Exhaust cutout...... can anyone give a short history?

[John Bloom]

My interest in earlier cars really got started about 10 years ago. Since then I’ve seen a lot of fabulous vintage/prewar cars that have an exhaust cut out that came equipped with it from the factory. It tends to be on the bigger higher performance more expensive models, at least that is my impression. I see it on cars in the teens and 20s, but it seems to have faded out in the 30s. Does anybody know when that feature as an option on cars was phased out and was no longer seen on various makes and models?  Was it typically ordered as an option, just like other trim or accessories were ordered.....?.... Or was it either standard on a model or not available?

[gossp]

They were available standard on many cars and as a common aftermarket accessory. 
 

My understanding is that it was to reduce the back pressure of a muffler as it could negatively impact performance and economy so you used the cutout when out on open roads but ran the exhaust through the muffler when in town to be polite. This is not at all unlike a street/strip car in the muscle era having capped side pipes and exhaust out the rear through a muffler. Simply remove the caps to go racing!
 

It is also my understanding that the back pressure argument only applies to very few situations nearly non of which were true in the early low compression era, so the cutouts went away for a few decades until they were needed again. 

[West Peterson]

The cut-out ran straight through the muffler on Duesenberg, Stutz, Packard, and I believe a couple of others. When the cut-out was "closed", exhaust would run back toward the front of the muffler, then curve back again and out the back side.

 

On less expensive cars, and the aftermarket systems, the cut-out was more of a "dump" before exhaust got to the muffler.

[John Bloom]

27 minutes ago, West Peterson said:

The cut-out ran straight through the muffler on Duesenberg, Stutz, Packard, and I believe a couple of others. When the cut-out was "closed", exhaust would run back toward the front of the muffler, then curve back again and out the back side.

 

On less expensive cars, and the aftermarket systems, the cut-out was more of a "dump" before exhaust got to the muffler.

West, thanks for that information. When Packard put that into their cars, was it available up and down the model line, or something more concentrated on the higher end cars? Also, was it standard and you didn’t choose it, or was it an option you paid for?  Any ideas (for instance Packard) when it stopped?  Do Six and Seven series senior cars have exhaust cutout from the factory?

 

[West Peterson]

4 minutes ago, John Bloom said:

West, thanks for that information. When Packard put that into their cars, was it available up and down the model line, or something more concentrated on the higher end cars? Also, was it standard and you didn’t choose it, or was it an option you paid for?  Any ideas (for instance Packard) when it stopped?  Do Six and Seven series senior cars have exhaust cutout from the factory?

 

I believe it was standard on Duesenberg. Not sure about Stutz or the other high-end cars.

For Packard, it was standard ONLY on the Seventh Series Speedster Eight of 1930. Never offered again on Packard, nor was it ever an "option" for other cars. I suppose if a buyer was aware that the cut-out was done for the Speedster, he probably could have ordered the system through a dealer.... perhaps depending upon how much clout the buyer had, and how much clout the dealer had in ordering something for a non-Speedster.

[JACK M]

My brain storm.

 

[rocketraider]

One of Pontiac's many great ideas that got them in trouble with the GM brass. 1970.

 

[Hemi Joel]

My 1906 Cadillac had a cutout that I believe was factory. It was a y-shaped fitting just at the entrance to the muffler. Being a one cylinder car, without a lot of horsepower, there was a very noticeable improvement in performance with the cutout open.

 

FYI, on the Duesenberg cutouts, West is correct that with the cutout open the exhaust flows straight through the muffler center core. EXCEPT on the supercharged models, which used a Y valve before the muffler and ran the exhaust through a separate straight pipe, bypassing the muffler when the cutout was open.

[Rusty_OToole]

They were common on early cars especially powerful cars. Mufflers were restrictive and a cutout gave quite an improvement to performance at speed. They were to be used only on the open road, in the country, and not in the city or suburban streets. They were also an aid to tuning and checking how your motor was running, a big low geared 4 cylinder car, you could count the individual explosions as you went along and tell if one cylinder was misfiring.

