ARP Head Bolts

[CrazyInBlack]

just to make sure I want bolts not head studs right?

and they can be reused?

[coupe]

No Spencer. :tlash:

Get the studs. :metal:

[QWKSNKE]

Its really a matter of preference. Studs are a pain in the ass to deal with if you have to remove the head with the engine in the car

[Italian LX]

Its really a matter of preference. Studs are a pain in the ass to deal with if you have to remove the head with the engine in the car
I disagree. Actually, (on a 302/351) I prefer studs especially when removing the heads in the car.

Before pulling the head, you can remove the upper studs pretty easily with and allen-head wrench/socket and leave the short, lower bolts installed. In my experience, this actually makes the job easier for the following reasons:

1. Since the lower studs stay in, there's a lot less coolant that flows out of the block.

2. Since the lower bolts stay in, there is no need to clean off the sealing gunk that's left on the threads.

3. No need to chase block threads to clean off sealing gunk.

4. When reinstalling the head, the lower bolts help guide the head onto the block.

Sure, there are some drawbacks, but in my opinion, the pros outweigh the cons.

[QWKSNKE]

Guess I am just a ARP stud hater.

They cause an interference problem with my strut tower brace when removing the head.

But like I said, its a matter of preference. Most people prefer them but I think they suck to work with

[coupe]

Strut tower brace? You use one of those? Hell, that would make working on just about anything difficult, not just taking off the heads. :think:

[qkjuicedpony]

Strut tower brace=engine anti theft device


:D:D

[Craig K.]

Actually you should use what the block was machined for.
In other words if the block was finish honed with a torque plate using studs on the plate, then use studs.
If the finish hone was done with a torque plate and bolts, then use the bolts.

The reason is that when the bolts are torqued into the block there will be a small amount of deformation of the finished bore. having a torque plated bolted down (instead of using studs) helps to minimize this deformation for the finished product.

If your block was not finished bore without the use of a torque plate, then that is a big mistake, if you are asking for use on an older engine, then put back what was there, unless your boosting cylinder pressures, then historically studs should help hold the down better.

[QWKSNKE]

Strut tower brace=engine anti theft device


:D:D

:rofl:

yeah before the install of head studs I could remove/reinstall anything but the block without removing the STB

[coupe]

unless your boosting cylinder pressures...

:nice: There ya go Spencer.

[qkjuicedpony]

ask yourself this question..


Would you rather replace pistons or head gaskets......

[Italian LX]

ask yourself this question..


Would you rather replace pistons or head gaskets......
Tune it right and you won't have to replace either. ;)

[coupe]

ask yourself this question..

Would you rather replace pistons or head gaskets......
:think: soooo... are you saying use studs or bolts?

tune it right and you won't have to replace either ;)
Spoken like a true veteran of experience... :D

[Italian LX]

Spoken like a true veteran of experience... :D
Can't always predict when a fuel pump will decide to go south. :p

[coupe]

:werd:

[qkjuicedpony]

:think: soooo... are you saying use studs or bolts?




If you dont mind replacing pistons...use studs

for head gaskets...use bolts.

We all know that when you boost a stock bottom end or spray it that it may not last too long so why not give it an out so it doesn't kill the bottom end


especially if you're on as low of a budget as the thread starter is


:D:D:D

[CrazyInBlack]

WHAT?!? :slap:

[qkjuicedpony]

WHAT?!? :slap:


Man...you're so tight i can hear the quarters in your pocket screaming all the way over here in georgia



:jester:

[coupe]

If you dont mind replacing pistons...use studs, for head gaskets...use bolts.We all know that when you boost a stock bottom end or spray it that it may not last too long so why not give it an out so it doesn't kill the bottom end

I think you misunderstand the concept behind a cylinder head fastener. If you blow gaskets with studs...the bolts wouldn't have saved them. Explain why you feel the bolts have less clamp than studs?

especially if you're on as low of a budget as the thread starter is

Yea. no kidding. :jester:

[qkjuicedpony]

I think you misunderstand the concept behind a cylinder head fastener. If you blow gaskets with studs...the bolts wouldn't have saved them. Explain why you feel the bolts have less clamp than studs?


Yea. no kidding. :jester:


a stud is setup to have a better clamping force on the head than a bolt is.Why do you think we run head STUDS in our diesels and not bolts....because at 40+psi of boost it wont lift the heads and it will with the bolts.


studs have much better clamping force over bolts.so under problems with a stud it may lift a ring land,break a piston etc....while with a bolt it may just lift the head or push the gasket out.

