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  #1  
Old 07 March 2014, 09:27 PM
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Referred by: http://www.snopes.com/autos/business/carburetor.asp

Comment: I read your article "Nobody's Fuel" about legendary
high mpg in cars. Tall tales aside, I did read, a few years ago, an
article about a mechanic who adapted Cadillac engines so they got high
mileage. I think he charged 1,100 dollars or so, and had more business
than he could handle. It seemed to be a regular piece of journalism, not
fiction. The writer discussed why the auto makers did not adopt his
method.

I don't recall the mechanic's name or location. I am presently googling,
but I don't have enough details to find the info readily.
Have you heard of this?
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  #2  
Old 07 March 2014, 09:46 PM
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There a lots of mechanic's tricks to increase a vehicles MPG. The problem is that many of increase emissions, cause poor engine performance, or can damage the engine over time. One of the more popular ones I heard about was to take a bar and smash the inside of the catalytic converter and empty it out. Without the back-pressure, the engine would run easier with less fuel. Of course, your car is now dumping HC and CO like nobody's business. Another trick is to adjust the car so it runs very lean. This makes the engine a bit rough sometimes, but increases the mileage. Of course, the HO emissions go sky-hight and if you lean it too much the engine will become a boat anchor.
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  #3  
Old 11 March 2014, 06:02 PM
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Why Cadillacs? Other than being thirstier, they're not that much different than other marque's engines. But then that's probably the point of the story. Having your cake and eating it as well.

If the OP story was true, think what the mechanic would be able to do with, say, a Chevy Cruze or some hybrid car.
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  #4  
Old 11 March 2014, 10:47 PM
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Prior to 80's, Cadillacs were bigger and heavier vehicles and tuning their engines for performance, at the expense of fuel economy, was both "necessary" because of the heavier vehicle, and expected - if a person could afford a Cadillac, they were not concerned with the cost of fuel. The vehicles didn't have any really specific technology, but maybe tuning the vehicle at the expense of output might make sense. But that's not to say that this couldn't be done with other vehicles. Changing from a 4-barrel to a 2-barrel carburetor would improve fuel economy at the expense of output, but that would work on any car.

After the 80's, well, there is probably even less that the mechanic can do - the retuning of the engine would involve reprogramming an engine control module - and not everyone has the technology to do that. Sure, some engines are more sophisticated because of variable valve timing, intake configuration, etc., but a Cadillac engine (aside from its tendency to be large and tuned for performance over fuel economy) would have nothing unique about it.
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  #5  
Old 16 March 2014, 01:07 PM
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Quote:
Originally Posted by Hero_Mike View Post
Prior to 80's, Cadillacs were bigger and heavier vehicles and tuning their engines for performance, at the expense of fuel economy, was both "necessary" because of the heavier vehicle, and expected - if a person could afford a Cadillac, they were not concerned with the cost of fuel. The vehicles didn't have any really specific technology, but maybe tuning the vehicle at the expense of output might make sense. But that's not to say that this couldn't be done with other vehicles. Changing from a 4-barrel to a 2-barrel carburetor would improve fuel economy at the expense of output, but that would work on any car.

After the 80's, well, there is probably even less that the mechanic can do - the retuning of the engine would involve reprogramming an engine control module - and not everyone has the technology to do that. Sure, some engines are more sophisticated because of variable valve timing, intake configuration, etc., but a Cadillac engine (aside from its tendency to be large and tuned for performance over fuel economy) would have nothing unique about it.
I'm not sure Cadillacs were ever really tuned for performance as much as they were just equipped with large engines with huge torque output to get their 5,000 lb curb weight rolling. By the early 70s even the 500 cubic inch engine was below 250 hp but still just short of 400 ft-lbs torque. They handled like a Chris-Craft and I'm not sure any Cadillac driver cared about how fast they went.
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Old 16 March 2014, 01:29 PM
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In the 40s and 50s, Cadillac engines were known for their power and were often used in racecars. Look up Allard and Fordillac for 2. Also used by Cunningham in his Le Mans cars.
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  #7  
Old 16 March 2014, 08:29 PM
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Quote:
Originally Posted by mobocracy View Post
I'm not sure Cadillacs were ever really tuned for performance as much as they were just equipped with large engines with huge torque output to get their 5,000 lb curb weight rolling. By the early 70s even the 500 cubic inch engine was below 250 hp but still just short of 400 ft-lbs torque. They handled like a Chris-Craft and I'm not sure any Cadillac driver cared about how fast they went.
Rolls-Royce never quoted horsepower figures for their automobiles, merely stating that their power was "adequate". Now any engine of that era, when saddled with both the size of the car, and the increasing restrictions due to emission controls (the need for emission controls outstripped the available technology at the time - engines today are cleaner, more efficient, have higher specific output, and reliability), would suffer, but a Cadillac owner would expect sufficient power to start quickly off the line, and to accelerate to pass, when compared with most other cars on the road of that era. Of course, it would fare poorly against a "sports car" - a small, light car tuned for good handling and quick response. It would probably fare poorly against a limited edition "grand touring" car - a luxury car with high performance - but those would almost all be very exclusive (i.e. small volume and probably hand built).

I am sure that Cadillac cared very much that their vehicles were just as fast as their contemporary competition - Lincolns and Chrysler Imperials - because it would become a selling point for the competition, if they didn't. You could have a Cadillac, or you could have a competing model, with all the luxury of the Caddy, *plus* performance. Which do you think would be more appealing to buyers?
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  #8  
Old 17 March 2014, 05:04 AM
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Quote:
Originally Posted by GenYus234 View Post
One of the more popular ones I heard about was to take a bar and smash the inside of the catalytic converter and empty it out. Without the back-pressure, the engine would run easier with less fuel.
The variant I heard was to just cut the exhaust pipe and bypass the cat and the muffler, or just letting the exhaust exit right under the passenger cabin. Super healthy.

Removing the catalyst can and emptying its contents is not very easy; the catalyst is typically washcoated onto a single piece of square-holed honeycomb substrate, and you'd need to go wild for a while with a long chiesel and mallet to break it up significantly.

https://www.dieselnet.com/tech/cat_subs_cer.php
http://www.preciousmetals.umicore.co...yticConverter/

There were some early catalytic converter designs that used ceramic beads instead of a monolith, and on these you could break up the steel filter on either side and dump it out, but these fell out of favor very early as the vibrations and thermal cycling turned the catalytic converter into a rock crusher, grinding itself to dust.

Quote:
Another trick is to adjust the car so it runs very lean. This makes the engine a bit rough sometimes, but increases the mileage. Of course, the HO emissions go sky-hight and if you lean it too much the engine will become a boat anchor.
The catalytic converter should be able to handle most CO and partially burned hydrocarbons during lean burn; the problem is that the reduction of NO and NO2 (NOx) won't proceed on a three-way-catalyst when you have excess oxygen. This is the reason that modern on-road diesel engines need both an oxidation catalyst and a NOx-reducing catalyst such as SCR or LNT/NOx absorber. (Prior to this, NOx emissions could be met simply by EGR; some class 6 truck manufacturers still get by using EGR and no aftertreatment.)

Quote:
Originally Posted by RichardM View Post
In the 40s and 50s, Cadillac engines were known for their power and were often used in racecars. Look up Allard and Fordillac for 2. Also used by Cunningham in his Le Mans cars.
And the M5 light tank ...

I think it's fair to say that Cadillac engines were quite powerful just to get acceptable acceleration in such a boat-of-a-car, and the engine made for a good racer when transplanted into a vehicle of less ridiculous size and weight. The trend of putting sporty engines in higher-end vehicles continues today, as those higher-end vehicles are typically heavier and require more horsepower only to get performance comparable to their midsize and compact brethren. Nowadays, compact sedans are nominally 2500 lb curb weight, fullsize around 3000 lb, mid-level luxury around 3500 lb, and luxury around 4000 lb.

