Blow by blow
DIESEL engine performance and efficiency generally deteriorate with age.
To a large degree this is due to the progressive accumulation of deposits throughout several parts of engines. Piston ring grooves, valves, diesel injectors, diesel particulate filters, turbochargers and exhaust gas recirculation valves are typical places where deposit build up occurs.
One of the more visible, early signs of deteriorating performance is dirtier engine oil, a direct result of increased oil soot levels.
It’s a direct indicator that all is not right. Elevated soot level is the main culprit in limiting the oil service period. It’s also known to increase engine wear and shorten service life.
Taking corrective action to physically remove these deposits will immediately restore operating performance and efficiency, while reducing wear rates to target longer engine life.
Engine blow-by
Engine blow-by is the term used for loss of cylinder compression, as it leaks past the piston rings and into the crankcase.
Blow-by is a direct cause of diesel smoke, oil consumption, loss of compression, and high levels of soot in the lube oil.
So, it’s not surprising that it’s a common trigger point for a complete (and expensive) engine overhaul. For a mine haul truck, it could mean $300,000 to $500,000 for repairs and downtime costs could go through the roof.
Blow-by is usually regarded as an indicator of wear, but the truth is that, in 80pc of cases, blow-by is a symptom of piston ring fouling, due to carbon accumulation in the piston ring groove, which prevents the ring from forming an effective seal to contain the compression gases.
Engine blow-by can initially start due to unsuitable operating conditions, excessive idling, over-extended service periods, problems with emission control equipment or other reasons.
The longer blow-by continues, the more deposits develop around piston rings, valve gear, emission control equipment, turbochargers and more.
Operating performance starts to decline, fuel consumption increases and eventually, catastrophic engine failure can occur.
There is generally nothing in recommended maintenance that addresses these deposits but there is a large window of opportunity to correct this condition, before wear becomes seriously impacted.
The solution
Introducing corrective maintenance into the preventative maintenance schedule extends component life, and reduces unplanned maintenance costs, while optimising whole-of-life production performance.
Carbon is the main cause of piston ring breakages, and it is easily prevented.
Cost Effective Maintenance specialises in corrective and preventative maintenance. With over 30 years’ experience in mining and road transport, CEM have a strong focus on reducing engine blow-by and restoring lost compression control and oil control in diesel engines of all types.
The company has developed an effective, Australian made, easy to use, two-part package that directly addresses the root cause of blow-by.
The first step safely dissolves, disperses and removes these problem deposits by using a detergent/dispersant type flushing oil concentrate to remove all contaminants from the engine crankcase.
The second part introduces a ‘decarboniser’ into the diesel, which actively burns off “top end” hard carbon deposits exposed to the fuel flame.
This mechanism directly addresses the root cause of engine blow-by. It restores and maintains a clean top piston ring groove for ongoing compression control.
Turbochargers, diesel particulate filters and exhaust gas recirculation (EGR) valves are common problem areas. Active decarbonizing from the combustion flame ensures long, trouble free service from these components.
This package has proven successful even in very high hour engines and offers a low cost means of screening engines that may appear to warrant overhauling.
Up to 80pc of these engines may have considerable service life remaining and if they are mechanically sound, blow-by levels will reduce significantly – allowing for an increased engine life of about 25 pc.
Optimising diesel engine life by this procedure has the potential to save a mine with 10 large dump trucks about $3.5m over a mine life of 10 years – that’s after costs, and without including any accompanying energy efficiency associated with improving engine operating condition.