68matic wrote:
i dont know to be honest
ive been told theyre for race cars
acl are composition gaskets... made of some sort of composition/fibre/asbestos
![Laughing :lol:](./images/smilies/icon_lol.gif)
, softer, more spongy
copper would be a tougher metal, seal better, for higher comp higher temp
but dont last as long because it would fatigue
?
Duc,
Real race cars (some) use SOLID copper gaskets. You can too if you wanna pay a coupla hundred to get one water jet cut...
O'Brien Aluminium in Smithfield do them.
You re-use them too, after they have been annealed. Sorta like a lifetime head gasket..
The common Mini so-called `copper' ones (AF070 etc) used to have asbestos in them, now they have SFA. And they don't last any more. Ask people here...
One problem is the bottom sheet appears to be mild steel- where it is extruded up thru the top copper sheet and wrapped out to form the fire ring, it is just too soft and burns easy.
The ACL smallbore one and the BK450 have what appears to be S/S fire rings. Very hard to burn out.
Composition gaskets have come a long way. The racers choice for 1275s now is the BK450, NOT the `copper' ones.
![Wink :wink:](./images/smilies/icon_wink.gif)
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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.
![Mr. Green :mrgreen:](./images/smilies/icon_mrgreen.gif)