Review of 1ZZ-FE - Toyota Will VS, 1.8 L, 2001

It's time to talk more or less in detail about Toyota engines of the new generation and, first of all, about 1ZZ-FE, the most common of them. Every day more and more cars with such units come to the country, and there is still depressingly little information on them. Let's supplement the data of our overseas colleagues with our local experience.

So, the Toyota 1ZZ-FE engine, the first representative of a completely new family, was put into mass production in 1998. It debuted almost simultaneously on the Corolla for the foreign market and the Vista 50 for the domestic market, and has since been installed on a large number of C and D models.

Formally, it was supposed to replace the 7A-FE STD, the previous generation unit, significantly surpassing it in power and not inferior in fuel efficiency. However, installed on the top version of the models, it actually took the place of the honored veteran 3S-FE, slightly inferior to him in terms of characteristics.

Engine 7A-FE 3S-FE 1ZZ-FE
Displacement, cm3 1762 1998 1794
Power, hp 110-115 / 5800 SAE
115-120 / 6000 JIS 128-132 / 5400 DIN
135-140 / 6000 JIS 120-140 / 5600 SAE
130-140 / 6000 JIS
Torque, Nm 154/4400 SAE
157/4400 JIS 178 / 4400 DIN
186/4400 JIS 172/4400 SAE
171/4000 JIS
Compression ratio 9.5 9.5 10.0
Bore, mm 81 86 79
Piston stroke, mm 85.5 86 91.5

Now let's take a closer look at the design of this engine, noting its features, main advantages and disadvantages.

Cylinder-piston group

The cylinder block is made of an aluminum alloy by injection molding, cast iron liners are installed in the cylinders. This was Toyota's second, after the MZ series, in the introduction of mass-produced "light-alloy engines". A distinctive feature of the new generation motors is a cooling jacket open on top, which negatively affects the rigidity of the block and the entire structure. An unconditional advantage of the scheme was the reduction in weight (in general, the engine began to weigh ~ 100 kg versus 130 kg for its predecessor), and most importantly, the technological ability to manufacture the block in molds. Traditional blocks with closed cooling jackets are stronger and more reliable, but those made by casting into disposable molds are more laborious at the stage of mold preparation (in which, moreover, in preparation for pouring, the mixture tends to collapse),

Another feature of the cylinder block is the crankcase that connects the crankshaft bearings. The block / crankcase parting line runs along the crankshaft axis. The aluminum (more precisely, light-alloy) crankcase is made as one piece with steel main bearing caps cast into it and by itself additionally increases the rigidity of the cylinder block.

The 1ZZ-FE engine belongs to the "long-stroke" motors - the cylinder diameter is 79 mm, the piston stroke is 91.5 mm. This means better low-end traction, which is much more important for mass models than increased power at high revs. At the same time, fuel efficiency is also improved (physics - less heat losses through the walls of a more compact combustion chamber). In addition, when designing the engine, the idea of ​​reducing friction and maximum compactness became predominant, which was reflected, among other things, in a decrease in the diameter and length of the crankshaft journals - which means that the load and wear on them inevitably increased.

Remarkable is the piston of a new shape, a bit reminiscent of a diesel part ("with a chamber in the piston"). To reduce frictional losses during long strokes, the piston skirt has been reduced - this is not the best solution for cooling it. In addition, the T-shaped pistons in the projection on fresh Toyota start to knock when shifting much earlier than their classic predecessors.

But the most significant drawback of the new Toyota engines was their "disposability". In fact, only one crankshaft overhaul size for 1ZZ-FE was provided (and even then - Japanese production), but the overhaul of the cylinder-piston was impossible in principle (and overheating the block would not work either).

But in vain, because during operation a very unpleasant feature of the engines of the first years of production was revealed (and we have had such and in the next few years will be the majority) - increased oil consumption for waste caused by wear and stuck piston rings (requirements for their condition in ZZ the higher, the longer the piston stroke, and hence its speed). The issue is discussed in more detail in this material. There is only one treatment - a bulkhead with the installation of new rings, and in case of severe liner wear - a contract engine.

