MattF36

Hello everyone I have a 36 olds with the 213 flat head. My exhuast manifold has cracked and is basically behond repair.
Has anyone made a set of headers/extractors for them? Other problem is the engine doesn't have a threat at the front and very rear of the block where it holds the exhaust manifold in place so worried there will be to much movement for extractors.

Any help would be great

thanks everyone
also in Australia so parts are a fair pain 😅

Olds64

Matt, you're either going to have to have the exhaust manifold repaired or have custom headers made for your car. You might be able to find and OE exhaust manifold in good shape if you search Ebay long enough. Good luck!

Ozzie

I've had good results with brazing cast iron; but you say that it is beyond repair. The group number is 3.601 and the part number is 410890. It should be the same through 1940. Here is one on eBay but there might be a problem with the shipping.
https://www.ebay.com/i/223957913289?...SABEgKuDPD_BwE

coldwar

Wait until this virus thing passes and international shipping opens up again, and buy another like the example in the linked auction WITH NO CRACKS. Repairs of this type on cast iron manifolds joined as a assembly almost never last on a engine in actual use.

I drove a straight eight Pontiac with a cracked exhaust manifold for quite a while, a buddy had a 1940 Pontiac six same story.

What I suggest is to find a local competent general machine shop. Bolt your replacement exhaust manifold to your intake manifold assuming it is good, with the heat riser gasket in place, and have the machinist blanchard mill the port surfaces of both manifolds as a assembly. Only remove the necessary amount to achieve the goal of the port surfaces for each port now being on the same plane. If you don't do this or try to fudge it with gaskets, the exhaust manifold will likely crack again. If the machinist is at all experienced he will know at once what you hope to accomplish with the needed work. On installation, tighten the manifold fasteners in a inside-out gradual sequence of order, and only enough to achieve the desired seal. My opinion is steel -shim type gaskets are acceptable, but I never liked the thicker 'metalbestos' types some guys use to try to achieve port seal, which are included in many modern gaskets sets.

It might seem shocking how much might actually have to come off the outside ports to get it flat ends to center, but it won't matter to the installation if you have this done to the manifolds as a assembly.

MattF36

Great thanks for the help everyone a lot more options to look at. Do have someone who can make custom headers but only issue we found was that the missing bolt to clamp down the headers. Only way would be to drill and tap some bolt studs in.
I'll start looking for another manifold now I know what ones can fit it helps a lot.
Once again thanks everyone who postes