I know what you are talking about, work is one of those four letter words that we have to deal with. I appreciate your efforts on this issue.

Thanks and I look forward to hearing from you.

scripley,

I ordered my head studs today. I found out that the Pinto kit reffered to earlier in this thread uses 4.9" studs. The minimum required for the 103 head is 5.2" The next size available through ARP is a 5.4" stud. When used with the stock washer will work just fine. If you 2.6 is a four cylinder, the Pinto kit may work. If it is a six cylinder, you will probably need to go with the longer stud. The P/N for the 5.4" stud is AU5400-1LUB.
I also recommend one of their 12 mm thread chasers which only cleans up the whole but does not take any material of the threads as well as their thread sealer and assembly lube. Good luck on you project.

Motor Head

Hello Motor Head:

First thanks for the info, I will be making my order tomorrow. Also the 2.6 is a 103 series 6 cylinder.

Good luck on your project.

Just got my ARP head studs (for the 2.5-16v). How do I tighten the head studs, is there a specified torque ?

__________________
190E 3.0-24v (M104 980) turbo @ 0.8 bar
1/4 mile: 2.483 / 13.540 / 175.17 km/h (street tires)

First, make sure you put the studs in the block hand tight and use thread sealer. ARP's sealer works well. For a 12 mm stud the torque is 80 ft/lbs if you use ARP's assembly lube. Tighten the nuts in the order prescribed in the manual in three steps: 45 ft/lbs, 65 ft/lbs, and 80 ft/lbs. Double check all final torques.

Good luck

You're going to get detonation at over 15PSI. You need to add extra fuel to cure that. An extra cold start injector or change your fuel map to compensate.

On Volvo 740T's and early 940T's, detoantion causes number 4 conn rod to break, destroying the engine. Weak conn rods is the cause fixed in later, 93 - 95 940T's. Additional fuel or boost limited to 14 psi cures that.

Any updates on your car you care to share?

__________________
Regards

Warren

Currently 1965 220Sb, 2002 FORD Crown Vic Police Interceptor

Had 1965 220SEb, 1967 230S, 280SE 4.5, 300SE (W126), 420SEL

ENTER > = (HP RPN)

Not part of the in-crowd since 1952.

I took some time off work and am finally nearing the end of the re-assembly process. I should have the car started today or tomorrow. After that I will be looking into the Mosselman twin turbo setup which is good for 10 psi of boost and about 300HP on a stock M103. The head studs worked out really well. There is plenty of room under the valve cover and no interference with the rocker arm pedestals. I'll right back after I get her started.

Motorhead

I'd be interested in how this works out!


At 80 ft-lbs, I wonder what your preload is compared to the Stretch bolts. Yes, using a torque wrench on a nut/stud does yield slightly higher results than torquing a bolt. But angle torquing is MORE accurate.

So, did you figure out what the orginal preload was? Steel is steel- so the stiffness of the two would be similar. To gain benefits, you need to see where the factory preload number is compare to your 80 lb-ft.

Michael

__________________
Michael McGuire
83 300d
01 vw A4 TDI
66 Chevy Corsa
68 GMC V6 w/oD
86 300E

I have completed the re-assembly of the engine and it runs great. No leaks, good oil pressure and cool running. The head studs fit nicely under the valve cover with no modifications. Hopefully it will continue to live under boost although I don't plan on going much over 10PSI... initially!

Michael,

I have read a lot of threads regarding how the angle torque method translates to a torque value. No one seems to know the answer.

I disagree with your statement regarding the similarity fasteners. Steel is not necessarily steel when you consider that different fasteners have different mixtures of elements to give the desired performance.

Comparing torque values is meaningless if you don't know the yield strength of the fastner. As for the fasteners I am using, the ARP head studs are rated at 190,000 psi of tensile strength. When multiplied by the 14 that are used to secure the head I have 2,660,000 psi of tensile strength securing the head.

The material used in these studs is the same as is used on race engines designed to develop much higher cylinder pressures than a street driven engine so I believe I have a good insurance policy under the hood. My first experience with this same stud was on a small block chevy race engine with 14:1 compression that we ran at 8600 rpm in a road racing series. We never had a problem with them and used the same fasteners one numerous rebuilds.

I'll write back when I get the turbo's installed.

Kurt

Kurt,

Your talking to somebody whom does this for a livin- and I believe you miss-understood my statement.

When they qoute you ultimate strength- 220,000 psi that is Ftu in Mil-HDBK-5I or a similar source. I'm saying Modulus of Elasticity which is a different property. The stiffness of the joint is really a function of the gasket, bolt, and the 2 metals we are clamping. Your not changing the head or block material. The headgasket is the same(?), and all steels are approximately 28X106 psi for the modulus of elasticity. We could debate the fine differences- but they would really have to be a 718 inconnel to start being different.
What you have changed is the actual force in the bolt shank. It's not terribly hard to calculate the bolt preload. You just have to know the thread pitch/diameter plus go to a basic machine design handbook. Some assumptions must be made about a stretch bolt unless someone can test their stress/strain curve or find some old SAE paper back when MB went to them long ago.

As for your statements:

"I disagree with your statement regarding the similarity fasteners. Steel is not necessarily steel when you consider that different fasteners have different mixtures of elements to give the desired performance"- not my opinion- it's engineering fact.

and"When multiplied by the 14 that are used to secure the head I have 2,660,000 psi of tensile strength securing the head. "

This is just plain bad mathmatics - you don't have "2,660,000 psi of tensile strength securing the head.
". Let me explain- psi means "pounds per square inch". For a 12mm bolt, that means you have approxiately 0.16 in square of area. That say the bolt will rupture(break into 2 pieces) at approximately 35,000 #. Now, if it breaks at 20,000 it is meaninless too. Because that will be at 20-30% elongation. What is relevant is how much force it takes before you loose enough bolt preload to cause the headgasket to fail/leak. SO you could say 14X35,000 lbs, but that wouldn't be really correct either. Only the 4 primary bolts close to that combustion chamber would be relavant or about 140,000 lbs.

I have not disagreement that it works for you. Just your reasoning behind it seems flawed. If you are having better sucess it is because of an increase in *preload*-not bolt strength.



Michael

__________________
Michael McGuire
83 300d
01 vw A4 TDI
66 Chevy Corsa
68 GMC V6 w/oD
86 300E

Hi Joreto,

Good to see you here,I'm also in the midst of installing my turbo kit,
Can i have the ARP P/N for the 16v stud kit?

BTW,where you get your 8.5 comp pistons,are they custom made,i was thinking of using the same made as yours.

How's your Megasquirting?

Regards
Ivan