Installing ARP Head studs with the head on

[WhatsADSM]

I am soon to be installing a set of cams (HK$ 264/272s) and at the same time plan on installing all new 3g lifters and ARP Head Studs.

My question to you all, is (just as stated in the subject line)... can I install the studs without taking the head off? I don't see why I can't, the only down side is that I won't be able to chase the threads..


Murray

 

[2-0turbo]

I plan on doing this and have spoken with a bunch of my friends with more engine building experience than me. We all agree that it should be fine as long as the engine is cool and you remove one at a time. If you pulled them all at once, it is possible you could unseat your stock HG and that would almost guarantee a leak very shortly down the road.

I do not plan on chasing the threads unless necessary, but cleaning them out with a small vacuum device and some cleaner to be sure the stud doesn't bottom out before it should.

 

[candela]

I was going to post on this but 2-0 got to it before. Anyhow, I would suggest that you follow what he said about pulling one at a time. I did this on my last motor and had no problems

Austin

 

[hostile]

Yeah you shouldnt need to chase the threads in the head. Just put the moly lube crap on the threads and do them hand tight with an allen wrench.

Then tourqe the bolt down to spec.

 

[larryd]

i cant see how you would be able to tighten down the studs with the head already on them, there really isnt anything to grab onto to tighten them.

 

[GTM]

Originally posted by larryd
i cant see how you would be able to tighten down the studs with the head already on them, there really isnt anything to grab onto to tighten them.

Haven't done this on DSM but plenty of others. You double nut them and using two wrenches tighten one against the other, then run the stud down until it bottoms. loosen the top most nut and the other will spin off if you didn't bruise the threads.

I also use the double or even tripple nut for removing exhaust studs, works like a charm 90%+ of the time.

Any questions?

Cheers,
GTM

 

[candela]

Exactly as said above.... this is also the way the Ive gotten all those damned stuck head studs out when removing the manny =)

 

[GTM]

Originally posted by candela
Exactly as said above.... this is also the way the Ive gotten all those damned stuck head studs out when removing the manny =)

If you get good at it and use a 12 point socket it can be done with a 3/8 angle air ratchet. I've had to cut nuts in half when there wern't enough threads to get 2 full nuts jammed.

It's so much faster than using any stud removal tool on the market. And forget it if you don't have room to swing those stud tools in tight quarters.

Cheers,
GTM

 

[larryd]

cool, never thought of that.. hell i didnt really think there would even be room for 2 nuts on the studs, but I could be wrong

 

[GTM]

Originally posted by larryd
cool, never thought of that.. hell i didnt really think there would even be room for 2 nuts on the studs, but I could be wrong

I did preface my first post that I am not familiar with doing a stud job on a DSM. If there are washers involved omit them when driving the stud in, this way you will gain an extra couple of threads. A rule of thumb is the number of threads must equal the diamater but this isn't always possible thus cuttin (may require grinding, to do this put another nut on a bolt and then screw the nut to be ground on top of that and snug it up) a spare nut to act as a jam becomes necessary. Always use grade 7-9 nuts for you don't want to damage threads or you will get an incorrect torque value when pulling the head down. It's also important to follow the mfg's spec whether they are with or without oil for this can make a big difference in wheather it stretches.

Cheers,
GTM

 

[BUCK]

No way would I do the stud swap - just wait until the inevitable Head Job & swap them then. The risk of losing head gasket seal & contaminating your oil is too great. Even re-torquing the existing fasteners is risky.

 

[GTM]

Originally posted by BUCK
No way would I do the stud swap - just wait until the inevitable Head Job & swap them then. The risk of losing head gasket seal & contaminating your oil is too great. Even re-torquing the existing fasteners is risky.

Here we differ in views, I have seen no evidence to support that given an engine has _not_ already had overheating problems cause by a weakened headgasket and has cooled to ambient temp it cannot be done safely. Most major mfg's require as part of a major service the head bolts first be unloaded and then retorqued to specs. I hardly think they would requre this process if they felt it was a danger to head gasket failure for they would be buying engines left and right.

