View Full Version : 21 cc heads

03-28-2003, 06:09 AM
i know head gasket thickness plays a role,but what should the cranking compression be with a 1997 merc drag?what is the minumum octane fuel required and what brands do u prefer?i have succesfuly ran 100 octane av gas for years with 26cc so iam thinking around 105 to 108 octane max.

Fl Boy in ILL
03-28-2003, 10:02 AM
I run 110 octane, with my tight heads.


ken medendorp
03-28-2003, 10:09 AM
around 230 i think

03-30-2003, 08:00 AM
my drag has 220 with thin gaskets and 215 with thick ones. i run 110 sunoco.

03-30-2003, 09:50 AM
i ussually run merc gasket#27-822844-1.is there a thicker one and what is #?will a thicker gasket hold up better with these 21 cc?

04-04-2003, 04:28 PM
Anyone try using pump gas and Toluene?