SERIES OF TWO REPORTS|ROAD TRANSPORT|PETROL ENGINES · COMPRESSION
ENGINE TREATMENT REPORTS · 10.10.2003
series of 2 acts
UAZ-3962 and VAZ-21093: compression up, cylinders evened out — no teardown
PRODUCTXADO revitalizant gelfor petrol engines · added without dismantling the unit
TEST OBJECTPetrol engines of two vehiclesUAZ-3962, plate No. E 294 VR 51 · VAZ-21093, plate No. E 935 VR 51
DOCUMENT TYPETwo company reports
with signatures and seals
with signatures and seals
What repeated on both engines
compression evened out across the cylinders
↑25-65.3%
compression per cylinder, 4.9-5.4 → 8.1-8.2 on the UAZ and 8-10 → 12-12.5 on the VAZ
| VEHICLE | CONDITION AT START | WHAT WAS MEASURED | REPORT DATE |
|---|---|---|---|
| UAZ-3962<br/>plate No. E 294 VR 51 | built 1994, 9 years in service | Compression in each of the four cylinders before and after treatment | 10.10.2003 |
| VAZ-21093<br/>plate No. E 935 VR 51 | built 2000, about 3 years in service | Compression in each of the four cylinders before and after treatment | 10.10.2003 |
Compression per cylinder — both engines
| VEHICLE | CYLINDER | BEFORE | AFTER | CHANGE |
|---|---|---|---|---|
| UAZ-3962, E 294 VR 51 | No. 1 | 5 | 8.2 | +64 % |
| UAZ-3962, E 294 VR 51 | No. 2 | 5.1 | 8.2 | +61 % |
| UAZ-3962, E 294 VR 51 | No. 3 | 5.4 | 8.2 | +52 % |
| UAZ-3962, E 294 VR 51 | No. 4 | 4.9 | 8.1 | +65 % |
| VAZ-21093, E 935 VR 51 | No. 1 | 9.5 | 12 | +26 % |
| VAZ-21093, E 935 VR 51 | No. 2 | 10 | 12.5 | +25 % |
| VAZ-21093, E 935 VR 51 | No. 3 | 10 | 12.5 | +25 % |
| VAZ-21093, E 935 VR 51 | No. 4 | 8 | 12 | +50 % |
Compression is given exactly as recorded in the reports: the documents do not name the unit of measurement, so the change is expressed as a percentage.
Cylinder evening-out — both engines
| VEHICLE | COMPRESSION BEFORE | COMPRESSION AFTER | SPREAD BETWEEN CYLINDERS |
|---|---|---|---|
| UAZ-3962, E 294 VR 51 | 4.9-5.4 | 8.1-8.2 | 0.5 → 0.1 |
| VAZ-21093, E 935 VR 51 | 8-10 | 12-12.5 | 2.0 → 0.5 |
The spread is the difference between the strongest and the weakest cylinder. The weakest cylinders gained the most: 4.9 → 8.1 and 8 → 12.
Conclusion from the two reports
Compression rose in every one of the eight cylinders of both vehicles, and most of all in the weakest ones: 4.9 → 8.1 on the UAZ-3962 and 8 → 12 on the VAZ-21093. Compression physically cannot rise above the manufacturer's rated value, so all cylinders reaching one and the same figure means restored sealing of the cylinder-piston group — the maximum attainable, not a random gain. The spread between cylinders shrank from 2.0 to 0.5 and from 0.5 to 0.1: the engine begins to run evenly. Both reports record the same findings: "engine vibration decreased, pulling power and throttle response improved, oil pressure and idle speed increased", "Fuel consumption decreased". These assessments are stated in words in the reports; compression is the figure that was recorded numerically.
The results relate to the four-cylinder petrol engines of UAZ-3962 and VAZ-21093 vehicles in a fleet's regular service; on other equipment and under other conditions the figures may differ. The originals of both reports, with signatures and seals, are published in full and available for download.
Current equivalent
- Revitalizant gel for cylinder restorationEngine cylinders, deep wear
- Revitalizant gel for petrol enginesPetrol engines
How such units are treated: