20s Exhaust System Question

[Guest Paterson Chris]

I'm considering replacing what appears to be the original (or at least very early replacement) "stovepipe" muffler with a close, off the shelf one meeting the same dimensions from the local NAPA store. The original, after I rebuild it, will be put aside with a few other spares original to the car. I want this to be a driver that I can use for more than just the occasional town parade.

Here's the rub:

The car -- '22 Paterson -- has no motor mounts. The engine (Continental 6) all the way back through the exhaust system is all bolted directly to the chassis. I'm concerned that if I ever hit a really bad pot hole (I live in the mountains), the exhaust assembly will flex in such a way as to transmit the stress back up to the engine and, god forbid, crack the exhaust manifold. Have others experienced problems here?

I'll add that when I got the car, it had been asleep since '53, the motor mounts were loose, and the threaded collar securing the exhaust header pipe to the manifold was also not threaded all the way in.

Am I being overly anal by trying to second guess 1920s engineering or would it be a good thing to install flexible exhaust hangers for the replacement muffler? I'd rather err on the side of caution than to find myself searching for an unobtanium part. At the same time I want to balance what I do by keeping the car as original as possible since there don't seem to be any more around.

What would you do?

Thanks --

Chris

[jan arnett (2)]

Chris: I don't think you are being anal about it but I also do not think it will be a problem. I have five cars in my garage and none of them have what you would consider the traditional motor mounts. All bolt directly to the frame. The earliest is my 1916 Model T but I also have a 1923 Moon (Continental engine) 1924 Star (Continental engine) 1923 Dodge and 1922 Dodge. I just worked on a 1908 Maxwell without any springing in the engine. Your exhaust pipe fits into the exhaust manifold in a slip fashion which does give you some flexibility. If you had flexible hangers you will allow the exhaust to swing up and down which will cause you a problem. I guess I am not sure why you feel that an original muffler will impact your driving ability.

Have a nice day

[Layden B]

While these earlier engines do not have "motor mounts" made of rubber to take vibration and flexing, they are not bolted solid either. Most or all should have bolts with castle nuts to take cotter pins. The bolts are left intentionally loose enough that the engine can slide around on the bolts and not be broken by frame flex. The cotter pins ( or double nuts) keep the assembly from loosening further. Model T Fords are notorious for breaking the engine mounting "ears" if they are bolted tight to the frame.

[Guest Paterson Chris]

Jan --

I don't want to see the original muffler rust out but now that I've disassembled it and see how easy it would be to rebuild it over and over maybe I will keep it on there. I'm puzzled as to why the inlet of the muffler is almost twice as large as the outlet (tail pipe) though. Seems very dinky and thus, restrictive?

Layden --

I'm going to look again at the motor mount bolts, see if they're castellated, and possibly loosen them enough in the way that you describe. I wonder if my 1925 copy of Dyke's will have anything to say on this also. It's been my main source of reference.

All --

It just seems to me that with the general state of the roads as they were back then and the way engines were secured to their respective chassis' (allowing for, to my perception, almost no movement) that there would have been lots of stresses applied to different parts. On the other hand as a guy who's never owned a car older than a '36 Pontiac coupe maybe I'm underestimating the robustness of the car chassis' of that era?

Chris

[TexRiv_63]

Chris,

When I got my Pierce the original muffler was rusted out and the tailpipe was just a few rusty pieces hanging from the brackets. I needed a quick temporary fix to drive the car - the exhaust pipe was good so I got a cheap generic muffler from NAPA that matched the size of the original plus (cringe) some flex pipe for the tailpipe. The only difference in the muffler was a larger outlet. I do not have a good frame of reference but I think the car is louder than it should be, I think the smaller tailpipe diameter was to control noise. I doubt they were too worried about backpressure in those days.