I would not consider releasing the bolt or stud and then going to lunch, but for the short duration of swapping bolt for stud I've never had any problems and until data supporting your position is obtained I will continue to endorse the process. Considering the goal is to prevent prematrue head gasket failure there is no doubt that this 1/2-1 hour job represents a major improvement in the longlivity of this engine.

Short of lubrication failure a leaking head gasket will do in more Japanese engines than any other cause. There are some cooling system design flaws which could be improved upon which would reduce the risk of overheating which in turn weakens the head gasket seal. Consider all the distorted pistons of which #2 seems to be most vunerable having that head locked down safely is most important.

My experiences sugget that a new thermostat housing should be enlarged into an aluminum expansion tank holding perhaps an additional quart of water before it is introduced to the radiator. The water pump is a high speed design which throws a lot of air in cavitation at the radiator cap so it is impossible to ensure bubbles do not collect in pockets only to be washed back into circulation throughout the system on every re-start. My point is since this does not exist then replacing the bolts for studs is the best thing that can be done to prevent failure.

Cheers,
GTM

 

[GRNDSM]

New ARP studs come with a socket head in the top end so that you can use Alen wrench to install them without having have to use double nuts. Having said that, I would not recommend you performing such swap with out removing the head…

First, you need ask if you really need ARPs in the first place. Sock head bolts (on 6 and 7 bolt motors) have withstood 400-450 wheel HP. So unless you are exceeding that HP level, I would leave it along unless you have your head off anyway.

Leon
RR

 

[GTM]

Originally posted by GRNDSM

...
so that you can use Alen wrench to install them without having have to use double nuts. Having said that, I would not recommend you performing such swap with out removing the head…

First, you need ask if you really need ARPs in the first place.
Leon RR

I had read they were made this way but no first hand experience.

Until I consult ARP and ask for their professional opinion I propose anyone who wishes to donate a set that have not been abused I'll put them in my son's car and raise the factory turbo to safe boost levels as a test.

I must confess 10 bolt 4 cylinder heads have never thrilled me when you consider the psi generated at combustion is several tons (2,000-3,000 psi comes to mind??). Times (X) area (/) 4 bolts will give the load on each bolt. With a conservative safety factor of 2.5-3.0x rated metal strength under tension the additional 25-30% when doubling the hp will not cause me to give it a second thought.

On thinking on it, I suspect ARP will not endorse the process since they cannot control _who_ does the job and they have a reputation to maintain. If it matters I've been twisting wrenches for almost 50 years thus given the conditions set out in my previous post I have a reasonable sense of security based on my past experiences this can be done. Having torqued thousands of head bolts I can use an impact wrench and be within the torque specified, this is based on repeated monitoring of stretch values built in to the design. Would I endorse someone else performing this assembly method... not in a heart beat. I have no ax to grind, the question was asked and I gave my professional opinion qualified with certain conditions having been met.

Cheers,
GTM

 

[BUCK]

On that note I recommend using only an impact grade 1/2" drive socket bit & 1/2 inch drive extensions when torquing the allen head bolts - other wise IMO you are "losing" actual applied torque to the fastener do to a lesser standard bit's tendency to "twist" at the last higher round of torquing. You are spring-loading the bit - not torquing the fastener. I personally believe that to be the reason a lot of these guys have repeated head gasket failures after a change-out.

During my 35 years of wrench turning I was taught to determine the RUNNING TORQUE needed to drive the fastener into the hole - then ADD THAT to the required final torque - if you insist on swapping fasteners with the head on - please consider doing that.

I still say it's not worth disturbing a head gasket unless you are replacing it - or that particular head gasket manufacturer requires a re-torquing after the initial install. Just my opinion...

