Monday, October 15, 2018

What could be done for ethanol-capable "flexfuel" cars to become less mediocre?

It is undeniably quite challenging to make a "flexfuel" car retain some reasonable mileage figures on gasoline while it also features ethanol capability, especially when it's fitted with a random outdated engine such as the one which my mother's former Chevrolet Celta resorted to. Apart from an increase to the compression ratio and switching from throttle-boy injection to sequential port-injection, that was roughly the same old Family 1-based introduced to Brazil in local variants of the Opel Corsa B which were rebadged as Chevrolet. Its ancient layout, praised for reliability and ease of maintenance, has some inherent drawbacks when it comes to overall efficiency.
Since 3-cylinder engines didn't have the same appeal in the Brazilian market as they do have now, the engine was basically a downgrade from the 1.2L to 1.0L because of lower taxes, and presumably also the economics of scale since it would still share some key design features with the 1.4L, instead of the 3-cyl 1.0L fitted to its European counterpart. The very same basic engine layout remains in use as the only powerplants available for the Onix, present-day entry-level Chevrolet in Brazil, in both 1.0L and 1.4L featuring flexfuel ability in the domestic market and also on regional export markets even though ethanol didn't really catch up as effectively anywhere else as it used to do in Brazil.
Maybe the competition with compressed natural gas in neighboring countries such as Argentina, Colombia and Bolivia has its effect on the seemingly lack of market opportunities for ethanol, plus the fact that it seems easier to compensate the inefficiencies inherent to the engine design on the fuel trim while resorting to CNG without side-effects while operating on gasoline, but an ancient engine layout also seems discouraging to take "flexfuel" capability so seriously. Despite being easy to work on this engine and even perform makeshift fixes, and most likely that's the reason why it wasn't phased out yet, there are some compromises that a handful of simple improvements can't effectively overcome.

It may sound kinda surprising, but GM has resorted to the bumped-up compression before it started to feature the "flexfuel" ability, at least to the 1.0L version, when local variants of the Opel Corsa C (guess what, rebadged as a Chevy once again) had it as a cheaper way to improve performance while the 4 valve-per-cylinder layout was prevalent among the competition. Since its fuel chambers were in fact kinda small, it seemed easier to overcome the risk of knock simply adjusting the ignition timing on demand. In the end, it led to a rough operation when the mandatory ethanol content on gasoline enforced in Brazil decreased due to sugar prices oscillations leading to a decrease in the ethanol offer for the domestic market. Corn-based ethanol, which could overcome this issue, is a taboo in Brazil...

Sure the initial interest on "flexfuel" capability in American vehicles such as the Chevrolet Lumina APV and the usage of methanol as an option mostly for the fleet market, for which the effects of the fuel availability limitations would've been somewhat more critic, has also led the intereset to a greater parts interchangeability with regular gasoline-only and pulled the plug on an eventual implementation of more advanced features in order to increase the efficiency while operating with alcohol fuels. Even though such conservative approach was not so pointless at all, there were possible ways to achieve similar goals without too much hassle to the maintenance, such as resorting to forced-induction as a way to emulate a variable compression ratio.
Sure a turbocharger could've been pointed out as a technical nightmare back in the day because of the thermal management which becomes somewhat more critical, plus there is a lot more pipes under the hood to limit access to other components, but the possibility of replacing the standard blow-off valve for an adjustable one to provide an over-boosting on demand. Maybe a belt-driven supercharger looks like a simpler option, since it wouldn't require too much mods to the exhaust system, but it requires some more mechanically-intensive mods to reach the same (or eventually superior) level of variation to the dynamic compression. No wonder it took a while for forced-induction to be taken really seriously on "flexfuel" vehicles...

At least in Brazil, the first "turboflex" available was the BMW 320i ActiveFlex, which also resorts to direct injection and therefore doesn't require any specific cold-start aid such as fuel pre-heating or the obsolete auxiliary gasoline tank which used to be available in dedicated-ethanol and earlier "flexfuel" cars in Brazil and decreases the risk of knocks even while resorting to a leaner air/fuel ratio on gasoline under some compression ratio which would otherwise remain more suitable to ethanol only. Turbo and direct injection became also available in smaller models too, such as the Volkswagen Virtus which features the 1.0L TSI 200 engine, alongside a naturally-aspirated 1.6L with port-injection more favorable by commercial operators such as taxi drivers simply because it's still easier to convert to CNG and the fear of turbochargers being prone to some catastrophic failure.

