Re: Exhaust Manifold Questions

Posted by Owen_Dyneto On 2009/5/7 13:07:57

I've changed a number of those choke stove tubes on various makes and models over the years, no doubt yours doesn't differ significantly. It's a very basic, simple operation. Probably the ends of the holes in the manifold are cast or machined in a very slight countersink. The tube, just plain simple steel, nothing special, is cut to length and the ends just swedged over to seal them. So to remove the old one, I'd use either a countersink bit or a drill bit and VERY CAREFULLY just drill away the swedge from one or both ends, and just push the tube out. When you install the new one, you can put a flare on one end before installing to save the need of swedging both ends. And again, be careful, old cast iron can be brittle as heck. Support the work by the steel tube and not the manifold as you swedge the other end.

You mentioned a "factory weld" on the exhaust manifold - I think not, better take a closer look - it might be a repair. If you want to weld cast iron, I'd recommend seeing a pro!

I wouldn't be overly concerned about minute exhaust leaks around the heat riser shaft, there has to be a certain amount of clearance for the shaft to rotate freely both before and after everything expands from the heat. Unless it's just totally worn out, you'll never hear the noise over the running engine. But of course if you want to install new sleeves and a shaft, it's does come apart for servicing.