 

[GRNDSM]

The hex drive on top the ARP stud is only there to help you drive the studs into the block or to remove them. ARP is very strict about not applying any torque to those studs inside the blocks other than "finger tight". That is why I am surprised that they added them...

One of the problems with installing any bolt/stud into a blind hole is that it can hydrolock from oil. So if you have any oil left inside the stud hole cavity it will not screw all the way down. This is a bit of a PITA to do on an engine that is full was full of oil and if you do it with the head in place, it will be nearly impossible to make sure that threaded holes are dry with head in place.

Leon
RR

 

[GTM]

Originally posted by BUCK
On that note I recommend using only an impact grade 1/2" drive socket bit & 1/2 inch drive extensions"
...

I've never like using any extension for as you point out the wind-up with cheap tools plus the extension does not give the same results when using an impact wrench. This would not apply when using a conventional torque wrench for you are looking at a finite value. I wouldn't use the impact wrench on an engine that I wasn't familiar with though my test have shown I can control it to within 10% of the specified torque.

"... I personally believe that to be the reason a lot of these guys have repeated head gasket failures after a change-out."

I suspect this does play an important part if they are using an impact wrench and run it in till it's tight.

" During my 35 years of wrench turning I was taught to determine the RUNNING TORQUE needed to drive the fastener into the hole - then ADD THAT to the required final torque"

Sorry, you lost me here.??

"I still say it's not worth disturbing a head gasket unless you are replacing it - or that particular head gasket manufacturer requires a re-torquing after the initial install. Just my opinion...

By no means am I endorsing this for an engine that has several thousand miles or months of use and then the stud swap is contemplated. My understanding of the question was based on a rebuild project which the head was installed and then the cam and stud change were contemplated with minimal engine run.

Cheers,
GTM

 

[GTM]

Originally posted by GRNDSM
The hex drive on top the ARP stud is only there to help you drive the studs into the block or to remove them. ARP is very strict about not applying any torque to those studs inside the blocks other than "finger tight". That is why I am surprised that they added them..."

Can you post their web site?? That finger tight goes counter to all I know about stud install. Perhaps they have had some twit shove it through into the crankcase... ah yes the days of back yard Porsche repairs and oil leaks.

" One of the problems with installing any bolt/stud into a blind hole is that it can hydrolock from oil. So if you have any oil left inside the stud hole cavity it will not screw all the way down. This is a bit of a PITA to do on an engine that is full was full of oil and if you do it with the head in place, it will be nearly impossible to make sure that threaded holes are dry with head in place. Leon RR

"

For this I use Tygon tubing but aquarium air hose will do, and carb spray or brake cleaner followed with compressed air down the tubing. It takes a couple or so douches to get them free of oil and crud. Throw a rag over the hole when you hit the air or suffer the splattered face look.

Cheers,
GTM

 

[BUCK]

GTM if the BOLT is not able to be finger tightened into the block - then the torque required to thread the BOLT into the hole is called the Running Torque - that running torque is added to the final torque spec. A STUD would bottom out - therefore the running torque you'd measure would be that of the nut - & unless it's a self locking nylon insert nut that running torque SHOULD be negligible.

 

[GTM]

Originally posted by BUCK
GTM if the BOLT is not able to be finger tightened into the block - then the torque required to thread the BOLT into the hole is called the Running Torque...

Ahha, now I see the word "BOLT" and I thought you were talking about "studs"... but of course. Engine running vs thread running "freely"... had me going there for a minute.

Back in the days of air cooled Porche and VW they had a lot of stud problems, there was a scam about baking the case, line boaring cam and crank, replace all the studs and torque to running specs. If you didn't get it right the first time you had to go through the whole process again. By this time the factory could have given the customer a replacement engine and melted down the original for rework. Rather than subject the customer to this crap we would park them out in the back lot, jam a screwdriver in wide open throttle and walk away. Sometimes they would suprise you and run for 1/2 hour most of the time was more like 5 minutes.

Cheers,
GTM