And even for those who fear the maintenance of a turbocharged engine or a direct-injection system, it could seem a good idea to give variable valve timing a chance. Fiat has fitted its Firefly engines with that technology, even though it's mostly aimed to improve performance in models such as the Mobi and the Argo, but it could eventually serve as another option to emulate a variable compression ratio.
Hadn't it been for the 1.0L limit for lower taxes, maybe that approach could be tried with the 1.3L version of that engine series in order to do so while retaining some acceptable performance on gasoline despite the decrease on volumetric efficiency while running a longer intake valve phasing overlapping the compression stroke, in a similar way to what Toyota did with the 8AR-FTS currently fitted to the Lexus IS and NX despite it not featuring "flexfuel" ability on them.

Sure the technical mediocrity has led to the lack of confidence on "flexfuel" vehicles as an approach to improve the marketing perspectives for ethanol, but the advances on engine design now available could overcome that issue. Countries such as Brazil where a higher tax bracket is enforced for bigger engines also have a political challenge in case the interest to take ethanol seriously becomes real, but the cards are on the desk. It's now basically a matter of which configuration to choose, but it's effectively possible to overcome the mediocrity and make "flexfuel" cars really desirable...

Tuesday, October 09, 2018

Is air cooling so outdated at all?

Air cooling has been an usual feature for "popular" cars, even though some models such as the first generation of the Volkswagen Gol would've switched to liquid cooling throughout its production run. When it comes specifically to the Gol, despite its modest performance with the "1300" and lately the "1600" boxer engines shared with the Beetle, the lower weight of the engine which was also shorter improved its handling due to the weight bias compared to water-cooled ones fitted with the MD-270, EA-827 and the Renault-designed CHT engine supplied by Ford when the AutoLatina joint-venture was active. But in the end, is an air-cooled engine so outdated at all???
When the Gol was released in Brazil in '80, antifreeze coolant fluids were more easily available, so the fear of blowing up a radiator or even the engine block due to ice expansion when parked outside in the winter were not a matter of concern anymore as it used to be in Germany when the Beetle was originally designed. Even though extreme cold temperatures are not so commonly reported in Brazil as they are in the Northern Hemisphere, another point that favored air cooling was the idea that such engines would be less prone to overheating because "the air doesn't boil", and so even the traditional Beetle soldiered on until '86 before its controversial reintroduction from '93 to '96. There were some customers who still enjoyed the Beetle by then and were willing to buy a brand-new one, even though the engine could've been not the main reason for such desire anymore.
Its ability to withstand to unimproved pathways, perceived as superior to the generations of compact cars released through the '80s and '90s in the Brazilian market, remained a strong sales argument for the Beetle. The air-cooled engine on the other hand, now much criticized for its noise, became mostly seen as a compromise that urban customers were not willing do deal with anymore, not to mention a lower thermal conductivity of air compared to water leading most air-cooled engines to require some richer air/fuel ratio in order to assist cooling down the combustion chambers at the expense of a slight increase to the fuel consumption and a noticeably higher emission of unburnt fuel as "hydrocarbons".
The ease of servicing the engine on the other hand, not only due to the absence of coolant pathways through the block and heads but also due to the gear-driven valvetrain, has also favored the Beetle in the eyes of a more conservative public for a long while. Sometimes it's also pointed out to be a reason for the mediocrity that still prevails among many independent mechanics in Brazil, who didn't seem to care about updating their skills in order to service more sophisticated vehicles that were starting to appear in the '60s and '70s. A somewhat surprising trend was to rebuild old French cars such as the front-engined Simca 8 around a VW rolling chassis starting in '76 when the availability of spare parts became more critical due to import restrictions.

