The Cal-look Lounge

Since I was 6 years old, I've been into cars. The older I get (I'm 38) the deeper I get into them too. By now you might say I'm obsessed. The timeless lines of a classic design (hello 275GTB/4, Miura, pre '74 911, and yeah the VW Type 1), the scent of hot engines, and exhaust fumes laded with lead, the shove in the back of a light car with too much hp, but for me, more than anything it is the cry and wail of a super tuned motor, under load, that really makes my skin go curdly with goosebumps. I grew up riding around in a two liter Alfetta GT with cat yanked off, and an Ansa rear muffler, and I have really fond memories of Mom warming the car up in the garage before driving us to school. here was a third grade kid with chills running down his spine listening to the growling, garbling, chattering, whizzing twin cam motor coming up to temp.
Anyway, I was thinking the other day, how good a lot of highly tuned VW motors sound, especially when you look at their wheezy humble beginnings. Can anything sound any less aggressive that a stock 40hp Bug? I hate the sound of a stock Beetle, that gasping carb, the rumbly whoosh of the fan and that horrible exhaust note chootling away. I'd rather run no muffler than a stock POS.

Anyway, what is it, in your mind, that makes a high HP Vw sound so good?
Cam timing? Valvetrain? Big venturies? Port work? Sheer displacement? Compression ratio? Header and muffler design?

I can tell you, I've heard plenty of "big" engines, that sounded pretty soft. Slow thottle response, no snap to intake growl, and a lazy exhaust note. And on the other hand, I've heard some pretty threatening sounding 1776's that cracked angrily when the throttles were dropped open.

I'm pretty sure, if you built a 7:1 42 x 37 huge port thing with Engle FK8 and big carbs, it's going to sound weak. Nothing to make any cylinder pressure.

Beyond everything else, I'm sure it all boils down to how well it's tuned in the end. A carb leading another, loose valve tolerances and retarded timing make for a weak motor, and it will sound like it too.

What makes your car scream?

Great topic Ratto!!!  I guess you were thinking about it since my email yesterday!!!!

Your car sure sounds mean dude.........!!!!   8)

I guess it's a bit of everything. I don't know what is a sounding engine, I still have my single port 1300cc ;D (with a phatboy exhaust though).

I have to say probably the meanest soundng street VW had to be Pete Statt's blue bug, with 2332cc ARPM Super Flow IDA motor.

I've heard stories that Mark Voegtly's green car was one mean sounding machine.

 I think you've got the recipe down pretty good yourself, Jim!  My lump sounded like a stocker the other day compared to yours.  What about Dave Mason's car.... that's one nasty sounding piece.  I think it's down to who's straight cut's you buy... then compression ratio.

I have heard both yours and Pete's - Jim, how many times do i have to tell you - Your car has that same sound comming from it. Pete did let me drive his car  :o  Every thing from start to finish must be done correctly to achive this status.

I love the wine of straight cuts, but i dont know much about engines, so ill just keep shush and read  :D

x2  ;)

Turbo Muffler, A long tunnel and 7k RPM! ;D

Thanks Sarge. That means a lot coming from you. Yeah i have to say mason's car has "the sound" down pat.
Thanks Tony, and to think he was running quiet packs! So it has to do with more than running a big hemheroid muffler.
I think it is cam overlap and intake area, along with sufficient CR, that makes that glorious sound.

The best sounding engine I ever heard was the one in Schwimmer's oval back at Showdown 7.

I saw a vid somewhere in the other cal-look site i think of Geers' light blue bug leaving a DQ gathering, that sounded mean....think it had some terminators on it w/ a muff and some high compression, probably 11+:1.

Any vids of your mean-sounding bugs revving up? Wud be nice to see and hear em...

You mean this one? :o
http://www.youtube.com/watch?v=jjSB9RwmGKA

I was behind Stephan S. for most of the Saturday cruise. When he got into it..... it sounded so sweet!!

