Reply to "Cylinder Heads"

Agreed 1000% with what those two guys said.

The 4v has plenty of power off of idle to spin the tires all the way into third gear "off the line"...THEN it hits it's rpm "sweet spot" and absolutely explodes with another 200 ft-lbs of torque. Almost as though it is a dual over head cammed engine, and the secondaries just opened?

The 2v heads are much like small block Chevy heads are. Very linear and predictable up to their peak...which is right in the 5,000 rpm area.

DEPENDING on what camshaft you have in a 4v, the "sweetspot" is in the 3,500 to 4,200 rpm range. At that point is has similar characteristics to a big block.

The "autocross" guys absolutely LOVE the 2v primarily because the courses are so tight and they never get much over 40 mph or out of second gear.

I "attempted" to autocross with a "Boss 351 engine replica with 4v iron heads" and simply couldn't drive the car as a stick.

The only way I could even contemplate being able to handle the car would be with a version of the current "PK" type paddle shifted transmission like in the current Porsche?

Go with the 4v iron heads. They are good heads but you need a measured static compression ratio with them of about 10.5:1.

Over that you WILL run into detonation unfortunately with premium pump gas and under about 9.5:1, the engine looses it's crispness.