Thanasis

iTrader: (3)

hi everybody,which is the better head of cosworth, 2wd or 4x4?and which is the difference.thanks a lot.

Niall.b

believe 4x4 one has better port design

cozmeister

iTrader: (1)

the 4x4 one's also stronger and doesn't need a turbo damper.

tabetha

Port design is the same, the 4x4 one is not stronger, but it does have more clearance around the top of the bolt holes so uses a larger clamp washer thereby distributing force over a larger area, when tightened up, which is obviously better.
As said early 2wd used a inbuilt damper protrusion(BOSS) on the heads whereas later ones did not .
Early 2wd heads had TWO holes for thermostat, later 2wd had 3 but still only used two, 4x4 always used all three.
tabetha

Niall.b

think the design of the 4x4 exhaust manifold negated the turbo damper

tabetha

It was probably not needed in the first place, most likely there as it was on the RS500, which used same head base casting.
tabetha