Getting ready to put the head back on my 3.4 (1956 XK140)…
Have a Payen head gasket from Moss, trying to figure out if I should be dressing / coating it with something when installing. been trying to research as much as possible within this forum and others but can’t find any specific info…
much info advises the installer to use whatever the manufacture recommends… can’t find any manufacture recommendations…
of course there is the standard “do what the service manual says” route… service manual says “lightly smear with jointing compound”, not sure what that is in 2022, and if it applies to 2022 gaskets…
much info on “mls” steel gaskets - but not sure if the one I’ve got is “mls”… it is steel, but doesn’t look to be made of multiple layers, looks like one layer to me…
some recommendations I’ve seen repeatedly involve spraying both sides with a copper product -but I note that one side of my gasket seems to already have some sort of vaguely tacky coating on it…?
other recommendations say to use RTV around the head studs… I’m really anti-RTV so not likely to do that…
so, any experience about installing one of these seemingly single layer steel gaskets?
Depends, if you have a composite head gasket you do not need anything.
When you have the old metal gasket I always use some sealant around the water jackets.
i was advised by a jaguar expert to always use this on metal gaskets. used it on my 3.4 head. had no problems. think it also mentions it in one of my jaguar books.
I didn’t use anything on composite (with some rtv already applied by a machine) or graphite (black cardboard) gaskets and no leaks so far. Two of each. A very light rtv smear at the timing cover joint, I’ll admit to that.
If steel is different I would look into the copper sprays and/ or call payen or the seller if there are no instructions.
Not being a fan of rtv either it can’t do harm to put a bit around the water jacket holes. What’s much more important is that you coat the head studs in antiseize liberally.
Dave, I’m about to fit the HG to my 140, a plain embossed steel one as you have. I know big Jim had difficulty fitting the composite gaskets to his car, as the extra height left no slack for the timing chain, so I’ll stick with the steel.
I asked Rob Beere Racing for advice on this, and they said that they fit a lot of these and give them a light spray with a VHT copper gasket paint on both sides. So that’s what I’ve got, and should be doing the job in the next couple of weeks or so (once I’ve got my Mustang’s clutch back in).
Big fan of RTV but it has to be a high-quality one (I use Würth), and it has to be applied correctly and in the correct amounts.
Dave, I don’t know what country you are in, but I used Permatex Copper-Coat spray from my local auto parts store. That was 25 years ago. Still no leaks.
Thanks for all the replies, I will track down some copper coat spray today. Just before I coat both sides…. The bottom side of this steel gasket seems to have some sort of slightly tacky product already applied, any thoughts of applying the copper spray on that side?
Seems like most times I come across RTV is when I’m repairing a leak usually when RTV has been used in place of the correct gasket…. Or maybe RTV use can be equated in some cases to not bothering to dress the surfaces etc just slap it together! I like to use the Permatex Aviation gasket sealant…
Hi David, when you say coat the head studs in anti-seize…. Can you elaborate?
The top end of the studs I would tend to use a wipe of oil before putting the nuts on, the bottom end that goes into the block I would tend to use anti-seize….
But I was wondering about putting a smear of anti-seize on the unthreaded length of the studs that goes through the head, might make the next removal easier! Is this what you are referring to?
I always put the front covers together just by using RTV, and leaving out the paper wick… I mean gasket! Done properly it works fine, and it works better.
The secret is to put a very thin coat of RTV on the sealing surface, then very gently, with only finger pressure tighten a few bolts down --finger tight I have to emphasize that – – then let it sit overnight. Then, and only then, do you assemble the rest of it and tighten it down, guaranteed to be leakproof.
RTV is excellent material when used correctly. It seals better and is easier to remove than the older style cements. I don’t use 1950s oil, grease, paint, tyres etc. - likewise joint sealers. But - it is not easy to use. If you’re not trained in its use, read the instructions carefully and watch a few videos, then it’s great.
Yes, a thin smear of anti-seize on the unthreaded parts only of the head studs. Get any on the threads and your torque settings will be way off.
If you must put something on the end that threads into the block, I certainly wouldn’t use anti-seize - probably a Loctite thread locker of appropriate spec.
Anti-seize is one of my pet hates, as others hate RTV. I’ve seen it slathered all over suspension parts and, in worst cases, engine fasteners. I’ve even seen it used in wheel bearings.
Thanks Roger, right you are with the thread lock, I would use that on the stud threads going into the block, not anti-seize as I earlier stated…. It’s early in the morning here on the west side of Canada, not fully functional yet!
There’s debate on whether the upper threads should be oiled or dry, that’s up to you. For the lower ones it’s counterproductive. But the unthreaded part should be coated, that makes the next disassembly easier, even though the short studs are not exposed to coolant (as in much later engines) they still gum up and seize in the head.
In a pinch, silver paint will do almost as good a job as copper coat. What I did find about the silver paint, unlike the copper coat, is that upon disassembly it does not come apart as easily.
Back in the old days the color was described most commonly as “aluminum”. Generally a dull, matte gray color, similar to as-cast aluminum. Usually a lacquer or enamel with aluminum powder as the pigment.