[qkjuicedpony]

But it still does all come down to the tune as said before...plus knowing when to let out of it.


If he is planning on leaving the stock bottom end as is i would just throw bolts in it.

[coupe]

A stud is setup to have a better clamping force on the head than a bolt is
The only way a stud has more clamp is if you tighten it more...but it's not good to practice to overtighten a stud just becasue it's a stud. The torque value should be about equal for the stud and the bolt becasue they are both 7/16" diameter. And they're the same material.

Why do you think we run head STUDS in our diesels and not bolts...because at 40+psi of boost it wont lift the heads and it will with the bolts.
The 40psi is not what causes the problems. It's the 20:1 compression ratio combined with uncontrolled flame ignition, which yields in excess of 1000psi, that lifts the heads.

[qkjuicedpony]

well if bolts are just as good as studs....why the heck do they make both:D

[qkjuicedpony]

Here’s why. When you use bolts to secure the head, the fastener is actually being “twisted” while it’s being torqued to the proper reading. Accordingly, the bolt is reacting to two different forces simultaneously. A stud should be installed in a “relaxed” mode – never crank it in tightly using a jammed nut. If everything is right, the stud should be installed finger tight. Then, when applying torque to the nut, the stud will stretch only on the vertical axis. Remember, an undercut shorter stud will have a rate similar to a longer, standard shank stud. This provides a more even clamping force on the head. Because the head gasket will compress upon initial torquing, make sure studs and bolts are re-torqued after the engine has been run.




I copied this from another site....direct from an ARP engineer

[coupe]

well if bolts are just as good as studs....why the heck do they make both?

Bolts are not as good as studs. That's what I'm saying...Studs are better for the reasons the ARP engineer posted. The very shortcomings he mentions are the reason I prefer a studded cylinder head in any application other than a rebuild or freshen up of a stocker.

There is a common misconception that you can get away with a lot more torque on a stud than a bolt...and it's simply not true. I've heard people say you should tighten a regular 302 7/16" stud to 100 ft. lbs! :eek:
Although it can physically be done, it's not good for the 7/16 threads because the proof load is too high for the "fastening connection."

I think we're on the same page Brian. :nice:

[Craig K.]

baaah what is torque anyway, other than a rude method of trying to calculate clamp load which is what really matters.

[coupe]

True. But it's difficult to measure stretch in the bolt when one end is down in the block! :D

[LeeH]

True. But it's difficult to measure stretch in the bolt when one end is down in the block! :D
A more accurate way of tightening a fastener if unable to check fastener stretch is by Tq turn, We Tq then pull however many degrees is require to achieve propper stretch then back them off and do it over again. This initial tq crushes the gasket so the very last tq is 90% fastener stretch, This method allows for a more even clamping force. There was a study done on this due to numerous head gasket failures on a certain series of engines, It was found that using a predetermined tq value vs tq turn to stretch the head bolts was not allowing for an even stretch(clamping load). The differences were quite alarming as in the variation from lowest to highest using a numerical tq value was 60-90% vs 80-95% using tq turn, It is all based on evening the frictional losses and torsional loads.

With that said it also depends highly upon the type lubricant used on the load bearing surfaces of the fastener.

[BAD INT]

I am sure most of you know that on a SBF the way the intake bolts down it tries to lift the upper side of the head so be totally aware of all things when building.Torque specs are to be followed but I have allways torqued upper and lower head bolts the same just because of the intake and I will double and tripple check when using lots of power adder.

[Wickd GT]

Speaking of these ARP studs. I bought these Iron GT 40s and they have the sleeve adapter to use the 7/16 stud, looks like these heads were on a 351eng which uses the 1/2" stud. My question is, do I need to put ARP washers when I'm ready to put these together or is these sleeve adapter for the heads at the top don't need a washer.

Edgar

[04 Mach1]

Both set of heads that I have also have the sleeve adapters. Thought the same thing about the washer but the arp studs didn't come with them however the arp bolts do.:shrug:

[coupe]

Edgar, you don't need an extra washer. The 7/16-1/2" sleeve adapter is fine.

[QWKSNKE]

Both set of heads that I have also have the sleeve adapters. Thought the same thing about the washer but the arp studs didn't come with them however the arp bolts do.:shrug:

my arp studs came with washers :shrug:

[Italian LX]

my arp studs came with washers :shrug:
:stupid: