HYDRAULIC COMPENSATORS ARE BETTER
This is one of the most effective proposals for improving the Lada engines was presented in the journal back in 1989 (No. 12). Later we talked about the positive results of their use on editorial cars of those years.
Recently, the manufacturer of hydraulic lifters - VEA Hermes modernized the design, which prompted us to install the device on the editorial Niva VAZ 2121 3. Behind the first 10 thousand kilometers, which gives reason to once again return to the device, which may be of interest to owners of Zhiguli all models.
Says Boris SINELNIKOV.
Let me remind you of the principle: instead of the screws that control the valve clearances, screw plunger pairs “bushings-cylinders - plungers” are screwed into the head of the block. Oil is supplied to them from the lubrication system through additional tubes, due to which the plunger forces the lever (rocker) to constantly press against the cam cam surface. What does it give? There is no need to check and adjust valve clearances, gas distribution phases are more accurately observed, parts of the gas distribution mechanism wear out less and make noise (they do not experience shock loads now). In addition, a decrease in toxicity of the exhaust (including the content of CO by five to seven times) and fuel consumption was noted.
But if this mechanism is so good, why is it not installed on the conveyor? There are several reasons for this. The main thing - the installation of the device requires thoroughness and fine adjustment, which means time, which is an impermissible luxury for the factory conveyor. For stations, such work is unprofitable. In addition, the device has a drawback: in case of removing the head of the block, it must be disassembled. And reassemble with old gaskets is impossible.
These circumstances prompted Hermes specialists to improve the design. First, they developed a plunger pair without supplying oil from the system - it got there from the oil mist filling the space under the head cover. This greatly simplified installation. However, the lack of oil flow led to the fact that hydraulic lifters at high speeds began to work as shock absorbers, and this idea had to be abandoned.
The latest upgrade is an improvement in the system that supplies oil to the steam. If before it had to be assembled on the engine from many parts using sealing rings, now they are replaced by a single ramp. Its nipples made of durable heat-resistant plastic easily, without sealing rings, are connected to plates (from the same plastic) in which steel rings for the plunger pair are embedded. This solution allows you to install plates on uneven bosses, which are often found on engines of recent years of production. In addition, the system is quickly and easily assembled and disassembled, and this can be done repeatedly.
Thanks to more reliable connections oil leaks are excluded. This made it possible to increase the gap between the plunger and the sleeve, which previously had to be kept within a few hundredths of a millimeter. Now their surfaces can even be cleaned with fine sandpaper, if necessary over time.
Another long-standing question of motorists interested in hydraulic lifters: is it difficult to mount them on their own?