Simplest engine, pros and cons?
 

If you're like me, you probably one time spent several thousand dollars in moding an engine to try to get the best fuel economy possible only to realize that it would take an eternity to get back the money you put into the vehicle.

If you're like me you might have even went and bought an old hybrid only to realize that the thing now needs an expensive battery, catalytic converter, maybe a brake actuator and possibly even needs an engine replacement... :eek:

So what about just going back to good old simplicity? Could a simple engine that get's 30mpg trump a complicated engine that gets 40?

The Simplest Modern Engine

For those that don't have time for the video it talks about the 2.0L engine from VW between 2010 and 2015 that wasn't turbocharged, had a single overhead cam, no variable valve timing, no coil on plugs, no EGR, and an iron block.

I'm favorable to simpler engines too, not only because they're easier to service (and this may lead them to also be cheaper to have serviced). A lower manufacturing cost may render them more affordable than some downsized engines which are too complicated and only justifiable in countries where the taxation is displacement-biased such as Brazil. No wonder the VW T-Cross is exported from Brazil most often with a naturally-aspirated 1.6L 4-pot instead of the 3-cyl 1.0 TSI or the 1.4 TSI which are the only engines available locally. Not to mention how some half-assed maintenance is still widely performed in neighboring countries such as Argentina where many folks go as far as adapting a carburettor into engines originally fitted with EFI...

Lost me at 'fuel rail'.

https://3.bp.blogspot.com/_66sTMVcQ7...tment_View.jpg
thisvw.blogspot.com/2010/03/engine-compartment.html

Even though I wouldn't hold my breath for carburettors making a comeback to new mainstream cars, some modern port-injection systems are not so much of a rocket-science. Do you remember when Asian cars relied on a lot of vacuum pipes and hoses to make the EFI work? That was a real PITA.

Maybe try going back a few decades to 1975, all US models?

At this very moment, I have a 1971 Superbeetle and a 1979 Dasher diesel (both with expired tags). So, one foot in both worlds.

The Dasher was a royal pain to get it to hold water. Why is the lower radiator hose one diameter on one end and different on the other? All the hoses are new now, except the smaller ones that go into the dashboard for cabin heat, those are still 40 years old.

The dashboard is a flexi-cable with LEDs. The oil pressure indicator light is unsorted. :(
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Thankfully, the XFi is roadable.

To be efficient an engine doesn't need to be complicated.
I got my best car fuel economy with a Toyota 1KR-FE:
Went 1000 km with only 35L of gas, so 3,5L/100 km or 67 mpg in a totaly stock car.
That engine was an inline 3 cylinder with port injection, no turbochrager and generaly nothing special.
These engines are also pretty robust.

My best motorcycle fuel efficiency is with a Simson S51, wich has an ancient 2-stroke engine, takes some roughly 2-2,5 L/100 km.
Haven't actualy measured it precisely yet as I didn't ride much this year.

Sometimes even ancient features such as a pushrod valvetrain may be worth, just look at Ford replacing the 6.8L V10 with the 7.3L Godzilla V8.

I'd argue that these are not exactly fuel efficient engines.
However in case of the 1KR-FE the valvetrain was a pretty simplistic DOHC with variable valve timing on one cam.
No hydraulic valve lash adjustment, no variable lift and no variable duration.

If my 1ZZ-FED blows again, I might drop in a 1KR-FE for ****s, giggles and superior fuel economy.
That little engine got me 3,5L/100km in a not very aerodynamic car.
I wonder what it would do in my spyder, especialy if I actualy ran tires with a fuel economy rating better than F :D

Perhaps we're making assumptions and confusion between fuel efficient engines and fuel efficient vehicles. Anyone have the new Godzilla engine bsfc handy?

Of course neither the 6.8 V10 or the Godzilla V8 would cater to the penny-pinchers :D


Even though it won't pull like a 14 with a Playboy, might be interesting to see what such a small engine could do to the MR2. Some sort of reinterpretation of the basic concept of the Typ-14 Karmann-Ghia? :thumbup:

I would actualy like to see that , but I doubt it's public.
I'd also like to see how it would compare to let's say a torque-monster like VAGs V-10 TDi.

