Rocker Studs

[Pyoor_Kate]

Okay, now... In my Haynes Ital manual it says that the head nuts should be tightened to 50lbft, and the rocker nuts to 24lbft.

The head nuts are fine... but the rocker nuts... When I originally put it on (the head) one of the nuts lost it's thread at less than 20lbft, so I replaced it with one from my other ital head and only dared take them up to 20lbft. I've just done the 500 mile retorque and decided to push my luck, as it were, and went up to 22lbft. And got that horrible sensation that the nuts have *started* to go.

Are the figures wrong in my book? Are the nuts worn out (darn, worn out nuts... no use to anyone ;) ). Any advice'd be appreciated...

[simmitc]

When I was young and inexperienced (aaahh) I just did them all to 40 (that's what my book gives for the head) and the rocker ones didn't strip. Since then I've always gone to 25 (again as per my manual) for the rocker studs. sometimes they strip, but only when they're old and/or much used. I reckon that yours are just trying to tell you something The moral of the story is "be like a squirrel" - always have some spare nuts to hand

[bmcecosse]

And 50 ft lbsf for the head nuts is really pushing it ! Don't go beyond 44 - even then - have thick washers under the nuts and the threads well oiled. The Metro had higher grade studs - and special head nuts with a flat face on the bottom side. Even in the old days - we used to search out the stronger 'dimpled' head studs - but 44 ft lbsf was more than enough.

[Packedup]

I just do the rocker studs up to "ratchet tight", never had a problem.

I can try pulling the head studs and chucking any nuts I can still find if you chuck me an sae or a couple of quid for postage (things really are that tight atm ).

As for the head, I'm desperately trying to remember what setting I use - But other than one sheared (A series) and one threaded i the block (Triumph) I've never had much in the way of problems there either. I reckon you're just having bad luck

[Cam]

Yeah, sounds like bad luck Kate. My Ital ones are 50 and 24 (not 100% sure about the 24 though, but it's whatever is written in the Ital manual). To be honest, I've not really had a problem with stripping threads. Are you sure your torque wrench is working properly?

[Pyoor_Kate]

And 50 ft lbsf for the head nuts is really pushing it

Remember, this is an A+ not an A, and has different head nuts. The Mog ones from my 1098 which currently replaces the missing one on my engine (I still have no idea what happened to that) is done to 44lbft. I did strip two before twigging that the A series head nuts don't go to that level of torque.

As for the head, I'm desperately trying to remember what setting I use - But other than one sheared (A series) and one threaded i the block (Triumph) I've never had much in the way of problems there either. I reckon you're just having bad luck

Aye, I had a feeling it was just bad luck. Ne'r mind. I'll see how it hangs together; hopefully I've not got to change anything so as long as the nuts don't come undone then *hopefully* it'll be okay until I next have to rebuild some bit of it. Say in about 30 years. Yes. ;)

Are you sure your torque wrench is working properly?

Well, it's not *exactly* a spectacular quality one. But it does seem to work for the 50, and the 40 lb ft settings. It may not work that well so 'low' (it goes down to 10lb ft, but up to 150, so it might just be that the 24 is not quite 24 )

[bmcecosse]

Is it a complete A+ engine - or just an A+ head on a normal Minor A series block? Either way - 44 ft lbs is enough, and yes ratchet tight for the rocker studs is enough - in truth they don't do much anyway - the pillars are clamped down by the head nuts. Note you should always undo the rocker nuts first - before undoing the head nuts - or they are having to hold the valve spring forces which may be too much for them. Equally - head nuts first and rocker pillar nuts last - so the bigger head nuts clamp down the springs. Does sound like the torque wrench could be a bit dodgey !

[bigginger]

It's A+ all the way (Sorry Kate)

[KirstMin]

Just as an aside, I have been told (by 1 minor specialist and 1 mini specialist) that it is not necessary to re-torque the head at 500 miles. Apparently it depends on the gasket you are using but the original spec (and what the manual is based on) was with an asbestos gasket which we no longer use. I have been told by quite reliable people that its only necessary after the first run-in/warm up.

I'm ready to be shot down here but that's what I have been told by A series engine builders!

[Onne]

I am sure it won't be a bad thing, checking them after 500 miles. But it is true, you don't have to do it on modern cars eother, as they have weird studs that shrink or something

[Cam]

I have been told by quite reliable people that its only necessary after the first run-in/warm up.

I'm ready to be shot down here but that's what I have been told by A series engine builders!

Simon tell you that by any chance? I've been told the same, but I do both. Torque on building, then after the first run up and cool down, then after 500 miles (first oil change).

[Pyoor_Kate]

Aye, I went with Cam's method.

It worked last time, I'm just praying it works this time. The exhaust frustratingly continues to foul the suspension despite playing with it for a couple of hours today, moving the mountings, and generally fiddling.

*grumbles quietly*

Still, managed to get my new bump stop on

[les]

Unfortunately I had a gasket blow last week, between 3 and 4, after about 100 miles I retightened but this time I turned the nuts one flat, because in the past when retorquing, the wrench always broke without getting anymore on the nuts, I've since learnt that there is a thing known as 'stick' which in effect is something that occurs if you stop turning a nut; the force needed to start it turning again, overcoming the friction of the mating faces, is more than the original setting.

[bmcecosse]

Shouldn't happen if the threads are well oiled.

[les]

I'm talking about when the nuts are being tightened again.