Projects Getting that Exhaust Sound Just Right

I'm going to have a shop redo the exhaust on my 53 Chevy since I suspect a leak causing my cab to smell. It has a SBC 350 with an RV cam, ram head manifolds, and 1.5" pipe going to the back. It sounds too "put put put put" at idle...

Here is a clip to how it currently sounds:


Below is the exact sound I want to a "T". The 66 c-10 has a 283 with 2" pipes to the bumper and brockman mellowtone glasspacks (but not sure what length, this was owned by a HAMB member named Shad).



I bought 22" brockman mellowtones and was thinking of replacing my pipes with 2" diameter pipes to the bumper. Am I likely to get a similar sound? I'm most annoyed with how mine sounds at idle and want to get rid of that "put put put" sound. Is this because my 350 has an RV cam? I already adjusted the idle to be a little higher but it still has that lopey sound I'm not too fond of at idle. The 66 C-10 doesn't sound annoying to me at idle. Thanks.

 

What's a RV cam?

 

RV cams are made for low-end torque rather than high-end horsepower. HRP

 

Like for a truck or motor home. Got it. Thanks. I've always heard it, but never really knew what the hell it was.

 

I don't really know either for that matter. I'm just quoting what the previous owner had told me about the motor.

 

The cam will have some effect on the exhaust note, but the size of the pipes and the mufflers will have more of an effect.
I run Hedman TightTuck headers, 2 1/4" pipes with Smitty mufflers. The engine is a 327 with a Hydraulic version of a '350hp' cam, single 4bbl and about 10:1 compression. The exhaust tone is nice and mellow but has a nice sound when going up through the rpm.

 

1-1/2" pipe is pretty small for a 350.

Compression or should I say the resultant expansion has more to do with the sound out of the pipe than anything else

 

Thanks. I saw this video clip of a 1951 Chevy that appears to have a 350 and 2" pipes with Brockman Mellowtones.
It almost has a similar "put put put put" that mine has at idle and it drives me crazy (that's just my own opinion).



I realize there are lot's of factors but will it be harder to avoid this sound if I put 2" pipes and 22" brockman mellowtones on mine? I have no idea how involved of a job it is to change the way mine sounds. I already suspect an exhaust leak so I need to have a shop replace the pipes anyways and I already had received the 22" brockmans but I can sell them I suppose.

 

The video with 2.5" pipe sounds great to me, but you can put glasspacks on and "cackle" if you want.

 

Thanks, the 1st video is my 53 Chevy with 1.5" pipes.. I made a mistake in the video text saying it was 2.5".

The sound I really like most is the 66 C-10 with glasspacks.. It has a nice mellow rumble at idle and that nice rasp when he steps on it. That's what I want mine to sound like exactly but have no clue what I'm up against. I'm guessing 2" pipes with my 22" brockman mellowtones isn't going to give me the same sound without work elsewhere on the engine but I have no idea.

 

No matter what you do, no matter what pipes you put

A 350 won't sound like a 283, it won't rev like a 283, it won't bark like a 283.

Now your pipes are smashed if I remember correctly from your other thread right? If they are - that in and of itself will make things sound off, especially if they aren't smashed evenly.

Run a cranking compression test on your engine and give up the numbers. Ill guess its low compression engine (ill bet the 283 is high compression) and that low compression engine will sound best by mixing the pulses in a single pipe for a short distance then back into 2.

 

I would weld the mufflers on the system you have now, ascertain that there are no leaks and see what it sounds like. If it's close to what you want then you can up-size the pipe.

Everything will effect the sound generated.......engine, cam and pipe diameter, as well as mufflers and their placement.

 

Try an "H" pipe in what you have before adding mufflers. Right now it sounds like one of those old Chris Crafts at idle.

 

Thanks that is interesting. I will have to buy something to measure compression with when I have time.

So should I perhaps hold off on the 2" pipe and 22" glasspacks idea? I have to fix those pipes either way but also don't want to do that work and find out I made it harder to get a mellower tone at idle yet that raspy sound when I rev it up.

 

Exactly, it sounds like a boat and I tell people this. I don't like the way it sounds right now but am not sure if changing the pipes and 22 inch glasspacks will get rid of it much.

