Rocker shaft removal and refit

[Ozdunc]

One of my tappet adjusting screws had one of its 'tangs' shear off the last time I was adjusting the tappets. Luckily I got the shard before it disappeared into the engine innards.
I was going to order a new one, when I 'remembered' I had a spare engine sitting in the corner of the garage.
I removed the rocker shaft complete and took off the tappet screw, then just lightly bolted everything back in just for safe keeping.

Now I've got a few questions before I take the rocker shaft of my running engine.
The five main bolts with 3/4 AF heads that hold the rocker shaft to the cylinder head are cylinder head bolts as well. Should I undo them in any particular order ( the same order in which they are tighten, or reversed) ?

In the LR manual it says to tighten the 1/2" UNF bolts to 65lb/ft.
Is 1/2" UNF measuring the bolt shaft thickness? At the moment I'm thinking those bolts to refer to the 3/4" AF head bolts.

I'm also presuming I refit the 5 bolts and just torque in the same sequence as the book 1, 7, 9, 15, 17, and I don't need to undo all the head bolts and re-torque the lot.

Final question - about my non running engine - is it ok to leave the 5 rocker/head bolts loose, or might this cause the head to warp over the year or so it might take me to get round to stripping it down.

[Ozdunc]

I have re-torqued the bolts on the non running head just incase.
It just seemed sensible.

[Johnno1969]

I was just about to answer your first post when I saw your last comment.

Definitely a good idea in my book to torque the head back down, following the correct bolt order.

John

[JDNSW]

I would be inclined to loosen and retorque all the cylinder head bolts in the correct order. Although, being a cast iron head it is not particularly sensitive to this sort of thing, there is no point in taking any risks, as it is not a major task.

I would also drain the coolant, just in case the loosened head allowed coolant to shift any debris into the joint (or even coolant into the cylinders), with a resultant poor seal. Again, the risk is small, but not worth taking.

John

[Killer]

You should be able to unscrew the udjusting screw out of the top of the rocker, and not need to dissemble the rocker shaft at all.

Cheers, Mick.

[Ozdunc]

I wish that were the case Mick, the screws in my 2a engine have a mushroomed dome that connects with the pushrod. These domes are bigger that the threaded hole in the rocker arm.

Thanks for the tips John. I hadn't even considered coolant. None of that is mentioned in the green bible.
Can the head bolts on these motors be re-used once torqued?

[Ozdunc]

The offending article.

https://www.aulro.com/afvb/images/imported/2014/07/715.jpg (https://flic.kr/p/o2W8AE)

[Killer]

Sorry for the false information.:confused: My memory can't be as good as I thought it was.:angel:

Cheers, Mick.

[JDNSW]

......


Can the head bolts on these motors be re-used once torqued?

Yes; when that engine was designed in the mid fifties, the concept of disposable head bolts would have been considered obscene, and contrary to the philosophy of making the vehicle easily maintainable.

Remember that the designers had lived through the great depression and WW2, and in some cases WW1, with shortages of everything for most of their lives.

John