Despite being relegated to the obsolescence in the car market, air cooling still finds its way across a wide variety of motorcycles, including the no-frills Honda CG 125i and the fancy Harley-Davidson Electra Glide. Naturally, the fact that motorcycles have been less regulated with regard to emissions than cars help the survival of air-cooled engines, either due to cost and ease of maintenance when it comes to the Honda CG or to keep an old-school theme to which an overwhelming majority of the Harley-Davidson owners remain loyal. Well, in a single-cylinder engine such as the one fitted to the CG it may seem easier to justify air cooling, not just due to the lower cost and complexity but also the more accurate cooling, while the V-Twin found in the Harley-Davidson has a poorer cooling on the rearmost cylinder.

Engine exposure to the air flow and the heat-exchanging surfaces increased by those fins cast into the cylinder heads and barrels, and sometimes the cranckcase too in order to improve oil cooling without having to resort to a dedicated oil cooler, are vital to allow an effective cooling. Horizontal-single engines, such as the ones used in small Honda motorcycles with some Cub-derived powertrain, are favored by having the cylinder head more directly exposed to the impact air flow en route, since it's where most of the heat is generated during the combustion process. Other noticeable case is the flat-twin BMW R-Series range, with the cylinder barrels exposed to the incoming air while the heads are now water-cooled.
Just to raise the controversy, it's worth to notice that not the entire R-Series range is now featuring the water-cooled cylinder heads, even though Euro-4 compliance remains in effect for all. So, while the R 1200RT does feature the new design, the R-nine-T which follows a more classic design still resorts to the oil-cooled heads. It may sound more critical to rely on the oil to assist with the engine cooling, since any restriction to its flow in a way similar to the effect of a thermostatic valve in a water-cooled engine would lead to some very dangerous oil starvation, but as a mid-term solution it could still be a cost-effective approach when the oil cooler bypass is operating properly. Since spark-ignited car and motorcycle engines basically operate within the very same principle, and both cooling systems seem to be able to meet similar emission standards, it may be a sign that air cooling is not so outdated at all.

Monday, October 08, 2018

Custom tricycle with Volkswagen EA827 engine

Spotted this trike yesterday. Presumably it was built over a modified Volkswagen Beetle platform, with the backbone tube enclosed behind the diamond-plate trim. Its front wheel looks like it was sourced from some Ford, probably a Ka Mk.1 or a Fiesta Mk.4, and slightly modded with an extra bowl attached to the same rim.

The engine, mounted longitudinally at the rear end, is the water-cooled EA827 instead of the old faithful air-cooled boxer which used to be more popular in other times. Couldn't find its owner to get some more detailed specification.
The radiator was positioned sideways to the right, in a position that is not so unusual to find the radiators in older Volkswagen cars converted from the air-cooled engine to a water-cooled one.

Sunday, August 26, 2018

Volkswagen's approaches to the "popular" car in Brazil in '93

Gol 1000: despite having already gone through a few facelifts, the bodyshell was basically the same released in '80 when the Gol still relied on the air-cooled boxer engine, now front-mounted and driving the front wheels, in a 1.3L version. Later the 1.6L boxer had been offered, but the Gol would only become a major player in the Brazilian automotive market once it switched to liquid-cooled engines. During the AutoLatina joint-venture by Volkswagen and Ford in Brazil and Argentina, Ford sourced its Renault-designed CHT engine for Volkswagen to use in entry-level versions of the Gol and its derivatives in exchange for the EA827 to be fitted to the Escort and some Brazilian derivatives of the Renault 12 project taken over by Ford's local branch after merging with Willys-Overland which was Renault's partner for the Brazilian market until '67. In the end, this meant Volkswagen would use a Renault-designed engine for its earlier 1.0L version of the Gol.
Even though it was already outdated by then, the hatchback provided an easier access to the luggage compartment compared to the classic Beetle with its tiny front luggage compartment under the front bonnet and that internal one between the rear seat and the firewall which was only accessible from the inside.
Despite this practical disadvantage, the Beetle was reintroduced to the Brazilian market in '93 after a 7-year hiatus started in '86. Even though it was supposed to not benefit from the same tax break that favored engines with a displacement equal to or below 1.0L or 61 cubic inches, the rule was amended by then-president Itamar Franco to allow air-cooled engines up to 1.6L to also be included in the fiscal benefit. Brazilian Beetles made during this brief '93-'96 reintroduction were soon nicknamed "Fusca Itamar", refering to the personal request of the president for Volkswagen to relaunch the model. Sure its cross-country capabilities, matched only by vehicles with a much higher price tag, were a valuable asset in a country where most roads are still unpaved, but the higher degree of automation on the production of newer cars and some changes on customers' preferences meant the Beetle was not so appealing to the general public anymore.

