REPRINT FROM OLD HTT: COMETIC HEAD BOLT TORQUE SPECS (HIPPO)

[ClassicRider2002]

DISCLAIMER: THIS IS A REPRINT TOPIC FROM "OLD" HTT

I have saved many great topical discussions as "links" over the years and would hate to see these lost, so I am reprinting this TOPIC here, which may "perhaps" help some.

TOPIC:  COMETIC HEAD BOLT TORQUE SPECS  (HIPPO) 02-02-04
   

From: werkinstif  (Original Message) Sent: 2/2/2004 3:43 PM   Message 1 of 14 in Discussion
I'm installing the .030 head gaskets.  Should I use what's said it the service manual for the head torque?

[ClassicRider2002]

From: Cold.Rider Sent: 2/2/2004 4:59 PM   Message 2 of 14 in Discussion
When I installed the Cometic .030 head gaskets I torqued them like the good folks at Cometic said to:  4 even increments with a final head torque at 44#.  I can't say what you should do, but I never did like that "and add 90 degrees" stuff.

Cold Rider


From:HIPPO_ Sent: 2/2/2004 5:03 PM   Message 3 of 14 in Discussion
Alternately turn each one of the  4 cylinder head bolts until finger tight then I use my own 5 step sequence, but you have to decide if you want to go with the factory spec or the Cometic spec. 

Put engine oil on the head bolt threads and then blow it off with air, and then put a drop of oil on the bolts shoulder where it contacts the head.  In some cases it can make a huge difference, in particular if the bike is a couple years old.   No Loctite is used for these bolts.   
Tighten and Torque in sequence according to the manual all bolts:
1)   to 9   ft lbs
2)   to 14 ft lbs
3)   to 22 ft lbs
4)   to 35 ft lbs
5)   to 45 ft lbs
Cometic says 42, I use 45.  42 might be the safe way to go if you don't have electronic torque wrenches.


From: werkinstif Sent: 2/2/2004 6:11 PM   Message 4 of 14 in Discussion
I didn't get any Cometic spec. with my gaskets. and I don't much care for that, "extra 90 degree"
stuff either, seems like guess and bygolly to me. Would someone enlighten me?


From: werkinstif Sent: 2/2/2004 7:26 PM   Message 5 of 14 in Discussion
Could someone tell me what the final torque would be according to Cometic?  Thanks.
 

From: HIPPO_ Sent: 2/2/2004 7:30 PM   Message 6 of 14 in Discussion
Cometic says 42, I use 45.
42 might be the safe way to go if you don't have electronic torque wrenches.  
     

From: elias_flsts Sent: 2/2/2004 7:31 PM   Message 7 of 14 in Discussion
 
When I installed the Cometic .030 head gaskets I torqued them like the good folks at Cometic said to:  4 even increments with a final head torque at 44#.  I can't say what you should do, but I never did like that "and add 90 degrees" stuff.

Cold Rider

I think ColdRider pretty much told you....
If you are still doubting... give the folks at Cometic a call.  They are really nice people to deal with.    elias


From: werkinstif Sent: 2/2/2004 7:32 PM   Message 8 of 14 in Discussion
Thanks Hippo, that works for me
 

From: HIPPO_ Sent: 2/2/2004 7:40 PM   Message 9 of 14 in Discussion
Put engine oil on the headbolt threads and then blow it off with air, and then put a drop of oil on the bolts shoulder where it contacts the head.   In some cases it can make a huge difference, in particular if the bike is a couple years old.  
   

From: werkinstif Sent: 2/2/2004 7:46 PM   Message 10 of 14 in Discussion

     

From: FXSTCHEWY Sent: 2/3/2004 2:58 AM   Message 11 of 14 in Discussion
I used 45 as my final torque and I didn't have a electronic wrench? what could happen? Thank's


From: HIPPO_ Sent: 2/3/2004 9:22 AM   Message 12 of 14 in Discussion
45 is 45 if both wrenches are calibrated, except that with the electronic ones you can watch the digital readout increase as you apply force, if the readout doesn't increase in a smooth curve and gets irregular or increases and tends to fall, you know you have a problem.

Not that big a deal but the difference between being able to see where you are going and going there blind. The more delicate the parts the more of an advantage, ie not a big deal with head bolts but maybe with the cam plate bolts.
Or maybe I just like the things.  
     

From: Cold.Rider Sent: 2/3/2004 11:27 AM   Message 13 of 14 in Discussion
 
Hippo said:  Put engine oil on the headbolt threads and then blow it off with air, and then put a drop of oil on the bolts shoulder where it contacts the head.  In some cases it can make a huge difference, in particular if the bike is a couple years old.

You said a mouthful there, Hippo.  I've built engines with a guy that uses anti-sieze on the threads and bolt shoulder, and it seems to work good too. 

Cold Rider


From: 1024drdave Sent: 2/3/2004 7:13 PM   Message 14 of 14 in Discussion
Adding 30wt or 40wt is the only way to go when you tq bolts.antisize will alow you to over tq dry won't give you enough acording to a study done by the arial corp.



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TWIN CAM HEAD BOLT TORQUE SEQUENCE SCHEMATIC:

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[ClassicRider2002]

While I realize this "THREAD" goes a ways back I feel the content warrants it being brought over here to the New HTT Site, hopefully it is helpful to others.

Anything added beyond this point is new information.

Regards,

"Classic"