Re-Using Head Bolts

[Dr.Evil]

Can you re-use head bolts? Or do new ones have to be purchased? I heard they are "torque bias" or something like that and you cant re-use them...

<small>[ February 27, 2004, 12:50 AM: Message edited by: Dr.Evil ]</small>

 

[SHOtimer]

When I did a head job on my old car we purchased new ones and I am pretty sure that is standard on all cars. I'd say for cheap insurance replace them.

Doug

 

[yamahaSHO]

Yes, you need new ones... They are stretch to yield. They are stretched once they are torqued down.

 

[revhardSHO]

they can be re-used, just make sure you verify the bolt is still good by using a straitedge to assure the bolt has not twisted, bent, etc.

AFK these are not torque-to-yield head bolts, but dont quote me on that.

<small>[ February 27, 2004, 11:02 PM: Message edited by: smithsil ]</small>

 

[yamahaSHO]

Do the above at your own risk.... nono

 

[Mr Anonymous]

While they are technically torque-to-yield bolts, I've seen them reused without any problems. In fact if Fred H. (Yamaha V6) happens to see this thread, I'm pretty sure he's mentioned doing it on a couple of motors without problems.

 

[twr]

The V6 head bolts are not torque to yield and can be reused. The V8 head bolts are torque to yield. IIRC it has something to do with the fact that the V8 block is aluminum.

 

[rangerj]

The head bolts can be reused. However, check them carefully for any damaged threads, straight, and use a straight edge to check the threads. Any threads that do not touch the straight edge indicates that the bolt has stretched.

All that having been said, the best practice is to replace the head bolts IMHO. How often do you remove and reinstall the heads? For racing you would be using studs with nuts and washers, so I assume since you are using bolts that you are not going to be pulling the heads every weekend.

Bottom line, if the bolts are in good condition reuse them. If you are not sure about the condition, replace them. rangerj