Greddy Head Studs - Comparison to ARP + Installation

[karmakaze]

first off, holy crap are these things nice. its like comparing SPL suspension arms to a set of Tiens.

the head stud nuts are one obvious difference. The ARP ones are 12-point 9/16th socket nuts, the Greddy ones however, take a 6-point 17mm socket. The Greddy nut is almost twice the height of the ARP one.



Next we have the bolts themselves. Which the picture pretty much speaks for itself...



The Greddy set actually bottoms out in the block as compared to the ARPs or stock bolts for that matter. The only threads that are not used in the block are a few at the very bottom.

now, there is one down side to the Greddy studs, and that is their installation...

Unlike the ARPs, The Greddy studs do not have a place to use a hex wrench to thread them into the block.

Now, I did not follow Greddy's recommendation of cutting the tip off of your timing chain guide so that you can install the studs and then install the head as I already had my bottom end assembled and didn't feel like taking the oil pump cover off to remove the tensioner and i didn't want to risk cutting it while it was on the block.

But this is what I did do:



Using the excessively tall nut that came with the Greddy studs, i threaded the Greddy bolt to the old ARP bolt, and used the ARP bolt to install the new ones. You do have to be carefull doing it like this because you do not want to have any tension on the bolts themselves. So once they get close to bottoming out, start going very slowly and as soon as you feel it hit, stop.

The only down side to this, is that to take my head of, I now have to start with removing the oil pans, and then the front cover, and then the timing chain tensioner, as I have no other way to remove the studs. If I had the entire engine apart, I would would think about modifying the timing chain tensioner, but i still don't know if I would go that route.

I am however sure that I will kick myself the next time I need to pull my head off.

The recommended torque sequence is the following:

22ft/lbs59ft/lbsloosen all18-25ft/lbs72-80ft/lbs final torque

and that is using the factory sequence of center bolts and then out.
Modified by karmakaze at 11:00 AM 4/15/2008

[Hijacker]

Odd that they have you stretch the studs before final torque. So I take it that these are torque to yield then?

Which timing chain guide did they want you to modify? The only one that should matter is the top guide as the tension and slack aren't anywhere near the studs, and Nissan recommends you just remove it entirely.

Also, I prefer to install the head and then install the studs, so I find it a little disconcerting that there is no easy way to install the studs after the head has been set in place. +1 to ARP for including an alley keyway to screw them in place.

Where did you end up buying the Greddy studs?

[karmakaze]

According to the 240sxMotoring's (where I bought them from) description...

Quote »"Greddy high strength head stud kits for S13/S14/S15 SR20DET. Convert factory torque to yield bolts to the stud type to withstand higher performance use, reduce the chance of cylinder head 'lift'. Greddy studs were made with pivoting ends to ensure proper sitting of the studs into the cylinder block. Similar design to Tomei counter parts for almost half the cost."[/quote]They say to cut the top top of the stationary timing chain guide that is on right if your facing the front of the engine. It gets in the way if you try to install the head with the studs already in the block.

The manual does contain 2 pictures. One of which shows you were to cut. I will scan them and post them in this thread as well.

i agree with your method for installing studs after the head install. I prefer not to risk messing up my threads. I thought about notching the studs so that i could use a flathead to install/remove them, but something about cutting into a $300 set of head studs bothers me.

[inkslingers13]

i would just stick with the ARP studs... i just picked up a set and i love them. nuff said.

[karmakaze]

i would just stick with the ARP studs... i just picked up a set and i love them. nuff said.

Unarguably, these will clamp better due to the large diameter nut and washer, and increased thread usage.

but, that is not to say that ARP studs are not good enough. but i feel better with the greddy ones.

zerothread/313498

[Hijacker]

The greddy ones definitely look to be a lot better. There's more thread angagement on the block side of the stud and the nut is taller, giving it more thread engagement.

However, I have yet to see anyone pushing moderate horsepower tear up a set of ARP studs. Scott from Enthalpy is the only person I've heard of that has had issues with ARP studs. It makes me wonder if there was a shop putting the motors together down in his area that screwed up the installation. ARP is one of the best names in the American performance parts market for bolts and studs and I stand behind their products 100%

Now, the Greddy unit will have a higher power ceiling. That's for certain with looking at the design of the studs.

I still find it hard to comprehend how the tension guide (sorry I use the Japanese terminology. Theirs is reverse from how we know them as. So the tension guide is the long stationary guide) is in the way of head installation, let alone stud installation. It's no issue to me since I rarely have the guides installed when I install a head. I do the chain assembly after the head and block are mated.

The reason why I do a head install then do the studs is that the studs tend to all be sticking up at different angles, and will gaud onto the aluminum of the head, locking it in place. Especially if you're lowering the head down a little angled. Then it'll take a few minutes of trying to walk it back up to get it off. It's just easier to put the studs in after the head is on.

[inkslingers13]

The greddy ones definitely look to be a lot better. There's more thread angagement on the block side of the stud and the nut is taller, giving it more thread engagement.

However, I have yet to see anyone pushing moderate horsepower tear up a set of ARP studs. Scott from Enthalpy is the only person I've heard of that has had issues with ARP studs. It makes me wonder if there was a shop putting the motors together down in his area that screwed up the installation. ARP is one of the best names in the American performance parts market for bolts and studs and I stand behind their products 100%

Now, the Greddy unit will have a higher power ceiling. That's for certain with looking at the design of the studs.

I still find it hard to comprehend how the tension guide (sorry I use the Japanese terminology. Theirs is reverse from how we know them as. So the tension guide is the long stationary guide) is in the way of head installation, let alone stud installation. It's no issue to me since I rarely have the guides installed when I install a head. I do the chain assembly after the head and block are mated.

The reason why I do a head install then do the studs is that the studs tend to all be sticking up at different angles, and will gaud onto the aluminum of the head, locking it in place. Especially if you're lowering the head down a little angled. Then it'll take a few minutes of trying to walk it back up to get it off. It's just easier to put the studs in after the head is on.

well said Hijacker

[karmakaze]

The reason why I do a head install then do the studs is that the studs tend to all be sticking up at different angles, and will gaud onto the aluminum of the head, locking it in place. Especially if you're lowering the head down a little angled. Then it'll take a few minutes of trying to walk it back up to get it off. It's just easier to put the studs in after the head is on.

Likewise, but now, that is also how I have to disassemble. Because I can not remove the studs with the head installed and I can't remove the head with the stationary guide still installed.

Don't get me wrong, I don't have anything against ARP, my main studs are ARPs. But i suspect that their sr20det head stud kit was just thrown together from studs that they were already making for something else. Which still isn't me saying anything bad about them as judging by the number of people who use them, they work.

The reason I had to change studs was not due to an ARP defect. I borrowed a torque wrench from a friend and it turned out to be faulty as I stretched 4 head studs and I decided to give the Greddys a shot. Had ARP engineered new studs for the sr20, I am sure they would of been a similar design as the Greddy or Tomei ones.

[Hijacker]

Ouch on the torque wrench snafu

When you do get around to it, I would like to see the instructions or maybe some pictures as to why the guide is in the way. I'm just having a tough time visualizing it.

[karmakaze]

Ouch on the torque wrench snafu

When you do get around to it, I would like to see the instructions or maybe some pictures as to why the guide is in the way. I'm just having a tough time visualizing it.

yeah no kidding.

i won't be back to the garage until probably tomorrow or friday. i will get some pictures for you then.

i will also make a pdf of the manual.