some folks here say that 400 is normal. but i dont see how. air pressure at sea level is 14.7 psi. compression on a 616/617 21.5 to one, on the 603 it is 22. multiply 14.7 x 22 = 323.4 ? right? and as u go higher in elevation the air pressure drops. i dont have a table handy but here in lafayette we are at about 700' above sea level. i am guessing about 14.5.

so the only way i see to get to 400 is carbon build up in the combustion chamber raising it.

tom w

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.