Having disassembled the “Muscovite” engines - the 1.7-liter UZAM and Renault-F3R, the masters discovered a lot of interesting things.


There is no doubt: since the appearance of the French Renault-F3R engine assembled in Mexico on Moskvich (a little more than 20 thousand of these engines have been delivered to us), the image of a car sitting head over heels in a pool of well-known flaws has somehow grown . Still: unlike the Ufa engine, the “Frenchman” accelerates the “Moskvich” to 100 km / h in some 12 seconds, leaving behind the stern not only “Lada” and “Samara”, but also many inexpensive foreign cars. For a real motorist, this quality means something!

In addition, for owners who do not distinguish a carburetor from a generator (and there are more and more of them), operating a car with an injection engine is much simpler than with a carburetor: the driver does not need to know what “suction” is, when and how much to stretch it out so that the engine safely started when to remove so that it normally pulls, and so on … You just need to follow one or two rules set out in the instructions - the electronics will take care of everything else! No jerks, no failures: pressed harder - drove faster. Yes, and the fuel injector will manage more reasonably - he will not give excess gasoline to the cylinders. Cleaner exhaust, less consumption.

Of course, at first, electronics sow certain doubts in the souls of former Soviet people: knowing what our recent televisions or receivers are, it’s hard to make yourself believe in the reliability of injection systems - and boldly embark on the road not only to the cottage, but also away - on vacation, business trip …

So, the F3R “electronically injected” engine is nice. But it consists of the same traditional parts - a crankshaft, pistons, valves, etc.

How well they are made, how the engine is assembled, is it reliable, how long will it last? After all, “Muscovites”, as a rule, are bought not by the richest people, and a car with a French engine is $ 800 more expensive than with a Ufa one. And when it comes to repairs, it turns out that not only the parts, but also the prices are imported!

To get answers to these questions, we … took apart both motors in the technical center of the Tushino ZR. Ufa new, and Renault-F3R - after a run of 1, 500 km. (By the way, this made it possible to assess the rate and degree of wear of its parts.) The mechanics firm helped to complete this work.

First of all, we measured the cylinder block. More specifically, the diameters of each cylinder at three heights - above, in the middle and below - and in two mutually perpendicular directions (longitudinal A and transverse B). As you see in photo 1, and the measurement results are shown in table. 1. Well, the “Frenchman” turned out to be a little “more correct”.

Now check the flatness of the block head (photo 2). Who doesn’t know what the deviations are? If the head adjoins the cylinder block unevenly, then in places of loose compression of the gasket, the heat sink from it worsens; this leads to "burnout", a violation of the tightness of the water and oil channels and the gas joint.

The “Frenchman” turned out to be good: not a single probe penetrated between the head and the calibration plate. UZAM has 0.03 mm. Within the tolerance.

The axial displacement of the crankshaft in the cylinder block of both engines turned out to be close to zero.

What are crankshafts (photo 3)? First, the runout of the root necks was measured - in Renault, it was 0.02 mm along the middle neck, and 0.01 mm along the second and fourth. UZAM … - everything is in the zeros! (They did not believe the eyes!) The scatter in the diameters of the main necks (Table 2) is about 0.01 mm for both motors. On the crank pins, the UZAM turned out to be slightly worse, but also within the tolerances.

We turn to the pistons. First, their diameters were measured - in the lower part of the skirt, perpendicular to the piston pin, that is, in the widest place (photo 4). The results are in the table. 3. As you can see, on this indicator the achievements of both firms are almost the same.

Now weigh the pistons assembly with the connecting rods (photo 5). In this nomination, UZAM lost: the scatter is up to 14 g. According to the masters, this is a bit much. Indeed, the piston and connecting rod should not give a total of more than 10 g. The table also shows how behind the construction of the UZAM itself is - the masses of its parts moving back and forth are much larger. It is all the more difficult to increase the engine speed, its throttle response, and improve efficiency.

The fact is that a considerable part of the energy from the combustion of fuel is uselessly spent on moving parts up and down. At the same time, with an increase in speed, the vibration load of the engine is proportionally increased. Vibration reduction is achieved by balancing the engine (this is a set of measures), but then again the crankshaft is heavier, and hence new problems associated with its bending and torsional vibrations. That is why the lightness of the engine (and, above all, the moving parts) is largely characterized by its technical excellence.

Finished the measurements by evaluating the gaps between the valve stems and the guide bushings. Then Renault was puzzled: it turned out that over one and a half thousand kilometers the valve stems were worn out by 0.02 mm! I wonder what will be the further trend?

He guarded the appearance of the pistons (photo 4, 5) of the French engine. The stripes of "natirov" - and, in fact, the seizure of them (!) - brought us to the warranty service station Moskvich. Maybe got an unsuccessful motor? If this were so, we would probably be less upset because we were faced with something completely unexpected …

It turns out that this fact has long ceased to be surprised and consider what is happening almost as the norm: yes, many owners of Svyatogorov with the Renault engine pay attention to strong knocks in the cold engine that disappear with heating. For all disassembled motors, the piston skirts look the same.

Why, then, do not the owners of "Meganes" and "lagoons" traveling around Russia with the same motors complain of such defects? Guaranteeers say: the French came, looked, shrugged, recommended pouring “synthetics”. And then they introduced an improved piston. True, the knock … is still here.