MTFCA Forum

In the process of dealing with the freeze plug, I noticed that the hold down was contacting the side of the new exhaust manifold. I considered grinding away part of the cast iron to fix the problem and then realized that the witness mark was only a symptom of the real problem. When I screwed the hold down and contacted the intake manifold, there was still a dime space before it even contacted the boss area of the exhaust. When I flip the manifold clamp around 180º, same problem. The boss area is lacking in boss. I did not have this problem with the original exhaust manifold.

Instead of torching, preheating, and adding weld material to the replacement part's boss, I elected to add it to the manifold clamp.

Vern, check that the stud over which the clamp fits is not bent. That will miss align the clamp ends on the bosses and leave one end of the boss at a different level. The fact that it was registering on the side of the exhaust manifold makes me think the stud is displaced to one side. If you have any spare clamps, I would replace the one you photographed.

Allan from down under.

I do not have any spare clamps but i do see that they are available.
I tried a different clamp but same gap issue.
The stud is new and straight. The new stud did not have a problem with the old manifold.
Good statements though.
Vern

Vern is correct in the fact that the manifold isn’t cast exactly right. The new manifolds have been that way for at least fifteen years. I’ve installed several of them and they require some grinding to the front outside of the rear manifold port to get the clamp to fit properly AND some fitting to get the hot air pipe to fit well.

The new manifold that I bought 2 years ago has the boss and fit perfectly with no modifications.

I bought a new exhaust manifold a few years ago for my 21 Touring and it worked OK.
Here’s an earlier post about manifold clamps. http://www.mtfca.com/discus/messages/59 ... 1473037627