Two words: zoom tube! ;D

<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/kr7_rF5is3I&hl=en&fs=1"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/kr7_rF5is3I&hl=en&fs=1" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>

My personal favorite sounding cars of all time

The Sloval had the best sounding straight cut's out there PERIOD!!!  You could hear it coming blocks away. 8) 8) 8)

yeah I forgot that key ingredient. ;D

Also light flywheel helps. Nothing sounds worse than a motor that revs up slow, then comes down back in rpm slow.

So what do we think a "good sounding motor" is anyway? Best to define that I guess

Some guys like the deep bassy rumble, some guys like the trebly cry of open stinger. Personally I like a consistent sounding valvetrain at lower rpms (not one clacky valve, and rest quiet... sounds thrashy), and a nervous, bad tempered, urgent idle. You hear that quivery idle (not lumpy) and you know it's an angry motor. I think a good motor running a bbl per cylinder shouldn't have a lumpy idle.
I think a good sounding motor should instantly bark from carbs without a stumble or burble when the throttle is cracked. No snapping up throats or bogging. The valvetrain should almost chirp in response if it revs fast enough. Not just click and clatter. The exhaust should almost bite in its tone, no matter the muffler. I like motors that sound like they're trying to spit the muffler off, like the muffler is holding it back. To me quiet packs have a crisper sound. But the right motor feeding a Magnaflow, once the revs come up on load, it is pretty close to any exotic Italian thing you can see on youtube.
to my ears, stingers sound way too primitive.

Herbert's SSB had a great bark to it, first time I saw that car in person, he flew into Knowlwood's parking lot about sundown night before classic, 1998, and it revved like it had no belt... but it did. Nothing else in the lot that night sounded as wicked as his car.
What Mark's secrets were, I won't know, and you know it's probably best his secrets stay his....  part of his legend.

Valve timing, valve timing, valve timing. I remember how much "better" my single 2bbl 36DRLA sounded once it was feeding a motor with 288 degrees instead a motor with a stock cam. All of the sudden that carb was growling. I was 17 at the time and it was like doing ___________the first time hearing that carb snarl.
Cam advance....    personally, I think it has a lot to do with how my car revs.

 8)

If only I could cram this motor in my Cal-look. I just got goosebumps! What feels like a shock wave when started and a ballistic whip when unleashed? Watch this...
http://www.youtube.com/watch?v=CGhTYk0z6X4

http://www.youtube.com/watch?v=McKRagEpqnk (http://www.youtube.com/watch?v=McKRagEpqnk)
OR, the daddy!
http://www.youtube.com/watch?v=FIoNRrI9hKA (http://www.youtube.com/watch?v=FIoNRrI9hKA)

yeah that's the one...thanks. my bad it's not DQ but Nick's, i'm from way out here in the Philippines hehe...Cris

Meanest sounding vw engine I have ever heard is this;

http://www.youtube.com/watch?v=gXWz0te48HU&feature=related

Besides cam,carb sound,straight cuts,compression nothing beats a wide open stinger ;D

Like the turbo muffler too

The little whining from the straight cuts is nothing compared to a HIGH compression, finely tuned engine screaming through a open exchaust system. If you add a aggresive race fuel in the mix then both your ears and eyes will cry - absolutely amazing. You can hear them from a mile away and they are the ones that wakes you up when you are at the races. Not many of them out there but a few - and they save every race day for me.

 

Limiting this to air cooled VW stuff the Geers and Crawford motors sprang to mind pretty quickly when seeing this topic. I remember seeing the Geers car parked up at Sacramento and it looked pretty cool sat there but it was when it fired up and pulled into the burnout box that the whole package came together. I love the sound that car makes, as soon as the motor starts you know it's going to haul. Another car I like the sound of is the Red Baron, that has a sound all of its own too, not sure exactly what it is about that tune but there's something going on in there. On a general street car I'm not sure stingers are so great, I ran one for a couple of months or so and it's pretty much just noise; it's better when you can hear the carbs and the motor. I have one currently but another factor is the header, I'd have to say stainless steel sounds like crap. Next time round I'm going with a ceramic coated mild steel system.

