Motivation Equation
by Imad Ali
1KZ or 2LT, 3B or 13BT, 1C and 2L, confusing numbers and alphabet game or engine designations, who knows... it might as well be Greek for those who aren't engine savvy. If you are even considering building a Jeep in Pakistan, you should know the various engine choices available to you. Read on and enlighten yourself.
Choosing the right engine is the most important decision for those of us lucky enough to own a real Jeep. As we all know, almost all Jeeps to be found in Pakistan, came outfitted with petrol engines from the factory, even though Jeep has offered diesels in the European market for years now. Why these vehicles never made it the Pakistani market is a story for another column. Anyone who has lived in Pakistan for any length of time can tell that the prohibitive price of petrol has created a diesel conversion craze. The diesel advantage in Pakistan is clear: You get an engine that is at least 30% more efficient than its petrol counterpart and it runs on fuel that costs less than two thirds as much. This economic advantage totally overshadows the facts that the majority of diesels available to choose from are antiquated designs that are noisy and rough, terribly underpowered for their size and weight, and gross polluters. The unfortunate motorcyclists and pedestrians of our country know the last fact all too well.
However, all is not lost. The diesels available to us may be antiquated and underpowered, but there are some tried and true performers amongst them that have withstood the test of time and the trail. In the course of building a Jeep, the mechanic will usually suggest which engine to go with. Opinions on the best engine for the job differ between mechanics, depending on their technical expertise and the ruggedness of the Jeeps they build. That makes it all the more important for the owner to be educated about the engines available. For instance if your mechanic is adamant about dropping a Hilux 2.4 litre engine into your project CJ-7, you may seriously want to reconsider your choice of mechanic. The following list can be used as a reference guide to selecting the ideal engine for different kinds of Jeeps.
1951-52 Willy's M38, CJ2A, Ford MB
These are the most commonly found flat-fender Jeeps. Their engine bay is by far the smallest, calling for smaller, lighter engines than those required for other Jeeps.
- Toyota 2L-T [E/HE]: This turbocharged engine is available in many variations. Although some are EFI and others have ceramic valve seats, power output is roughly the same in all models. In my humble opinion, this is the best engine for flat fender Jeeps as far as performance is concerned. It is rather pricey and also a tight fit in the engine bay but you cannot go wrong with turbocharged performance.
- Toyota L and 2L: The 2.2 liter L used to be the most popular engine for flat fenders until it was replaced by the 2.4 liter 2L. The 2L is basically the naturally aspirated version of the 2L-T. While the stroke is the same as the L, it has a larger bore for increased displacement. This makes the 2L a very rev happy engine, with the redline starting at a stratospheric 5000 rpm. The 2L is second only to the 2L-T. This engine is a good balance of economy and power.
- Nissan 2.2 liter: This naturally aspirated 4-cylinder has always played second fiddle to the L. Although the same displacement, but weaker, cheaper, and noisier, it is the poor man's L.
- Toyota 2C turbo: This small, lightweight engine develops roughly as much or slightly less power than the 2.4 liter 2L ands costs roughly the same too. It is not a widely available engine, and its turbocharged histrionics make it unpopular with the turbo-averse crowd. The 2L is regarded as a superior engine because of its larger displacement.
- Toyota 1C and 2C: These two engines have been included here only as a warning. The 1C and 2C, pushing a whopping 1.8 and 2.0 liters of displacement respectively, are absolutely worthless for use in a Jeep. The only thing they are capable of powering with marginally acceptable performance is a Corolla, the vehicle they were originally designed for. Best used as boat anchor otherwise.
Early model CJ-5, M38A1 and M170 ambulance
These Jeeps have a shorter length engine bay than the later model CJs but have more vertical room than the flat fenders.
- Toyota 2L and 3L: The 2L really is a marginal engine for these heavier Jeeps. The 3L is the 2L's big brother. At 2.8 liters, it produces ample power and torque to propel these middleweights.
- Toyota 2L-T: The 2L-T is roughly as powerful as the 3L, if not more. It can be easily squeezed into the engine bay on these Jeeps. Being turbocharged, they have potential for even more power in the hands of those people who know what they're doing.
- Toyota 2LTE and 2LT-II: The is the EFI version of the above engine. The other major difference is the larger head as compared to the non-efi version.
Late model CJ-5, CJ-6, CJ-7, CJ-8 Scrambler, and Wagoneer/Cherokee
This group of Jeeps can be called the heavyweights. They have the largest engine bays of all Jeeps. Redesigned suspension and chassis on these Jeeps make's them capable of higher highway speeds, calling for more powerful engines.
- Toyota B series: The B series engines have powered not only many different Toyota vehicles since the 1960s, but also refrigeration units and industrial equipment. Made primarily by Hino and also by Daihatsu, the B series is probably the most reliable diesel engine to find its way into a Jeep. The gear-drive timing set replaces the timing belt found on other diesels. Although slightly noisier, timing gears and pushrod operated valves eliminate the risk of timing belt failure and subsequent destruction of the engine's rotating assembly.