Well, the MR2 Spyder weights less than 1000 kg and the 1KR-FE has a forged crankshaft, forged connecting rods and only 10:1 compression ratio.
So with some forced induction it could possibly reach the 143 PS of a 1ZZ-FED with a better powerband and less weight.
But given the ridiculously low CDA of the MR2 Spyder, wich only gets lower with a hardtop and even lower than that with my mods, it should yield some 3L/100 km when on proper economy tires.:D

You didn't mention forced induction before, yet the KR engine does have at least one turbocharged variant in Japan.

Interesting.
However it would be more ecomodder style if I made up for the lack of power by adding an electric motor and a small batterypack.
To match the 1ZZ-FED I'd only need some 50 kW of electric power added, preferably to the rear axle.
Given that the engine is shorter, one could sandwich an electric motor in between engine and gearbox.
Or use some gearbox with an electric motor from a hybrid.
Would be nicer to be able to run purely electric without friction from the ICE.

Simplicity is a virtue, in my book, but I think we can objectively answer this question.

The average American drives 15,000 miles per year. At $3 per gallon:

A 30mpg vehicle will spend $1500 per year in fuel, and $25,000 in fuel over a 250,00 mile lifespan.

A 40mpg vehicle will spend $1125 per year in fuel, and $18,750 in fuel over a 250,000 mile lifespan.

If the purchase price (from the engine alone) and maintenance (on the engine alone) are less than $6250 different, the 40mpg version is the better buy.

Aerocivic's original Honda D series from 1992 lasted north of 500,000 miles, and was replaced, running. There are plenty of examples of first generation Insight engines with variable valve timing, EGR, oil to water heat exchangers, coil on plug, and exotic materials to reduce weight (magnesium), which are still running north of 600,000 and even 700,000 miles. You can pick up one of Honda's relatively complex K series engines (dual overhead cam, variable timing and lift, etc. etc.) for as little as $250. The engine tends to outlast the car, so they become abundant and cheap.

Some modern ignition systems may seem quite complex compared to the ones with a distributor, but they're far from being much of a rocket-science deal. The very same Opel-designed Family 1 engine still made in Brazil and fitted to some local Chevrolets was introduced locally with a TBI and a distributor, turned to a multi-port injection (continuous-flow at first) and wasted-spark ignition, and now resorts to the coil-on-plug arrangement. Sure a few different sensors are required, yet the basic design of the engine remains unchanged.


Even the VW Beetle resorted to a high magnesium content to the aluminium alloy its engine was made of, and that was a quite simple design.

Don't be so sure. That 7.3L V8 Godzilla engine is the economical choice for the right application. Ford is counting on it when NOx emission regulations drop another 75% in 2024 combined with a 50% cut in PM.

Commercial fleets are all about pinching pennies.

Of course there is a right application, and that's why I refered to the Godzilla and the V10 Triton.


No wonder Ford opted for port-injection, which is also much easier to convert to gaseous fuels.


Sure commercial fleets are all about it, but when I refered to penny-pinchers what I had in mind were those folks who get a subcompact with a manual transmission which nearly no-one else wants, not a gas-station cowboy who gets the biggest truck only to haul a handful of grocery bags while pulling a ghost-trailer :D

I was hinting a a paradigm shift in the heavy duty market that is going to surprise a whole lot of people. I wasn't talking about "gas-station cowboys" I was talking about these:

https://tfltruck.com/wp-content/uplo...odzilla-v8.jpg

8 yard dump truck requires a paradigm shift? Ok,,,, I guess. Looks like a F650 I saw the other day towing a 5th wheel trailer. Did need a ladder to get into the cab.

A Class 7 truck with a gasoline engine is a pretty big shift.

The fact that Ford designed a brand new gasoline engine for the medium and heavy duty market in 2020 is a pretty big deal.

