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MG Midget and Sprite Technical - Which head gasket 1098.

Today I picked up my Peter Burgess tuned 12G295 head from his premises in Alfreton..To recap, this is to fit the fresh engine I am building to replace the one that sustained a cracked head and block last September.
I am in a bit of a quandary as to which is the best head gasket to use on the 1098cc engine that as been overbored 40 thou and has new Calver flat top pistons. Also, do I use an adhesive such as Wellseal or Loctite 3020.?
Peter uses a Payen gasket with Wellseal, but Thomas Classic and Modern who have some great engine build videos on YouTube use Victor Reinz gaskets with Loctite 3020. I was taught to fit head gaskets dry.
So I would be very interested to hear what members of the BBS have to say on the subject.
Thanks.
Bernie.
b higginson

Payen black was always good.

I have NEVER used any HG sealant/adhesive on my 1275 engine. Nor come to think of it on any of the HGs of cars I've had in the past of 60s 70s 80s origin.

And can't remember the last time I had an HG fail.

Stay dry. 🙂



anamnesis


First off if I can say--If you've been to Peter's to get a head he's done---If Peter uses a Payen gasket and Wellseal and has advised you in that direction then it's a no brainer.

But having said that,and we don't get wellseal here,I'm a fan of coppercote spray -just a real light spray on both sides of the gasket and let it dry off until it's not tacky to touch then whack it on straight away and bolt it down----I also use it on gaskets that already have a coating on them, and mls style gaskets as well just to be sure--just a light spray just to cover the surface, it doesn't need to cover like a thick coat of paint.
ALSO--Be aware, some Payen gaskets that come with a coating(I coppercote them as well)are designed to be cooked in----You need to start the engine initially with no coolant, run it until it's nice and toasty then retension, let it cool off and retension----The instructions are on the packet for these gaskets- Good gasket but it'll leak if you don't cook it in and retension retension-------

willy
William Revit

To your question on which head gasket.

Wasn't the 1098 hg, a copper job? Before composite? So I guess that's where the 'glue' or copper spray would come in; if needed.

Payen af070 for a 1098.

Or Fai hg118.

But the composites don't need anything do they?

Wouldn't it say on the packet if it needed an additional sealant of some kind?

As Willy says, refer back to Peter Burgess. Ask him what gasket he uses.







anamnesis

You should really follow Peter’s advice if he has prepped the head.

I will just throw Cometic gaskets into the ring as I have fitted a couple for people. They are useful for adjusting compression ratios as they can be ordered in various thicknesses: this was the purpose of my using them.
Apparently they are good to use several times although I have not had occasion to prove / disprove that.

Alan Anstead

I use Payen gaskets, fitted dry these days. In the long distant past I would put a smear of axle grease on one side. So long ago I have no idea why. Just something that you did!
I avoid over torquing as that crushes the fire rings, transfers the clamping pressure across the whole head surface and actually reduces the sealing pressure on the fire rings. (Read up on Calver's advice on this)

And, definitely not a recommendation, but I have reused head gaskets on occasions. I've never had a fail on an A series engine, though did have a 1500 let go once near Inverness on after a long run up the A9 on a hot day.
GuyW

Alan--I agree Cometic gaskets are fantastic, I run one on our elan, ordered a special mls to suit the overbore size and the thickness I needed to get the compression right and the online ordering link said there would be a delay of 7-10 days for special orders---nearly fell over when it arrived here 4 days from ordering it from Cometic USA --
If you have a decent stud set the Cometic mls is a gasket that can be tweeked up real tight without hurting the gasket but the block/head surfaces need to be spot on for good sealing.

Not 100% sure but I believe there is one combination of A series block-head that there is an issue with Cometic mls gaskets where one of the rivets holding the gasket assy together can get pinched between the block and head and needs removing so the gasket fits up correctly, Don't know which combo it is but I've heard of it a few times-----something to look out for.

willy


William Revit

Good to see you yesterday Bernie

We use one of two head gaskets on the small bore engines. We use XRN(County) CAF070-C approx 2.7cc compressed or AF070PT which is approx 4.39cc depending whether we are trying to get cr up or down or happy with what we have got.
Sometimes we struggle to get cr high enough with the small bore engines with 202/295/206 or even the smaller 24.5 cc basic mini heads.
However Bernie has flat top special pistons about flush with the top of the bore. I reckon the CAF070-C will give him approx 10:1 cr ideal with his 266 cam.
Either gasket and we use Wellseal both sides.
Copper head gaskets have to be re torqued as opposed to single torque composite head gaskets.
Peter Burgess Tuning

Regarding Willie's use of the copper spray, it is great stuff - we use it to seal between the de-compression plate and the cylinder head on the supercharged K engine. Just the spray, nothing else.
Has survived coming up 20 years of hard use.
Paul Walbran

Thanks to all, particularly Peter for coming on. In the excitement of getting my head on Monday, I completely forgot to ask Peter about head gaskets. Can Wellseal be bought as a spray or just in the tubes?

Another question. With the flat top pistons, do I increase the torque on the head bolts? I have uprated nuts, studs and washers, (not ARP though). So what torque do I use?
Sorry for being a PITA. ☹️
b higginson

Hi Bernie
Go for 50 lbs/ft with engine oil on the threads.
I don't think Wellseal is available as a spray, messy fingers and hands time!
Peter Burgess Tuning

Is it worth mentioning that I seem to recall that there are several grades or varieties of Wellseal?
I use black grade, for head gaskets especially.
Caterpillar specify it for the 3412s I used to work on, which are 27 litre twin turbo V12s running up to 30psi boost and 1250 hp.
I never had a HGF.
More recently it was the only thing that finally resolved persistent failures on a 1983 Honda CB250N, although Honda never recommended it.

Apparently it was invented by Rolls Royce!

PS: how great to see Peter back!
Greybeard

This thread was discussed between 02/02/2026 and 05/02/2026

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