Starting with the B at 2.8 liters, the 1B, 2B, and 3B displace 3.0, 3.2, and 3.4 liters respectively. With its ever abundant torque and power, the 3B is the most favoured engine of the lot. It's rated power is 90hp@3500rpm. The 3B also boasts the best oiling system of all the B series engines. Unlike other naturally aspirated diesels, it has oil injectors at the bottom of the cylinder skirts for better cylinder wall lubrication. Toyota replaced the 3B with the 13B-T. This is basically a technically updated and turbocharged version of the 3B and produces 120hp@3400rpm. It can also be found as the 13B in local markets. After much research, I have come to the conclusion that this is simply a 13B-T engine stripped of its turbo setup and outfitted with intake and exhaust manifolds off a regular B series engine. All commonly available B series engines can also be found with plunger or rotary fuel pumps. The plunger pump is slightly noisier, but it is also completely rebuildable and seems to have far more torque throughout the RPM range.
Other B series engines not so commonly available are the 11B, 14B, 14B-T, and 15B. With the 14B at 3.7 liters and 15B at 4.1 liters, these are probably the largest 4-cylinder engines in use today. While B series engines are by far the most popular choice for CJs, they also have their drawbacks. The weight of the huge cast iron block and cylinder head adversely affect the Jeep's already marginal handling characteristics and require beefed up front suspension.
- Toyota 1KZ-TE: The 1KZ-TE is Toyota's turbocharged replacement for the 3L. This 3.0 liter engine is a new design from the ground up. It boasts high tech features such as electronically controlled fuel injection and engine and emissions management systems. The result is outstanding performance from a light weight engine, but for a pretty heavy price.
The engine is not easily available in Pakistan at the moment, although that might change in the future.Most mechanics have no idea how to wire up this EFI engine, let alone make it work properly; the more conventional non-EFI 1KZ-T may be a better choice for the technically challenged, but it also makes a good deal less power.
1KZTE Specs: 96kW@3600; 343Nm@2000
- Nissan RD28: This peppy, high revving, 2.8 liter 6-cylinder engine has found its way into quite a few CJ-7s. The 6-cylinder configuration makes it exceptionally smooth for a diesel. Its high revving nature means plenty of horsepower at the top end of the RPM range, but small displacement takes away low end torque. This is a good engine for daily driving on the street, but not ideally suited to off road situations where low end torque really counts. This is the main reason why the technically inferior but torqueier B series engines have always been preferred over the RD28.
- Toyota 1HD-T: This is Toyota's ultimate diesel - 4.2 liter, 6-cylinder, turbocharged monster - and it powers the legendary 100 series Land Cruiser, also popularly known as 'Cruising' and VX turbo in Pakistan, and also 70 and 80 series 'Cruisers. This engine has changed a fair bit over the years since its inception in 1993, going from conventional non-EFI and 12 valves to EFI and 24 valves with computer-controlled automatic transmission. Depending on the year, it produces anywhere between 165 to 205 horsepower. Although a few (read VERY few) people are reported to have put these engines in their CJ-7s, whether these Jeeps even exist still remains an unsubstantiated myth. The engine is roughly the same length as the CJ-7's original 4.2 liter petrol engine, but it is much wider and weighs much more too. As with anything even remotely associated with the 100 series Land Cruiser, the cost of this conversion is prohibitively expensive and it requires more custom fabrication than any other conversion. Early model 12 valve engines were also prone to rod knock due to inadequate oiling. Apparently, the engine's oiling system doesn't develop enough pressure at low engine speeds to prevent metal-to-metal contact on the big end bearings on the connecting rods. Elevated cylinder pressure under high turbo boost pushes the piston down much harder than the oil pressure on the bottom end can counteract. The resulting metal-to-metal contact occurs only under low RPM, high load conditions, such as trying to accelerate in too high a gear, but the metal particles swimming around in the oil attack other internal components also, leading to the engine's early and untimely demise. Toyota had a issued a recall for engines with this problem, but there is no telling whether a used engine will need a rebuild unless it is disassembled and inspected. The cost of rebuilding a 1HZ was at least Rs. 60,000 2 years ago. Inflation and changing import duties have probably added another 5000-10,000 to that figure.
Common Rail Diesels
Almost all new diesels are common rail - which is significantly different from the older designs. A common rail engine uses a high presuure pump to maintain 26,000 to 30,000 pounds pressure in a fuel rail which feeds the injectors. That means at any engine speed, every injector gets the same maximum pressure. The higher the pressure, the smaller the injector nozzle openings can be, producing smaller pulses that provide better fuel atomization. Combine that with more frequent, strategically timed pulses during each compression-stroke injection, and the result is more complete combustion.
The majority of current common-rail systems employ solenoid injectors - these are actuated by a magnetic field generated by electric current. However, newer injectors use piezoelectric technology.
CRD diesels are quieter, pollute less and more powerful. A win-win situation, except for one drawback - they require regular maintanence and clean fuel, both of which are in short supply in Pakistan. Common rail engines are asssembed in 'clean rooms', which means they cannot be opened up in any local workshop. A 28,000 psi encounter with a bit of dirt is not going to be pretty!
Whenever any work is done in the fuel system, like changing the fuel filter or an injector or just about anything else, the technique here to get the air out of the system is to loosen the injectors one by one and let them squirt out the air. With a common rail, that technique is obviously not going to work - or if it does it won't be too healthy for the mechanic tightening the injectors. This is not to even mention the often dodgy diesel outside the big cities.
As of April 2005, common rail engines aren't available in the local market. Once they are, more will follow.
Related Links:
- Landcruiser FAQ :: Has detailed information about the entire line of Toyota landcruiser engines.
- Toyota Landcruiser: Engine Specifications
Please post engine/tech related questions at the forums.
Posted in Tech, October 15, 2003, by Imad Ali
