dporto

I posted this in my "CEL came back" thread, but I figured I'd give it it's own space...Anyway, in re-installing the exhaust cam sprocket last night I took a look at my Bentley manual and noted that it called for a torque of 10 nm (7.5 ft lbs). This seemed light to me, so I looked it up in the Knowledge Gruppe Torque book... Sure enough, those bolts are listed at 14 nm (10ft lbs) in there... I went with the 14 nm spec. as I'd hate for these bolts to come loose at some later time. I also put a little blue locktite on them... Anyone else ever notice such discrepancies?

Soul Performance

Hmm, interesting. Generally speaking the Bentley is my go to source that I trust. Is it possible that the two publications were written at different times? Maybe the Gruppe Torque book was written at a later time and the torque spec had been changed?

I think the difference is relatively small and that you will be in a safe spot with the lock tite and 10ft.lbs spec.

Evan

dporto

The Knowledge Gruppe specs. are newer AFAIK. They were also compiled and/or developed by Jake Raby/Flat 6 Innovations... When it comes to the M96 I think it's pretty safe to say that they are the authorities. This is not to say that the Bentley manual is wrong, but as you say, it was developed much earlier (Most recent update - 2012) than the more recent (2015) 996 Torque Spec Book.

Soul Performance

Absolutely, 100% agree. I would trust Jake Raby over anyone regarding the M96. Talk about someone who has been there and done that! Massive respect for that man.

Evan

Device2

Dporto I did the same thing on that task, blue Loctite and torqued to the 14nm.

dporto

it just seemed right... I sure hope so

Byprodriver

6mm thread bolts that are 8.8 grade are 7.5 ft/lbs & 10.8 grade are 10ft/lbs.

Flat6 Innovations

The higher torque is an updated torque per Porsche. The Bentley specs are several years older than the 2016 specs that I compiled. These torques change often. As of the date of the torque books release last year, all specs were confirmed less than 2 weeks prior to publishing.

I will be forced to supersede the torque book specs, and update them again in mid 2018.

The exhaust cam sprocket bolts are grade 10.9, they hold more torque than the other 6X1.0mm bolts that are used on this engine at grade 8.8

dporto

Thanks for chiming in Jake. Even 14 nm doesn't seem like it would over stress those bolts. 10 nm seemed a little scary to me as that's not an area where you'd want a bolt coming loose (talk about a can of marbles...). In any case, I feel confident that at least this sprocket isn't going to come apart inside my engine