Motorsport Mickey Posted January 25, 2023 Report Share Posted January 25, 2023 2 hours ago, Nigel C said: like that Peter! Yes the height from the block is 0.020 Mick, just the cc slightly different and gives me 9.6:1 CR with the 60 tho gasket and if I were to use their gasket offered @ 40 tho it would rise to 10.3 which still sounds good enough to me? Yep, sounds like a variety of options there, just make sure it's annealed well ...or any gasket has compression rings around water and oil apertures. Mick Richards Quote Link to post Share on other sites
Charlie D Posted January 25, 2023 Report Share Posted January 25, 2023 I’ve followed this thread with a certain amount of interest. (I’m not personally concerned with improving the performance of my engine. I’m happy enough if it goes at all.) However, I’ve seen references to annealing copper gaskets many times over the years and it has always puzzled me a bit. I do understand that annealing will make hardened copper sheet soft again. But it won’t get rid of any dings/dents/impressions that are there. (Will it?). It’s not like flowing self-leveling compound onto a wavy concrete floor, and ending up with a smooth surface. Surely you need a smooth surface on a gasket to get a good seal, and if there are ridges around the cylinder holes where the liners have squashed the copper then they will still be there after the annealing process. Or am I wrong? Charlie. Quote Link to post Share on other sites
Ian Vincent Posted January 25, 2023 Report Share Posted January 25, 2023 To add to the debate on annealing, when I was at school (1960s) doing metalwork we were told to anneal copper by heating it cherry red and quenching. Clearly allowing it to cool naturally isn't going to adversely affect the annealing process but neither is quenching going to have permanently bu**ered it. However, I also remember being taught that you can only go through the annealing process a limited number of times before the crystalline structure of the metal is affected and it can no longer be 'worked' to the same extent. The alternative apparently is to purge the area with nitrogen before and after to minimise the formation of carbon (released from CO2?) within the crystalline structure. Rgds Ian Quote Link to post Share on other sites
Nigel C Posted January 25, 2023 Author Report Share Posted January 25, 2023 1 hour ago, Charlie D said: I’ve followed this thread with a certain amount of interest. (I’m not personally concerned with improving the performance of my engine. I’m happy enough if it goes at all.) However, I’ve seen references to annealing copper gaskets many times over the years and it has always puzzled me a bit. I do understand that annealing will make hardened copper sheet soft again. But it won’t get rid of any dings/dents/impressions that are there. (Will it?). It’s not like flowing self-leveling compound onto a wavy concrete floor, and ending up with a smooth surface. Surely you need a smooth surface on a gasket to get a good seal, and if there are ridges around the cylinder holes where the liners have squashed the copper then they will still be there after the annealing process. Or am I wrong? Charlie. I hear (read) what you are saying Charlie but the whole issue with this gasket is that after attempting to fit it twice it has not compressed one iota, there are no dings/dents or compression rings around the liner positions because it is so hard. Ian, interesting about your education and the merits of quenching but very few (and I have talked to a lot of people) agree with it. My schooling in the late 60's and into the 70's in metal working was based around steel, we never saw the likes of copper, if we needed lead for a project then the church leaked on Sunday! Quote Link to post Share on other sites
Charlie D Posted January 25, 2023 Report Share Posted January 25, 2023 Nigel, Thank you for the clarification. I wonder if there are certain grades of copper, like aluminium. Obviously (???) it's not pure copper (Or is it?), so maybe it's a sort that you can't ever aneal. I once tried to cut a piece of tempered glass with a glass cutter. I eventually smashed it into a million pieces in frustration. Quote Link to post Share on other sites
Ian Vincent Posted January 25, 2023 Report Share Posted January 25, 2023 23 minutes ago, Nigel C said: Ian, interesting about your education and the merits of quenching but very few (and I have talked to a lot of people) agree with it. My schooling in the late 60's and into the 70's in metal working was based around steel, we never saw the likes of copper, if we needed lead for a project then the church leaked on Sunday! Maybe my education was posh (although not that posh or else we wouldn't have been doing metalwork ). One of our projects was beating a sheet of copper into an ashtray and then polishing it. It needed to be annealed several times during the process as it would go hard and if you carried on it would start to split, (and you would be told to start again!). Rgds Ian Quote Link to post Share on other sites
Drewmotty Posted January 25, 2023 Report Share Posted January 25, 2023 I was speaking with John (Chilliman) about head gaskets and he advocates the use of a gas barbecue to anneal copper head gaskets. Quote Link to post Share on other sites
BlueTR3A-5EKT Posted January 25, 2023 Report Share Posted January 25, 2023 Quenching is said to help remove some of the scale formed on the copper by heating. Quote Link to post Share on other sites
BlueTR3A-5EKT Posted January 31, 2023 Report Share Posted January 31, 2023 By way of a test….I have just annealed a sheet of 0.030” thick copper. I used a MAP gas blow torch and it got the copper red hot without issues. Just worked over the sheet from top to bottom, side to side in a slow zig zag motion so all went red hot at some point. Laid the copper on a sheet of cement fibre soffit fireproof sheet sat on bricks. Did not quench. It is now as floppy as a sheet of paper. Quote Link to post Share on other sites
iain Posted January 31, 2023 Report Share Posted January 31, 2023 4 hours ago, BlueTR3A-5EKT said: By way of a test….I have just annealed a sheet of 0.030” thick copper. I used a MAP gas blow torch and it got the copper red hot without issues. It is now as floppy as a sheet of paper. That is annealed :-) Quote Link to post Share on other sites