Oh... are we allowed to include other engines? Well, then it is easy - this is the best sounding engine ever, period; (turn the volume up)

http://www.youtube.com/watch?v=dLByHf0rzb4&feature=related

I've loved cars my entire life, and I really have to say that I have never craved the sound of any engine more than I have the sound of a healthy flat four VW.

Two things that I think are universal with any engine is:

a mechanical valvetrain—they have sound and response that hydraulic lifter stuff doesn't
breathing ability—when the recipe is right and the engine has good lungs, things sound killer

IMHO stingers suck, it's more a noise than a sound if you ask me, , I'd rather hear the induction roar of some 48s!

PS: my dual quiet packs are LOUD (cop magnet!) I have another one to try, I hope it sounds better and is not so noisy

Totally agree - SS sounds hollow somehow, sucks all the warmth out of the sound.

Yep,nice sound from "Sloval"

p.s.what are those frontwheels,any info on them?
  ;)

Locked dizzy?

--louis

Wow Jim, good subject!

Firsthand, I've owned--built--worked on--been around plenty of mean engines (both sound and otherwise) over the last three decades or so. One that stands out was by no means the biggest or fastest, but respectable, memorable, and definately had the right sound. Many moons ago, back around 1976-77 I built a 1750cc for my '59 Ghia... Simple, lowbuck engine but it had some attitude. The engine consisted of a stock, NON counterweighted 69mm crank, NPR 90's, stock but lightened and polished connecting rods, super-light flywheel (even drilled), power pulley, Engle 120, DP heads milled so deep the first fin was missing (LOTS of compression), stock valves, ported by me, topped off w/48 IDA's on tall manifolds & a Bosch 010. I ran a Four Tuned 1 5/8 merge with a single Berg Q.P.-- Please note-- this was not the mass produced Q.P. everybody and their brother sold... it was actually an american made muffler designed for war time Jeeps sold as surplus that Berg used to sell in the early days... or so the story goes.
Anyway, THAT engine was crisp, responsive, and very quick revving... as a side note, that Berg muffler sounded so good when you were driving.. it would actually "buzz" a little out the pipe some. I liked it because the exhaust was somewhat quiet and you could really hear the 48's. The Ghia ran low 14's on race gas w/o the fan belt.

I have to say, I like healthy engines... anything from a built VW, V-8, hopped up Diesel with tons of turbo, or whatever.
Way back when Riverside Raceway was open I got to ride with a friend of mine out to the track to do a few laps and then back home... about 160 miles round trip plus track time... best part, the car is a 1964 Ferarri 250GT SWB California Spyder!!!! THIS car needed no radio! Top down, open air with the dual exhaust out back... just friggin sweet! This guy was somewhat cautious, but was not afraid to actually drive the car how it was ment to be driven... he still has that car, I'll have to go beg another ride soon ;)

~DR.

glasspacks help too...
:)

Randy Jewell's old 1914 on ida's. It whined like fuck eith his straight cuts, awesome noise  ;D

other engines? When we were at school my friends Mum had an Alfa GTAV6, and that sounded ace. Lots of country lanes around our way, and it sounded magic on one between 2 high stone walls  8)

Maserati Birdcage sounded awesome at Goodwood a few years ago. also loving the sound that Chip Foose's Lincoln V12 engines 32 makes

some of my fave non-VW

http://www.youtube.com/v/myxMudtFX6g&hl=en&fs=1

and you can't beat the sound of one of these
http://www.youtube.com/v/XR7aF4hY9rU&hl=en&fs=1

aside from a hot vw motor that is  :P

if i had the money to buy one of them , NOBODY would be getting a go  ;D  ;D

He bought it from Circle Porsche in 1972 for $7000.00 ::)

...maybe we could offer him $10K ;D

~DR.

www.youtube.com/watch?v=vK-mIWHjypY   

 My 1915 with superlight flywheel engle 120  early cb044 dual dellorto 40

 :D :D :D  what'd Ferrari make...13 of those? Wow that must have been a FUN jaunt.

