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MG Midget and Sprite Technical - Cylinder Head studs and nuts - dry or lubricated?

Rather than prolong my other thread regarding my blown head gasket and now that reassembly is imminent I thought I'd ask this on a new one.
Should the studs be inserted into the block dry or lightly lubricated? Should the threads at the top be lubricated before fitting the nuts?
I've cleaned the threads in the block as well as I can noting that the five short stud holes go into the water jacket space, and the four longer ones go into a space that had dirty oil in it, but I can't see whether this is open into the push rod space alongside or not.
I've read that a dry or lubricated state of the stud threads can significantly impact the tensile load on the fixture at a given torque.
My inclination is, having already degreased both the coarse and fine threads of the stud with carb cleaner, to spray with WD40 or similar, and then wipe so there is just a small amount of lubrication. Fitting to the block absolutely dry must risk some galling/pick up, and a similar risk at the nut end?
Thanks again....
R Pearce

Studs are inserted into the block either dry or having a small bit of Loctite applied to hold the stud in place.

Torquing of the cylinder head nuts is accomplished with the studs "lightly oiled" using a petroleum based oil. This was called "standard knowledge" back in the day and was something taught to aspiring mechanics, machinists, and others who expected to be performing such actions. As a result of this form of common training, things like factory workshop manuals do not bother to address how to properly perform several procedures because the people who were the intended article of such publications had already been taught the basics of machine operations. This can cause some problems when the average individual of today, more familiar with computers than dial indicators and micrometers, attempts to use sources such as the factory workshop manual--some things are just not mentioned because it was not thought necessary.

As to WD-40, it has less lubrication value than required since it is a fish based oil rather than a petroleum based oil. WD-40 was an excellent moisture displacing spray some 40 years ago. Today, we have better products available to the professional and WD-40 is most often used/misused by people who do not understand its very significant limitations.

Les
Les Bengtson

Whilst I'm not a fan of WD-40 or the WD-40 Company I do use it but most often put there are better products for certain jobs than standard (Multi Use) WD-40 I've got to put two (well three) things here.

WD-40 (Multi Use) would be a sufficient for the use here and it's not made of fish oil, even WD-40 Company admit this. - https://www.wd40.com/myths-legends-fun-facts/

I'm not going into the torque debate but what was done back in the mists of time may well still be best practice or sometimes suspendered, engineers and mechanics are extremely conservative in their practices, for most what they were taught when young they stick with all their working (and later) lives with most very resistant to modern ideas, those going back many decades in many cases, forgetting what they learnt was often many decades back.

WD-40 company is another of those very invasive USA companies that expands and takes over everywhere and everything.

Personally I prefer GT85 as a lubricant and penetrant to ordinary (Multi Use) WD-40 - unfortunately WD-40 Company bought the GT85 Company (and 3-In-One Company). - https://gt85.co.uk/
https://www.3inone.com/about/

PlusGas used to be the go-to penetrating/releasing agent in the UK, still made but again by another (offshore) Company. - https://www.plusgas.co.uk/en-gb
Nigel Atkins

Thanks Les and Nigel

I was aware that WD40 is not a good lubricant, but had read on another forum about using it sparingly on the head studs and nuts, so wondered what the advice from knowledgeable people here would be.
The other option I had considered was very sparing use of 3in1 oil but I wondered if the effective lubrication with that might be too high and so would increase the tensile load too much at the given torque setting of 40 lb ft.
Another option could be to use Duck Oil but I believe that to be pretty equivalent to WD40(?).
Rod
R Pearce

As I put I think WD-40 is fine for what you want, it is a lubricant just not the best at penetrating or lasting but neither really apply in this case, a quick spray of the thread just before insertion.

I think many would just use whatever (hopefully clean) oil is to hand. The oil at top will eventually bubble off if you get the engine hot enough. 😄

As for torque values, dry, lubricated, new or used materials, ect. as you've read there's debate.

And then which torque figure are you going to take, book or allow for gasket/studs and is your torque wrench's certificate up to date? 😄

I've had heads fitted by professionals, as have others, and still later have HGF, I think you are rightly taking care but you're not dealing with an ultimate precision machine or engine there are acceptable margins.

I had a mate torque mine with his annually tested wrench but to a figure we compromised on as I had a selection of studs existing in my engine. Oil on top threads - engine, 3-in-One or SU carb 20SAE I can't remember all were to hand in the shed.
Nigel Atkins

It is just as important to run a tap into the the hole in the block as it is to use the correct lubricant. If the threads are damaged or dirty it will affect your torque readings. Also if there is dirt, oil or water in a blind tapped hole you run the risk of cracking the casting as you tighten the stud or bolt.


Jan T
J Targosz

WD40 is excellent at Water Displacement, hence its name but it's not good for lubrication and it's rubbish as a penetrating fluid.
As Nigel says there are better products designed to oil or penetrate rusty bits.
Jeremy MkIII

In my local supermarket WD40 is now a brand, not a product. They even have WD40 brake cleaner.

