exhaustmanifold

[Alexander50]

I intend to change the castiron exhaustmanifold on my straight 8 1931 Model 54 by a welded steel one. Two reasons; I want to save the original castiron one because these are vulnerable for cracking and this one is still perfect, the other reason is that I think the cast iron manifold is basically a very bad design. The gasses of the rear cilinders collide with the gasses of the front cilinders so the efficiency of the engine is not good. I want to produce a steel manifold with two groups of four cilinders (1,2,7,8 and 3,4,5,6) go into two pipes that come together in one muffler. Because such changes are reversible it is not effecting the originality and value of the car. Who has experiences with such welded manifolds?

[The Old Guy]

Essentially you are going to build a set of headers for your engine. The Hot Rodders have been doing it for years. It will work just fine and get you a little HP

[Alexander50]

I know, but does anyone has experiences with the manifolds on the thirties Buick straight eights? For example: the small engine I have (1931 model 50) does not have bolts at the end of the manifold (next to cil 1 and 8) like the bigger brothers have. The manifold is not pressed against the head at these places. Does a steel manifold warp at these ends?

[The Old Guy]

I don't know about the 31, but the later small aeries straight eights, had what looked like a dowel , but it screwed in . You could remove it and replace it with a stud and bolt the rnd down

[Guest 1938McLaughlin]

I'm no expert, but I would think the thicker the flang the less likely it is to warp.

Hope the project goes well for you. Sounds interesting.