It speaks to the challenges of hitting the next level of HD emission standards with a diesel vs a gasoline engine.

Expect some surprising changes in the market mid-decade.

Not so surprising at all, considering some European-based truck manufacturers are resorting to spark ignition and CNG/LNG on engines derived from the Diesel ones.


I know it actually makes sense for some commercial applications, but when I mentioned the Godzilla engine I had in mind the average Joe who gets a truck to use as a personal vehicle.

We've had factory original CNG / LNG trucks in the US market for more than a decade and they haven't ever taken off due to increased purchase price and limited fuel availability.


Natural gas truck meet 2024 emission regulations today without any sort of expensive aftertreatment.

Cng/lng will take off in future years. Cleaner than diesel and filling stations will be more abundant, pipelines everywhere. LNG may still need to be trucked, but there are small lng systems available..

That has been the natural gas industry's statement for decades. To date it hasn't happened.

Sometimes there's just one small disadvantage that doesn't let a technology take off.

CNG requires expensive tanks that hold far less fuel for a comparable gasoline tank. Not only that, the tanks require more maintenance over time.

Also, CNG tends to burn hotter under full load since there's no liquid fuel to evaporate during combustion, which can be hard on exhaust valves and such.

Fueling stations are a chicken and egg situation. A city might get away with converting their bus fleet to CNG since they only need a few stations, or maybe even just one like in my home town. But a trucking company needs several spread out over all their routes. And with the on board tanks giving each truck less range you'll need more of places to fuel than current truck stop locations. But without the trucks there's no incentive to build CNG stations, and without the stations, there's no incentive to buy CNG trucks.

No wonder for heavy-duty trucks I only see CNG as a supplemental fuel in my country, even though it's widely used for light-duty vehicles in cities with a good refueling infrastructure.

Engine without catalyzer requirements can have better stoichiometric ratio of air.

Toyota 1E engine at Tercel 1st gen could run 4,5 l/100km. Weight was same as 1krfe Aygo, which may run 3,5 l / 100km, without being aero.

That's true, but the shipping(ocean and rail) industry will move to LNG which will drive the price/technology/packaging to the point that it will become attractive to the trucking industry also.

LNG seems to make more sense for ocean shipping than for terrestrial applications. Many ports nowadays have re-gasifiying stations to receive LNG imported usually from Malaysia, and feed it to NG pipelines.

Moving giant oceangoing ships to LNG isn't going to help transfer Class 6-8 trucks to LNG. The problem isn't technical - we have technical solutions that work today. The problem is economics and logistics.

CNG and LNG trucks cost more than a diesel truck - a lot more. That isn't going to change without a huge increase in volume to bring down the cost of the tanks. They require less maintenance and the fuel is cheaper - sometimes. That variation is the price of natural gas vs diesel is a problem if you want someone to spend tens of thousands more upfront to save over the long run.

Then there is fueling. Right now long-haul CNG and LNG is mainly done by large fleets like UPS or FED EX that have installed their own fueling stations.

Where natural gas trucks make the most sense is local routes were trucks come back to the same depot every day. These are also generally city routes were the decreased emissions make the biggest difference. The problem for NG on local routes is competition from electric trucks. The have the same economics: higher purchase price in exchange for lower fuel cost and maintenance.

Even though Scania has recently switched its focus from compression-ignition ethanol engines to spark-ignition NG engines, mostly with CNG which is readily available in more regions than LNG, most of the long-haul trucks I have seen with a CNG fuel system in my country relied on it as a supplemental injection and retained the ability to run on Diesel fuel. The last time I remember seeing a dedicated-CNG truck, it was an Iveco in 2014.

When it comes to a simpler engine, one of the examples that I usually remember is the 447cc air-and-oil cooled Honda parallel-twin. No wonder once in a while I still see beauties like this '86 Honda CB 450.
https://1.bp.blogspot.com/-EuUZ5i9fn...ro-direito.jpg