yea , actually I noticed there was some play in the flapper valve shaft with no apparent seal to the atmosphere. Its just the standard two bolt manifold I have at the moment, although I do have a three bolt manifold in my spare parts collection. I might try ripping out the flapper valve assembly and tapping out the hole and plugging with a bolt. failing that will upgrade to the 3 bolt header, need the bottom flange tho
Quote:
Dodgeman wrote:
Are you sure it is coming from the flange?
A very common problem was leakage past the worn shaft & bushes of the hot spot flapper valve.
This was one of the advantages of the 1000 coupe exhaust manifold that i ran in my sedan before i got my tri-Y's This manifold has no flapper valve, but has a three bolt flange with a regular gasket & a dual GX-like outlet. For an A12 with mild specs & an original single carb manifold, they are the go.