Nigel C Posted January 31, 2023 Author Report Share Posted January 31, 2023 thanks you for your time Pete, that's very good of you. I do know that the gasket in question was annealed the first and third times by a similar torch, the second time by myself and knowledgeable friend with a propane torch. All the outcomes have been the same, very hard. On the matter of this type of torch, my father has had one for sometime and the bottle is an exchange item....he tasked me with finding an exchange (on that computer thing you use) as he's done builders merchants etc with no luck, and I can't either....in this day and age you'd think it a good idea but they all seem to be disposable items now...unless one of you know better? You will pleased to know I have set this gasket aside! I will call Revingtions and perhaps ask them about stock rotation or have they experienced any problems in the past, I don't think I have a leg to stand on regarding returning the gasket as to many people have been involved etc. A little further trolling has brought me to TR Enterprises as their gasket is pre-annealed and guaranteed. We will wait and see Quote Link to post Share on other sites
Nigel C Posted February 1, 2023 Author Report Share Posted February 1, 2023 New gasket landed today, a lot softer than the previous item...fingers crossed Quote Link to post Share on other sites
iain Posted February 1, 2023 Report Share Posted February 1, 2023 A pre annealed gasket will be soft…….until you work it, especially the shaping and relieving you need to do for matching to the head and block. It will need annealing again I suspect to be successful. Quote Link to post Share on other sites
Nigel C Posted February 1, 2023 Author Report Share Posted February 1, 2023 thanks Iain, I was advised to cut and gently file as apposed to vigorous machining. Quote Link to post Share on other sites
Lebro Posted February 2, 2023 Report Share Posted February 2, 2023 The action which will harden the copper is known as "work hardening", & applies to most metals. It happens when the metal is altered in shape, i.e. bent, or hammered. The molecules get moved around, & link together more closely, making it harder. I can't see that filing or cutting would do that. Bob Quote Link to post Share on other sites
Motorsport Mickey Posted February 2, 2023 Report Share Posted February 2, 2023 11 minutes ago, Lebro said: The action which will harden the copper is known as "work hardening", & applies to most metals. It happens when the metal is altered in shape, i.e. bent, or hammered. The molecules get moved around, & link together more closely, making it harder. I can't see that filing or cutting would do that. Bob +1 I wouldn't be perturbed about cutting the gasket, if you file or grind it only the actual edge is touched and the molecular structure is left unchanged. I cut the pressed steel gaskets in that way with no visible affects in it's stiffness. Mick Richards Quote Link to post Share on other sites
Nigel C Posted February 2, 2023 Author Report Share Posted February 2, 2023 I used a bobbin sander on the last one and for shaping it worked very well, perhaps I'll try an area lightly/short period and see what heat it generates? Quote Link to post Share on other sites
iain Posted February 8, 2023 Report Share Posted February 8, 2023 Sorry but I disagree, the amount of material you will be removing will work harden those edges. You will have hard copper in those exact areas that must be soft to form a seal on the raised liners. Iain A PS for Ian V , I remember making one of those beaten copper ashtrays myself, plenty of annealing in the forge was required. When Woodwork, Metal work and Technical Drawing were part of the school curriculum. Quote Link to post Share on other sites
Charlie D Posted February 8, 2023 Report Share Posted February 8, 2023 41 minutes ago, iain said: You will have hard copper in those exact areas that must be soft to form a seal on the raised liners. Maybe a silly idea, but would it not be possible to fit the gasket without any alteration, torque it down, then take it off again and do any sanding/cutting. The impressions of the liners would by now formed in the copper, so hardening it a bit (if that actually happened) would not be a problem. Charlie. Quote Link to post Share on other sites
iain Posted February 8, 2023 Report Share Posted February 8, 2023 If it’s pre annealed, you might get a good impression of both the block face and head…..or you might not. If compressed it will need re annealing. Personally can't see the benefit. It’s a game of patience and detail to make the gasket appropriate for the reshaped combustion chamber and possibly where the liners have been relieved In the valve shroud area. Any sharp edges or protrusion into the chamber is likely to result in a hot spot and running on problems. Quote Link to post Share on other sites
Waldi Posted February 9, 2023 Report Share Posted February 9, 2023 Maybe theory and practice do not meet here, but…. In industry….a solid metal gasket relies on some plastic deformation and a gasket seating stress (which is achieved by the combined bolt load) to properly seal. If a gasket is locally compressed and has some plastic (permanent) deformation, annealing will not bring the deformed (thinner) area back to the original thickness. So how can you achieve sufficient gasket seating stress in the area where it is mostly required? Or does a copper head gasket seal on other sealing principles? Waldi Quote Link to post Share on other sites
Charlie D Posted February 9, 2023 Report Share Posted February 9, 2023 1 hour ago, Waldi said: annealing will not bring the deformed (thinner) area back to the original thickness. That the bit that I don't understand either. Quote Link to post Share on other sites
Lebro Posted February 9, 2023 Report Share Posted February 9, 2023 No it won't magically restore the plate to being flat, but it will make the copper soft, & so the thickness will adjust next time it is torqued down to press equally on the liners & the block surface Bob Quote Link to post Share on other sites
Waldi Posted February 9, 2023 Report Share Posted February 9, 2023 So the result is that the area where the actual sealing occurs shifts a bit away? If you compare a head gasket with an industrial flange, the ratio between bolt-area and gasket area is much (much) different. A large flange can have bolts 1/2” diameter with a gasket that is only 15 mm wide. In some cases, there will be more bolt area than gasket area. An amount of deformation of the gasket is required for proper sealing. Large industrial compressors and pumps can have no gaskets and simply rely on the flatness and stiffness of the flanges, maybe the head gasket is more like that. Waldi Quote Link to post Share on other sites
iain Posted February 9, 2023 Report Share Posted February 9, 2023 The plasticity of copper I believe is 20%, therefore it will, when annealed ,move considerably. I guess this is why they can be used 4-5 time. Quote Link to post Share on other sites
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