The changes in them are quite significant:
- this is a camshaft drive using a toothed elastic belt (Fig. 7). Belt 5 is made of special rubber reinforced with fiberglass cord, and its toothed (122 teeth) surface is covered with a special elastic fabric. Since the toothed belt, in addition to the camshaft, also drives the oil pump and ignition distributor, its length is quite large. Therefore, the design provides for a new tensioner. Conveniently, the new drive does not require lubrication and is reliably protected from dust and dirt. In this regard, its operability is maintained for 60-70 thousand km of run;
- these are new pistons. To eliminate cases where, due to the fault of an inexperienced driver, the piston "catches up" with the valve (this occurs on engines of previous models when the crankshaft speed increases above 6000 rpm), the piston bottoms now have dimples. This eliminates the possibility of the piston meeting the valve plate even in unforeseen circumstances;
- this is a new ignition system. The engines are equipped with a new ignition distributor R-125D, equipped with a vacuum advance automatic. As soon as the engine load decreases, the automatic immediately increases the ignition advance angle and thereby maintains the most economical mode;
- this is an air filter equipment device that automatically maintains a constant temperature of the air entering the carburetor;
- this is a significantly improved carburetor, the advantages of which we will discuss below.
No matter how perfect the engine is, no matter how many automatic devices are mounted on it, its normal operation can only be ensured by regular and competent maintenance of its good condition, i.e. timely implementation of adjustment work.
The information is published on the website [vazbook.ru]