Buzz & rattle question

huddy

huddy

Senior Member
For background: Enrico (my '30 coupe) has a balanced crank, cut down flywheel, and V-8 clutch. He's also got FAM rear mounts and the FAM transmission pad. He doesn't have a lot of miles on the engine - but I don't know exactly how many.

However, I noticed he has a lot of buzz and vibration at certain speeds - particularly around 43-46 mph. Smooths out around 50, and is fairly smooth below 40.

It doesn't seem to be the throttle/spark levers, so I'm wondering if it's the brake rods. I think he has the original type flat brake anti-rattle springs (I'm in CA and he's in NY right now, so I can't go look).

Thoughts?
 
The only thing I can say is to try and pin it down. The brake rides could very well be the problem, but, there are a bizillion other things too.
Mine runs perfectly at 38 MPH. Thats the only speed in which there are no buzzes, shakes, rattles, noises or vibrations. I can tell you exactly how fast I'm going because of the buzzes, shakes, rattles, noises or vibrations.
 
Many 4 cyl. engines have an inheritant harmonic problem, even in the '70's & '80's some Datsuns would "drum" you out of the car at highway speeds, may as well turn the radio OFF! The factories tried all their "tricks" to muffle them, replying with the statement, "IT'S COMMERCIALLY ACCEPTABLE" Some Volvo sedans would roar you out of the car, unless you STOOD on the back floorboard, & that's VERY uncomfortable.
My point is, what was my point??--OH! I remembered, just accept your Model A for what it is, you can't make a ***** cat out of a RHINO ear.
Bill W.
 
The exhaust pipe where it goes through the rear hanger bracket can make a suprising amount of noise. Get a small piece of wood shim stock and temporaly wedge it in there and see if some of your noises go away. I bet some of them do.
Oh by the way don't use a really large chunk of wood wedge. Don't want you to catch fire.
 
Here are some of the bizillion things I found buzzing, squeaking and rattling on my car. Have you checked these?

- Spark and throttle rods (which you already ruled out)
- Brake rod
- Horn button
- Windshield, rattling inside the frame
- Windshield swing arm
- Sun visor
- Throttle assembly, rattling against firewall
- Doors
- Floorboards
- Choke rod
- Front motor mount, tightened down too far
- Front license plate
 
Enrico and I thank you all for the suggestions. When I get home in October, I will go over all those ideas and see what's loose and rattling.

Also, I kinda figured that buzzes and rattles are inherent with the four-banger engine, and they are just something to accept. I love the old flivver even with all its eccentricities. Wouldn't trade for a Ferrari. Just want to be sure I don't have something about to come unglued and require me to pick up the pieces from the highway.
 
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