 

By 1960 they were illegal in most areas. So instead hot rodders installed a bypass pipe with a cap that unbolted. This was something of a gray area and I believe they were ticketed too. So the next step was to unbolt the exhaust from the headers. It was not illegal to have an exhaust bolted together as long as you didn't get caught with them open.

 

Cutouts were still sold in the early seventies, I helped install one on a Thunderbird about that time. Even though they were illegal to use.

[Bryan G]

I remember my grandfather talking about having one, probably on his 31 Chevy? I believe his next car was a 37 Chevrolet but he'd probably started to outgrow loud exhausts by then.

[Dandy Dave]

Here's a Correct Cutout for a 1914-1915 37HP B & C series Buick. The peddle is pushed straight down and locked in a notch on the floor of the car to dump the exhaust. Inside is a poppet valve that diverts the exhaust gas and allows it to flow out of the dump. This was a factory equipped item on these cars. 

   

[JACK M]

Many styles still available today.

2.25 Dual Electric Exhaust Cutout Kit|Remote Exhaust Cutout|Motor Vehicle Exhaust|SPELAB (spelabautoparts.com)

[Mark Shaw]

5 hours ago, Dandy Dave said:

Here's a Correct Cutout for a 1914-1915 37HP B & C series Buick. The peddle is pushed straight down and locked in a notch on the floor of the car to dump the exhaust. Inside is a poppet valve that diverts the exhaust gas and allows it to flow out of the dump. This was a factory equipped item on these cars. 

It is the same on my 1913 Model 31 and 1915 Model C25. 

Most of those I tour with use their cut-outs primarily for climbing hills.

 

[TAKerry]

Not a car, but my brother has a 1913 Rudge motorcycle. On the end of the muffler is a perforated cap that rotates with a lever that is foot operated. In the owners manual it refers to city driving/country driving. 

[TerryB]

Usually when you change the exhaust back pressure for better engine breathing you also need to riches the fuel/air mixture.  I guess in early cars the mixture setup wasn’t that optimally adjusted as to be a concern with the cut out open.

[Mark Shaw]

16 minutes ago, TerryB said:

 I guess in early cars the mixture setup wasn’t that optimally adjusted as to be a concern with the cut out open.

Actually, most will get a run at steep hills at full throttle and eventually reduce spark advance to prevent the engine from pounding when the engine slows to a lower RPM range. 

 

However, in many cases, I will get stuck behind another vehicle with different shift points (like a Model T) that will require me to down-shift.  Down-shifting on a steep hill in my 13 Buick, usually means starting over in first gear.  

[TerryB]

Yes Mark, I’m forgetting that everything has separate controls in that era.  Thanks for the explanation.

[46 woodie]

Restoration Supply Company sells exact copies of the originals. They are correct right down to the foundry number and patent date, June 24th 1913 and come in two sizes.

[edinmass]

On 4/8/2023 at 2:50 PM, Hemi Joel said:

My 1906 Cadillac had a cutout that I believe was factory. It was a y-shaped fitting just at the entrance to the muffler. Being a one cylinder car, without a lot of horsepower, there was a very noticeable improvement in performance with the cutout open.

 

FYI, on the Duesenberg cutouts, West is correct that with the cutout open the exhaust flows straight through the muffler center core. EXCEPT on the supercharged models, which used a Y valve before the muffler and ran the exhaust through a separate straight pipe, bypassing the muffler when the cutout was open.

Joel is correct on the Duesenberg cut out comment. Interestingly, JN 565 was supposed to have a blower and they ran out, so the car with 19k miles on it when we found it in the barn still had the blower cut out set up and manifolds with pipes. As one of the last ten cars, lots of things on the shelf were being used up. Like the air horn and compressor Duesenberg offered as an accessory.

 

 

Edited April 10, 2023 by edinmass (see edit history)

[George K]

Still couldn’t be as loud as Jake braking .