(jealous)

what's interesting, take any halfway-decent basic motor, with a good breathing head on it, crank in some overlap and add some 40mm+ Weber carbs on top, good equal-length tube exhaust, and they all sound pretty damn good.

go through you tube.... type in 365BB or Miura or 365 Daytona. Listen to them,....   they sound pretty familiar. Sure they have all those cylinder pulses, smoothing out the exhaust note, but the screaming cam drives, the "WHOMP" of the carbs, the fast throttle response....  not too far off from a good IDA fed VW 8)

Some friends in years past had some Weber-ized stuff. One guy ran a Mini Cooper 1275 around with a single 45DOCE on it (that protruded into the cabin thru the firewall.... you peek under dash panel and there were two velocity stacks by your knees! Hope she don't backfire! :o). That little Austin 1275 screamed through that carb... that car was a rocket. He ran a Caterham 7 too with Ford motor with Lotus head and twin DCOE's.... again, sounded awesome.

More recently, a friend of mine built a 2088cc BMW 4 cylinder for his 2002, with a Schrick cam (like 86b Web actually), ported head and twin 45mm DCOEs with 38mm vents. THAT car had a growl that would make your arm hair stand up. Real fast too, but apparently not fast enough....as he recently swapped it out for an E30 M3 DOHC motor.  :o :o :o

Yes, good times.
Once a year the Ferrari and Pantera owners clubs would rent the track for a day... On the track, the Ferrari guys would mostly tip-toe around each other while the Pantera guys were out for blood ;)

~DR.

I love the sound of my 2332. It has IDA's, a 498 lift by 312 degree cam, straight cuts, Jeff Denham heads and 1 3/4 merged system with an A-1 built magnaflow muffler. However, a long, long time ago I had a 1600 with 1.25 rockers a 300 cfm Holley bug spray and an S&S header with low mount duals. That was the meanest sounding little engine. I was about 16 years old and I had no idea how to tune that stupid Holley. I couldn't find replacement jets or anybody here who knew how to do work on it either. It sounded like a Harley at idle and when you revved it up it was very deep and throaty. It also broke throttle cables on a weekly basis. I kept it on the car for a couple months before I gave up on it and bought some Kadrons but for those couple months, it was sweet. I think that Holley is still in the shed at my parents house.   

and i like the smell of vp fuel, ;D

82mm SPG 92mm DDS B&P and a set of Italian 48 IDA's  ;)

Sounds like something to put in the "won't work" thread  ;D ;D

Just kidding Dude  ;)

To me, induction and exhaust are what make a motor sound killer. IDAs and nice, quiet maganaflow are my choice ;D

Did any people use straight cut cam gears in the 70s and 80s. It seems like a recent trend. Just to change it up the next engine that I build will not have straight cuts. Does anyone know of a hot engine that does not use straight cuts? I bet it sounds better.

Ahhh, refreshing, thanks for posting. How light is superlight if I may ask?

Best rgs
Kalle

Really? To me the timing gears give the audio qualities of a hot VW it's "edge", especially at idle. BTW, Pete Statt's car had straight cuts in '86-87

I built that engine around -94. I do not remember the actuall wheight but looking at it now makes me wonder what I was thinking. It does rev like a motorcycle engine and gave 150hp on the Bug run free dyno 1995. If you want more hp than the motor can give I strongly recomend the bug run dyno. My personal belief is it makes around 135hp.

Did anyone say tunnel and 7k rpm ??  ;D ;D ;D

http://video.google.com/googleplayer.swf?docid=-5782694275058868534&hl=da&fs=true

.... when you can hear the sound of the induction of a NA engine over the open stinger exhaust.  Old school drag cars of yester-year (super high compression, IDA's, big heavy-breathing heads, big cams). 

The Motion Sickness Ghia is prety awesome sounding too!

