Head stud vs. Head bolt clamping force

[tmacie]

I searched a bit but didn't come up with anything.

What is the difference in clamp force on stock head bolts and replacement head studs?


Travis

[Billyram]

I can't give you #s but the stock bolts have course threads and are carbon steel good for 80-90 ft lbs. Over that they just keep stretching.
The ARP studs have fine thread nuts and washers lubed with moly and can be torqued to 125 ft lbs. They seem to stop stretching at arround 90-100 ft lbs.
The clamping force has to be more than double.

[inline6359]

I also dont have any numbers but there is a saying for them.


Head bolts are an accountants design and head studs are an engineers.

[tmacie]

Thanks for the info guys. If anyone has data to post, that would be sweet.


Travis

[snow ram]

i hate sending people to other web sites, but DonM put a little bit of time into this test, its a pretty good read
http://www.dieseltruckresource.com/dev/showthread.php?t=47503&highlight=head+stud+torque

[tmacie]

good info, thanks!!!

[Bobcat698]

I talked to a customer of mine that had the stock bolts and the ARP bolts sent in for analysis and the results showed the ARP's didn't have much advantage over the stock bolts..
Just posting what I heard though, I didn't see the actual numbers.

[McRat]

Not that I'm against head studs, matter of fact the new engine will have them.

But with an aluminum head Dmax, I've ran the crap outta of the truck with the stock headbolts and gaskets and no leaks (59PSI, 755rwhp). I'm not sure holding down the head any tighter is going to make it go faster.

If you are planning on running big boost or nitrous, buy the insurance. If you are staying under 50 PSI and no bottle, I think the money would be better spent elsewhere. My amigo Tim runs about 60 PSI and nitrous in a 24v and last I heard he had stock bolts.

[THATpreston]

I know a 12 valve running well in excess of 60 pounds of boost (WELL in excess) that has factory head bolts and runs an 8.7x 1/4 mile.

We will now wait for Mr Hogue to tell us what a tragic error we are making ...... :pop:

[snow ram]

i would rather spend the couple hundred bucks for studs then the amount of downtime and and head aches of taking a risk with stock head bolts.....
for the last however many years, engine builders (gas and diesel alike) couldnt be wrong if a stock bolt holds just as good as a precision made stud (that needs to be about an 1/8 inch shorter)