The Stovebolt Site Forums The Shop Area Engine Shop 235 exhaust

I heard a Chevy car with a 235 and straight pipes (split with a “Y”) coming out under the rear doors. It was so loud I couldn’t think or hear anything else.

Here is my truck related question: I’m curious as to what everyone is running on their stock trucks (216/235/261)so you can hear the radio and your wife talking to you (The desire to Hear the wife might change in the future! 😂) while cruising down the road, yet still have a little rumble.

I assume that the muffler and exhaust placement will also make a difference.

Thanks

Chris

Chris I'm probably not the right person to answer. I want my 235 to be as quiet as possible, so I go out of my way to keep things silent. I use single exhaust, a muffler originally designed for either an Oldsmobile or Cadillac, hydraulic lifters, all sort of stuff like that. And no fan on the water pump. Just electric fans. Those old fan blades are balanced about as well as a concrete mixer and can make horrible noise at any speed over 30. Also...and I mentioned this a few days ago...I make absolutely certain the front part of my cab does not touch the frame at the mounting points. These trucks can telegraph all manner of noise through the cab via the frame. I've even considered using nylon bolts and nuts. And...I have the muffler as far back toward the rear as possible. I'm even considering adding another one in the exhaust line somewhere.

Jon,

Thanks! I want to make it much quieter! Currently, I can’t hear my radio without cranking it up. I have an electric fan, but I find that it’s actually louder than I thought the electric fan would be.

Chris

My electric fan (a Spal brand) is something I hear in town but not at cruising speed as it shuts off when enough air is passing over the radiator. I have it set to kick on around 185F. Then I have a pusher (also a Spal) which runs any time the A/C is running. It is a smaller capacity and 1.5" smaller in diameter. Sitting out front and being a pusher fan it doesn't make as much noise.

You have to work at getting the cab quieter but some things can help. Another area that seems to transmit noise is the metal on the outer side of the kick panels. I buy spray on undercoating (Permatex brand is okay) and layer it on to about 1/8" thick or so.

When I was younger and got to ride in several of these trucks when they were new-ish they never seemed too loud to me. A few rattles but usually that was due to something under the seat, in the bed, etc. The whine of first gear was an unmistakable sound I'll never forget. I remember one an uncle owned which had very little "stuff" in it that was very quiet. I think it was a 1950 or 1951. His had a radio and we would listen to it all the time. However, I have decided the world was a quieter place back then. Sort of like the first days of Covid. You could hear birds again.

I just put on a pretty quiet oval Walker with single exhaust on my 216. Now the lifters can be heard as the loudest thing, lol Like you I want the quiet so I'm also insulating the cab and inside the doors wherever possible just don't forget to allow the drain locations to do their job.

The sweet song of Stovebolt valve train clatter. I love it.

My truck (stock 216) came to me with the stock manifold and down pipe, but with a Cherry Bomb or similar glass pack right under my butt, and a side exit right in front of the LR tire. It's super quiet at idle and low RPM, but pretty loud in the cab at speeds over 40 or so. The floor is also rusty, there's no weatherstrip, no headliner or roof insulation, no floor insulation, no cardboard door panels... I almost always have the windows down unless it's too cold or raining. So there's lots of wind noise and the inside sounds like an empty soup can, so I know the volume isn't solely due to the muffler and tailpipe configuration.

No real point to all this, besides sharing what I've got going on.

I have a set of heated Fentons and Porter mufflers I intend to run. Just need to tweak the throttle linkage to clear the rear header, and get it to a shop to get some pipes bent and welded. I plan to have the mufflers back under the front part of the bed. I also have new floor panels that need to be installed, and when that's being done I want to ensure the cab is square, mounts are good, and the doors hang right, then I'll put some weatherstrip and floor insulation in it. Jon, I saw your note above and the other recent thread about the deteriorating cab mounts and cab to frame contact transmitting noise. I need to check and remedy that if needed. I'm tired of how overstimulating it is to drive for longer distances due to the noise and heat. Looking forward to it being a little more civilized while also having a good exhaust note.

Eric maybe this image will help. I have my front end off doing some repainting so I can get to this area easily. You can see the little pvc sheets I cut and stacked up and you can see I have maybe 3/16" of space between the cab and the mount there. About twice the thickness of a popsicle stick is what it is. When that pad wears out and compresses it will let the front part of the cab sit right down on the frame and cab mount there. Before I did this mine was smack on top of the mount piece.

Thanks, Jon.

Ok, Chris, back to your exhaust question!

Moving the muffler as far back as possible will help. Mine was at the rear of the cab, moving it back another 18 inches helped a lot

My two cents: aggressive exhaust on a Stovebolt (usually) sounds like crap. I generally much prefer a stock-ish sounding system.

I have a heard a few systems that have a nice deep, low tone. But I don’t know the secret to getting one sounding like that.

Chris, mine is pretty quiet with headers and dual exhaust. The pipes go all the way to the rear bumper. The cab is insulated everywhere, except behind the kick panels. Didn’t think about spraying something there. I had a muffler put on that sound wise, was in the middle not perfectly quiet but not loud either. The headers Y back into one pipe to the muffler then split bac out to the rear. The muffler is pretty close to the rear end. You can hear it, the link is on my signature line.

That sounds good, Donald.

Hi Chris, the old cast iron split manifolds not only help the engine breath better, they also make the engine not sound like it is working its nuts off while under load. depending on what type of mufflers you decide to use will decide the sound you get. I use a set of the old turbo mufflers and it is very quiet unless I want to wind her up.Then you get the split manifold sound. Using an equalizer tube between the two pipes before the mufflers will also mellow it out some more.