Saturday, August 25, 2018

Gurgel BR-800, the Brazilian subcompact that nearly became an effective replacement for the Volkswagen Beetle




Creating a car that would fill the gap left by the Volkswagen Beetle's first phaseout in Brazil in 1986 was not an easy task, considering the harsh road conditions and lack of infrastructure calling for some mild off-road ability that was not so relevant in the overwhelming majority of the European-designed economy cars of the '80s that were simply stripped down in order to be sold locally. That could not be so much of a nuisance for someone who lived in bigger cities, but the countrymen needed something else, and the engineer João Augusto Conrado do Amaral Gurgel decided to take the challenge. Gurgel was already known in Brazil for the Volkswagen-based mini SUVs made by his company, but he was already envisioning a way to not be dependent of Volkswagen anymore. Even though the Transporter known in Brazil simply as "Kombi" would remain for a longer time, the relationship between Gurgel and Volkswagen has deteriorated after some of his products became a fierce competitor to the Typ181 "Thing" for regional export markets in the Caribbean, so an attempt to become independent of their engines supply turned out to become a critical matter.

With the first production-ready prototypes featured in Brasília during the Independence Day Military Parade in september 7th, 1987, and the deliveries starting in the following year, the Gurgel BR-800 was not so much of a commercial success but had some technical features that rendered it effective as a viable replacement for the Beetle. Despite having a front-mounted engine while retaining the rear-wheel drive, which called for a presumably less-efficient transmission setup due to the presence of a driveshaft, the 50-50 unloaded weight bias meant any compromise to the the cross-country capability would be minimal. Relying on the same 4-speed manual transmission and rear axle found in the 1.4L versions of the Chevette, the Gurgel-designed 0.8L water-cooled OHV flat-twin was meant to reach the then-impressive 25km/l (around 62MPG) fuel consumption. Overall performance was not really something to brag about, but neither were some comparable European-designed cars that were never brought to Brazil by the local branches of foreign automakers such as Fiat. Featurng a space-frame chassis with a fiberglass-reinforced plastic body, its manufacturing was somewhat labor-intensive and time-consuming in a comparison to the pressed-steel unibody layout which was already widespread among major automakers.

Marketing was not so great, with the sales between 1988 and 1990 being tied to stockholding of the company and therefore it became a less attractive option for those buyers who were just looking for a no-frills car and nothing else. The situation became worse for Gurgel in 1990 when Fiat applied for a fiscal incentive for cars up to 1.0L instead of 0.8L and the Fiat Uno Mille could be offered at a more competitive price due to the greater production scale inherent to its design. As a former director of the local branch of Mercedes-Benz once said, Brazilian people consider the size of a car as one of the most relevant matters comparing different models close in price, so the 3.195-metre long and 1.47-metre wide BR-800 was in a clear disadvantage against the Fiat Uno, being phased out in 1991 with a technically-similar model named Supermini replacing it from 1992 to 1994 when Gurgel went out of business. However, nowadays with a new generation of small city-cars flourishing even in Brazil, it's worth to remind the Gurgel BR-800 and the attempt to effectively replace the Volkswagen Beetle.

Tuesday, July 17, 2018

A quick reflection about the suitability of motorcycle engines for swaps into cars

Sometimes it might feel kinda temptating to adapt the engine of a motorcycle into a car, due to some inherently simpler design features, plus the expectations for an eventual decrease in fuel consumption and maintenance cost. It may eventually work, but it's not so likely for a 250cc motorcycle engine such as the one fitted to the Yamaha FZ-25 to be a perfect match even for a subcompact car like the previous-generation Chevrolet Spark originally available with 1.0L and 1.2L engines in most markets. Even though the smaller displacement might sound at first as an obvious approach to save fuel, combined to a smaller amount of parts that would require a few replacements throughout the useful life, matching a smaller torque output to some gear ratio that makes it remain useful is quite a challenge, even when the useful RPM range is broader.

