ARP Head stud kits

terryjm1

Well-known member
Jan 23, 2011
465
59
I have been reading up on rebuilding the 4.0 and 4.6 engine. There are a lot of differing opinions on using stretch bolts or spending the extra dollars on an ARP stud kit. Before I started researching the ARP stud kits, I read up on top hat liner options. One of the well known builders, Turner, RPi, or maybe D&D (wish I could remember which one) reported they had recently seen a handful of their builds with top hat liners installed develop head gasket compression leaks after only 40,000 ish miles. One of the suspected reasons for failure was uneven quality of the stretch bolts, even the OE supplied bolts. They stated they would now be using ARP studs.

Until I read that I had decided to simply get the better quality stretch bolts. Now, I expect I will go with the ARP stud kit.

I am curious, anyone here experienced a failed head gasket after a relatively short time period not related to overheating or other obvious cause?
 

terryjm1

Well-known member
Jan 23, 2011
465
59
I have also read that ARP has revised their torque specifications. They have reduced the torque from 100psi to 70psi.
 

WaltNYC

Well-known member
Mar 3, 2010
506
23
NYC
A reusable head gasket? I'm not at all sure I'd want that 'feature' in a HG. I mean, isn't the point to do it once and do it right? They can't possibly be reusable after 80-100k miles, can they?
 

terryjm1

Well-known member
Jan 23, 2011
465
59
When I was a lot younger I worked part time at a total shyster foreign car repair shop. I remember one time he “rebuilt” a Subaru engine. It had a rod knock. His rebuild consisted of sending the crankshaft to a machine shop and having one journal ground .O10 undersized and replacing only that rod bearing. He also cleaned the outside of the engine and made it look pretty. Reuse of head gaskets was standard practice, if they “came off clean.” I was amazed at what he got away with. He had a number of loyal repeat customers. If a customer left a car too long without paying the bill, their cars became parts suppliers for other customers cars.
 

StangGT5

Well-known member
Feb 4, 2019
64
16
Atlanta, GA
Tens if not hundreds of thousands of Rover V8s have been rebuilt with stretch headbolts and been fine. That said, I too am interested in using ARP's stud kit. I have come across a couple stories of cracking around the headbolt dwells that were attributed to the studs. It could just be coincidence that ARP reduced the torque spec, but there are plenty of people that have used the studs and not run into this issue.
 

pdxrovermech

Well-known member
Jul 3, 2009
1,725
26
Portland, OR
I like the ARP stud kits. I dont use them on all my HG jobs though. I'll use bolts on a block if the heads have never been done before because i can trust its integrity, but if I see that the heads have been off before and it was a shitty job (most the time it is) then i'll use the studs. these steel studs and bolts are threaded into an aluminum block and i've stripped a few bolts out while trying to torque them down properly. The studs dont put that same stress on the threads, so they hold up better.
 

Swedjen2

Well-known member
Sep 12, 2018
405
64
California
When I was a lot younger I worked part time at a total shyster foreign car repair shop. I remember one time he “rebuilt” a Subaru engine. It had a rod knock. His rebuild consisted of sending the crankshaft to a machine shop and having one journal ground .O10 undersized and replacing only that rod bearing. He also cleaned the outside of the engine and made it look pretty. Reuse of head gaskets was standard practice, if they “came off clean.” I was amazed at what he got away with. He had a number of loyal repeat customers. If a customer left a car too long without paying the bill, their cars became parts suppliers for other customers cars.
total shyster foreign car repair ©

Mine now.
 

11b4v

Well-known member
May 5, 2009
219
6
N. Alabama
I used ARP studs at 185k, now at 215 with no issues. I seem to remember torque was the lower, 65-70 ft pounds, definitely wasnt 100.
 

jymmiejamz

Well-known member
Dec 5, 2004
5,694
157
32
Los Angeles, Ca
I've always been very anti-studs. The few vehicles I've seen with them have had leaks after not many miles (installed by independent shops). I will say though , I read an article about Robison switching to studs and that same week a Disco came in with a loose head bolt (stretch bolt) on cylinder 6 with an external leak. I've never seen this before, but apparently Robison has a few times. IIRC, Robison said in their blog that the quality of Genuine bolts has gone down.
 

seventyfive

Well-known member
Jan 3, 2010
4,274
99
over there
I've always been very anti-studs. The few vehicles I've seen with them have had leaks after not many miles (installed by independent shops). I will say though , I read an article about Robison switching to studs and that same week a Disco came in with a loose head bolt (stretch bolt) on cylinder 6 with an external leak. I've never seen this before, but apparently Robison has a few times. IIRC, Robison said in their blog that the quality of Genuine bolts has gone down.
how many 'mechanics' really chase the block threads and parts cleaner-suck-parts cleaner-suck, etc?
torque the nuts properly, run the engine thru a heat cycle, then recheck torque the next day when cold?
 

jymmiejamz

Well-known member
Dec 5, 2004
5,694
157
32
Los Angeles, Ca
torque the nuts properly, run the engine thru a heat cycle, then recheck torque the next day when cold?
How many people are willing to pay to have the valve covers removed to recheck the torque? At the dealership you'd probably be looking at another $1,200 to do that.

If it were mine, I'd still go with TTY bolts.
 

seventyfive

Well-known member
Jan 3, 2010
4,274
99
over there
How many people are willing to pay to have the valve covers removed to recheck the torque? At the dealership you'd probably be looking at another $1,200 to do that.

If it were mine, I'd still go with TTY bolts.
not many. especially on an SAI truck. 9 times out of 10 the studs weren't installed properly. typically you should only need to re-check torque on a race engine. i ran an indy shop, so you can wrap the valve cover r&r up in the head job. SAI would add extra time, but it it's still a wash since we weren't dealer $$$.
 
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