Stipped head bolt thread in block.

[101RRS]

The ARP recommended torque with their assy lube is 80lb, 85lb with oil. Done in 40, 60, 80/85lb stages.

The new kit instructs " Following the manufacturers torque sequence, tighten the nuts in three equal steps to 100ft lbs.

I have not installed mine as yet and will be doing it in the next week or so - I have a major concern going that high as one of my stud holes has previously stripped and has been repaired with a helicoil.

Garry

[clubagreenie]

Helicoil should be as strong if not stronger than original. In race prep blocks I used to helicoil every thread hole just for security of it not stripping on reassembly. TTY actual tensions average (not much) less than 100lb and some that don't give as much go well over.

[DiscoClax]

100ft.lbs on a relatively weak alloy block with hardened, oiled, fine threads? Not me. The degree of bore distortion would be significant and almost certainly contribute to bore and piston clearance and scuffing issues. Probably OK if the studs have a full 1.5" of engagement AND the block has been torque-plate bored and honed to eliminate that. Anyway, that's my 2c. I found no listing for that application when I got mine (actually a bit over 2 years ago now that I look back). Does anyone have the dimensions of the new kit (thread lengths, etc?)

[TriPolar]

Well i did the heli coils today. I just want to double check. As the piece of paper included in the ARP kit stated 80ft torque and the standard is 20nw 90+90. Should i be doing 40,60,80 for these studs or 20nm 90+90?

Because pics are cool:

[Hoges]

I am assuming the ARP kit included their special lube goo?

The optimal torque needed with ARP studs and their special goo with composite head gaskets (Elrin or Payen) on a Rover V8 is 65 ft lbs. Let me repeat 65 ft lbs.

The reason is that with the special goo, you are minimising the applied torque component to overcome thread friction and maximising the clamping force ... if your studs were in an iron block and you were clamping an iron head and using engine oil as lubricant then 80-90 ft lbs or more OK. Because a greater percentage of the applied torque is used in overcoming the thread friction between nut and stud and between nut and washer..But not with low friction ARP goo, composite heads and an aluminium block...

Think about why you don't oil wheel studs before tightening the wheel nuts ...dangers of over tightening and having them snap...same principle...

EDIT: 20, 40, 65 in the correct sequence!! Because the goo is effective in getting the correct clamping force, plus the improved quality of the composite gaskets, there is no need to re-tension the heads at a later date.

[TriPolar]

Sweet. Cheers man. Going to go do some torquing now.

Who wants to get paid to put my motor back together?

[Hoges]

One more thing.. be sure the stud holes in the block are dry with no solvent/lubricant/swarf etc in the bottom before you put the studs in. You don't want superheated fluid in the small cavity under the stud. A touch of blue thread locker if you like on the stud and hand tighten with the Allen key firmly but don't over tighten....take it slow and you'll do a good job!

[101RRS]

I sent an email to ARP last week asking about the high torque levels they have in their instructions but I have had no response.

Garry

[Kevin B]

How can I mass email every owner of a Rover V8 and say;

PLEASE USE STUDS.

Im sure there's an App for that...

[spudboy]

Can someone give me a quick heads up on ARP studs? I looked in Wikipedia - but no info.

Are they special because you put in a stud to the block, and then you tighten a nut on the top of the stud? Why is this better?

Sorry for the dumb question, but if you don't ask, you don't learn......