I agree that the original WD40 is useless for anything except water displacement and banned it from my (now being liquidated) workshop.
Dominic Clancy

I have seen "experts" on TV car restoration programmes advise soaking rusted nuts in releasing fluid before attempting to undo them. The fluid is always WD40 but as others have pointed out it is not made for this job. I have an ancient can of Plus Gas penetrating fluid and this stuff does work. The can has a long thin spout to enable you to put the fluid right into the rusty threads not everything within a 6" radius as with an aerosol. Unfortunately my can is almost empty and the only Plus Gas I can find on line is in an aerosol and I fear it will be a different formulation to the "proper" dark grey stuff. I have booked my ticket for the NEC Classic Car Show and will be searching the autojumble stands for a new old stock can. If anyone sees one before me hands off it's mine!

Cheers

Jan T
J Targosz

Dominic,
same over here, WD-40 is another of those all invasive USA companies. They also took over a favourite English lubricant of mine GT85. WD-40 Company also have the 3-In-One with which they market a wide-range of product under that brand too, plus there are a few other brands. - https://wd40company.com/our-company/our-brands/
Nigel Atkins

Jan,
I think you'd be lucky to find NOS old enough, that's if you can find any for sale at the NEC CMS, if you do please post after as others of us might be there for the three days.

I've got a blue tip and spill can (no good at going against gravity) from a few years ago and it has a yellow flash on the tin "now even faster". E△A△C - English Abrasives & Chemicals (previously English Abrasives Limited), Doxey Road, Stafford, were liquidated in 2011.

The blue can label design I have goes back goes back to possibly 2002, a previous blue can label design with the spanner goes back to possibly 1980 and the current black labels from possibly 2014.

The brand was re-established (in 2014?) as part of the Saint-Gobain group. - https://sure-creative.com/portfolio/plus-gas/

I'd be interested to know, or photos, of the front and rear information of the can you have.





Nigel Atkins

Another product, not what it once was is Hammerite. Used to be very good but the formula was changed when the original company was taken over and now nothing like as good as the original from Prudhoe.
GuyW

I remember buying my first tin of hammerite probably back in about 1969 ish - mail order from an advert in Exchange and Mart !
Nobody sold it locally then - used it on the wide wheels of my Morry Minor !

I remember it was produced by a company called Finnigans - who also made Waxoyle. They were initially bought out by the Hunting group (who also built some of the early fibreglass boats - chemicals again under the Halmatic name including lifeboats- Aruns I think ?) and eventually ICI now part of Axel Nobel.
richard b

PlusGas in tins can still be had: https://www.dm-tools.co.uk/product.php/site/froogle/sn/PLG803/google/?gclid=Cj0KCQjwv5uKBhD6ARIsAGv9a-zL_2JcDQSrRwVVoDC8zwRnb_pXG4Dvy1PR4sa-064zXbY_u9Lhg-8aAtPWEALw_wcB#.YUc9uC14Xi0

Cheers
Mike
M Wood

Jan, I have a PlusGas aerosol in the Shed. FWIW I think it's good stuff.
In my line of work I have to wrestle stuff that has been long exposed to salt water etc. and this stuff seems to work very well.
I've just bought another couple of cans from the Bay of Evil.
As Mike says you can still get the liquid in dribbly tins, but the aerosol is good for lazy blokes like me.
WD40 is good for taking sticky labels off jars and that's about it. I only use it where the Planned Maintenance book insists on it.
Greybeard

If you have a tip and spill can then it must be in the correct packaging for 1968(?) and later cars or you loose points.

This is just the can, not contents, true concourse original! - https://www.ebay.co.uk/itm/254954805016

Can has -
. "The famous Plus-Gas Formula 'A' penetrates deep-down to break the grip of harmful rust, scale, carbon, paint or gum."
. "CAUTION Powerful Formula 'A' can adversely affect certain paints, plastics and rubbers."
. "Fosmin Chemicals Limited, Stiring Road, Acton, London, W3 8DN".


Nigel Atkins

I use modern plus gas often. Used with heat I've found it never fails to free even the most severely rust seized bolts. I used it just the other day on bolts that hadn't been out in decades. Excellent stuff.

Dinitrol is good too for anti rust. I have an old can, still with pressure in it. Not sure how old, it came from a neighbour's garage clear out. Feel free to rotate, I haven't got a clue how to on a 'fone'.





anamnesis

Adding heat to PlusGas somewhat negates its use, better to add time and patience or just use the heat.

I was late on to PlusGas as I had a tip and spill can of Rapideze for so many years (decades?). Just looked it up and I was surprised to see the company only went out of business in 2013 but I'd not seen Rapideze for very many years before that.

Old folk with fones, tush!


Nigel Atkins

Most aerosols of this type of product are supplied with a thin red pipe for accurate spot application.
The problem is they have an exceedingly short half life.
GuyW

Heat speeds the process Nigel. 10 minutes vs waiting overnight or over two nights. Heat on it's own often works, but whilst it's still hottish, a spray of plus gas makes it even easier.

Old folks have all kinds of tech' these days, even if they don't know how, and or can't be bothered to use it fully. 😆
anamnesis

This thread was discussed between 15/09/2021 and 20/09/2021

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