Bruce McDowell "magnums" where around a decade before that jim ;) he sold the company early eighties but they carried on the magnum name . sarge was probobly on the sand with him at the time ....

lawrence , i think fit / lash of strait-cuts plays the biggest part in the noise ... some can be as quiet as stock .
if youre going "heavy" springs , its better to fit strait-cuts .....

heres an early set from 1981
(http://i180.photobucket.com/albums/x216/iancross182/magnum1981.jpg)

Fantastic sound Rasser. That is also one of my favorite pastimes. We once drove to Bad Camberg in a split with an Abbarth exhaust and every tunnel and underpas was a blast. I rolled down the window and told my friend to hit it. Sounded like a world war two airplane.

Tunnels?
Short but sweet
http://www.youtube.com/watch?v=FIJI_2hnKEw (http://www.youtube.com/watch?v=FIJI_2hnKEw)

can this qualify as mean?

http://www.youtube.com/watch?v=CBdP5hlGwNU

BTW I strongly miss such topics as this one!

1. Set comp at one tiny speck below melting lol.
2. Heads with REALLY fast air velocity.
3. Pick a cam with enough overlap to spit a bit at idle.
4. Throw the Webers in the bin and use a centremount.
5. Light flywheel.
6. Pick your favourite muffler.

My personal favourite is 4 glasspacks with no collector, and a Holley350 on an isolated centre. It sounds really impatient at idle, and the back of the car rocks at about 8-900rpm (rup, rup, rup, rup.......)  :D For some reason the little ones like under 1600 sound better when revving than the big 2L motors.

I'll let everyone else go fast with the power and speed of a tuned 4-1 and IDAs. Me? I'll stick with setting off car alarms down the street with the exhaust bass note.  ;D

Oh, my contribution to my favourite sounding engine. Had a few of these set up like this, very old school..........
http://www.youtube.com/watch?v=HDoW8vyFjXk

Sorry for the lousy format, but I love the sound of my own engine.

I'll miss the sharpness when I'm swapping to turbo..

http://www.youtube.com/watch?v=CMpfEtVRIqs (http://www.youtube.com/watch?v=CMpfEtVRIqs)

I hate straight cuts, nothing beats the sound of a quite and smooth valvetrain, the resonance of s/c gears just gets in the way of what most times could be a beautiful sounding motor.

What do you guys think?

http://www.youtube.com/watch?v=2yUrsgSlX4o&list=UUdSmBpRSikwdmfpTgi9RnXQ&index=8

X2

http://www.youtube.com/watch?v=O2wGWxVQorw

My car with the previous smaller engine

I don't exactly hate straight cuts but I always thought they were gimmicks, a means to make an engine sound nastier than it is, a means to impress people who really don't understand what real power sounds like. That's not to say that there aren't any really powerful engines that run straights (there are) or that there's no need for them (there is) but 99 percent of engines that run straights don't benefit from them for any other reason than the noise they make.

Someone pondered earlier what makes some louder than others. In most cases it's usually material. Gear sets with an aluminum gear like that Magnum a few posts back can be downright quiet. All-steel gear sets are usually obnoxious.

You want a good sounding flat four? Try one of the Autocraft or Scat engines built for USAC midgets in the '70s. Two liters, 320 degrees duration, close lobe centers, 16:1 CR, methanol, Hilborn injection, magnetos, and a coupler instead of a flywheel. They idle at 2,000rpm and tach to 8,000 before you get the pedal halfway down.

The sound of an anchor  ;D
http://www.youtube.com/watch?v=NmUGAr-8iBY

Now, WHICH straight cuts?  The Scat ones?  Do tell....

The CB performance ones

Cb performance straight cuts  can be heard in my earlier post. I used them because I wantrd to take away axial forces on cam thrudt bearing. It is noisy, but I have other car when I eant to travel in silence..

As was said before, it is definitely cylinder pressure and cam that attribute a lot to how nasty a VW motor sounds. Compile that with a good amount of compression and a tight deck height and you get some pop in a NA motor. Plenty of guys do not measure it our correctly or take stuff out of the box and put it inside a motor and call themselves an engine builder....with a .130 deck height!!  That is just an assembler.
 Once the final product is together, it also needs to be tuned properly. As we know, the IDA can sometimes be a finicky piece and may take some time to get right. But when you do, they are a very well working piece to many high performance motors. Another element that you need I believe. is a good ignition system. No sence in making good power if you can't light it off.

