[Shyguy]

Originally Posted by Conroe trucker

Here's mine.

I have a rebuilt engine and am having hell getting the exhaust manifold to seal after the first cylinder at the bottom.

I am also curious if the exhaust preheat valve could be sticking and causing additional back preasure.
It is not sticking, but what if I wired it open?
The first picture is at rest with the manifold warm, the second the spring is under slight preasure to hold in that postion.

I have a really quiet muffler on it, so I expect I have some back preasure anyway.

I put the second gasket on and it did not seal at all, looking for ideas.

I thought I read that you must put the intake and exhaust on together but not bolted up, tighten everything, then tighten the preheat cavity.

Also looking for a tuning schematic for the 1BBL carbs if you might know where to find one.

Mike
CUSTOMAL@FLASH.NET

The pre-heat valve can be wired open ok. We wired open the one on my son's 250 in his '71 Chevelle and it runs great.

I have not checked the one on the 250 in my '67 yet so I don't know if the previous owner wired it open or not.

Danny