Re-Torquing Heads after Rebuild

agfours · agfours's Garage

I know I'm asking permission here for a shortcut, which is not recommended, but I'll make my question either way to gauge the response on seriousness of my actions...

Last week I opened up the valve covers to do a valve adjust. There was a top end done about 10k miles ago, and this was overdue as a second valve adjust (did one at ~1k, but got clicky again soon thereafter). There was a bit of an oil leak from the 1-3 cyl bank, and so I decided to check the head stud torque specs... sure enough the nuts/studs were about 5-10lbs shy of 23.5lbs specification. The 4-6 bank were all in spec.

Now, for the shortcut...I didn't remove the rockers to get to studs/nuts #1-8 in the head diagram for torquing order (as specified in Bruce Anderson's rebuild book), but went ahead with retorquing studs #9-18 in order and pattern recommended. This means that the outside nuts/studs are in spec but the inside 8 could be undertorqued...but the perimeter nuts/studs are tight.

Will this be problematic? Any experience on this approach?

Flat6pac · 03-06-2015, 10:49 AM

Are you torquing the head nuts (10mm) Allen or the cam carrier 8 mm nuts?
Bruce

agfours · agfours's Garage

The head nuts (10mm) and Allen bolt heads - of which there are 18 total as specified in the cross torquing pattern for the heads.

smokintr6 · 03-06-2015, 12:30 PM

Quote:

Originally Posted by agfours

The head nuts (10mm) and Allen bolt heads - of which there are 18 total as specified in the cross torquing pattern for the heads.

The head barrel nuts are 4 per cylinder, so 12 per side. Sounds like you may be talking about the cam carrier bolts

agfours · agfours's Garage

Er, um. Yes. The cam carrier bolts...just went back and looked again at the diagram with caption, and I evidently misread what I was tightening...so I actually just retorqued the cam carrier bolts.

I must have gotten in a hurry and read right past it, not to mention not even taking notice of why the pattern of 'studs' was so haphazard and numerous... eek.

Good news is that they were loose and I retorqued them but about 1.5lbs shy of spec. Also good news is that this is a first step before tightening the head studs. Guess I will be trying again next time I have the covers off....

Question remains, if the cam carriers are not retorqued with the inner nuts but only those accessable with the rockers in place, am I looking at issues...i suppose less serious given these are not head studs

MikeD · 03-06-2015, 02:48 PM

Well, the torque spec for those is 18 ft-lb so they were ok to start with and you over tightened the ones you could reach. I'd just leave it alone at this point.

smokintr6 · 03-06-2015, 03:34 PM

I actually might be inclined to fix it. ..you want the cam to run true in the center of that thing. I wouldn't want a mix match of torque throughout. Could be over kill but the last top end I did we followed Waynes book using lock tite under the cylinders. The loctite set unevenly and the cam locker up tighter than a drum when we bolted the carrier down....so they are somewhat sensitive to variation. I'm not a pro builder like others on the board, so it's good to solicit other opinions.

smokintr6 · 03-06-2015, 03:34 PM

I actually might be inclined to fix it. ..you want the cam to run true in the center of that thing. I wouldn't want a mix match of torque throughout. Could be over kill but the last top end I did we followed Waynes book using lock tite under the cylinders. The loctite set unevenly and the cam locked up tighter than a drum when we bolted the carrier down....so they are somewhat sensitive to variation. I'm not a pro builder like others on the board, so it's good to solicit other opinions.