calling all 250 and exhaust guru's

[shelby987]

the headers and intake/carb are finally in place, I just dropped the truck off at the shop, and will get my system installed tomorrow. The garage builds custom setups, so I have some options. I am thinking about keeping the dual setup with an X-pipe. I was wondering if anyone had any advice/experiece with regards to a good muffler setup for this combination. I would like something with a low rumble, during basic driving, but a nice performance sound at the top end, will dump below the rear bumper, so hopefully that will help with in cab noise. What will give me the best result, flowmaster (series?), dyna-flo, glass packs, ???

[ThatOneBlue67]

I've been pondering on this subject for sometime (as I will be adding headers and dual exhaust by September).

You can actually go to the Flowmaster site and listen to soundlips of each of their muffler models. As for me, I like to stick out. That's why I'll be going with the "hecka loud" 40 Series.

http://www.flowmastermufflers.com

I'm not a guru, I'd just thought I'd throw in my share. Lemme know if cherry bombs would be louder.

[chevybill]

Is your truck a 250 inline six?

Do some searching around on the 6 cyl. sites for exhaust sound samples.

[samwise68]

check out www.inliners.org if you haven't already.

there are some sound clips in the bench racing forum, if you look back far enough.

personally...i like glasspacks.

but. thats just me.

.later days.
.sam.

[longorange68]

I think that the Flowmasters sound like garbage, but if YOU are into that then that is all that matters. One thing to keep in mind that I heard from a buddy of mine who owns an exhaust shop is that Flowmaster has lost their patent on their "scavenging" muffler system. (Long story short you build a muffler with a triangle shaped piece of sheet metal that produces the Venturi effect, which then helps to vacuum the spent gases through the muffler.) Not a bad system, but there are other no name companies out there who can now produce this style of muffler without the patent police all over them. That is if you are into saving money.....I also run the 250, and have thought of what to use for the exhaust, since mine is starting to rot out. Are you really using a dual set up? Wouldn't that just murder your backpressure, unless you used a ridiculously small diameter pipe? I lean towards Dynamax myself, but I am not above the glasspack either. Let us know how the job turns out.

Josh

[ThatOneBlue67]

Josh:

I could understand your rationale if I was referring to the original manifold. However, the dual setup would only occur if with the headers by Stovebolt. They bolt up in place of the manifold and are two seperate pieces. I would imagine one for cylinders 1-3, and one for cylinders 4-6. Therefore, you're not splitting one exhaust pipe into two, but having two pipes that do not merge at all.

Or are you saying that a stock inline 6 (with the exception of the headers) can simply not produce enough exhaust to necessitate dual pipes?

If I sound angry, I'm not. I'm still a student to the wonders of an internal combustion engine, so please educate me.

My personal stup would also include an upgrade to a 2bbl, and in the other guy's case, a 4 bbl.

['68OrangeSunshine]

I have been running Clifford 3-into-2 headers since '78 on a 292. In the mid '80s I went to a 1-3/4 dual pipe system thru turbo mufflers. The system has a cross over -- it's more like a russian "N" than an X or an H. Since the 1,2,3 collector ends about 5-6" in front of the 4,5,6 collector. Sorry, no pix.
But it works great, scavenges good, backpressure OK. It has that angry bee sound on the freeway. [Higher pitch than a V8].

[ThatOneBlue67]

So, do YOU have dual exhaust or just one pipe?

[longorange68]

Originally Posted by ThatOneBlue67

Josh:

I could understand your rationale if I was referring to the original manifold. However, the dual setup would only occur if with the headers by Stovebolt. They bolt up in place of the manifold and are two seperate pieces. I would imagine one for cylinders 1-3, and one for cylinders 4-6. Therefore, you're not splitting one exhaust pipe into two, but having two pipes that do not merge at all.

Or are you saying that a stock inline 6 (with the exception of the headers) can simply not produce enough exhaust to necessitate dual pipes?

If I sound angry, I'm not. I'm still a student to the wonders of an internal combustion engine, so please educate me.

My personal stup would also include an upgrade to a 2bbl, and in the other guy's case, a 4 bbl.

I'm with you now Blue, I wasn't aware of their being a split 6 header. Makes sense to me. I would still go with the Dynomax muff's though, IMO Flowmasters sound a little fake to me. I have plans to re-exhaust mine, but now that this Stovebolt header thing came into view, I might do it sooner than later. I had planned on tucking the tips near the rear bumper to curve down similar to a mid 90's Caprice, as to not draw too much attention to the exhaust. Well that and I hate exhaust tips too, too hard to clean.

[ThatOneBlue67]

lol I can vouch for ya on that hard to clean bit about the tips.

Ok, so dual is alright. As for the mufflers, I decided to stay vintage and go Cherrybombs! Smog exempt... stock... why not stay with glasspacks? Even the name sounds cool. And they're cheap cheap.

I'll probably have the tips come out at the stock exits like the V8's. I want peple to KNOW that this bad boy 250 has dual exhaust.... a sure rarity.

Now about that Angry Bee sound.... ah man that sounds wicked! One member said they sound like the 250 is coming to "eat your family". Haha! That was just too funny. Those quirky sounds are just what I'm looking for out of an exhaust setup. Something special, you dig?

