CASE SERIES|PASSENGER ROAD TRANSPORT|ICE · COMPRESSION
TECHNICAL REPORTS, KhMPATP No. 3 · NOVEMBER – DECEMBER 2001
series of 2 acts
Ikarus 280 and LiAZ 677: compression increased on both engines
PRODUCTXADO technologyrestorative engine repair while the vehicle stays in service
UNITS IN THE SERIESTwo city busesIkarus 280, fleet No. 532 · LiAZ 677, fleet No. 609
DOCUMENT TYPEEnterprise technical reports
signed and stamped
signed and stamped
Key results
↑8.3-40%
compression by cylinder, Ikarus 280, 25-27 → 28-30 kgf/cm²; the rest unchanged; gain in 13 of 14 measurements; the rest unchanged
↑8.3-40%
compression by cylinder, LiAZ 677, 5.0-6.0 → 6.0-7.0 kgf/cm²; the rest unchanged; gain in 13 of 14 measurements; the rest unchanged
| VEHICLE | ENGINE | TREATMENT → REPEAT MEASUREMENT | WHAT WAS MEASURED |
|---|---|---|---|
| Ikarus 280 bus, fleet No. 532 | Diesel, 6 cylinders, No. 101490218 | 9 Nov 2001 → 6 Dec 2001, mileage 2063 km | Compression in all cylinders |
| LiAZ 677 bus, fleet No. 609 | 8 cylinders | 9 Nov 2001 → 26 Nov 2001, mileage 2987 km | Compression in all cylinders |
Result for each vehicle
| VEHICLE | ENGINE | COMPRESSION BEFORE, kgf/cm² | AFTER, kgf/cm² | GAIN BY CYLINDER |
|---|---|---|---|---|
| Ikarus 280, fleet No. 532 | Diesel, 6 cylinders | 25-27 | 28-30 | +11-16 % |
| LiAZ 677, fleet No. 609 | 8 cylinders | 5.0-6.0 | 6.0-7.0 | +8-40 % |
The absolute levels of the two engines are not comparable with each other: the gain in each cylinder is what should be compared.
Compression by cylinder — both engines
| VEHICLE | CYLINDER | BEFORE, kgf/cm² | AFTER, kgf/cm² | CHANGE |
|---|---|---|---|---|
| Ikarus 280, fleet No. 532 | 1 | 26 | 29 | +11.5 % |
| Ikarus 280, fleet No. 532 | 2 | 27 | 30 | +11.1 % |
| Ikarus 280, fleet No. 532 | 3 | 25 | 29 | +16.0 % |
| Ikarus 280, fleet No. 532 | 4 | 26 | 29 | +11.5 % |
| Ikarus 280, fleet No. 532 | 5 | 25 | 28 | +12.0 % |
| Ikarus 280, fleet No. 532 | 6 | 25 | 28 | +12.0 % |
| LiAZ 677, fleet No. 609 | 1 | 6.0 | 6.5 | +8.3 % |
| LiAZ 677, fleet No. 609 | 2 | 5.5 | 7.0 | +27.3 % |
| LiAZ 677, fleet No. 609 | 3 | 5.0 | 7.0 | +40.0 % |
| LiAZ 677, fleet No. 609 | 4 | 6.0 | 6.5 | +8.3 % |
| LiAZ 677, fleet No. 609 | 5 | 5.0 | 7.0 | +40.0 % |
| LiAZ 677, fleet No. 609 | 6 | 6.0 | 6.0 | 0 % |
| LiAZ 677, fleet No. 609 | 7 | 6.0 | 7.0 | +16.7 % |
| LiAZ 677, fleet No. 609 | 8 | 6.0 | 7.0 | +16.7 % |
The more worn the cylinder, the larger the gain: in the LiAZ cylinders that started at 5.0 kgf/cm², compression rose by 40 %.
Conclusion for the series
Two buses of different classes were treated on the same day, 9 November 2001, and came back for measurement after ordinary service runs — 2063 and 2987 km. On the Ikarus 280 diesel, compression rose in all six cylinders: 25-27 → 28-30 kgf/cm². On the eight-cylinder LiAZ 677 engine the whole range moved up, 5.0-6.0 → 6.0-7.0 kgf/cm²: the weakest cylinder reached the level that had been the engine's best before treatment. The gain followed the wear — where compression was lower, the gain was larger: the revitalizant builds up the coating where metal is missing. Compression cannot rise above the factory nominal, so bringing the lagging cylinders up to the common level is the maximum achievable. The result repeated on two different engines, without taking the vehicles out of service.
The results apply to the Ikarus 280 and LiAZ 677 bus engines in city service at KhMPATP No. 3, Khabarovsk; on other equipment and under other duty cycles the figures may differ. The originals of both technical reports, signed and stamped, are published in full and available for download.
Current equivalent
- Revitalizant gel for cylinder restorationEngine cylinders, deep wear
- Revitalizant gel for diesel enginesDiesel engines
- Revitalizant gel for petrol enginesPetrol engines
How such units are treated: