larger head stud 2.4 block

[boots]

Has anyone went to a larger head stud like 1/2" or 9/16" on a 2.4 block?

[Reaper1]

I'm curious if people did this how they got it to work with the head. I know it can be done with the old 8V heads because I've personally seen it done. I am sort of interested in doing this to another engine, but there are things about it that scare me away, too. BTW, the engines that I know were done were all N/A engines.

[boots]

I currently run 11mm h11 studs, they work but the company that makes them went out of business. and they are not cheap. I think going to a 1/2" stud will defiantly be just as good.

[A.J.]

Is it really needed? Have there been failures using stock size ARP studs? And if so at what power level?

[boots]

Yes, the regular arp will not hold 60psi.

[Ondonti]

Oh the joy of having 12mm headbolts from the factory.

Is there enough meat to just run a long pilot reamer through the holes in the head?

[Reaper1]

For the 8V heads I know 1/2" hardware can be used. I don't know what this does to cylinder wall distortion, etc. On the engine I saw this on it was no concern (N/A), but on super high boost applications...yeah, I dunno.

The other thing is that for things like my Masi head, I think bolts could be done with custom heads, but I don't know that 1/2" studs could be done because I'm not convinced there is enough meat or room to get a nut down in there.

[black86glhs]

With a hammer and grinder, anything is possible!

[boost geek]

ARP 12mm tapered shank studs suck as Bakes said they wont hold 100 psi I have a pic of one on my photo bucket,maybe I will post it tomorow if I have time

[83scamp]

For the 8V heads I know 1/2" hardware can be used. I don't know what this does to cylinder wall distortion, etc. On the engine I saw this on it was no concern (N/A), but on super high boost applications...yeah, I dunno.

The other thing is that for things like my Masi head, I think bolts could be done with custom heads, but I don't know that 1/2" studs could be done because I'm not convinced there is enough meat or room to get a nut down in there.

Shoot, in the early days, before quality ARP hardware was available, they used to use Hemi lower row head bolts on the 2.2... Somebody figured out they were the correct length... I'm pretty sure those were 9/16", but I would have to get out my old book and check...

[Sgt Craig]

Yes it can be done!We use to do it to the 2.4's for the pro 4cyl neon when i worked at Hahn back in the nopi days.1/2 " studs.The exact process im not sure of but it did go to machine shop to get done on both head and block.The dowel pins also had to be redrilled.

[Reaper1]

Shoot, in the early days, before quality ARP hardware was available, they used to use Hemi lower row head bolts on the 2.2... Somebody figured out they were the correct length... I'm pretty sure those were 9/16", but I would have to get out my old book and check...

Yup. My friend who did this used the Hemi studs. I am pretty sure he said they were 1/2"

[boost geek]

I may switch back romopar hedbolts if I have to,crankthem straight to 100 psi I do chase the threads and low tem outwith compresed air

[Ondonti]

I am still a bit confused on the install lubes that have been available from ARP and the torque specs. Seems like their newer lube doesn't change the torque value as much as the old stuff? Use the old stuff with a new torque spec and you would have a disaster. I really don't like how ARP handles this technical issue. I don't think anyone wants to give them a call in the middle of the night during a build.

[Reaper1]

Here's are some realistic questions, though:

How many of the really high power guys are having problems with the head studs/bolts stretching?
What power level is this happening at?
Was there any detonation during the service life of those parts?
How often is this a problem?
Are there certain positions in the headbolt pattern that seem to exhibit stretching than others?

I know Warren Stramer did some pressure paper studies on his car to determine what clamping was going to work the best for his application. (notice I did not say the best option overall!?) That's how he came up with needing to add the extra bolts to his build. I believe he also uses bolts and not studs (at least I know there's one of the higher power people that claim this).

I like the idea of using better/beefier hardware, but I'm not convinced it's totally needed.

[lengel]

I up graded to 1/2" studs just for piece of mind. Even made a cool fixture that anybody could do it with a hand drill.

[Reaper1]

I up graded to 1/2" studs just for piece of mind. Even made a cool fixture that anybody could do it with a hand drill.

That's pretty cool! Would you mind sharing?

[lengel]

That's pretty cool! Would you mind sharing?

Here you go.
http://www.turbo-mopar.com/forums/sh...ht=1%2F2+studs

[contraption22]

Here's are some realistic questions, though:

How many of the really high power guys are having problems with the head studs/bolts stretching?
What power level is this happening at?
Was there any detonation during the service life of those parts?
How often is this a problem?
Are there certain positions in the headbolt pattern that seem to exhibit stretching than others?

I know Warren Stramer did some pressure paper studies on his car to determine what clamping was going to work the best for his application. (notice I did not say the best option overall!?) That's how he came up with needing to add the extra bolts to his build. I believe he also uses bolts and not studs (at least I know there's one of the higher power people that claim this).

I like the idea of using better/beefier hardware, but I'm not convinced it's totally needed.

I think boots has already figured out it might be needed for his application. He is one of those really high-powered guys.

[boots]

One of the main reasons I'm looking into is to not have to spend a arm and leg on exotic material head studs. Like I said my direct replacement h11's have worked great. But the aren't cheap and readily available.