Ford 641, Is my motor blown?

[YODO]

i'd still pull the valve cover and see the train move.

also look at the heat shields above the manifold to make sure not loose.

I took the cover off, didnt see any broken springs or stems, took a short video of it running and some pics, It didnt seem any louder after cover off . will continue to look

 

[JC-jetro]

Camshaft assembly looks good. For just a temporary fix in the past, I have taken high temp exhaust repair putty (epoxy), can't remember brand name, therma something and applied the thick grey paste to the muffler and let it dry and cure overnight. After the engine was running for a while the heat continued to cure the putty to the point it became rock hard. To my surprise it lasted beyond the rest of the muffler. My suggestion is to go to an automotive shop and ask for what I suggested, put it on in the manifold crack, set it overnight for it harden and cure some, and next day run the engine to see if it helps. That exhaust might rattle some sheet metal making the noise. Look closely where the exhaust leak is going to find the cause of metallic rattle. Need to be looking for a new/used exhaust manifold. It'll be difficult to weld/repair the crack in the manifold but not impossible.

JC,

 

[allen6634]

have you looked on e-bay that is where i have been getting my parts, if i rember right i think i saw a manifold there for sale, (it was a new one)