After fitting new head gasket..

[mazfg]

I'll soon be fitting my new head gasket. Just wondered after torquing it all down and re-fitting all the ancillaries etc and finally getting the engine up and running......is it best to re-torque all the head nuts again. If so when.....after engine warmed up, after  afew 100 miles?

My only concern is that to get to the nuts on the manifold side, I have to remove the manifold(+ carbs) and downpipe again.......bit of a pain......is it worth me not putting on exhaust paste around the manifold to downpipe gasket until after the re-torque, or should I have to get new gaskets again for this and manifold to head...?

Thanks

[Richard B]

I think about 500 miles.

From your complaint I presume you have a MkI engine  ;)

[ferny]

This is why some people never re-torque those heads. Not that I'd ever do such a thing... (whistle)

500 miles is easy to remember, I think the book says 600? Either way, you're not going to need to worry about 100 miles either way.

With the exhaust, buy a new gasket. I always put some Holts Firegum on the surfaces and treat them like a head gasket - start with the studs in the middle and work out then repeat until they're all correct.  I use the gum to take up small imperfections and to let the gasket slide as they can grab and be put under stress as you do them up. You won't notice until you remove it and it's split. Again, it's no big deal but I have removed and reused them before in the past and put it down to being careful when fitting. It's not something I do often, but when you've got to rebuild your red hot exhaust whilst laying on your back on a dusty chalk driveway in France you have little choice! ;D

[Pete Lewis]

there is no mention of re torque in the 1600 workshop manual when replacing the head gasket as a repair.
  but it does call for a head retorque at 1000miles in the owners handbook as part of its first service   !!!

    good old triumph cloak and dagger specifications ,, there always something you need squirreled away in a black hole

if you do a re torque/ recheck always !!!  back the nut off 1/2 turn before re tightening  

Peter

[mazfg]

After much faffing about and stripping a few studs, which meant taking the head off 3 times and cleaning the Wellseal off....I have finally got it on and torqued them up at 43 lbs/ft. Ended up buying the taller HD nuts as recommended by Canleys. Still had a bit of a wobble with stud no. 3, but they are all nicely torqued up and I'm happy with it.
My only concern is the re-torquing...some say back off, others say just nudge it to re-check.....Horses for courses... Maybe if I set the torque to 44-45 lbs/ ft then I'm increasing enough to nip up anything? Bit loathed to start backing off by half a turn Pete....had so much trouble getting it together in the first place :(
Anyway, still a way to go before firing up.

[junkuser]

Stationary friction is higher than sliding friction.
This is the reasoning behind the suggestion to back off and re-tighten.
Trying to move the nut from its tightened, stationary, position takes more effort (higher torque) to move than if it is sliding when brought up to the specified torque.

"Still had a bit of a wobble with stud no. 3"
     That does not sound ideal, but could be interpretation of the words used.

[mazfg]

If I do back off and then re-tighten, do I do this for each nut in turn following the tightening sequence in the book? So, back of no.1, re-torque, then same for no.2 and so on til no.14? Or do I back them all off in reverse order then re-torque in correct order?

When I say wobble, I mean i thought I was getting near a thread strip again, it didn't feel it was tightening as the other nuts did.... having previously had 3 failed attempts at torquing up due to this very problem i was a little worried with stud no.3. Hopefully should be ok when i re-torque  :o !!

[junkuser]

Good practice to replace any stud that "didn't feel it was tightening as the other nuts did."
"New" nuts and "new" studs.  Often second hand original studs are better quality than actual new ones available, but I don't know your market, being in Australia.

[mazfg]

I'm not taking that head off again...maybe just over sensitive and worrying too much. It's been off 3 times already due to bad studs. They are all new ones now with new HD nuts. I'll just carefully re-torque after 500 miles!

[ferny]

I'm no engineer but not a fan of the loosen to tighten idea. In my mind you're re-torquing to make sure the gasket is being clamped properly and taking up any slack created by it compressing and settling. If you loosen and re-tighten then you're risking unsettling it and almost back to square one. I've never tested my wheel nights are tight by undoing them first.

Still, if the manual says to do it then you'd be following the manufacturers recommendation, so I would. I'm not known for reading them often though.  :B

[mazfg]

Maybe doing one at a time would stop and unsettling of the gasket..?

[rubberhead]

i would def go for retorque as per manual,these people who designed the engine know whats required and pass on info in manuals etc ,if you dont bother with to retorque it could cause another head gasket to blow.if your not sure about number 3 i would have it off sooner rather than later,put it right then refit knowing you wont have to go back there again.do it right and you only do it once.

[f1zzm]

Hi
Usualy undo and re tourqe induvidualy, i always mark the nut first and then you can see the amount of extra turn you get on the nut you will be supprised.
Dere  

[mazfg]

Thanks guys. Just been out and backed off and re-torqued them up (since initial head fitting) and am now happy with them being torqued ok. No.3 stud wasn't actually a problem. Re did that and it's stopped at correct torque fine without feeling funny or anything. I have faith in those HD nuts. I think I was being over sensitive as I've had no end of trouble with this and this is my 4th attempt.
Very happy now. Torqued at 45 lbs/ft and will re-torque after around 500 miles (of carefull driving :) )

[Nick Moore]

Usually I recommend reusing as many Triumph parts as possible, as the factory had the buying power to ensure that parts were made properly. Original fasteners are a good example. That said, I'm using ARP head studs in my GT6, and they're beautifully made. They even have a six-sided hole in the top so that they can be screwed into the block with an Allen key.

If you do have recurring head stud problems, I'd recommend the ARP ones.

[Pete Lewis]

dont keep re torquing you could go a one pull too far these studs are limited in yield as to  'how many ' times to do this  

its initial  fit and torque once,  re torque after 500miles   once

back off to eliminate the stiction  one nut at a time is std engineering practice , as is said.

test run is imminent then ????



Pete    

[mazfg]

Thanks Pete. I'm not touching it again now until 500miles complete. Time to put the rest back together and re-tune it all back :)