Extended life, extended oil drains
This Genset receives both!
This is a continuous run generator powered by a Hercules G1600 inline four cylinder engine. It is used to provide electrical power for a remote site.

In January of 1996 the engine on this genset was rebuilt and put into service. It ran continually until the end of June, 1998 where it was disassembled for inspection. When disassembled the engine had accumulated over 19,000 operating hours. This genset has used Amsoil 100% synthetic lubricant and Amsoil bypass and full flow oil filtration products exclusively following an initial break-in on petroleum oil.

The following report details the findings of the disassembly inspection.
GIVEN
Engine Manufacture Model Displacement Fuel On-line Percentage RPM
Hercules G1600 1600cc LPG (Propane) 100% 1800
Motor Oil Oil Filtration Oil Drain Interval Air Filtration Air Filter Service
AMSOIL 10w-30 100% Synthetic AMSOIL Full Flow and Bypass 4000 - 5500 hrs AMSOIL Oil wetted foam Once per Year
Oil Consumption, Petroleum 15W- 40
(at end of break-in period) 		Oil Consumption, Amsoil 100% Synthetic 10w-30
(never varied throughout 19,000 hr operation)
1 qt. per 24 hours of operation 0.5 qt. per 24 hours of operation
DISCUSSION
To those that know, the above information has highlighted some service practices that to conventional minds are unthinkable. For instance, the factory recommended oil drain interval for this engine is 1000hrs. and yet this engine is operating with oil drains that are 4 to 5.5 times that recommended.
Why? Is this an example of neglectful operation of a piece of equipment?
NO, NOT AT ALL!

This engine is an excellent example of the service life and oil drain extensions achievable as well as the plain savings of a great deal of money that is realized when an extended drain 100% synthetic AMSOIL motor oil is used in conjunction with AMSOIL's full flow and bypass oil and air filtration products.
Applying conventional wisdom with previous knowledge of conventional engine wear rates dictated an engine of this size would require a complete overhaul long before 19,000 hrs, and is the reason for the disassembly inspection now. Also, conventional wisdom indicated continued operation of this engine with this may operating hours on it was inviting catostrophic failure of the engine. As you will see from the picture evidence provided of the fitted clearances of various engine parts, conventional wear rates do not apply to this engine!
AS MEASURED
The #3 rod cap and bearing. The plastigage mark is just to the left of the hole in the sleave bearing. It indicates a clearance of 0.0015" after 19,000 hrs. of operation. The bearing is in very good shape. New fitted clearance was 0.0010".
The middle main bearing journal. Note, this engine has but three main bearings, not five as might be expected. Therefore more wear should be expected.
This is a close up of the picture above. The plastigage indicates a clearance of 0.0017" after 19,000 hrs. of operation. New fitted clearance was 0.0010".
The rocker area of the head. Note the spotlessly clean internal surfaces. There is not a single deposit anywhere.
An overview of the engines bottom end. Again, spotlessly clean for any engine, especially one with 19,000 plus hours of operation using 4000 ~ 5500 hr. oil drain intervals.
Cam follower area (engine is upside down on engine stand) on the side of the block, spotlessly clean, again, no deposits at all.
The oil pan. Note, the debris in the pan is cork material from several rocker cover gasket changes. It seems more care needs to taken to ensure less of it enters the engine at valve clearance inspections! Again, exceptionally clean for a 19,000 hr old engine operating on 4000 ~ 5500 hr. oil drain intervals.
Cross hatch is easily viewable on all cylinders.This is #2 cylinder. All piston rings had almost no wear. The largest increase in clearance was the top piston ring with an end gap increase of 0.002" from new as measured at the top of the ring travel in the cylinder bore. This picture is not showing us a ring ridge. There is NO measurable ridge as the ring end gap stayed the same anywhere in the bore, even above the ring travel. The lip observed is combustion deposits.
The vertical line is not a scratch, it is where the top ring end gap was. Nothing could be felt with the finger nail across this line.
Piston ring land side clearance changes
Top Ring Middle Ring Oil Ring
New 0.003" 0.002" 0.0015"
19,000 hrs 0.005" 0.002" 0.0015"
OIL ANALYSIS
Oil analysis was initially performed every 1000hrs. These intervals were extended as the reports back continually showed oil in excellent condition. This is a fax of the last oil analysis lab report prior to engine disassembly.
OTHER FINDINGS
The Amsoil bypass oil filter setup was in operation before the existing paper air filter element was replaced with the Amsoil foam air filter. Once the Amsoil air filter was installed, service life of the Amsoil bypass oil filter was greatly extended still flowing fine when the Amsoil oil was changed in the 4,500 to 5,500hrs range. With the paper air filter, 1,500 hrs was the maximum service life we could get. What does this mean? The Amsoil foam air filter was blocking much more dirt than the previous paper air filters, so there was less dirt entering the oil for the bypass oil filter to remove.
CONCLUSIONS
As seen from the measured clearances and the photographic evidence submitted to support these measurements, combining Amsoil synthetic lubricants and Amsoil filtration products together provides an engine with the potential for a very long life indeed. To suggest that this engine would have completed another 19,000 hrs. of trouble free bottom end operation is completely reasonable. All the measurements of the bottom end show this engine still meets NEW clearance specifications.

