[QUOTE=KTL;10287963]Whereas incremental steps with torque is questionable since each step requires you to initially overcome the bolt friction to start it turning.

Exactly.

Each time you introduce error.

How about if you are using a stretch gauge - then incremental steps wouldn't affect anything.

I don't see how you could use a stretch gauge any way other than incrementally. If you are using a torque wrench and have the technique down pat, and so hit the stretch target every time, maybe? But otherwise?

Which has had me wondering if there is a tool out there which allows you to have a stretch gauge - perhaps not the usual kind - in place as you twist the bolt, so you could do what you do with a beam (non-click_ wrench - watch the pointer until it gets to where you want it. A long closed end wrench, so you have the leverage needed, might not interfere with the measuring instrument? A cheater pipe over an ordinary wrench? Fortunately, the stretch targets are a range, so we can creep up on them.

Yes an ARP stretch gauge or something similar and a Snapon torque link extension with a 3/8 square provision on one end and on the other a 7/16 or 11mm depending on what size the rod fastener is and a electronic torque wrench that will maintain the reading while allowing some manipulation around the stretch gauge.
You may not have to use an electronic wrench but you can set the offset 2 inches for the torque extension in the software and read both stretch and torque.
I realize that this is a bit of an expense but you have a hell of an investment in a Porsche engine now days.

regards

Followup questions regarding the procedure.

I have reworked and rebushed conrods from EBS Racing. I have my original rod bolts and nuts that came back from EBS, along with a set of new Porsche bolts and nuts. Engine is a 1989 911 3.2, bored and Nikasil coated to 3.4 so small increase in torque from stock.

I am planning to bore guage the BE of rods after retorquing original bolts/nuts. What is the torquing procedure for my set up? Single sweep to 14.7 ftlbs, followed by 90 degree additional? Is any form of lubrication specified or torque with bolt threads and mating surfaces clean and dry?

Assuming all measurements and calculated gap between Crankshaft journals and BE of Rod are to specification, i will then use new Porsche bolts/nuts.

Do I perform final torque with Porsche bolts/nuts clean and dry, with no Loctite or lubricant? Do I torque to 14.7 ftlbs with an additional single 90 +/- 2 degrees?

From reading this thread I should NOT use the Porsche bolts/nuts for Bore measuring?

Sorry for the continued questions. To someone unfamiliar with the process, some of the threads regarding torque procedure can be interpreted several ways. Wayne's book and Bentley state 14.7 ftlbs and one single 90 degree additional turn for stock bolts.

thank You,
Mark

You should check with EBS and have them contact the machine shop for what they torqued them to. I could vary and I doubt the machine shop used torque angle.
Anyway if that is not forcomming put you rods together with your new bolts and follow the factory procedure alway use some type of lubricant I am sure the factory stipulates in their procedure out of the manual. Measure with your gauge and check any out of round situation pull it back apart and hang them on the crank.
The torque angle they will give you should not lead to Plastic Deformation and you will be able to reuse them for final assembly.

regards

Racing97, Are you sure on the lubrication?

At this point I think the machined diameters of the rods are what they are, so shouldn't I be focusing on the torquing method and numbers for the final install when I am checking the bores? Any measurements I take based on "not final' torque or what the machine shop used are erroneous.

So again, Wayne's book and Bentley both say torque to 14.7 ftlbs, then an addtional 90 degrees. Threads in other locations in Pelican show a TSB with a lower initial torque and TWO 90 degree rotations for the 12.9 bolts, but the date on the TSB is 1990. People post pictures of it though and mention the process has changed. Hence my confusion. Wayne also mentions the original spec includes loctite but nothing about lubrication, which maybe the loctite is acting as a lube? People have also mentioned 10mm vs 9mm for rod bolts. The threads on the new 12.9 bolts I have are M10. The threads on the old 00 bolts that I removed are also M10. Is the 9 and 10 mm a shank measurement?

Thanks again,

Mark

3.2 and 3.6 rod bolts are the weakest rod bolts of any of the aircooled engines. Porsche reduced the diameter of the bolts for the 3.2/3.6 engines. These engines are some of the best justifications for upgrading to aftermarket rod bolts as the factory units are marginal. You may want to rethink your use of factory bolts and look at upgrading. After market bolts are made for measuring with a stretch gauge and easy to do so whole torque procedure goes away.

john

Thanks a ton John. I've been questioning my decision for a couple of days now. Was trying to manage the slippery slope, knowing low likelihood of racing my old Targa, but the more I read, the more I'm convinced that I need to go ARP or equivalent.

Mark