[Milburn Drysdale]

Rolls Royce Phantom II Continentals had them. They were labeled not for use in the city 

[ron hausmann]

         Kissel’s Gold Bug Speedsters 1919 to at least 1923 came with big exhaust cutouts as standard equipment. These were big exhaust dump fittings which were opened and closed with a convenient lever on the passenger side floor. The driver could reach and “kick” the lever easily. These were located on the large exhaust pipe under the passenger side of the car.

        I use the dump on my Kissel Gold Bug often, but it interferes with starting . The engine needs back pressure to be started easily 

        When open, the cutout allows the engine to growl very smoothly and it sounds like a big old semi truck. Car show announcers hate it when I open her up onstage.

        Ron Hausmann P.E.

[Dave Henderson]

Here are examples of what was sold in the aftermarket.  The cut out is marked IDEAL 1 3/4.  The two were probably not by the same manufacturer and may not be compatible, but you get the drift.

[John Bloom]

22 minutes ago, Dave Henderson said:

Here are examples of what was sold in the aftermarket.  The cut out is marked IDEAL 1 3/4.  The two were probably not by the same manufacturer and may not be compatible, but you get the drift.

Thanks Dave. That is a good visual.  Lots of good background from all who have jumped on this thread. 

[hddennis]

Most brass era adds for aftermarket cutouts tout them as both  performance and testing devices.

 

Howard Dennis

[Stude Light]

The 1909 REO Touring Car used a cutout controlled by a foot pedal. As mentioned, the exhaust was pretty restrictive and the cutout helped power at higher speeds. This was a two cylinder car. Here is a short video I shot when I was working on this car and you can hear with and without the cutout. The pedal is mounted to the far right of the steering wheel and can be latched open.

 

[John Bloom]

Great video, that is cool. Interesting to see the ways that performance was enhanced 110 years ago. 

[Terry Wiegand]

The 'standard item right from the factory' on our 1916 Buick D-45 is identical to what Dandy Dave posted in his photos.  The difference being from Dave's 4-Cylinder car and our 6-Cylinder model is that the Six will talk to you pretty good when the cutout is opened up.  There is a noticeable difference with the cutout open and a person really steps on the gas - it will get up and go since the back pressure is releived.  An early day attempt at performance enhancement.

 

Terry Wiegand

South Hutchinson, Kansas

AACA Life Member #947918

[West Peterson]

On 4/8/2023 at 12:38 PM, West Peterson said:

The cut-out ran straight through the muffler on Duesenberg, Stutz, Packard, and I believe a couple of others. When the cut-out was "closed", exhaust would run back toward the front of the muffler, then curve back again and out the back side.

 

On less expensive cars, and the aftermarket systems, the cut-out was more of a "dump" before exhaust got to the muffler.

I was incorrect in regard to the path that exhaust takes on the Packard system. The butterfly valve is in the rear of the muffler, forcing exhaust gasses to flow through an inner pipe with hundreds of holes. Then, out past the outside of the butterfly valve. Plus, Ed tells me that the Duesenberg cutout is much different in that exhaust is directed toward another 7-foot long pipe alongside the muffler.

[Walt G]

Thanks West, great photos to give all a better "visual" understanding. Appreciate that.

Austin Clark had an exhaust cut out on his type 35 Mercer raceabout and I believe on his Simplex speed car as well. Needless to say, very loud

when open and "roaring " down the road. My first 100 mph ride in a pre 1915 car was with Austin in the Mercer on the North Sea Road here on long island.

We got "clocked" with a radar gun from the local polite then pulled over voluntarily as the police were interested to see what was under the hood.

Especially the newer members of the force.  Great ride, and it took several gulps of adult beverage to get any color back into my hands and face as by then I looked like an albino.

[John Bloom]

2 hours ago, West Peterson said:

I was incorrect in regard to the path that exhaust takes on the Packard system. The butterfly valve is in the rear of the muffler, forcing exhaust gasses to flow through an inner pipe with hundreds of holes. Then, out past the outside of the butterfly valve. Plus, Ed tells me that the Duesenberg cutout is much different in that exhaust is directed toward another 7-foot long pipe alongside the muffler.

West, those photos are great to help someone like me who is less familiar with the setup understand the engineering. Thanks for that. 
 

[bruffsup]

Here are 2 that I have .  No idea what if anything in particular they were meant for. One has the maker's name "Hovey " ? 

Edited August 31 by bruffsup (see edit history)

[alsancle]

All Model J Duesenbergs came with a Country/City exhaust which is basically what West explained.  The supercharged cars and then any with the pipes got Country/City/Dump where the later was a direct cut out the side.

 

On the PII Continentals I believe the exhaust cutout was an option.  Along with a tach and a few other things that are never ever seen.  I have seen one cutout installed in a PII RR in the last 25 years.   They were prone to rusting up and would get tossed frequently.

[bruffsup]

Here's a neat 100 year old advert from Motor Age. 

[Marty Roth]

Our 6-cylinder Hudson will flat-out fly on her own, and seems to have all the power necessary to overpower her 2-wheel braking system.

Opening the Cut-Out, enhances the "feel" of power, but I doubt the necessity under most touring conditions -

this will be confirmed in a few weeks as we drive both the PA/MD Glidden Tour based at Liberty Mountain Resort,

and then the HCCA Hershey Hangover Tour at Morgantown, PA

 

In one of our Brass-era cars we had a Jericho whistle at the end of the conventional tailpipe, and a 4-tube harmonic set of pipes attached to the exhaust cut-out,

but also had an explosion whistle, a Wolf Whistle, and a Klaxon, all this on a 1927 4-cylinder Chevy. It once got recognition as 

"The Littlest Car on tour with the Biggest Noises" - Fun in any case!

[Jack Bennett]

In 1960 I was still a sophomore in Phoenix Union High School, located in Phoenix, Arizona.

This high school offered a wide variety of vocational/technical programs to students which included subjects such as welding, leather work, carpentry, electricity and electronics, aircraft engine/airframe and too many others to mention here.

Automotive mechanics was my choice, and I welcomed the option to use my 1947 Chevy Fleetline as the focus of my studies while enrolled.

We literally built our cars, including body/fender, engine/powertrain, steering/suspension, and of course, making them faster, lower and more outlandish in appearance than any other car in existence.

The positive relationship between law enforcement and the teen population was a universe away from the negative relationship shared by the youth of the 1990’s and 2000’s, and we (the teens) actually considered the police and sheriffs department as our friend and mentors.

Every Saturday, at midnight sharp, until 2:00 Sunday morning, Vanburen Street, the Main Street which runs through downtown Phoenix, all the way to Glendale, was blocked off and turned over to us to drag race, make solo runs and tweak the performance of the cars we had built.

Cops, who closely supervised every aspect of our gatherings, were the epitome of speed, and to have a policeman or Deputy Sheriff critique and make recommendations on how to improve your engine/suspension performance was a highlight of the week.

During these meets/cruises/shows/races…….etc……etc….etc…..it was imperative that we abide by safety and city ordinances, and this included noise abatement.

I ran 2 1/2” straight pipes, from a set of Hooker headers to allow the 455 Olds engine I had installed in my Chevy to breathe.

I also had Thrush mufflers installed beneath each running board, and they were connected to the same head pipe as the (Scavenger) straight pipes, and were put into the exhaust system by pulling a choke knob installed atop the transmission tunnel in front of the drivers seat.

This knob was attached to a butterfly type shutter which blocked off the Thrush mufflers and allowed my engine to vent directly into the straight pipes.

Or, when pushed in it vented the exhaust through the mufflers and gave the engine a throaty growl, but kept it at a acceptable level of noise that driving the car through a neighborhood was totally acceptable, and was a token of respect given to the law enforcement officials who helped us with our cars as well as those residents who did not appreciate a kid cruising their streets in a noxious sounding car.

I suppose this choke know eventually evolved into a sophisticated electronic switch and operated a complicated device called a “cut out”, but to us it was simply a way of plugging and unplugging our straight pipes to get that beautiful blue flame (we put moth balls in our gas tanks) and loud noise a engine we had built with our own hands “talk”………

I sure miss those days and those guys and gals……..

Jack

Edited September 10 by Jack Bennett (see edit history)