The engine was reassembled with new bearing shells, pistons and rings, valves, valve springs and exhaust seats, headbolts, water and oil pump. On later disassembly, the oil pump was in as-new condition, only very light swirls on the endplate, with not even a mark on either gear. No machining other than cylinder deglaze and head work was performed on this engine.

Note: The cylinder head was taken to the engine rebuilders before disassembly pictures could be taken. The report from the rebuilders indicated that the head needed new guides and valves as well as exhaust seats. A solvent leak test was performed on site and all but two valves held tight. The two valves that did leak had a just perceptable wetness indicating a minor leak.

Cylinder Head Service History
At 12,000hrs cylinder #2's compression was down 11% from new. The head was removed and inspection indicated continued use without new parts was possible if the exhaust valves and seats were ground. This was done and the head was put back into service. The cylinder head then operated without further parts or service until the 19,000 hr. inspection. (As a comparison, conventionally operated gensets of this size require complete cylinder head overhauls at about 6000 hrs.)
SUMMARY
Ultimately the cost of operating this equipment with conventional petroleum oil and OEM equivalent oil and air filters needs to be compared to the cost of using Amsoil products.

There are many presumptions made here, and all of them are made to make petroleum look better than it is. A really big presumption is that the conventional oil consumption would have remained at 1qt per day. This consumption value was measured just after its initial break-in, just before the engine was converted to Amsoil synthetic oil. As the engine wore out, consumption would have risen. Makeup oil is a big factor in upfront operating cost. Amsoil consumption typically is about 25-35% that of conventional oil consumption. The Amsoil oil consumption was flatline, 0.5 qt/day for the entire 19,000 hrs. This presumption of flatline petroleum oil consumption has incorrectly lowered the makeup oil cost, ($1303.50). In actual operation this engine would have seen much increased petroleum oil consumption as the engine would have gone through 2) overhauls with OEM filtration and petroleum oil.
Cost of Operation for 19,000 hrs using Retail Prices, (US dollars)
Conventional Amsoil
Oil used for oil changes $156.75, 95qt $123.75, 25qt
Makeup oil used $1303.50, 790 qt $1955.25, 395 qt
Oil Filters $54.50, 19 $134.40, Full Flow & Bypass 4sets
Air Filters $57, 19 $23.25, 1 cleaned 2x
Labor to change oil @ $20hr $190, 19x $42, 4.2x
Overhaul Engine $7000, bottom end 2x, head 3x $2000, bottom end 0.5x, head 1.5x
Totals $8761.75 $4278.65
Copyright © Oiltech 1998