Even something not so small, for example a Chevrolet Cruze, might seem as if it would be better served by a Honda CB 600 F Hornet in the eyes of a random shade tree mechanic, instead of the 1.6L Ecotec originally offered in some countries. Despite the lower total power and torque rating for the motorcycle engine, which is no surprise since the Ecotec has a roughly 166% greater displacement, the speed at the drive wheels could be matched in most traffic conditions resorting to a lower final gearing which would still allow a reasonable cruising speed even if the top speed decreases slightly. Considering a 2.5:1 reduction to match only the peak torque speed at the wheels, the stock rating of 63.5Nm at 10500RPM from the fuel-injected Hornet would equate to 158.75Nm at 4200RPM which is slightly better than the 155Nm rating for the Ecotec. However, the fact that most modern motorcycles have their transmission integrated to the engine's crankcase as a single unit makes it harder to bolt them straight to a car transmission, unless both are kept and some cross-shifting might be applied.
The fact that motorcycle engines usually don't have a provision for accessory drive should also be taken in consideration, since it would require either some extensive modification to enable the fitment of an accessory drive pulley or replace all engine-driven systems such as a hydraulic power-assisted steering pump or an air-conditioner compressor with electric ones, eventually overloading the magneto usually fitted to motorcycle engines to provide both electric power and ignition timing. Simply adapting a belt-driven car-type alternator could then become quite troublesome. So, despite being technically possible in some circumstances, the swap of a motorcycle engine into a car may not be always suitable to fulfill the expectations.

Sunday, July 15, 2018

What's so great about the Citroën 2CV compared to the Beetle?

Among some "people's car" projects which development started in Europe at the interwar period, the Citroën 2CV is arguably one of the smartest designs. Versatile, simple to mantain and capable to overcome harsh environmental conditions, it served not just the urban folks but also became a valuable workhorse for small farmers. Popular not only in France, but also in Argentina, Uruguay and Chile among other countries, in some of those it reached the same cult status enjoyed by the Volkswagen Beetle in my homeland Brazil.

Debates about which technical solution is effectively better become quite fierce when the front-engine front-wheel drive approach is compared to the Beetle's rear-engine and rear-wheel drive, but the 2CV doesn't disappoint when it comes to off-road capability. Its suspension system with each side wheels interconnected through a longitudinal spring leads it to incline a lot while cornering at higher speeds, but FWD makes its reactions quite predictable, plus it helps balancing the weight bias even while loaded and therefore not compromising its aptitude to go through rough terrain and unimproved roads. The engine, which is often anedoctally quoted as a copy of some early BMW R-Series, is actually quite advanced for its time, featuring overhead valves when BMW still relied mostly on the flathead layout at the time the 2CV was initially designed. Even though the air-cooling and wasted-spark ignition could be deemed outdated, these features were desirable to improve its capability to survive under the extreme cold weather which could damage a water-cooled engine, while the lack of a distributor meant the ignition to be more resistent to water/moisture. With so many clever design features, no wonder the Citroën 2CV served as a base for what might be one of the earliest "crossover" SUVs, the Méhari, which also had the availability of a dual-range 4-wheel drive system as a premium feature despite the regular front-wheel drive serving just right for the overwhelming majority of its buyers.

Front-engine also led to an easier accessibility of the luggage compartment from the outside, and eventually some load hauling. The 4-door body provides an easier access to the luggage compartment from the inside too, and to accomodate bulkier items compared to the Beetle with the rear seat folded. Much like soccer matches, choosing one "people's car" design and singling it out as the smartest or more influent on a worldwide basis becomes quite a passionate matter. But in the end, despite the noticeable difference in the performance which is usually more modest for the 2CV, it's still quite a masterpiece as much as the Beetle.