Never mind the civilian Hummer, thankfully laid to rest, which initially weighed the same as two mid-size sedans welded together, and performed about as well. My dinky 140 hp 1.4L Cruze could absolutely smoke one of those things in a quarter-mile. And for that matter, I'm not sure that people appreciate that entry-level cars now have engines as powerful as the sports cars of the 1950s-1970s - back then you'd be looking at something like 0.6 hp per cubic inch displacement; now it's typical to see 1.6 hp/cu in. All this, of course, is hand-in-hand with extraordinary improvements in emissions reduction. Every bit of weight, every teaspoon of displacement, is used to its utmost to convert fuel into power as cleanly and efficiently as possible.
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  #9  
Old 17 March 2014, 02:05 PM
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Quote:
Originally Posted by GenYus234 View Post
One of the more popular ones I heard about was to take a bar and smash the inside of the catalytic converter and empty it out. Without the back-pressure, the engine would run easier with less fuel. Of course, your car is now dumping HC and CO like nobody's business.
I did that on one of my cars. I didn't do it to get a better mileage, it had just sooted up due to a computer box error that caused the engine to run on full choke all the time, so the catalytic converter was unusable. I didn't want to pay for a new one, so a little work with a powerful drill and some grinding bits cleaned it out nicely.

The thing is, with a properly tuned engine, the catalytic converter is almost meaningless. Iirc, the limits on the emissions for my car was 0.5 something or other. My car, even without the catalytic converter, ran so clean that it measured 0.0 at the annual inspection.
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  #10  
Old 17 March 2014, 08:55 PM
jimmy101_again jimmy101_again is offline
 
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Quote:
Originally Posted by Alchemy View Post
And for that matter, I'm not sure that people appreciate that entry-level cars now have engines as powerful as the sports cars of the 1950s-1970s - back then you'd be looking at something like 0.6 hp per cubic inch displacement; now it's typical to see 1.6 hp/cu in. All this, of course, is hand-in-hand with extraordinary improvements in emissions reduction. Every bit of weight, every teaspoon of displacement, is used to its utmost to convert fuel into power as cleanly and efficiently as possible.
I think 1.6HP/cu in is a bit high, probably closer to 1.2hp/ci in a typical modern engine. Still, that is a lot better than a typical engine from the 60's, 70's or 80's. The old rule of thumb was a performance engine had 1hp/ci. These days nearly every engine reaches that "performance" benchmark.

On top of much higher output engine, much better gas mileage and much lower emissions, modern cars are soooo much safer than cars were 30 or more years ago.

Still, people rant about how unsafe cars are because they are so light, and what a PITA all the new regulations are, and the new CAFE standards are unreachable and won't accomplish anything and ...

stupid gits
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  #11  
Old 17 March 2014, 09:34 PM
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Quote:
Originally Posted by jimmy101_again View Post
I think 1.6HP/cu in is a bit high, probably closer to 1.2hp/ci in a typical modern engine.
Ford's EcoBoost family of engines develop between 1.5 to 2.3 HP/cu in (the "average" of all the versions is 1/8). They manufactured 750,000 EcoBoost engines in 2012 (1/3 of their total vehicle sales).
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  #12  
Old 17 March 2014, 09:54 PM
jimmy101_again jimmy101_again is offline
 
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The Camry's standard engine is 2.5L (152ci) at 178HP, which gives 1.17HP/ci. Looks like they make about 450K Camrys/year. I believe the same engine is also used in a couple other Toyotas.

The standard Honda Accord is a 2.4L (146ci) at 185hp, 1.27HP/ci.

The EcoBoost engines vary in size. For the Fiesta (which is a lot smaller than a Camry or Accord) the standard engine is 1.6L (97ci) at 120HP, which gives 1.24HP/ci.

Which ones give >1.5HP/ci? Perhaps we are comparing engine horsepower (measured w/o things like the alternator, which is the old way of quoting HP) versus HP at the actual wheels (or at least at the transmission).
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Old 17 March 2014, 10:09 PM
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The standard Ford Fiesta has a 1.0 L engine (61 cid) not a 1.6 L which means either 1.63 or 1.96 hp/ci (100 or 120 hp). There is a sport version with a 1.6, but that gets 197 hp, for 2.02 hp/ci.

