Girdle and ARP...

need4speed · Post by **need4speed** » Thu Jun 05, 2008 8:08 am

If i use ARP studs and a ladder girdle on the bottom end, will that eliminate the fretting problem? Reading Des Hammills book he seems to think that using studs may require the block to be line bored due to the higher clamping forces distorting the main caps when tightened. I take it if i assemble a bottom end and torque it all and it still rotates freely then its ok?

Post by **katanaman** » Thu Jun 05, 2008 8:59 am

Depends what your building but in general ARP studs is really all you need to stop fretting. Yes its possible that it would need line bored but its not that common and is usually because there was something wrong anyway. I guess if you have signs of bad fretting then you might need to line bore but then you should do anyway because your mains will be oval. I would rather measure or get things measured properly as opposed to it turns so it will be fine. Again though it all depends what your building as to how good everything has to be.

need4speed · Post by **need4speed** » Thu Jun 05, 2008 1:00 pm

Im actually starting with a brand new block. So with this in mind i should be ok not to line bore when i use ARP's? It wont be doing mega rpm 6.5 very occasionally 7k...All this talk of distorting the main caps when using studs got me a little worried....

Post by **katanaman** » Thu Jun 05, 2008 1:16 pm

I think you will be ok but no guarantees. Only way to find out is to fit them and measure.

CastleMGBV8 · Post by **CastleMGBV8** » Thu Jun 05, 2008 1:45 pm

And carefully follow Des Hamills advice on how to fit the stud kit, ie fit the caps first then screw in the studs or you will damage the registers in the block.

Kevin

sidecar · Post by **sidecar** » Thu Jun 05, 2008 2:05 pm

I thought that Des reckoned that it depends on what torque you take the ARP studs up to as to whether you will need to inline bore the block. I'm sure that he gave a figure that would be OK without boring. (70 ftlbs?)

I guess you should still check the for the correct clearance whatever the book states.

Pete

ChrisJC · Post by **ChrisJC** » Thu Jun 05, 2008 2:19 pm

Agreed - get some plastigauge and check the clearances after assembly.

Chris.

Wotland · Post by **Wotland** » Thu Jun 05, 2008 5:30 pm

When I made my own girdle plate I used J.Eales extra long studs. He adviced me to line bore the block after the installation of the girdle and torqued the stud nuts to 110NM.

But by experience in the past, I never needed to line bore block after the installation of ARP stud and torqued nuts to 90NM.

HairbearTE · Post by **HairbearTE** » Thu Jun 05, 2008 5:41 pm

Interestingly ARP studs for a SBC appear to be identical to those for the rover, save for a bit of extra length. That's something you might want to know if you're planning on fitting a girdle.

need4speed · Post by **need4speed** » Thu Jun 05, 2008 6:26 pm

thanks for the good advice guys. Given that im not building a revver, i'll just use the ARP studs without the girdle. I'll check with plastiguage...

Boosted LS1 · Post by **Boosted LS1** » Fri Jun 06, 2008 9:28 pm

I fitted a girdle with studs and had no problems. Studs were torqued up as normal and the crank rotated fine. In fact, I've never used any arp studs and found stiction on cranks or rods. I think the honing/line boring suggestion is them covering their asses.

So, you need to fit some spacers appx .400" iirc between the caps and underside of the girdle to enable crush. I measured the gap and probably added .010" to get the spacers of the correct thickness. Not hard to do, just a bit of measuring. Studs on their own will work fine.

350matt · Post by **350matt** » Tue Jun 10, 2008 12:03 pm

Mike

What torque was this with?
as Whn I've fitted ARP's in the past I've used the lower 70Nm figure not the full 95NM which ARP state requires line boring

Matt

Boosted LS1 · Post by **Boosted LS1** » Tue Jun 10, 2008 2:18 pm

^ I can't remember the torque figure used but it would have been within the tolerance specified by arp at the time.