Below is my dads 2332 with superflows that made 226 horsepower to the wheels on a dyno.

http://www.youtube.com/watch?v=SfySmUGt0h4&list=UUDlNqs5XyU8n8720KoPV69g&index=8




I am not sure if the video will show, but here my 2332, CB Strip Dominator heads, 14:1 compression being broken in on carbs before the FI

https://www.facebook.com/photo.php?v=10151504186746210

Agreed:  my street strip Beetle runs IDA's and A1 Magnaflow muffler which produces a nice growl, but also keeps it "street legal" for cruising around the city ;)

thats a snappy sounding rat......love it.

From what I've heard from the older folks, Solex 40 p11s make a beautiful sound when at full throttle, but those are all extinct from the vw scene today  :(  Does anyone have video proof?

Still a fav, and one of the meanest sounding, on video anyway!

http://www.youtube.com/watch?v=v4b84MICGZc (http://www.youtube.com/watch?v=v4b84MICGZc)

Can't believe this thread has got to 3 pages without someone referring to this engine.

http://www.youtube.com/watch?feature=player_embedded&v=VPVqYRrQBA0

Short stroke, light reciprocating parts and good cylinder pressure. Pump gas and through a muffler too.

Better still you can buy it as its currently for sale on here, to be honest I can't believe it didn't sell the moment it appeared. 11 second 1603cc motors do not come up every day!

Certainly does it for me.

You can hear it on the quarter here too.   http://www.youtube.com/watch?feature=player_embedded&v=v15y0b480GY

As the original thread said crank up the volume and enjoy!

They do sound fantastic, but I'll never do another pair. Extremely expensive, complicated, heavy, and phisically much too large for a beetle's engine compartment.

An engine to me is an instrument, and how it reacts to the right foot creates the music. In other word, throttle response, I prefer when there is NO hesitation...  nice but lethal.
If you aim for throttle response, you will create music...  or is that too blunt?

I can dig that!  ;D

 ;) :)

Makes perfect sense. This is what I explained to Henry Oelkers when I was doing the tune on his engine. His car definitely has a distinct note to it.

<iframe src="http://www.facebook.com/video/embed?video_id=10151059036420666" width="720" height="480" frameborder="0"></iframe>

dunno how to embed the link sry  :D

Here is a video of my old car. it was a mega snappy engine and loved rpm.

 http://m.youtube.com/watch?v=pmLMSVE3zSo#

spec was 2165cc

42x37.5 street elimimator heads
web cam 226
12.5 compression
IDA's
1 3/4 header and red lined at 8500 rpm

Made me smile every time I drove it!

Here you go:

http://www.youtube.com/watch?v=XYum3Qohexw

2017ccm, Solex 40PII, CSP Super Competition exhaust  8)

Nice car!

What impact will the shape of the stacks have on the sound?

Think of the manifold, carburetor body, and velocity stack as an organ pipe. Increasing its length and/or the diameter of the assembly reduces its resonant frequency.

It explains why IDAs make basso profundo. The manifold passages are usually larger to accommodate the flow potential and the carburetor bodies are a lot taller than the other carburetors. The velocity stack further increases the length.

If the PII carburetors sound any different I am at a loss to explain why. They have the same basic dimensions as a 40mm IDF/DRLA with 32mm venturis. If they do in fact sound any different it may be because of the manifold design. The PII manifolds that I have do not seem to look any different than most IDF/DRLA manifolds but I have never made a direct comparison.

The engine combinations may explain why engines with PII carburetors sound different. Most engines running PII carburetors were built long ago. Older camshaft profiles usually have slower ramps which can increase seat timing. Increased seat timing can increase the overlap and/or the intake-valve closing event. Both of those influence reversion. Reversion plays a significant role in induction honk, AKA Alfa Song if you spent any time around Italian cars.

I loved the sound of my P11's. Very similar to an IDA, in my opinion. IDF's and Dellorto's have that annoying chirp...

