Carloz Posted August 15, 2015 Share Posted August 15, 2015 The effect of bigger diameter studs can be achieved bij fitting helicoils (of suitable length of course!!) => the effective diameter of the thread in the aluminium gets bigger and therefore bigger contact area. Also the thread wil not get damaged so easely. For the mainbearings it is maybe an idea to remove(!?) the first 5mm of thread in the hole to prevent breaking out the corner together with the first part of the thread. Still you also need off course suitable thread length left lower in the hole. Quote Link to comment Share on other sites More sharing options...
garrycol Posted August 15, 2015 Author Share Posted August 15, 2015 The thread in the block, yes. The thread on the other side of the stud is UNF yes but that is steel on steel where the other is steel on alumium - hence the coarser thread. Quote Link to comment Share on other sites More sharing options...
elbekko Posted August 15, 2015 Share Posted August 15, 2015 The point is that the thread that you're torqueing (sp?) is UNF, which will provide a higher clamping force (and hence pulling force on the block) than the same torque on UNC. Of course you can get away with a little more with studs, because you're not moving inside the aluminium at all. Quote Link to comment Share on other sites More sharing options...
garrycol Posted August 15, 2015 Author Share Posted August 15, 2015 Oh Ok - thanks Quote Link to comment Share on other sites More sharing options...
Team Idris Posted August 16, 2015 Share Posted August 16, 2015 I don't regret pulling my mains and heads to ARP toques, even though I was fully aware I was probably doubling the clamping force. I had concearns and it made my ring twitch. But at the end of the day I wanted these parts pulled down harder to stop the mains walking and to increase head gasket life. Next time I would use rover torque settings and be happy that I was pulling more clamping force from the UNF thread. I think the honest truth is that; "you are the engine builder" when you buy aftermarket upgrades. I couldn't bring myself to condemn ARP any more than I could the billet-vernier duplex-sprocket guys, the max-torque cam, the dry sump pump or Craig Davis. When all said and done I own a machine manufactured by Steve Knight. I'm responsible for my own crazy party Quote Link to comment Share on other sites More sharing options...
Carloz Posted September 1, 2015 Share Posted September 1, 2015 @ Idris: I guess you just be one of the Lucky ones... Quote Link to comment Share on other sites More sharing options...
garrycol Posted January 1, 2017 Author Share Posted January 1, 2017 I was just checking the ARP website and looked at the instructions - the instructions supplied with my studs was to torque to 100 ft ibs but checking them now they have been reduced to 70 ft ibs http://arpinstructions.com/instructions/157-4301.pdf Quote Link to comment Share on other sites More sharing options...
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