do mufflers give you that hot rod engine noise?

i am looking at an antique truck. The original engine was replaced with a Chevy 350 crate engine. Otherwise it looks original. Problem is, when you start the engine it sounds like a hot rod -- throaty muscle car type of sound. I want a sedate old car sound. My question -- is this sound simply a funciton of the muffler? Could I tone it down by changing to a different muffler? Or is this engine sound due to the engine, and no muffler is going to change it?

thanks

Reply to
John Smith
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Yes.

Partly, but a muffler change will fix it.

Reply to
mst

Depends on what you find objectionable about the sound. If it's simply the volume, then yes changing the mufflers will help. However you will have to seek the advice of a GOOD muffler guy as most aftermarket mufflers are aimed at the "performance" crowd who value low backpressure over quietness. Stay away from "turbo" mufflers, glasspacks, and Flowmasters or imitations thereof. They sound good, IMHO, but aren't what you seem to be looking for.

Alternately, you could run a glasspack in series with the existing mufflers, if they're "turbo" style or similar. This will yield a deep, throaty sound without a whole lot of volume. Also adding a balance tube, crossover, H-pipe, whatever you want to call it, will mellow out the sound without any performance hit.

If what you dislike is the lumpy idle due to a performance cam (which crate motor are we talking about, anyway?) there's really not much that can be done short of installing a milder camshaft, which IMHO isn't worth it.

good luck,

nate

Reply to
N8N

Ditto on what N8N says about adding the H-pipe/crossover pipe for quieter operation. I've seen many guys who were unhappy after paying for dual exhaust systems (with turbos, glasspacks, or Flowmasters) when they were too quiet. Only after going back and removing the original crossover pipe did the sound level increase to their expectations. sdlomi2

Reply to
sdlomi2

It depends. If the engine has pretty high compression and an aggressive cam, then quieter mufflers will HELP quiet it down, but it will still be a little thumpy, and probably won't run very well with the more restrictive mufflers.

Reply to
Steve

I think many of us like a somewhat throaty sound, but don't want a loud glasspack type of noise.

Remember how the old MG-B's and similar European cars had a growl? It was not loud, but sounded far racier than in fact they were. Could this sound be duplicated with an American V6 or V8?

Reply to
<HLS

Every engine has its own unique sound, there's no way to duplicate the exact sound you're thinking of on anything but an inline four or six. You could come close with a V-8 but it will always have a deeper "beat" to it due to the irregular firing impulses. And a V-6 will always sound like crap (just MHO)

nate

Reply to
N8N

Count me in there. I love Dynomax mufflers, can't stand glasspacks or

2-chamber Flowbastards.

V6 maybe, inline-6 definitely (ever hear a slant-six with Dutra Duals?), but a v8 has an asymmetric left-right firing pattern (l-r-l-l-r-l-r-r) that gives it the characteristic v8 "burble" no matter what you do short of using headers that criss-cross a couple of pipes from right bank to left exhaust pipe and vice-versa (aka "180-degree headers"). Personally, I prefer the burble if its subdued. Inline-4, Inline-6, V6 and V12 engines tend to sound flat and "farty" to me unless they're muffled heavily. The most godawful sound on the road are these rice-rockets with coffee-can exhausts.

Reply to
Steve

The selection of a muffler will make a big difference. This assumes that you have ruled out a hole in the exhaust or a bad exhaust gasket as the source of the existing sound first.

Reply to
Paul Hovnanian P.E.

John Smith wrote: i am looking at an antique truck. The original engine was replaced with a Chevy 350 crate engine. Otherwise it looks original. Problem is, when you start the engine it sounds like a hot rod -- throaty muscle car type of sound. I want a sedate old car sound. My question -- is this sound simply a funciton of the muffler? Could I tone it down by changing to a different muffler? Or is this engine sound due to the engine, and no muffler is going to change it?

thanks Depends on what you find objectionable about the sound. If it's simply the volume, then yes changing the mufflers will help. However you will have to seek the advice of a GOOD muffler guy as most aftermarket mufflers are aimed at the "performance" crowd who value low backpressure over quietness. Stay away from "turbo" mufflers, glasspacks, and Flowmasters or imitations thereof. They sound good, IMHO, but aren't what you seem to be looking for.

Alternately, you could run a glasspack in series with the existing mufflers, if they're "turbo" style or similar. This will yield a deep, throaty sound without a whole lot of volume. Also adding a balance tube, crossover, H-pipe, whatever you want to call it, will mellow out the sound without any performance hit.

If what you dislike is the lumpy idle due to a performance cam (which crate motor are we talking about, anyway?) there's really not much that can be done short of installing a milder camshaft, which IMHO isn't worth it.

good luck,

nate

From the OP...this is an "antique truck".&nbsp; Can we assume there's little or no sound insulation material around the cab area?&nbsp; When you "start the engine it sounds like a hot rod".&nbsp; Does the sound diminish/go way after startup?&nbsp; Is the sound acceptable after startup?&nbsp; Are there headers or the stock exhaust manifolds?&nbsp; Do you care what it sounds like outside the cab (i.e., what others hear, but not you)?

Reply to
Agave

no this is the sound it is intended to have. The engine and muffler system is entirely new.

thanks

Reply to
John Smith

IMHO, unless you get more info about how it was hot rodded, you'll be buying a pig in a poke. As others have written, even if you reduce the engine noise you may end up inadvertently increasing the back pressure, or cause other counter-efficient engine issues.

FWIW, a "crate engine" can mean just about anything from a factory stock replacement to 650 hp stroker...with an awful lot in between.

I think you said it best when you wrote "but I am more interested in something that looks and sounds like a more or less faithful renovation of the original truck." The phrase "more or less faithful renovation" is key there. I'd be patient, pass on this one, and wait until you find the one you really have your heart set on.

Besides, how can you trust a guy who put a day glo steering wheel in a classic truck :)

Reply to
Agave

heck, if it's one of those semi-translucent metalflake plastic ones I'll buy the steering wheel from ya!

nate

(friends don't let friends drive stock)

Reply to
Nate Nagel

"John Smith" writes in article dated Sun, 2 Oct 2005 23:12:41 -0400:

Lots of people have made suggestions about the exhaust system. Most of the noise comes from there, but some noise comes from the intake, through the carb and air cleaner. If the air cleaner is one of the open style (where you can see paper through all 360 degrees) you will get a lot more intake noise than the stock air cleaners where all the air comes in from a single tube which points forward.

-- spud_demon -at- thundermaker.net The above may not (yet) represent the opinions of my employer.

Reply to
Spud Demon

dated Sun, 2 Oct 2005 23:12:41 -0400:

a.k.a. the "giant sucking sound" which is a beautiful thing!

nate

Reply to
N8N

"Agave" the one you really have your heart set on.

hmm, you have a point there

Reply to
John Smith

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