Torque head bolts past spec for big boost ?

[87gtNOS]

where are you getting the arp studs from

looks like they are using R1 bike studs. cutting them down some too maybe??

 

[snowy1]

(www.aperaceparts.com) has the studs you need, they are the same as the 1999 thru 2001 r1 studs.

 

[4strokes are better than2]

dont see them on the web site i will have to call i guess have to call.

 

[Ted Jannetty]

Just my 2 cents, Being an engine builder for 26 years now, here is the procedure I use.

Clean all taped holes thoroughly, apply Teflon Sealer if holes are open to coolant, or Oil if holes are blind.

Install studs hand tight.

Apply Moly lube to threads and washers both sides.

Torque using factory Proceedures and specs.

Here is the part the makes the big difference.

Now go back in the proper sequence, One at a time, loosen the nut 1/4 turn and retorque to final spec in one motion.

You will see that the nut goes past where it was by up to 1/2 turn and you are not exceeding any torque values.

Never had a head gasket fail this way.

Ted.

 

[BlueMax]

Ted I couldn't agree more with your procedure. All of the Asian motorcycle manufacturers recommended after a rebuild to start engine, bring to operating temp, shut off, cool down and retorque heads. This was to ensure a good seal and proper final torque setting on the aluminum blocks. The newer models require a lot more work to get back at the head bolts so they have dropped that procedure. The old procedure worked great. I also look at stud threads and clean as necessary. I have an ultrasonic cleaner I use for the studs. One final comment. Follow the manufacturer recommended pattern for tightening bolts. The cylinder head studs are the same for the R1 (1998 - 2005) motorcycle and the RX1/Apex sleds. The Yamaha part number is 90116 - 10619.