I have a stock '72 1800E with a B20F (low compression) engine. I have obtained (free of charge!) a good condition 1971 B20E (high compression) head complete with valves and springs. I am interested in swapping the B20E head for the B20F to gain a bit more power. Is this a straight remove and replace operation? Do I need to change timing, injectors, fuel rail pressure etc.? Is this a common swap or is it more trouble than it is worth? Thanks for your help.
Dave
aitken@echelon.ca

David says: The "E" head fits in place of the "F" head. But, you are going from an 8.7:1 compression ratio to a 10.5:1, so you'll need more fuel. Without it, you may burn pistons from lean mixture. Volvo achieved this with a different control unit and manifold pressure sensor. Installing these parts with the head is the easiest. I don't know how the control units differ! The pressure sensor could be modified.

We run over 11:1 in our 1800E racecar. We raise the fuel pressure; I suspect this would not be good for MPG on the street.

The timing specs are the same "E" or "F." You should use at least one heat range colder spark plugs -- for example, NGK BP7HS instead of BP6HS. For mostly wide-open throttle driving, go to 8s.