"There were problems with the engines until 2001, then they were fixed and now everything is in order"
Alas, things are not so good. After November 2001, the ZZ and NZ series engines began to be equipped with "modified" rings, in the same year the ZZ cylinder block was slightly changed. But firstly, this did not affect the previously released engines in any way - except that it became possible to install the "correct" rings during the bulkhead. And second and foremost, the problem has not disappeared: there are more than enough cases when bulkheads or engine replacements required, among other things, warranty cars manufactured in 2002-2005 with mileage from 40 to 110 thousand km.

Cylinder head

The block head itself is naturally light-alloy. Combustion chambers are of conical type, when the piston approaches the top dead center, the working mixture is directed to the center of the chamber and forms a vortex in the area of ​​the spark plug, contributing to the fastest and most complete combustion of fuel. The compact size of the chamber and the annular protrusion of the piston crown (which improves filling and, in its own way, forms the mixture flows in the near-wall region - at the early stage of combustion, the pressure increases more evenly, and at the later stage, the combustion rate increases) contributed to a decrease in the probability of detonation.

The compression ratio of the 1ZZ-FE is about 10: 1, however, the engine allows the use of regular gasoline (87th SAE, Regular in Japan, 92nd with us). According to the manufacturer, an increase in octane does not lead to an increase in power indicators, but only reduces the likelihood of detonation. As for the other members of the family (3ZZ-FE, 4ZZ-FE), the compression ratio is higher in them, so the fuel omnivorousness should be treated more carefully.

The new valve seat design is interesting. Instead of traditional steel press fit ones, the so-called ZZ engines are used. "laser-sprayed" light-alloy saddles. They are four times thinner than conventional ones and contribute to better valve cooling, allowing heat to be transferred to the body of the block head not only through the stem, but also largely through the valve disc. At the same time, despite the small diameter of the combustion chamber, the diameter of the inlet and outlet ports increased, as well as the diameter of the rod decreased (from 6 to 5.5 mm) - this improved the air flow through the port. But, of course, the design also turned out to be absolutely unrepairable.

The gas distribution mechanism is a traditional 16-valve DOHC. The early version for the external market had fixed phases, but the bulk of the engines then received the VVT-i system (variable valve timing) - an excellent thing for achieving a balance between traction at the bottom and power at the top, but requiring careful attention to the quality and condition of the oil.

Reducing the valve weight made it possible to reduce the force of the valve springs, at the same time, the width of the camshaft cams was reduced (less than 15 mm) - again, a decrease in friction losses on the one hand and an increase in wear on the other. In addition, Toyota refused to adjust the valve clearance with washers in favor of, so to speak, "adjusting pushers" of various thicknesses, the cups of which combine the functions of the previous pusher and washer (for a high-speed forced engine, this would make sense, but in this case - made the adjustment of the gap as difficult and expensive as possible; it's good that this procedure has to be done very rarely).

Another radical innovation - the timing chain now uses a single-row chain with a small pitch (8 mm). On the one hand, this is a plus to reliability (it will not break), in theory there is no need for relatively frequent replacement, it is only necessary to check the tension occasionally. But ... But again - the chain has its significant drawbacks. It's probably not worth talking about noisiness - except that, mainly for this reason, the chain is made single-row (minus durability). But in the case of a chain, a hydraulic tensioner necessarily appears - firstly, these are additional requirements for the quality and purity of the oil, and secondly, even Toyota tensioners do not differ in absolute reliability, sooner or later they begin to let through and weaken (the dog provided by the Japanese does not at all always). There is no need to explain what is a chain released into free floating.

Well, the main problem is stretching, the more the longer the chain itself. Best of all, this is the case in the lower shaft engine, where the chain is short, but with the usual arrangement of the camshafts in the block head, it lengthens significantly. Some manufacturers are struggling with this by introducing an intermediate sprocket and already making two chains. At the same time, it is possible to reduce the diameter of the driven sprockets - when both shafts are driven by a single chain, the distance between them and the width of the head are too large. But in the presence of intermediate chains, the transmission noise increases, the number of elements (at least two tensioners), and even with the reliable fastening of the additional sprocket, some problems arise. Let's look at the 1ZZ-FE timing chain - the chain here is defiantly long.

