Head gasket sealant?

[Grumpy21]

Hopefully will get my reconditioned head back this week and I’m interested in the perceived wisdom read head gasket sealant.

In the past I’ve used all sorts and nothing with equal success. Hylomar, grease, Vaseline, welseal, copper slip, payen gaskets, composite gaskets etc.

I’ve ordered the copper head gasket set from ESM, so what’s the advice re fitting. Fit it dry or with a sealant, if a sealant which one?

Also head torque setting? I’m hearing 42 and 50 ft lbs?

It’s a standard 1098, removed because of valve guide wear, found not to have hardened inserts so that’s being done too with a light skim. Evidence of slight blowing between 3 and 4 on the old copper gasket, not yet blown through.

Thanks

[simmitc]

Before fitting the head, have you checked that the block is flat? If the face there is not perfect, then having the head slimmed will not be sufficient. I have always found that a Payen copper gasket with a light smear of grease works best, but others may have differing views.

As regards torque, the book says 40, but if you fit higher strength studs and nuts then you can easily and safely go higher. For example https://www.minispares.com/product/Clas ... o%20search or https://www.minispares.com/product/Clas ... o%20search

[philthehill]

A slight smear of grease on the faces of a copper gasket is all you need.
As above - you do need to make sure that the block is perfectly flat otherwise the gasket will fail.
Regarding torque - only if you have the higher tensile strength studs and flanged nuts can you set the torque to 50lbf ft.
Later 'A' Series engines have the high tensile studs and flanged nuts fitted as standard. These can be identified by a dimple in its top, a pointed top or 'K' stamped on its top. If you can get hold of a good S/H set of studs and nuts so much the better. Paying through the nose for a high spec set is not required.
Make sure that the stud holes in the block are countersunk. This alleviates any problems with the gasket not seating around the stud.
Here is a set of the later studs with flanged nuts
https://www.ebay.co.uk/itm/265939297685 ... R_TT7-qKYQ

[Grumpy21]

Thanks gents, block is flat as tested by known good straight edge and backlight.

Stud holes are not countersunk but might do that before reassembly, I like the idea.

My studs are a mix of HT and standard. Odd. Rocker studs are HT (tapered tops) outside shorter studs are standard but have shouldered nuts!

[philthehill]

My recommendation is to standardise on the HT studs with flanged nuts and tighten to 50lbk ft.
Below is the stud countersink schematic.

countersunk studs.jpg (348.39 KiB) Viewed 1412 times

[Grumpy21]

Thanks Phil, takes my back to the good old days doing ‘tech drawing’ in school. Ended my working days doing 3D cad! Lovely.

Cheers

Gary

[philthehill]

Technical drawing was the only lesson I really enjoyed at technical college when doing my City & Guilds course.
I enjoyed it so much that I attained a distinction mark for my final technical drawing examination.

[Grumpy21]

Phil

I bought those studs and they arrived today - they look identical to the studs I already have!

[philthehill]

The new studs - do they have the dimple in the top, a tapered top or marked with a Y (not K) on the top?
The studs are advertised as ex 1275cc MG Metro so they should be the stronger studs.
The MG Metro workshop manual gives the 1275cc head stud torque as 50 lbf ft.
Phil

[Grumpy21]

both old and new have a Y on the top

old on the left new on the right, both 1275 sets then?

Or neither??

[philthehill]

The studs marked Y and flanged nuts are the correct MG Metro 1275cc items which can be set to 50lbf ft torque.
I would not use the nuts without flanges as you never know what tensile strength they are.

[Grumpy21]

Thanks Phil.