(Note: this comment does not apply to the 3.0 SC)
On my (77) 2.7 what I believed was just a check valve type
restrictor connected to the breather hose, turns out to be technically a
Backfire Grid and in some Porsche part listings, a Flame and Filter.
But even on the 77 I don’t get any drop in idle when removing the oil cap with this device in place.
So now if this prevents backfire, what purpose was the air box flapper….? Additional protection for the oil tank to prevent blowback into the oil tank?
Part # 901.107.729.00 is listed for 78 on up.
