Wanted...to borrow preferably: Rod bolt stretch gauge.

[KatoKid]

Anyone in Melbourne I can borrow one of these babies from? Just need to replace the rod bolts on the M3 engine but dont really want to spend $100 for a one off and never use it again!

Thanks

[luvemfast]

Don't even know what one is, sorry Dave. 

[KatoKid]

http://www.summitracing.com/parts/ARP-100-9942/?rtype=10

Dial indicator gauge used to measure the length (stretch) of a rod bolt to its ideal elasticity vs just torquing which isn't ideal due to friction playing a part in the process.

[Whittie]

$200 

I LOVE having the right tool for a job, but that seems excessive for what is just a calibrated depth gauge!

What's wrong with just using the ARP 'special formulated' torquing grease/compound and using their measurements based on that, not going to be enough out to warrant the hassle surely?!

[peter mc]

its a cool tool that's for shore
About 20  years ago i was lucky to spend some time in a F1 engine shop and i watched a engine builder and he just oiled the bolts and torque the bolts, and i asked man don't you check stretch , and he just gigled and said whats stretch lol  ..
he said i can feel if the bolt is ok ... many years later i know what he means ...
 so i have not used one since . and have not had one big end bolt fail .... and i have torqued some

[Wayne G]

I have used an outside micrometer to measure the bolt, usually when torqued.  Good vernier calliper may also do.  As Peter MC said, with experience, you know by feel if the bolt if *ted and needs replacing. 

[Lightmaster240z]

Try to talk peter in to coming up and doing it for you my be cheaper 

[KatoKid]

ARP do provide a torque spec and lube but strongly recommend the stretch method.

From what Ive read on some BMW forums these engines really need good rod bolts for insurance (7,500 factory red line). The bloke that bought my 3.0L single Vanos engine fitted ARP bolts and the torque specs didn't induce any stretch at all, he consequently used the stretch method and had to apply a fair bit more torque over and above the original spec to get the desired stretch. Bottom line is that I don't want to grenade an engine and if it means spending a few bucks on a tool then I reckon its worth it. I don't have a calibrated arm like Pete and Wayne!

I did find a stretch gauge on VPW for 89 bucks.... so that's pretty reasonable and I can sell it afterwards anyway.

[nizm0zed]

for $89 its not worth selling.
Any potential failure you avoid from using it will make it worthwhile and for that price even if it sits on your shelf for several years till you use it again its no big loss.
Besides you probably wouldnt recoupe much in the sale of it.

(give you $30 for it )