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Exhaust Note

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rjc157

rjc157

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What effects the exhaust note I have a NOS Ansa system on my BJ8 and It just doesn't have that low growl of a healey is it the manifold
 
rjc157 said:
What effects the exhaust note I have a NOS Ansa system on my BJ8 and It just doesn't have that low growl of a healey is it the manifold
Click to expand...

The manifold probably has some effect since it is the overall resonance of the complete system that produces the note.

Additionally,
Pipe lengths,diameters and materials used will also play a significant part.
 
rjc157 said:
What effects the exhaust note I have a NOS Ansa system on my BJ8 and It just doesn't have that low growl of a healey is it the manifold
Click to expand...

Ah .... Something I've given some thought to (actually read a book called 'The Scientific Design of Exhaust and Intake Systems' ... an excruciatingly tedious read). The overall design matters most, but as Keoke mentioned pipe lengths, etc. have a great effect. One major thing is the exhaust type; there are two basic designs: 'turbo' and 'glasspack.' The turbo design uses baffles to muffle sound, and glasspacks are usually straight-through with some kind of sound-absorbent material--usually fiberglass or steel wool--to muffle the sound. Glasspacks are favored by hot-rodders because they don't restrict flow as much as other designs, and they're generally loud. The Ansa exhaust for Healeys uses glasspack mufflers and resonators (for BJ8s). In addition, the Ansa has a couple small glasspacks at the tip which I think dampens the note (never found out for sure what the OEM Healey mufflers were). My BJ8 has a bastardized system with Ansa piping and aftermarket glasspack mufflers and resonators. It has a loud bark, and people sometimes think I have a V8 under the bonnet. It's noisy at low speeds, but at highway speeds it's barely noticeable.
 
Abarth make a lovely sounding system for BJ8s, but my BJ7 with an 8 engine has a brand new original single Burgess on it. It sounds pretty good, but even when I'm not speeding, angry and terrified mothers shake their fists at me and sometimes yell abuse.
 
Here in the States, Harley drivers with straight pipes are so obnoxious they've basically inoculated other, less-loud exhausts--like Healeys--from scorn.
 
Bob_Spidell said:
Here in the States, Harley drivers with straight pipes are so obnoxious they've basically inoculated other, less-loud exhausts--like Healeys--from scorn.
Click to expand...

Absolutely agree re Harley drivers; when I was a kid, the cops were always writing noise tickets.

I've tried 3 mufflers: the Monza was 85 DB plus at speed, even with the addition of Monza muffled tips. The Moss mild-steel replacement a couple DB less and the original Burgess around 80 DB. The Monza and Moss' had unpleasant resonances around 3000 rpm; the Burgess does not. As far as tail pipes - I ran a 1.5" Bell SS for a couple of years - it's very loud with an unpleasant SS tinniness. Am currently running the Monza 1.75" mild steel which is loud but not tinny.

Am curious as to whether reducing the tail pipe diameter back to the stock 1.25" would A) reduce power noticeably and B) quiet it below 80 DB.

Has anyone ever cut a muffler open and re-stuffed it with fiberglass or steel wool?
 
steveg said:
... Has anyone ever cut a muffler open and re-stuffed it with fiberglass or steel wool?
Click to expand...

I tried to do it with my Ansa. It's doable--muffler fiberglass and steel wool are available--but because I'm not a great welder I realized I would probably not be able to weld it back together without a lot of leaks.
 
Steve is curious as to whether reducing the tail pipe diameter back to the stock 1.25" would A) reduce power noticeably and B) quiet it below 80 DB.

Most likely the most noticeable change would be to increase the high frequency component.
 
Any body know where Massachusetts is ???---LOL-.
jester.gif
--
 
I think it (Massachusetts) is near The Vatican? I keep hearing about the Pope going to Mass quite regularly..........

Bad puns aside: we have a stock BJ7 with a stainless steel exhaust system installed by a shop. I believe it's stock-equivalent (rather than an ANSA or some such) and the sound volume is fine, but I think I preferred the 'quality' (the AH 3000 exhaust note!) of the original mild steel system better. I can't really quantify it, and the car has been in the shop for two years, so my observations aren't real current, but my two-bits worth.
 
SpinTech side exit muffler also will raise the exhaust note.

 
Last edited:
OK, try this,

 
I have a BJ7 which I think sounds like the traditional 6 cylinder Healey. The system is regular steel and has been on the car for many, many years. I believe it is a little louder than when it was new as such i have been planning a change to make it a little quieter. having said all that, I think a significant aspect of the original early 3000 exhaust sound is derived from the fact that it has two separate manifold down pipes but, as on mine, the early 3000s went into one co-mingled muffler.
 
I had the occasion, back in the day, to saw a 100/6-3000 muffler lengthwise. At the time my intention was to isolate the two sides from each other with the intent to make the exhaust note "crisper" (ala 6 cylinder Chevy with a split manifold). Total failure as it made no difference at all. FYI , in 1959 the stock muffler was nothing but a factory glasspac with two separate tubes wrapped in fibreglass.

When I restored another 100/6 a few years ago it came to me (in many boxes) with some unknown brand of exhaust system that resembled the stock system but was incredibly loud and raspy which was just what I was looking for 55 years ago !
 
I wanted a bigger bore exhaust on my BJ8, but was too cheap to just go buy one, and I wanted headers too. So, I am running a set of stainless headers from AHSpares and I custom made my exhaust, which follows the original path. Dual pipes, 1 7/8" OD, with a Smithy's glasspack for each under the seat and two more out back in place of resonators. It provides a bit lower tone to it, but on par with stock for volume and really smooth. I love it. On the highway you can hear it slightly, but with no drone or other nastiness.
 
I just installed a Moss motors Stainless steel system on my BT7, replacing a mild steel system. The new unit has a nice mello sound and is not any louder than the prior system at speed. It does has a very sweet growl between 2500 and 2700 RPMs. Not obnoxious, but I find myself looking forward to hearing it when the revs reach that point. After that it all
calms down and is quite acceptable for cruising.
Did I mention how cool the polished SS muffler and pipes are?? I get it that it's not "original" looking, but man is it beautiful which is funny, because I don't like the looks of chrome wire wheels. They look to "blingy" for my taste. Oh well, we all have are own foibles.....
 
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