Gland ring recesses

M

Mad Mac

Senior Member
I am shortly going to re-install my exhaust/intake manifold after having it planed flat at a machine shop. However I found that the gland rings don't fit snugly into the recessed parts of the head or the manifold. This is because the floors of the recesses are uneven, causing the rings to be tilted up unevenly when I trial-fit them. I have cleaned out the rust and carbon, but the floors are still uneven. Should I have the manifold recesses machined?

It would be cheaper (though very fiddly) to file the gland rings down differently to match-fit each recess, and as the rings are a bit too deep (about 8 mm) they will need filing in any case to avoid pinching them when I tighten everything up.

I have used the search function here and read some interesting posts on gland rings, but they do not seem to address the problem of poorly defined recesses.
 
Mad Mac,
Gland rings - yes or no. Years ago, when I bought my car and was a real novice, I changed the manifolds. I bought a used set, didn't know about planning, and I lost two rings before I could get it back together. I put the manifolds on without the rings and haven't had a problem since! You'll get a lot of opinions on this subject - this has been mine.
Marty
 
I no longer use the gland rings except on new manifolds and with the recess in the block very clean and even. Everything has to be perfect for them to fit and work as they should.


On old manifolds I plane them as a set (intake and exhaust bolted together) then use the best qualith copper clad gasket available.
 
Gland rings are good as they prevent the "4th port droop" caused by the weight of the exhaust pipe on the back end of the manifold. (i.e. a misalignment of the 4th port in the manifold relative to the 4th port in the block.)

Are they necessary if you have a new or "undrooped" manifold without droop? Not really. Are they good to have? Probably yes - as they prevent entirely any possibility for droop to form.

I have never used them on my current motor. But I think I will use them on the NEXT motor. But now I have the luxury of messing around with it, a fair number of used manifolds of which one might actually fit (most won't anymore because of droop), and the ability (read $) to buy a new manifold if necessary.

Joe K
 
Last edited:
Thanks guys, but I really wanted to know whether to machine the recesses or file the rings or both. I already decided to use the gland rings if I could fit them properly. Fitting them is my problem.
 
I would only file the rings. That way if you mess one up you can just replace it. The block I would only clean up any rust or carbon.
 
As long as they fully go into the manifold and stick out enough to go into the block and bottom out with the gasket you will get the support. If I can I use them. I would file just enough to allow them to enter and get gasket crush and not worry about a little unevenness of the hole in the block.
 
To update this thread: In the end I decided not to use the gland rings because it was too difficult to seat them properly in the recesses. I would have had to file each one down unevenly, to match the unevenness of the floor of each recess (in both the head and the manifold) and that was just too much of a pia. Maybe my recesses are more eroded and uneven than some. Also, as I have been driving the same RPU for many years now without any gland rings (and without any problem) I don't think they are necessary. I cannot see any indication that the rearmost exhaust port has dropped out of alignment, due to the weight of the muffler even after 90 years use.
 
You must log in or register to reply here.
Back
Top