I want to build a 100-mpg car (and I want it to look vintage)

[Ecky]

Originally Posted by racprops

Interesting, is it a diesel or Gas engine?? And can you beat a kid on a bike, and can you keep up with other cars on the freeway??

Rich

Gasoline. 3 cylinder. 66hp isn't actually too bad for propelling a 1700lb car. It has Honda's VTEC and above ~2800rpm it switches to a very aggressive cam profile, opens a second intake valve, and actually makes some power - for a 1 liter 3 cylinder.

Originally Posted by racprops

No it does not.

Not any more that dose a Carb, TBI, Port Injection, etc.

Try breathing the tail pip[e of one and see.

Even with the cats etc. it still stinks.

Rich

Honda's smaller engines (and I'm sure others as well) make pretty much zero noticeable fumes. My car came with a "Super Ultra Low Emissions Vehicle (SULEV)" sticker.

In one of my Insights (I have two) I put a fire breathing 250hp 4 cylinder into it, and that one now has noticeably stinky exhaust. I'm still getting as high as 65mpg with it, however - around 40% less than with the 3 cylinder it came with, but still very respectable.

[Ecky]

Originally Posted by racprops

No it does not.

Not any more that dose a Carb, TBI, Port Injection, etc.

Try breathing the tail pip[e of one and see.

Even with the cats etc. it still stinks.

Rich

Honda's smaller engines (and I'm sure others as well) make pretty much zero noticeable fumes. My car came with a "Super Ultra Low Emissions Vehicle (SULEV)" sticker.

Going into a bit more detail as to how Honda really cleaned up emissions:

At idle and low RPM, fuel is injected early, before the valves open, and is sprayed directly onto the back of the hot valves, which vaporizes it. Then, the valves open asymmetrically. One valve opens moderately, and the other, only slightly. This creates a vortex as the fuel is pulled into the cylinder, giving a very even distribution of the fuel vapor in the combustion chamber. The spark plug is placed at the side of the cylinder head and is indexed so the side electrode is not in the way of the fuel, which is forced to swirl through the plug.

On many Honda engines, dual spark plugs are used, one on either side of the cylinder, and the timing of the vales opening is also delayed, to give more time for fuel to vaporize while sitting on the valves, and to create an asymmetrical compression and expansion ratio - the piston has already started moving down the cylinder before the valves are opened, which cuts pumping losses.

So as not to compromise high speed power, above a certain RPM, oil pressure pushes a locking pin into and locks the valvetrain rockers to a second set, which rides on more aggressive cam lobes. The camshaft is then advanced relative to the crank, also done via oil pressure. Some of their larger car engines have smooth, (relatively) clean idles while being able to make power past 9,000rpm from the factory.

I'm certain other companies use similar technologies, but I'm less familiar with them, as I've been a Honda owner for a long time.

~

This is really worth reading:

https://jalopnik.com/when-honda-gave...kdo-1576732771

To summarize, back in 1973 Honda was able to build engines that could meet the EPA's emissions targets, without the use of a catalyst, whereas every American manufacturer was unable to.

It was such a big deal that Ford and Chrysler had both signed up to license the technology. But not GM. In fact, here's what the CEO of GM, Richard Gerstenberg, said of Honda's technology:

"Well, I have looked at this design, and while it might work on some little toy motorcycle engine…I see no potential for it on one of our GM car engines."

Eventually, this statement got back to the head of Honda, Soichiro Honda. For those of you unfamiliar, Soichiro was an amazingly gifted engineer and a very determined man, starting Honda in a wooden shack making add-on engines for bicycles and eventually turning it into one of the biggest motorcycle and automobile manufacturers in the world. The hidden message here is you don't ****ing call his engines "little toys."

Clearly interested in "one of our GM car engines," Soichiro bought a 1973 Chevy Impala with a big-ass 5.7L V8 and had it air-freighted to Japan. I think you can see where this is heading. Honda instructed his engineers to design and build a CVCC system for the GM V8, and that's exactly what they did: they replaced the intake manifold, cylinder heads, and carburetor of the engine so that it used Honda's CVCC technology. He then had it flown back to Ann Arbor, where it was tested by the EPA.