IDFs chirp?

DRLAs chirp because of that slot machined in the throttle-bore base. Fill that with silicone (or use the special base gaskets) and the chirp magically disappears. Never once have I heard an IDF chirp.

A lot of time. That's my problem.

I don't want to take this off topic too much, but I think typically Italian cars, though fairly vocal thru induction, are known for their strident, howling exhaust notes. I tend to think us VW guys get off on intake noise more so than a raspy, nasty exhaust note. Like Mark H used to talk about... he purposely ran a Super Turbo over a Magnaflow "dune buggy muffler" so he could get a better grasp on intake growl. I agree with Mark. The Magnaflows sound OK but they are a bit "straight pipey", I prefer the Super Turbo sound.
I know overlap/reversion has a huge influence on intake sound. In 1988, @ 17 yr old I was driving my '67 around with stock cammed 1641 with single 36DRLA on IR manifold. A few months later, the same motor had .470" @ valve and 256' @ .050" and the growl from the carburetor was sonic. Prior to this, with the stock cam, the carbureotr merely "hissed" @ idle and gasped when the throttles opened. With the big cam, the carburetor growled @ idle and literally barked when the throttles were cracked.
I think to really sweeten the "sound" we need airspeed, compression and cam timing advance.

Dude, if you're complaining about excessive induction honk then we can't be friends. That's like complaining that rich, hot chicks with loose morals find you irresistible. :)

It should be noted that compression ratio can also influence reversion. A cylinder with insufficient CR has a very low rate of pressure decay. It's usually most prominent during the combustion stroke but as it's been explained to me it can also overwhelm the exhaust tract sufficiently to maintain some pressure in the cylinder at the end of the exhaust stroke.  

A lot of my life has been directed in search of Italian engine sounds. While I could have been making money, friends, moving forward in life, instead I'm chasing 365GTB/4's and LP400's on the freeway or nursing my '84 GTV6 around the foothills of CA's oak dotted hills. I think we'll get along just fine,

 8)

I'm relieved.

My dad's a bit of an Alfisti--he sold them in the '60s and '70s and I have the backlit dealer sign (a pre-'70 Milano badge) in my garage. We even got to go to the Alfa museum in Milan--invite-only deal and only if you know people. Over the years we had a '76 GTV, a '77 Alfetta GT, and a few loaner cars. Those Spica-injected cars with the coffee-can filter housings make glorious noise.

And yeah, you're right about the Italian exhaust note. It's more of a raspy shriek almost as if there's something buzzing in the muffler. You might not like the association but the stock exhaust system on the AE86 Corollas shrieked similarly when you removed the cat con...which is the first thing I did when I bought my the '86 that my dad special ordered. Of course it didn't hurt that the engine redlined at 8,000rpm.

I grew up in back seat of '75 2000GTV (with Abarth muffler), '77 Alfetta (with Ansa rear twin pipe).
Ain't no cure for that childhood abuse....

back to VW sound topic.... what causes the pronounced intake noise "underneath" the carburetors/injector stacks? Is it initial opening of intake valve (in some cases, well before TDC, while exhaust stroke is cleansing cylinder and there is still >atm pressure in cylinder), where the intake tract "becomes" and exhaust stack (due to cyl press, where piston is between BDC and TDC...etc), or is it the "draw" of postive>increasing negative>back to positive cylinder pressure during intake stroke? Or is it the combination, along with the power/exhaust cycles, and the (sometimes) open path from intake stack to tailpipe that "sings"? Yep, I can see how CR and overlap can "tune" the sound. I ran a 288' (0.050") with 11.5:1 in the early 2000's with 48's, etc in my '67, and it was one of the most vocal engines I can remember not only in my VW but in other big motor'd VW's as well.
My current 94 x 78 with 271' (0.050), advanced 4 deg, and 9.9:1, I think sounds even sharper and more vociferous though. My favorite motor yet. Like I alluded to pages ago, to me, more important than 1/4 e.t., mph, is how the car reacts when I put a demand on it, and its "voice." I'd trade explosive throtle repsonse at low-mid rpm for a limb, though I want that "come on the cam" nasal howl @ 4000-5000rpm as well. This motor (cam, mostly) does that.