['68OrangeSunshine]

When I was in college I didn't have much cash. I tapped on some Weiand steel packs [like glass packs but with steel wool instead of fibreglass] onto the ends of the collectors and hung them off of coathangar wires to the frame. Talk about redneck engineering. It rap-rapped all right. After I graduated somebody talked me into the full exhaust pipes system. I got tired of having to troubleshoot manifold leaks every time I crossed the railroad tracks. Now I have stock looking dual exhausts with chrome tips on the ends, exiting at a 45* angle after the rear tires. I wanted to read the color of the exhaust smoke by the rearview mirrors on warm up.
Sometimes the emissions test people think it's odd that I have dual exhausts on an L6 -- like I'm lying about some secret V8 -- but screw them anyway.

[shelby987]

I ended up getting a magnaflow muffler with internal x-pipe. The guy did a really nice job, ran two pipes off of the collectors through the transfer case crossmember, routed both of those into the muffler/cross pipe, then exited with duals over the rear axle and straight out under the bumper. The angled stainless tips look really nice, and the sound was really nice (no winding bee at high RPM's)......just enough cab noise to know its running, and just enough grunt that my girlfriend following me said when I took off at lights it sounded 'mean'......pics to follow

[69chevytruck]

Don't forget the picts. Just a reminder. So hurry up, please.

I am about to rebuild/complete mine so I could use some visuals.

[shelby987]

As requested pics!

[ThatOneBlue67]

By God, that is a beautiful thing. Oh man..... I can't wait til I get to that step.

[shelby987]

I gotta tell ya, the sound is very nice, I was getting on the highway the other day, laying into it on the on ramp, there was some construction (on the other side of the road), as I pushed it through second, and pulled into third my girlfriend said she saw about 10 members of the construction crew turn to watch as we flew by.
If anyone wants to get a sound bite, let me know what is involved in that, and I will see what I can do.

['68OrangeSunshine]

A guy on a motorcycle gave me a curious look the other day -- like he could'nt quite place the engine.
By the way are your pipes welded straight thru from the collector? From the pics it looked like there was no gasket between the collectors and the exhaust pipes. You'd have to cut and re-weld if you ever did work on the tranny.

[ThatOneBlue67]

I believe my father's truck is like that as well. Now the H pipe is gone and the pipes never get to say hi.

lol SUnshine. I can see it now.

Hmmm... this truck has dual pipes. Let's take a look under tha- HEY!!! That's not a V8!

And then you can say, "Damn Straight."

'CUs it's a straight six. Oh... how clever.

Please teach Shelby how to do sound bytes!!! Anyone! I must hear!

[shelby987]

yes, welded straight through, wasn't all that thrilled about that, but when the time comes to remove the headers, engine, transmission, what-have-u I will just have to get a set of flanges welded on (the collectors ORIGINALLY had those, but my exhaust guy cut them off, not terribly happy about it, but I was under the gun to get this truck back on the road to tow another vehicle, so I didn't have the time to argue).
Blue, if you figure out how to do the sound clip thing, I will see what I can do to post or email it.....also, under your plans, if you haven't already, you might want to look into a small 4bbl carb (mpg #'s still pending) instead of 2bbl, when the secondaries open up on mine, the exhaust sounds even BETTER, and the truck just screams to life with low and high end power that once would have been thought non-existant in a little I6, even on the highway, I was towing a trailer with a 3/4t 4x4 behind me, lay into it on a hill at 45mph (just over 2,000rpm) and the truck still had power to accellerate....not quickly, but when you are talking about almost 11,000lbs of metal, I was pretty impressed!

[ThatOneBlue67]

Originally Posted by shelby987

Blue, if you figure out how to do the sound clip thing, I will see what I can do to post or email it.....also, under your plans, if you haven't already, you might want to look into a small 4bbl carb (mpg #'s still pending) instead of 2bbl, when the secondaries open up on mine, the exhaust sounds even BETTER, and the truck just screams to life with low and high end power that once would have been thought non-existant in a little I6, even on the highway, I was towing a trailer with a 3/4t 4x4 behind me, lay into it on a hill at 45mph (just over 2,000rpm) and the truck still had power to accellerate....not quickly, but when you are talking about almost 11,000lbs of metal, I was pretty impressed!

Shelby,

I had looked into a 4 barrel carb, but for a lot of reasons... I didn't follwo through. For one, i would not feel comfortable with putting a 4bbl on a tired old 250. I would do it had I the moeny, time, and experience to rebuild the motor first and install a more beefy crankshaft. I feel that those old parts inside might not be able to handle the 4bbl and I'll end up with a dead motor

Otherwise, I'd be all for it. Speaking of my 2bbl conversion, I'll be beginning a thread on that pretty soon. Decided I'm sticking with Rochester.

I'm very happy that yours is finally road-ready! If you weren't half way across the country, I'd have stopped by a long time ago for a ride!

As far as recording your exhaust sound, the best I can think of is if you have a laptop with a plugin microphone. Just record the file and save it. I dunno how you'd go about uplaoding it onto a server, unless you had a 'MySpace'.

[69chevytruck]

Thank you!

You have inspired me to tear out my pipes. And put them back cleaner.