ARP HEAD BOLTS WTF???

[socal_wrench]

We are using ARP bolts throughout the engine and I don't have a strech gauge and the factry specs for the rods is 75lbs and the sheet calls for 45lbs on the arp bolts.
and the same for the heads, factory specs are 105 lbs and the sheet from arp calls for 65lbs.
Am I missing somthing or is that right?
The arp specs sound a little light...

P.S this is the second set of arp rod bolts ---Snapped the last set @ 70 lbs

[fatassbuick]

Are they stainless?

[Deyomatic]

I know it is Sunday and there isn't anyone there, but whenever I'm in doubt of any product I find it best to call the manufacuterer and ask them. If you do, make sure you document everything, the person you talked to, the time, the date, and their answer to your question. That way, if it does break and you call them to try to find out why or tell them where to send your refund check, you aren't saying...
"Well, a couple of guys on the internet told me I didn't need to torque them down that tight and my heads flew off when we fired it."

Instead you can say...

"I spoke with Joe Sixpack from your tech dept. on 11/9/03 at 11:15 am and he told me that ARP bolts need less torque because of...."

[ray]

i think if you broke the first set, that kind of answers your question.

[socal_wrench]

No we haven't called the tech dept. It is sunday and no they aren't stainless they are the 220,000 psi
(supossedly badass) jobbys. I was just hopping someone had used them before and could answer my question.

[beatnik]

I've always used ARP bolts or studs for heads and mains and I've always used there specs, never had a problem.

I had a box of ARP head bolts sitting in the shelf for a 302 SBF they say:

65 ft-lbs with arp moly assembly lube

85 ft-lbs with 30WT motor oil

Hope that helps.

[fab32]

After going to to Hendrick Motorsports and watching their engines go together. YOu get an appreciation of what torture testing really is. Think your street engine can stand up to 8,000 RPM for 500 miles? Didn't think so. I think you will find most Nascar shops rely on ARP fasteners and for good reason, THEY WORK. One of my heros, Smokey Yunick gave them his approval and if you know anything about Smokey, he didn't get paid to endorse products.
As already stated get on the phone and talk to them, not waiting until monday isn't worth loosing a motor over.

Frank

[Hot Rod To Hell]

Their bolts require less torque because the threads are rolled, so there is less galling. You get the same clamping force with less torque, provided you use tha moly lube as mentioned above. I've use them exclusively on everything I've worked on in the last 5 years, and using their torque specs I haven't had a single complaint whatsoever.

[socal_wrench]

Thanks guys You always come through
I was just wondering if the specs were right and from what you say they are..
Once again thanks

[36-3window]

what engine are you working on? your numbers of 105 for the heads and 65 for the rods seams high for any engine. 65-70 for the heads and 45 for the rods is about right for a SBC with the big journal rods. i think you are tourqing them too high

[socal_wrench]

ford 390 FE.
those number came right from the book.


Even real men somtimes need instructions

[enjenjo]

If it's an old Ford book, chances are it's wrong. Ford put the wrong bolt torque specs in their books for some time, until it was pointed out by field techs.