My 44's did. Maybe not the exact same tone as a Dell, but definitely similar.

Out of all the cars my dad had when I was a kid (and boy he had some good ones) I remember the '77 Alfa sedan the most. It wasn't the fastest but it was a lot of fun. I'm surprised (and frankly relieved) that I didn't get into Italian cars.


I would defer to someone who actually has real-time experience with camshaft events to a greater degree but I would imagine that both pressure signals translate to sound to one degree or another. Take an FK-41 cam. It opens the intake valve when the crank is at 14* BTDC. That's a pretty short-duration cam and I would imagine that it wouldn't create much reversion. Conversely, a W-125 opens the intake at 26* BTDC. So it creates considerably more reversion at low speeds where the intake charge velocity can't over come it. I know from experience that wilder cams like that are a bit more honky, so to speak. Even more extreme, an FK-89 opens the intake valve at a whopping 36* BTDC and we all know what kind of sounds engines with THOSE cams make at low-mid-range speeds.

I would also imagine that the closing event has something to do with it. The air doesn't just stop moving when the valve closes. It bounces off the back of the valve and proceeds back up the manifold and carburetor.

Think about how an organ pipe works. The 'resonance' results from pressure waves bouncing back and forth in the pipe. Take an empty beer bottle and repeatedly smack the opening. It'll make a soft 'boink, boink, boink' sound. That's close to the resonance created by rapid changes in pressure.



Well if you look at it, both the intake tract and the exhaust system are technically tuneable. In our cases it's not very feasible--the intake tracts would be long--like 20 to 22 inches long. That's the basis for ram tuning--you tune the resonant frequency of the intake to match the resonant frequency of the engine at its peak torque. That's why intake runners on modern injected cars are so long--they're tuning for a peak torque at like 3,000rpm.

Most of us are pretty familiar with exhaust tuning (though few people actually exploit it). The pipes resonance should match the engine's peak torque.

Both tuning methods exploit the elastic nature of air and resonant frequencies. Get them all right and you can make a lot of power. It's just really tough to do.


Well advancing the cam opens the intake valve sooner so that creates the potential for reversion at lower speeds. That could be one. And the cam also shuts the intake valve sooner by duration AND advance. Because the intake shuts before the piston moves too far up the cylinder then chances are that the column of air moving down the intake tract is moving at quite a velocity when it bounces off the back of the valve.

Of course now I'm just pulling things out of my ass but it sort of makes sense if you think of the dynamics.



Well here's something to ponder. Where does that cam make its peak torque? I noticed that my w110-cammed 2110 honked good from 3,000 to 4,000rpm. The W110 makes peak torque at about 3,500rpm (mine certainly did). It wasn't super loud but it was good and growly almost as if you could hear each induction event. After that the engine sort of screamed up to 6,000rpm.

Naturally a longer duration moves the peak torque to a faster engine speed. And at those speeds the engine noise is likely to drown out the induction noise, at least from inside the car. I distinctly remember what a big-cam engine sounds like from a block away at the street races, though. At lower speeds the intake howls more than the exhaust.

One of my favorites:

http://www.youtube.com/watch?v=pdwvRedHVM8

That's mean sound for me, hope you will agree...  8)

The unique motor sound that I remember well is berg's "merlin'  motor in the black car.  2610 cc. (?), 94 x 95..roller cam. The sound at idle was so deep. I also remember the distinct sound heard from the pits meant gary in the burnout box. AWESOME, anybody have sound, or vidio's ?

You pinned it for me too, Bill!

I remember Gary's trademark burnouts like it was yesterday. Building up from maybe 5000 rpm slowly and finally reaching a pitch probably a full octave over anything else I've ever heard! MUSIC.
All that without a 2 step, just pure control ...

TxT

/\ yep I remember hearing F.I. Merlin run @ Sacramento, sent chills down my spine. Nothing else sounded as good.