When Should I Retorque the Cylinder Head

Dan1950

Dan1950

1974 MK II Roadster
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Finally got Trixie running. I have about 50 miles on here with 4 heat cool cycles. Would this be an appropriate time to retorque the head bolts?
 
For the longest time I was having a hard time wrapping my head around retorquing or worse, reusing wasted bolts.
Why would you do that?? Then it became clear retorquing a waisted bolt is a good thing whereas retorquing a wasted bolt is not.
You probably don't want to use a wasted bolt in a waisted application, but you could perhaps use a waisted bolt in a wasted application.
Or maybe not....Regardless, it is so much clearer now........
Carry on.......
 
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Depends on what head gasket you use, I use a copper head gasket and retorque at 500 miles only but using a fiber head gasket then it should be done a few times before leaving it but of course everyone have their own opinions on this subject so with my Norton retorque once then leave it been doing this for 47 years but I have only removed my head about 4 times in its life, but if my copper gasket get a slight seepage then I will retorque the head again but that's usually after a few years of running and many miles, I am still running my original head bolts.

Ashely
 
I don't know if mine ever had a re-torque by the PO, following it's rebuild. It was misting at 4,000 miles when I took custody and was cured with a re-torque (and a reed valve breather at the same time). Been good for over 2 years and about 5,000 miles since.
 
Using OEM stock bolt /washers and nuts:

Re-torque should be done on a dead cold engine. Or get the engine to ambient temps.

Normally on a new composite flame ring gasket. Run the engine up until it is too hot to the touch with your hand on the cylinder head. Leave it overnight to cool completely then re-torque. Take it for a ride then after 50-100 mile run, again re-torque. Then finally after 1000 miles, one more time. . Adjust tappets after each re-torque based on your cam.

The Gasket should be stable after that.

The wasted bolts and studs are something new and I have yet to try them but I would probably follow the same procedure.
 
concours said:
My waisted bolts didn't move, before the torque wrench clicked.
(Copper gasket)

Check 'em Dan, let us know the results!
Click to expand...
Perhaps waisted bolt method is different, but I'd heard and agree with the method of first cracking a torqued bolt or nut loose, then torque back to correct setting. Honking on a non-loosened bolt, the torque wrench will likely click before static friction on the threads is overcome, meaning less actual clamping force gets applied than actually spec'd.
 
Type of head gasket is really important .
I used copper type for many years and these needed re-torquings .
Nowadays I use fiber type and have been running one for a long time , 10 years now , and I do a lot of driving on my Norton .
 
Tornado said:
Perhaps waisted bolt method is different, but I'd heard and agree with the method of first cracking a torqued bolt or nut loose, then torque back to correct setting. Honking on a non-loosened bolt, the torque wrench will likely click before static friction on the threads is overcome, meaning less actual clamping force gets applied than actually spec'd.
Click to expand...
Rolling torque is not specified in the manual.
 
jaydee75 said:
Do waisted bolts eliminate the re-torquing requirement?
Click to expand...
No, check the torque levels regularly. Consider the ever growing downside of not keeping fasteners at spec.
Just smart maintenance, its a good thing to look after your stuff.
 
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