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Never had any of this back in the day - used Payen copper gaskets, torqued them down and drove the car, rechecking 50 miles later.

Costafortune wrote: ↑Wed Oct 14, 2020 6:04 pm Never had any of this back in the day - used Payen copper gaskets, torqued them down and drove the car, rechecking 50 miles later.

I agree. Back 30 years ago when I was into Minis the first time around, I never gave things like this a second thought. Never bothered with a sequential process in order to get something simple like a head gasket to do what it was supposed to do! Back in the day I slapped things together and they just worked. Now I agonize over every detail on a multi-year restoration and everything that can go wrong does go wrong (well almost)...

When I was younger ignorance was bliss...dove into my projects headfirst and stuff
worked well .

The Cooper Gaskets were all I would also once use and more than once, reuse them all without issue. When they removed the asbestos from them, they weren't nearly as good, all the same, when everything's preped spot on they do work well and for fresh builds, it's still my choice. One aspect I like of the Copper Gaskets is that they transfer heat better than many of the others that only insulate.

On a few builds where I've needed more on the deck, I've also used solid copper gaskets also with good success.

atm92484 wrote: ↑Mon Oct 12, 2020 8:17 pm I've always used ARP thread lube with their 45 ft-lbs spec, torqued it in 3 steps (25, 35, 45) and used the torque pattern in the BMC factory service manual. The pattern is a little different from what you posted but same idea of working from starting in the middle and working out.

The diagram I posted up was from a later Rover manual, it's one of very few factory documents that show the numbers are wet instead of leaving one in doubt.

A few days ago I was joking about buying 0.040" thick copper sheet and making a custom head gasket on the mill - can't be any worse than the first two gaskets I tried!

It makes sense that wet vs. dry was clarified (albeit after many years) but kind of wonder why they changed the pattern? Both accomplish the same thing in theory.

atm92484 wrote: ↑Wed Oct 14, 2020 9:32 pm A few days ago I was joking about buying 0.040" thick copper sheet and making a custom head gasket on the mill - can't be any worse than the first two gaskets I tried!

It makes sense that wet vs. dry was clarified (albeit after many years) but kind of wonder why they changed the pattern? Both accomplish the same thing in theory.

Copper gaskets are one of those things that seem a great idea but never work, if they do it won’t be for long.

I was speaking to a well known A series race engine builder, he had also been suffering a spate of bad Payen gaskets not sure which type. Was quite surprised he used them and not a MLS cosmetic gasket tbh.

Hipwell wrote: ↑Thu Oct 15, 2020 12:19 pm Copper gaskets are one of those things that seem a great idea but never work, if they do it won’t be for long.

Can't say I've had any issues, but I guess it depends on what you might think of as 'long' ? I've a few fitted, the oldest being 8 years and off hand about 30 000 km. No issues yet.

The copper head gaskets these days are absolute rubbish. Stay away from them. Old copper/asbestos gaskets were ok, but good luck finding a good one these days.
As for reusing a head gasket. No thanks, any professional engine builder will have a good laugh at that idea, regardless of how much experience you keep telling everyone you have.

The BK450T has been the go to gasket for many years, they handle high comp ratios, boost and race fuels well.
These days the MLS/Cometic are usually the no.1 choice for race engines, as long as the block & head are surface ground correctly

Solid copper sheet have been available water cut for awhile now, used with stainless "O" rings mainly for high boost turbo & supercharged engines.

https://mossmotors.com/solid-copper-head-gasket-1275

Its official - I am pointing the finger at some bad head gaskets. The gasket survived a weekend at the track - no leaks, no water in the oil, no oil in the water, nothing. I suppose I will have to measure every head gasket now prior to installation.

Thanks again for the help.

Could this be the issue?

No rings around the main water gallery holes. Found a gasket from an earlier batch and rings are present.

I've made email enquires to the supplier and been met with utter silence.

Sadly I missed this assembling a fresh motor and ended up with major water ingress to the bores requiring and full strip down, hone and reassembly. Grrrrr!!!!

I had a new gasket fail after just running up a few times. I have it at home still, so will take a look at the coolant ways for rings - I don't think it had them. Will confirm, but I think it was the BK450. Block was not machined, but checked out OK. Head was fresh skimmed. Failure was from between the centre cylinders and blew into the water jacket. I was careful with install and tightening, but did use old type studs, nuts and washers. Light mist of spray grease on the gasket.

Bought an AF470 & a GEG300. Went with the GEG300, sprayed both sides with Hylomar. Weeded out a few more of the old style studs, and replaced with centre popped type. Replaced or flipped over any heavily marked washers. Used a high pressure lube on the studs and tightened in sequence. Touch wood, it all seems good now. Crush ring to gasket difference was 10 thou on both the AF and GEG gaskets.

Regards: Chris.

minibitz wrote: ↑Mon Nov 09, 2020 2:57 am
No rings around the main water gallery holes. Found a gasket from an earlier batch and rings are present.

Very interesting. A change like this could definitely explain the issue.

I have a used gasket from several years ago that resides at the machine shop. I'll have to look and see if it has rings next time I'm out there.

Here’s a photo of a NOS Payen AF470 probably +20 years old, if that helps in any way.
It hasn’t got rings in the water gallery holes either.

I picked up a 1974 parts Midget last fall with 20k miles - mainly wanted the engine. After getting the engine on the stand I found that it still had the original head gasket. Its post-use dimensions were pretty much identical to the "good" modern AF470 head gaskets I've had.

Racing is around the corner and we're working to get everything back together and ready for the season. I tried yet another new AF470 gasket (a green one this time) on this same engine and had the same results. This time I was smart enough to build a leak tester with some hose, a pressure gauge, and a plug. Figured if it would hold air for a few hours, it would be a good indication that it would hold water. The newly bought "green" AF470 gasket leaked down from 20 psi to nothing very quickly. After running it for a few minutes, letting it cool, and retorquing the head, the leak rate definitely improved but it was still leaking substantially (verified by spraying soapy water around the head gasket and watching the bubbles form). Being nervous about filling the freshly refreshed engine with water (again) and wiping out the bearings (again), I decided to try another gasket. This time it was the Minispares GEG300. Guess what? No leaks. Nothing. Sealed up fine and only lost a few PSI over 24 hours. Again, the leaky Payen gasket had fire rings that were many thousandths thicker than the rest of the gasket.

Fast forward to last night when we were working to wrap up another Sprite - we pulled the head last fall to install different rockers. It had an AF470 gasket that was installed about a year ago when we first built the engine and was fine. We installed a new recently received gasket and low and behold it leaked air just as bad as every other one. We didn't even bother trying to run, retorque, etc - in the trash it went and a GEG300 went on. Again, leak rate was substantially improved.

I don't understand how a brand name in a niche market can go from making a pretty darn good product to making pure garbage almost over night. I have one Cometic gasket on hand and a second on its way. For as much time as I've spent chasing this issue (and destroying $200 worth of bearings), a $100 gasket is a good value.