Although the use of the chain implied a decrease in maintenance costs, in fact the opposite happened, so that the average life of the chain is ~ 150 thousand km, and then its constant rumble forces the owners to take action.

Inlet and outlet

The location of the intake manifold is striking - now it is in the front (previously it was almost always on the side of the engine shield on transverse engines). The exhaust manifold has also moved to the opposite side. To a large extent, this was caused by a traditional environmental madness - it is necessary to make the catalyst warm up as quickly as possible after starting, which means it should be placed as close to the engine as possible. But if you install it immediately behind the exhaust manifold, the engine compartment overheats strongly (and completely in vain), the radiator is additionally heated, etc. Therefore, on the ZZ, the release went back, and the catalyst was under the bottom, while the second option for the struggle for certificates (a small pre-catalyst behind the manifold) was not required.

A long intake tract helps increase recoil at low and medium revs, but with a front intake manifold, making it quite long is difficult. Therefore, instead of the traditional one-piece manifold with 4 "parallel" pipes, the first 1ZZ-FE has a new "spider", similar to the outlet, with four aluminum tubular ducts of equal length, welded into a common cast flange. Plus - air ducts made by rolled metal have a much smoother surface than cast ones, minus - not always perfect welding of the flange and pipes.

But later, the Japanese nevertheless replaced the metal collector with a plastic one. Firstly, saving non-ferrous metal and simplifying the technology, secondly, reducing the heating of the air at the inlet due to the lower thermal conductivity of the plastic. In passive - dubious durability and sensitivity to temperature extremes.

Attachment drive. Here Toyota did about the same as with the chain. The generator, power steering pump, air conditioner and pump are driven by a single belt. Plus the compactness (one pulley per crankshaft), but minus the reliability - the load on the belt is much higher, the hydraulic tensioner is not particularly reliable, and if something happens, because of the cooling system pump, it will not be possible to reset the belt of the jammed device and waddle further ... ZZ, by the way, also turned out to be endemic - because of the highly improved mounts.

Filters. Finally, Toyota engineers were able to correctly (although less convenient for maintenance) position the oil filter - with the hole upwards, so that the traditional problems with oil pressure after start-up are partially solved. But changing the fuel filter is now not so easy - it is placed in the tank, located on the same bracket with the pump.

Cooling system. The coolant now flows through the block in a U-shaped path, enveloping the cylinders on both sides and significantly improving cooling.

Fuel system. There have also been significant changes here. To reduce the evaporation of fuel in the lines and the tank, Toyota abandoned the scheme with a fuel return line and a vacuum regulator (while gasoline is constantly circulating between the tank and the engine, heating up in the engine compartment). The 1ZZ-FE engine uses a pressure regulator built into the submersible fuel pump. New injectors with a "multi-hole" end atomizer were used, installed not on the manifold, but in the cylinder head.

Ignition system. The early version used the DIS-2 (one coil for two candles) tamblerless scheme, and then all engines received the DIS-4 system - separate coils located in the candle tip (by the way, the most common candles are used on 1ZZ-FE). Pros - the accuracy of determining the moment the spark is supplied, the absence of high-voltage lines and mechanical rotating parts (not counting the rotors of the sensors), fewer operating cycles of each individual coil, and this is the fashion, after all. Disadvantages - the coils (and even combined with switches) in the wells of the block head overheat, the ignition cannot be adjusted manually, more sensitivity to candles growing "red death" from local gasoline, and, most importantly,

Summary

So what's the bottom line? Toyota has created a modern, powerful and fairly economical engine with good prospects for modernization and development - probably ideal for a new car. But we are more worried about how the engines behave in the second or third hundred thousand, how they tolerate not the most benign operating conditions, how much they are amenable to local repair. And here we must admit - the struggle between manufacturability and reliability, in which Toyota almost always stood on the side of the consumer, ended in the victory of hi-tech'a over durability. And it's a pity that there is no more alternative to the new generation engines ...