY* going to be fine for a mild L-series. ARP headstuds are not required for a good engine, but like others here have said, if you're going to be working on it a lot, go for it. You'll like the extra insurance. In OTM's situation, the ACE hardware store bolts will probably be fine, as long as he keeps an eye on them.

[OlderThanMe]

Ya, was kind of a jack lol, sorry for my part of it.

No problem... It just turned from decently cheap head bolts at ACE hardware to ARP head STUDS...LOL I just wanted to know if I'd punch 83mm holes in my hood if I used them...

 

being forced to do every single tedious thing myself.

I consider that a PRIVLIDGE that I CAN work on my OWN CAR. A majority of the people in this world have neither owned one nor even ridden in a car. Much less have the opportunity to build a hybrid Z car.

Let's not act too spoiled now shall we?

 

 

I even followed suite on your coil over idea as it was the cheapest most effect method I could find.

It seems to work fairly well. Just if I had the $$$ to do the proper upper mounts rather than the ghetto modified stock spring perches. I have noticed some rubbing on the threaded collar from the spring bending from the top seat.

Definitely a good low dollar setup though to get one started on the suspension. My coilover setup cost less than my Illuminas!

 

OTM

[Guest TeamNissan]

No problem... It just turned from decently cheap head bolts at ACE hardware to ARP head STUDS...LOL I just wanted to know if I'd punch 83mm holes in my hood if I used them...

 

 

I consider that a PRIVLIDGE that I CAN work on my OWN CAR. A majority of the people in this world have neither owned one nor even ridden in a car. Much less have the opportunity to build a hybrid Z car.

Let's not act too spoiled now shall we?

 

 

 

It seems to work fairly well. Just if I had the $$$ to do the proper upper mounts rather than the ghetto modified stock spring perches. I have noticed some rubbing on the threaded collar from the spring bending from the top seat.

Definitely a good low dollar setup though to get one started on the suspension. My coilover setup cost less than my Illuminas!

 

OTM

 

 

SPOILED!!!! no way man lol, there is nothing fun about chipping 30yo tar our of your car or spending 40 hours hand sanding. I expect to contract tetanus on a daily basis ha. How about using a 100$ mig 100 to stitch weld body work? You and I both know if we were wealthy there are plenty of things we would rather not do, tools we would love to have etc. I'm deprived if anything......

 

For the coil overs I was wondering about that same issue so I used lengths of 2" black pipe welded center under the top hat about 6" long to help keep it from flexing out of tolerance and centered. Will it work? Idk, we will see I guess. I also used that black pipe for the collar perches as well, 1" length then cut in half and welded on. The gap between the 2 halves is almost perfect to run a bead down, then around. Shocked how well that worked.

 

You should try the ace head studs 1st though, your idea and that motor is coming out anyway . I think I'll have to go APR or otherwise anyway since I'll be 13+ comp. Don't think that should be the test bed.