ETA: I'm using reported engine hp numbers, which probably means dynamo w/o accessories. But since the engines can be installed in different vehicles with different accessories and transmissions, "at the wheel" numbers are going to vary, even for the exact same engine with the exact same ECM.

Last edited by GenYus234; 17 March 2014 at 10:24 PM.
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  #14  
Old 17 March 2014, 10:45 PM
jimmy101_again jimmy101_again is offline
 
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Quote:
Originally Posted by GenYus234 View Post
The standard Ford Fiesta has a 1.0 L engine (61 cid) not a 1.6 L which means either 1.63 or 1.96 hp/ci (100 or 120 hp). There is a sport version with a 1.6, but that gets 197 hp, for 2.02 hp/ci.

ETA: I'm using reported engine hp numbers, which probably means dynamo w/o accessories. But since the engines can be installed in different vehicles with different accessories and transmissions, "at the wheel" numbers are going to vary, even for the exact same engine with the exact same ECM.
According to Ford the standard Fiesta engine is the Duratec 1.6L (98ci) and it generates 120HP (1.22HP/ci). The 1L EcoBoost is an option.
(http://www.ford.com/cars/fiesta/specifications/engine/)

The 1L EcoBoost (123HP) is a turbocharged engine which is cheating. The engines I quoted are fuel injected but not turbo's.

Comparing a turbo to a non-turbo is like comparing a gasoline fueled engine to a gas+NOx engine.
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Old 17 March 2014, 10:59 PM
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Quote:
Originally Posted by jimmy101_again View Post
According to Ford the standard Fiesta engine is the Duratec 1.6L (98ci) and it generates 120HP (1.22HP/ci). The 1L EcoBoost is an option.
(http://www.ford.com/cars/fiesta/specifications/engine/)
You said:

Quote:
Originally Posted by jimmy101_again View Post
The EcoBoost engines vary in size. For the Fiesta (which is a lot smaller than a Camry or Accord) the standard engine is 1.6L (97ci) at 120HP, which gives 1.24HP/ci.
The EcoBoost engine is not the same as the Duratech engine. I was referring to the EcoBoost line of engines, not the older Duratech line of engines.

Quote:
The 1L EcoBoost (123HP) is a turbocharged engine which is cheating.
All EcoBoost engines are turbocharged. So at least 1/3 of Ford vehicles* sold in 2012 have turbocharged engines.

Quote:
The engines I quoted are fuel injected but not turbo's.
So basically your argument is that it is rare to see high performance out of engines that have low performance designs?

* Some of the engines may be for non-Ford uses, but the ratio of engines manufactured to vehicles sold is 1/3.
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Old 18 March 2014, 12:00 AM
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If memory serves me correctly, it's been about 20 years since one could buy a new vehicle in North America, with a carburetor. To say that an engine today is fuel-injected, is a given.
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Old 18 March 2014, 12:41 AM
jimmy101_again jimmy101_again is offline
 
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Quote:
Originally Posted by GenYus234 View Post
So basically your argument is that it is rare to see high performance out of engines that have low performance designs?

* Some of the engines may be for non-Ford uses, but the ratio of engines manufactured to vehicles sold is 1/3.
You are correct, I mistyped and the original Ford should have been the (still standard) Duratec not EcoBoost.

No, my point was a "conventional" new engine (fuel injected, not turbo) is more "high performance" than a "high performance" engine from several decades ago.

All modern engines are "high performance". Some may be more "high performance" than others but compared to a 1965 V8, even a '65 specifically sold as the high performance version, all modern engines fit the bill.

Of course all engines can have their performance increased (at the expense of efficence). An Indy car for 2014 will be something like, IIRC, 2.2 liter (135.25 cu in) and 650 horsepower. That's 4.9HP/ci. So even an EcoBoost engine is sedate. (Of course the indy car only gets a couple MPG.)
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  #18  
Old 18 March 2014, 02:21 AM
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Quote:
Originally Posted by jimmy101_again View Post
The engines I quoted are fuel injected but not turbo's.
The term you're looking for is "naturally aspirated," as opposed to "forced induction."
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