Super Jet Girdled Head Torque

[tor*p*do]

ADA says 18 on the head bolts 23 on the girdle
Yamaha service manual says 25/29 (29 is for cylinder bolts, assume same as girdle)
Saw a thread where Chucky recommends 23/35
I was quoted 21/30-35 in another thread.
What do you run??
Thanks!

 

[Vortex]

Do what ada recommends. 35 is way too much. 20/25 max

 

[JetManiac]

ADA specs are too low. Use 20-29 and remeber to retorque girdle bolts after a couple of heat cycles and periodically after that.

 

[JMew03]

I do what maniac says on the ada heads.

Torque like half of what it says then do a second pass to get to the 20/29

 

[Vortex]

Hmm. When I installed mine anymore torque felt like the bolts would break. This was an older head, new stuff might be fine with more torque.

 

[Dartman]

Hmm. When I installed mine anymore torque felt like the bolts would break. This was an older head, new stuff might be fine with more torque.

must use the ada modern rolled thread studs
not the very early cut thread studs
chucky and maniac are right on on needing more torque
ada specs is way off
23/35 is what works with the newer studs

 

[Vortex]

It's natural to overtorque. If 5 or 10 more lbs torque makes you feel better by all means do it. Torque wrenches are often inaccurate. trust your instincts.

 

[Dartman]

no... its not feelings or trusting instincts
its called experience and snap on certified torque wrench

 

[Vortex]

no... its not feelings or trusting instincts
its called experience and snap on certified torque wrench[/QUOT

That's right. Keep chasing the click until the bolt breaks. Snap on isnt always accurate either.

 

[tor*p*do]

Luckily I have a torque wrench at work that I can borrow
that gets NIST calibrated every 6 months

 

[bored&stroked]

That's right. Keep chasing the click until the bolt breaks. Snap on isnt always accurate either.

I've never snapped a bolt while using a torque wrench. Been working on airplanes, cars, motorcycles and jetski's for over 16yrs now so chances are pretty good it won't happen. If you go by instinct and not a torque wrench in the aviation community your in for a world of hurt.

 

[Vortex]

I've never snapped a bolt while using a torque wrench. Been working on airplanes, cars, motorcycles and jetski's for over 16yrs now so chances are pretty good it won't happen. If you go by instinct and not a torque wrench in the aviation community your in for a world of hurt.

Its rare, but it happens. Ive been in the classic car biz for 12 years. Clutch bolts are bad for breaking when you have all that leverage. Really need two people for that.

 

[Dartman]

i raced using some of the first able/ada topends and head stud kits before you born
so i have experience with this subject
i think you should invest in having your torque wrench certified and then use CORRECT torque settings

 

[Fro Diesel]

So survey says 21-23/30-35

And my wrench is superior!