And you know what? It worked. The system Gerstenberg had derided as only suitable for "some little toy" engine allowed the big, thirsty V8 to pass the new EPA emissions requirements without a catalytic converter. Horsepower remained at 160 HP, and some tests even showed a slight fuel economy improvement.

...the CVCC V8 was still massively cleaner than most other engines of the era and easily passed the EPA's requirements. Here's the high-speed results, for example:



So, let's just recap: CEO of GM talks some **** about Honda's technology. The man who founded Honda hears it, and instead of releasing some pissy statement to the press, gets a car from GM themselves and makes it better than they could do themselves. And he lets the EPA prove it.

^ Note that it was cleaner in both HC and CO without a catalyst, than the GM-built engine with a catalyst. It had a 93% reduction in unburnt hydrocarbons.

[racprops]

Very interesting data.

I had read of the prefired chamber.

This system seemed to mainly improve emissions but not MPG, based on the reports. Also this was 1973 I am fairly sure they could not met or beat the more strident standard emission later and not now.

I have also read the same kind of improvements were/are possible with computer controlled fuel injection. And again I do not think even those systems can pass now a days.

Diesels were embraced overseas until they found out they cause even worst pollution than gasoline cars due to NOX emissions and now they are talking about a total ban.

I also read the trick of helping vaporizing by allowing fuel to sit on the intake valve, the same claim for the 85 to 90s TPI system port injector system.

So the questions are would these engine beat the current emissions requirements??

I believe the much higher cost of making those heads stopped their manufacture if I remember correctly.

At the same time I am fairly sure the fix is in to keep MPG low and that cars like these Honda and other are held back and that they could make things better.

Which is one thing I have tried to do: To find a system that could be added to current cars, trucks and Vans as an aftermarket add on.

I worked with HHO, which did not work more than a couple of times, out of about 20 cars and tests.

I looked into Propane but the law changed so you had to buy it at gasoline prices as a motor fuel which removed any savings.

Other than special PCM tuning there seems to be no other systems that can make any major improvement other than 100% pure vaporizing of Gasoline.

And that is beyond any small shade tree mechanic to engineer.

I am left to build the best engine I can for my 93 Van.

I am using every bit of what I have learned and seen and read using known systems for the maximum miles per gallon I can.

My current quest is to make my 93 Chevy Custom Van to get better than 14MPG, I am working to get it over 20MPG and hope for near 30MPG…

I know that these MPGs will only be possible on level, windless highways at 65 to 85 MPH.

My old Mercury Grand Marques was able to get 30MPG at 65MPH but at higher speeds dropped to 24 MPG at 85MPH..it needed another gear…the 30MPG was at 1700RPMs at 65MPH.

With American cars I have noted on a number of cars and a 02 Ford Explorer SUV that the best MPG happen at speeds at under 2000 MPH. And even then I have only seen near 30MPG.

So to have a BIG Van, a mini RV get near car MPGs will at lease allow me to enjoy taking trips and not feel bad about not taking a car.

The problem is this only works with engines that are not lugging, that are camed to handle the HP and Torque needed to pull a car/van at these low RPMs.

To do this I am building a low RPM high torque 383 and doing a number of High MPG changes/mods. This engine is built to have its base torque peak at 2000RPMs which will allow it to work at 1500RPMs.

There are a few other ideas I can use with an older OBD1 PCM like a lean burn system to run lean at cruse speeds, added EGR to farther help, by reducing NOX, offsetting incoming charge, and perhaps by helping overcoming pumping losses .

Along with this engine I am looking at changes to the drive line to best use this new engine, including transmission changes like to a newer 6 or 8 speed automatics, (Found to not be a good cost vs. benefits cost wise for me) rear end changes to lower rear end gear ratios, (impossible to get new gears below 2.73) and lastly adding a second over drive.

The second overdrive seems in my case to be the best idea. Sadly this is only true for me as I have a pair of older Borg Warner 3 Speeds with overdrives that were an add-on to three speeds and can with some effort devoiced and set up as a stand-alone Overdrive.

