Re - torque or not re - torque the head.

[brian GT6.]

I've just done 500 ish miles on my rebuilt engine and i'm wondering whether to re-torque the head or not. I know this used to be the done thing but have read that it's not necessary. Should I do it? Half of me thinks disturbing something that doesn't need disturbing might be more harm than good.

[Colin Lindsay]

I never retorqued the GT6 engine after the rebuild and will probably do it now that it's almost back on the road again, about 500 miles later. I doubt if you'll disturb anything, but at least you'll have peace of mind. 

I changed the oil a few days ago and there was some white emulsion in the bottom of the drainer, I'm putting that down to condensation and 18 months without the engine starting but want to check just to be sure, so will give the head nuts a check over this weekend. 

[Pete Lewis]

this depends a lot the make up of the gasket 

there are two things that can  we can suffer with which will loose clamping 

soft deforing head nut washers 

the gasket

i would back one nut at a time half a turn and re torque 

then reset the tappets after completing the task

pete

[dougbgt6]

I have always done it after a couple of hundred miles. Just as Pete describes and in the original order stated in the manual.

The last time, a couple of years ago, the nuts did seem to turn a little more, but that may be my capacity for worry. 

If you do it you should also check you tappet gaps.

Doug

[brian GT6.]

Thanks, will do it now before it comes out of hibernaton.

[NonMember]

Unlike the others, I've never felt the need to re-torque the head on a push-rod Triumph. It was definitely needed on the 1850 Dolomite (but that engine is designed to be re-torqued without even taking a rocker cover off).

[dave.vitesse]

When the head gasket is changed it is cold as are the studs and head. Once you start the engine things heat up and when you turn it off things cools down. The result is things start to change, and the torque setting should be checked and re-set if required. The old timers standard was after a couple of 100 miles. If I remember the Triumph service people used to recommend after 500 miles. Basically you have to allow for these initial changes, after that it should be OK.   

I agree with Pete, it can vary with different makes and types of gasket.

Dave

[JohnD]

The excellent Payen gasket is coated with a heat sensitive sealant, that will soften and 'squidge' a bit after the engine starts.    That makes me think - no evidence - that a retorque is a good idea with those.

[Anglefire]

I re-torqued mine both times I changed it (first Payen failed )  and has been ok since. It is a pain in the arse though to do as the rocker has to be stripped down to get access to the bolts (As many will know!) 

I'm itching to go out in it again - I have no problem using it in the winter - just like to leave in the dry - and any good days have been either work ones, or I've had jobs on at home.

[Pete Lewis]

might be the squidgy washers are more problem than the gasket 

in the end gasket material, crap washers and soft nuts are all contributors to HG failures 

i keep ramping on about them but your washers are in most cases   just  awful dished , deformed and  useless at maintaining nut torque.

pete

[Anglefire]

I re-used the studs and minispares washer in nut type the first time - but bought all new the second time - just didn't want the lack of a few quid to cause the same problem. Over cautious probably, but hey its only money and there ain't no pockets in shrouds!

[dougbgt6]

I’m told you can use the studs again, but my studs had to come out to get the head off and Mr Lewis’ grippy thing completely buggered the threads.

Doug

[68vitesse]

52 minutes ago, Anglefire said:

I re-torqued mine both times I changed it (first Payen failed )  and has been ok since. It is a pain in the arse though to do as the rocker has to be stripped down to get access to the bolts (As many will know!) 

Try a Mk1 head you have to remove the manifolds to get at one row.

Have always retorgued head and the manifolds.

Regards

Paul

[yorkshire_spam]

I did a partial rebuild on the Spitfire 1500 engine in 2015, head gasket, big ends, mains and thrust washers.

I used ARP studs, nuts and washers and a Payen HG, never re-torqued and has done about 15K miles since (including a 2x10CR runs) YMMV

I would be happy to re-use studs and the mini-spares nuts, but I've never managed to extract a full set of studs without ruining at least a couple and I have no trust that new studs would be OEM quality, so I "waste" my money on ARP.

[Pete Lewis]

as doug said my impact extractor naffed his studs but it did take a 3ft breaker bar and two of us on the heave ho 

tight or what !!!

pete

[dougbgt6]

Yes indeed, a vast physical effort was required, I couldn’t have done it on my own. We had to retire to ye olde Lands End for liquid refreshment.

Doug

[yorkshire_spam]

Part of my issue with wrecking head studs might be my lack of patience... I soak em in plus gas, try the "double nut" method and as soon as I start to strip the threads out of the nuts I give up and weld a nut onto the top of the stud and use the windy gun on it. Doesn't take long, but does ruin a couple of studs in every set I've done.