Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

A SINGLE CYLINDER GASOLINE ENGINE VALVE TRAIN WEAR TEST FOR LUBRICANTS

IP.com Disclosure Number: IPCOM000124243D
Publication Date: 2005-Apr-12
Document File: 7 page(s) / 64K

Publishing Venue

The IP.com Prior Art Database

Related People

SARITA R. KELLEY: ATTORNEY [+4]

Abstract

Use of a modified small engine test for the evaluation of experimental lubricants and experimental engine oil additives. The test provides useful results which correlate positively with the industry standard test.

This text was extracted from a Microsoft Word document.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 33% of the total text.

TITLE

A SINGLE CYLINDER GASOLINE ENGINE VALVE TRAIN WEAR TEST FOR LUBRICANTS

INTRODUCTION

Small scale test methods are needed for the evaluation of the anti-wear properties of experimental lubricants and experimental engine oil additives.  Standard bench test methods have been used to test lubricants, but these methods fail to simulate the environment of an operating engine, and often do not predict engine performance.  Engine tests are widely known.  Most engine tests for lubricants are expensive, and require large quantities of lubricant; this makes them unsuitable for the evaluation of experimental lubricants, particularly experimental engine oil additives.  Thus, there is a great need for a less expensive and more precise method for the evaluation of experimental lubricants and experimental engine oil additives.

  

SUMMARY

We have developed a small engine test for the evaluation of experimental lubricants and experimental engine oil additives.  A common air cooled single cylinder gasoline engine was modified such that the load on the valve train components was increased to accelerate wear.  We have developed conditions for the operation of this modified engine that have provided a ranking of oils of known wear performance from an industry standard engine test, the Sequence IV-A engine test,ASTM D6891, in order of their known performance.  Most importantly, the test using the modified small engine uses small amounts of lubricant and is inexpensive to perform.  The test conditions for the small engine are unique in a number of ways. The engine used is of a simple design which does not employ oil filtration.  Oil distribution is achieved via a splash system, as opposed to a pump system.  The previously mentioned industry standard engine test employs special components and oil filtration.  Lack of oil filtration, and load modification allow for a very short small engine wear test, and provide useful test results which correlate positively with the industry standard test.  

DETAILED DESCRIPTION

The Engine

Air-cooled single cylinder overhead valve engine was used as received from the manufacturer with the exception of a modification to the valve train.  The valve train components of interest, particularly the cam shaft, are made from non-hardened (soft) cast iron making them susceptible to wear.  The engine is a naturally aspirated gasoline engine that produces about 8 horse power.  It is splash lubricated.

 

As received, the engine was outfitted with single wound valve springs.  In order to accelerate wear, the load on the valve train was increased by replacement of the factory valve springs with a set of dual springs.  At the maximum spring compression achieved during engine operation, the double wound springs provided 1.45 times the stock spring load.

For each test, the engine was outfitted with a new factory camshaft and tappets.  The engine was used until a visual inspection of the crankshaft, cylinder liner, and car...