 

I'd bet the pickup you like has a stock motor and stock cam. Yours and the other one you don't like have high performance cams of one flavor or another. Dump your cam for a stocker and you'll get the smooth sound you want at idle. Oh, and going with 2" or 2 1/4" pipes will help, too.

 

Thanks, I believe that c-10 truck has stock cam and stock motor according to some threads I had read from the previous owner of that truck. I do want more of a smooth sound at idle. I have the put put put sounds it makes right now.

Will I have defeat the purpose of going with 2 1/4" pipes but terminating with 2" Chrome tips? I already bought them and also don't want too big diameter chrome tips for cosmetic reasons.

 

Scotts 51 sounds like S..H...I...you know the rest. It sounds like a B-25 with a couple of jugs shot off.

That 66 in the second video sounds like it's idled too high.
Your 53 sounds very good to me. Like has been said it will be difficult to get that short stroke 283 sound out of a 350.

If you want the best sound.....put a FE in it.

 

2 1/2 inch pipe with walker universal turbo mufflers or thrush turbo muffler, it will sound great. Thrush and dynomax are owned by walker, your exhaust shop probably has walker universals on the shelf. Add an h pipe if you have room.

 

Thanks, I just wish it didn't sound like a Chris Craft at idle with that "put put put put" sound. I also like a bit of growl from the glasspacks when revin'g up and letting off. What is an FE?

 

Thanks, the only thing is that I really like that bit of growl with the glasspacks when you rev and let off just like with the C-10 that has the 283 motor. I realize I can't have it all.. hmmm

 

If you're worried about your exhaust tips, be sure to mount them just inside the bumper so they will not get smashed on your next trip across a steep driveway. Otherwise, get used to replacing them every week or two.

The larger size tubing will help tone down the exhaust note, but if you're worried about cosmetics go with the 2" exhaust pipes and 2" tips. Don't go with 2 1/4" or 2 1/2" exhaust with 2" tips. That would just make you look like a complete rookie.

The biggest drawback to getting the smooth idle sound you want, however, isn't the pipes or the mufflers, it's your lumpy cam. BTW: most rodders LIKE the bumpy idle, but hey, do what makes you happy.

 

Thanks for the advice! What about 2 1/2" pipe that tapers to 2" pipe the last 12-18 inches so its not visible? Will that defeat the entire purpose of 2 1/2" pipes? The only problem is that the brockman glasspacks are for 2" pipes.

Unfortunately that cam has to stay as I don't have the tools or skills to do something that major. I'm not a rodder (I wish)

 

Yes, it will defeat the 2 1/2 pipe. Just run dual 2 1/4" or 2" pipe with a crosser and good Walker muffler.
Where is your vacuum advance hooked up at, ported or full time vacuum? Full time will help smooth out the idle and get rid of some of the motor boat noise.

Joe

 

I agree. The "H" pipe (or equalizer) will reduce pulsations considerably.

Have you considered turbo mufflers? They are quiet on idle and moderate acceleration, then growl when you get on it.

 

I'm going to guess you'll want to read thru this as well as the links I'm there.

http://www.jalopyjournal.com/forum/threads/where-are-the-exhaust-scientists.747599/

 

Or maybe a turbo 5.3 LS
I think it sounds great but if you want to smooth out the pulses a little bit an H or X pipe will help balance it.

 

2 1/4" or 2 1/2" duals with Tri-Y headers, an H or X (Balance) pipe around gearbox mount with turbo mufflers brought mine to life, great sound at speed and idle. Block huggers IMHO are similar to cast iron manifolds. Exhaust originally dumped in front of rear axle however resonance at speed (60mph) was deafening so I extended all the way to the back of the car.
When I finish my current project with SBC and dual Fentons, I will trying to maintain THAT sound with performance and some economy. Think 2 1/4"s on each exhaust port into a 2 1/2" dual system should suffice.

 

I have been using the Super turbos for many years with 2 1/2" pipe. It's my favorite combo for exhaust.

 

Thanks for all the advice. What's the best way to drown out all that lumpy idle from the RV cam yet still get some of that rap from glasspacks when I step on it and let off? I don't want to go through the effort of increasing compression or changing the cam.

Will an H pipe ahead of 22" glass packs possibly work?