when are ARP 625 studs "necessary"?

mike diesel

I'm alright.
Sep 6, 2012
4,005
0
36
SLC, Utah
My heads are held down with standard arp 2000 studs, I guess also known as the 425's. I've got the black Victor Reinz head gaskets on it as well.

Right after putting this s588sx on, after a hard run at 75psi boost I noticed I had a dribble of coolant come out of the overflow tube. Nothing I even thought twice about. Did it the 1 time and never again...

Fast forward till now...with the 75/98 compounds it's making 80 psi boost and has never had an issue. Truck sat for the last week, got home from work tonight and pulled 150rpm from my shift points and went for a drive. I did 3 or 4 launches to 90mph and 2 or 3 50 mph runs to 90mph. All on the big tune. Well when i got home i noticed coolant on the passenger mirror so i popped the hood and my little 12oz "overflow" bottle had been pumped full of coolant and even sprayed a bit out of the breather. I'd say around 16oz were spit out.

If you drive the truck normal it appears to make normal pressure in the cooling system...

Does this sound like i need some 625 studs? Or should the 425's still be within the "safe" zone? I'll drive it to work tomorrow and see if it will do it again.
 

PureHybrid

Isuzu Shakes IT
Feb 15, 2012
3,496
477
83
Central OH
Have you retorqued them since the rebuild?

I think Mark @ Danville put serious boost/HP to standard ARPs before a head lifted, like 100+
 

mike diesel

I'm alright.
Sep 6, 2012
4,005
0
36
SLC, Utah
Yea these are socal stage 1 heads. This is the 2nd time these studs have been torqued.

I did not do a retorque on these since ARP recommended not to when using their ultra assembly lube.

But I'm thinking I will now..I guess thursday I know what I'll be doing in the morning:D
 

S Phinney

Active member
Aug 15, 2008
4,008
18
28
Quncy, Fl
It probably isn't the studs failing to do their job. Check torque and if problems continue you going to have to pressure test the heads.

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02greysixer

Active member
Jun 4, 2011
1,829
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North Central FL
I'm going off memory here but didn't another member have a problem with a cracked socal head or was it a different company?

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andy-stevenson

New member
Jul 7, 2013
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I'm going off memory here but didn't another member have a problem with a cracked socal head or was it a different company?

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Sounds right to me. I think I know exactly who you're talking about just can't think of the name. But I believe he did a rebuild with a fresh set of heads and he had issues right away?
 

prostreeter600

Street rodder
Jul 18, 2010
895
7
18
Dallas Tx
I had a similar problem, I had the 425s with my previous compounds 72 DP VVT paired with an S483 pushing 60 # all was good . I then stepped up to GTX4508R paired with a GT5541--94mm pushing 90-100# . Right away it started pushing coolant out at the top end of the track , then started doing it while boosting it at the line . My heads are ported , so during my new build I have had the heads pressure tested, they were fine . So I had my block O ringed and I stepped up to the 625s . From personal expierence it seems 60---70 # may be the limit on those 425s .
 

S Phinney

Active member
Aug 15, 2008
4,008
18
28
Quncy, Fl
I never had a problem at 84 psi boost. I thought I had a problem with the studs holding. I did have a cracked head myself. It wasn't from Socal. Heads can test fine intially and cracked upon use. I have heard of several guys attempting to lift the heads in the 70s on boost. I beleive a lot of that has to do with tuning. If in doubt step up to the 625 studs.

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prostreeter600

Street rodder
Jul 18, 2010
895
7
18
Dallas Tx
My heads are not from Socal, nor did I say they were . And like I said , my statement is based on personal expierence , and the previous post says the same thing .
 

DAVe3283

Heavy & Slow
Sep 3, 2009
3,727
296
83
Boise, ID, USA
I'm going off memory here but didn't another member have a problem with a cracked socal head or was it a different company?
Sounds right to me. I think I know exactly who you're talking about just can't think of the name. But I believe he did a rebuild with a fresh set of heads and he had issues right away?
Yep, that was me. Stage 1 SoCal heads. They were cracked basically immediately (coolant in the oil by 850 miles). The thread is [THREAD=63518]here[/THREAD]. SoCal did end up replacing the head on their dime, and covering shipping, but I still had to deal with the labor and gasket costs.
 

Harbin_22

Active member
Dec 4, 2010
3,858
7
38
Southern Indiana
I have H11's in mine. From my readings, they are in-between the 425's and 625's tensile strength wise. Haven't had a problem with a "high drive pressure" causing VGT and 483 making around 75-80#'s boost. I have the LML black and gold gaskets in mine. My drive pressure stays around 100#'s with an occasional spike to 120#'s. What's your drive look like?
 

TROJAN366

Gold Rush
Jan 13, 2012
2,474
1
38
MASS
My truck has the same set of 425s that I used in my original build. I was debating 625s and Lorenzo told me to go with 14mm studs but the block was already partially assembled. I never had issues with them in the past, I I just make sure to get the truck up to operating temp before throwing any boost at it. I have my fingers crossed they will hold up to the 75ish psi my truck makes.
 

JoshH

Daggum farm truck
Staff member
Vendor/Sponsor
Feb 14, 2007
13,714
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Texas!!!
What kind of pressure is in the cooling system when it blows the coolant out? Have you considered maybe your tank is too small and can't handle the volume when the coolant temp climbs and the coolant expands?
 

mike diesel

I'm alright.
Sep 6, 2012
4,005
0
36
SLC, Utah
What kind of pressure is in the cooling system when it blows the coolant out? Have you considered maybe your tank is too small and can't handle the volume when the coolant temp climbs and the coolant expands?

I do not know what pressure it is but I did think about this. I figured if the tank was too small, it would have done this from the get go. I believe Russ runs this same tank on his nova with no issue.

With these new compounds I have not checked drive pressure. I will do that thursday.

These heads were on Brett's c10 for around 1000 miles I believe he said. I have put maybe 4000 additional miles on them.

I have my stock heads sitting here, worse case scenario I swap over the valve springs to my stock heads and send them off to be cleaned up and decked. I wouldn't imagine the heads are cracked, the porting job is so light on their stage 1 heads, doesn't appear they remove hardly any material. But i guess anything is possible.