I believe some motorcycles had aluminum head gaskets.
Is here a reason that copper is used, instead of aluminum? Don has the capability to make aluminum head gaskets.
It seems to me that if a soft aluminum were to be used, it would work very well with our o-ring/receiver groove setup.
I'm thinking of a soft, annealed aluminum:
6061-O Soft Annealed Aluminum Alloys - Sheet
Sheet
larger image This is the most versatile of the heat treatable aluminum alloys. It has most of the good qualities of aluminum, and it offers a wide range of mechanical properties and corrosion resistance. It can be fabricated by many of the commonly used techniques.
In the annealed condition it has good formability. In the T4 condition fairly severe forming operations may be accomplished. The T6 properties may be obtained by artificial aging.
It is welded by all methods and can be furnace brazed. It is available in the clad form ("Alclad") with a thin surface layer of high purity aluminum to improve both appearance and corrosion resistance.
Specifications: QQ-A-250/11, AMS 4025
Color Marking (Rod and Bar): Ends painted Blue
What if we quit trying to get the gasket to crush into the receiver groove? We enlarge the gasket cylinder opening, until it is just to the outer edge of the receiver groove, and have the o-ring go directly into the groove. We could use copper wire, and that would become our 'fire ring'.
The only remaing issue at that point is sealing water. We could used acid etched mild steel, aluminum, or copper, and seal with spray on Hylomar.
What do you guys think?
Flattie,
Sorry to be MIA, running a serious development project AND working for the red queen . . . . . .
Gaskets can be made of anything; ie: steel, copper, aluminum, cork, sewing thread, shirt cardboard, etc. BUT, HEAD gaskets, by their very nature, need to fulfill a wide variety of sealing, especially when water & oil passages are combined with the task of sealing combustion. The gasket material of choice needs to be selected primarily for the ability to contain combustion heat & pressures within a flexural zone, with the clamp load applied by threaded fasteners. Distortions can (in your case, surely) occur in the castings, as the clamp load is applied. How significant the distortions are, will influence the amount of stiffness and/or conformability required of the gasket material, for reliable service. (ie, solid annealed copper Vs. aluminum Vs. MLS embossed steel, etc.) Since oil and water passage sealing can be selectively "band-aided" by various sealants & methodologies, I suggest you do the following:
Buy a roll of white butcher's paper and a roll or several sheets of carbon paper. Make two paper patterns of your head gasket(s), 2 per side, and 1 pattern of the head gasket from the carbon paper. Lay the butcher paper on the block, lay a single layer of carbon paper (no overlaps!!) on the paper, and cover with another layer of butcher paper. Torque the fasteners carefully to your spec, DO NOT OVER TORQUE!! Do this for both heads. The carbon imprint left on the paper will give you a good idea of how stiff/flexible your block to head area is, with a clamp load applied. This little exercise can also be done with a gasket in place. The cost to do this is virtually nothing, except for your time, and I guarantee you will learn quite a bit, OR scare yourself!! Low tech, but very effective . . . . .
RELATIVE clamp load can be altered by changing the torque, size of the fastener, etc. Fastener torque, sealants, sewing thread, O-rings, etc, all change and/or concentrate the clamp load. Once you have an idea of how well you can concentrate the clamp load, you can make an intelligent choice of gasket material. Even clamp loads will allow you to use a conformable material such as MLS steel or aluminum. Uneven clamp loads will need a stronger (stiffer) gasket such as copper.
My choice, if it were up to me: Since your engine has a blower, and the resultant high combustion pressures & temperatures, I would use solid annealed copper gasket with a hardened steel o-ring in the block and a receiver groove in the head. I would work out the dimensions for the O-rings & receiver groove based on the carbon paper testing. The more evenly you can distribute the clamp load around the combustion chamber opening, the better ANY gasket will seal.
As others have pointed out the best head gasket for blower engines is: NO HEAD GASKET!! Ala Offy or Ferrari Lampredi.
If I were you though, I would just be glad I had more than 3 head bolts per cylinder, ala your BMC buddy Milwaukee Midget!
Fordboy
After thought: You could also "drydeck" the water and oil passages for rubber/neoprene/Buna-N O-rings. O-rings don't need much compression for effective "static" sealing. Oil passages would need a compound compatible with hot oil . . . . . .
F/B