For everyone else the cost of a Gear Vendor system is in the range of $3000.00 to $5000.00 installed.

These old transmissions can still be found but they are running $500.00 to $1500.00 plus the cost of rigging them to be used only adds to the cost, which gets into the cost VA benefit area.

On the cost VS benefit area if I had not started this engine build 15 years ago I would not be a good deal now a days….not even sure it works now, and if my ideas do not work than it will not have been a good idea after all.

But one way or the other I need to save my major custom Van. So I am going for it.

Rich

[rmay635703]

If the op wants vintage

1. Subaru 360 sedan, with p&g Ibwas in the high 80’s with minimal effort, a Honda Insight motor would no doubt hit the 100’s

2. HMV Freeway with a strong 12hp motor 100mpg right out of the box

3. King Midget

[Ecky]

@racprops, I doubt that head design would meet US EPA 2020 emissions requirements entirely on its own, but when these cars were sold in Europe and Japan (as late as 2006) they were entirely without a catalytic converter. They also have external EGR, lean out to as little as 24:1 AFR, and pull smoothly with wide open throttle as low as 800rpm (with a 3 cylinder).

I'm getting off into the weeds but the point I'm trying to make is, fuel vaporization is a non-issue for modern engines. That's already been figured out and solved. Honda had 100mpg conventional gasoline cars 20 years ago. It was low hanging fruit but has been picked, and manufacturers are looking elsewhere for gains now.

[freebeard]

4. Crosley Hot Shot.


https://cdn.hswstatic.com/gif/crosley-hot-shot-3.jpg

They ran at Sebring and Le Mans.

[racprops]

Originally Posted by Ecky

@racprops, I doubt that head design would meet US EPA 2020 emissions requirements entirely on its own, but when these cars were sold in Europe and Japan (as late as 2006) they were entirely without a catalytic converter. They also have external EGR, lean out to as little as 24:1 AFR, and pull smoothly with wide open throttle as low as 800rpm (with a 3 cylinder).

I'm getting off into the weeds but the point I'm trying to make is, fuel vaporization is a non-issue for modern engines. That's already been figured out and solved. Honda had 100mpg conventional gasoline cars 20 years ago. It was low hanging fruit but has been picked, and manufacturers are looking elsewhere for gains now.

In the weeds is where I live.

Sorry I have not seen any revised efficiency ratings, the running at 24 AFR will help a lot, as does be a toy car, BUT I bet all that went out the window at WOT as does all our cars, 10 to 12 AFR ratios is not uncommon for WOT.

And I bet that in 2006 they had not discovered what a problem NOX was to become.

I still believe vaporizing can still greatly improve an engines fuel mileage and lower pollution.

Rich

[aerohead]

Some where along the way, a journalist mentioned that one of Honda's tricks for the ultra low emissions was, the 32-bit processor and its very high sampling rate / high resolution output commands to reactive engine components.

[Piotrsko]

Pretty sure they knew in the LAPCD what a pain NOX was to eliminate, even back in the '80s. On my '66 I had two seperate methods to control it installed. They were probably a ploy to make me get a newer compliant car instead of actually reducing pollution.

[Ecky]

Originally Posted by racprops

In the weeds is where I live.

Sorry I have not seen any revised efficiency ratings, the running at 24 AFR will help a lot, as does be a toy car, BUT I bet all that went out the window at WOT as does all our cars, 10 to 12 AFR ratios is not uncommon for WOT.

And I bet that in 2006 they had not discovered what a problem NOX was to become.

I still believe vaporizing can still greatly improve an engines fuel mileage and lower pollution.

Rich

NOx actually drops above a certain AFR, because combustion starts to cool off again. Nonetheless, Honda added a second catalyst to the USDM Insights which was designed chemically to specifically break down NOx - a NOx trap, if you will.

And, it will hold a 24:1 AFR out to around 95% load. Above that it drops to stoich, though this is probably more because of power expectations with the pedal to the floor.