clearly both Karl and Mountune know what they are talking about but, as with most pros in the tuning world, they would rather keep their secrets to themselves (Karl has even complained on this forum about other tuners divulging information). I have not 1% of the experience of b19 or the knowledge of Chip but i do have some experience of long studs which on two occasions were machined and studs provided by Mountune.

The point of this post is to try and demonstrate how tuners can deliberately (or even accidentally) cause confusion among amatuers and how rumours can craete expensive problems and arguments on forums.

Machining the block for long studs involves removing the metal below the original stud holes and in some cases the metal removed means that there is daylight below the hole when viewed from the block deck. It also leaves a step whic is designed for the O ring to seal against.

The studs themselves have a shoulder which holds an O ring for sealing. Torquing down the studs to the designated Mountune spec (iirc 93 Lbft) means that the shoulder on the stud pulls the step on the machinined hole down towards the bottom of the block and the torque on the stud is actually a function of the stress on the block rather than the stud bottoming in the machined thread in the main bearing saddles. Beacuse of the daylight which now exists under the holes, this means distortion of the block face and it can easily be measured with a dial gauge set on the block deck.

Mountune were 'surprised' and suggested I'd done something incoreectly when i raised this with them but there was clearly an issue. It was frustrating dealing with them so gave up and simply screwed the studs in with thread sealer till the dial gauge showed distortion then backed off hald turn. the engine never gave a problem.

The second time the same thing happened. Again Mountune couldnt explain even though on this occasion they got pictures with written figures etc. Coincendataly i spoke at the same time with a very well known tuner and asked him about this and he said ignore the torque settings Mountune gave you, clean out the block threads with degreaser, dry them and use thread locker. Screw them in gently till they just pull on the block face - then back off - just what I'd previously done in fact.

The person who told me this advice also elaborated and explained that the machining of the block weakened the structure and that the torquing of the studs into the block (as per mountune advice) was indeed correct and that when the head is torqued down the stud will pull on the saddles and the deck will then go straight again!

Well fuck me what a way to introduce confusion into the diy brigade!

and who gave this advice........



Ahmed Bayjoo.

SO, what does all this tell us?

A little knowledge is worse than none!