Rocker arm for valve actuation

Abstract

The present invention provides an improved rocker arm system for actuating poppet valves in high performance internal combustion engines. The rocker arm provides journals extending from each side fitted to outboard bearing mounts to guide the motion of the rocker arm.

Description

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This is a U.S. non-provisional application relating to and claiming the benefit of U.S. Provisional Patent Application Ser. No. 60/635,468, filed Dec. 13, 2004 and is a Continuation-in-part of U.S. patent application Ser. No. 11/302,181 filed Dec. 12, 2005.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to the field of internal combustion engines, high performance and conventional manufactured engines in general use, pertaining to poppet valve operating systems, particularly rocker arm systems for valve actuation pivoting on a shaft, the rocker arm being actuated by push rods and a camshaft.

2. Description of Background Information

Internal combustion engines, including high performance engines and conventionally manufactured engines, having poppet valve systems actuated by rocker arms and push rods that operate at high engine speeds or having high dynamic forces within the valve system require specially designed rocker arm systems for stability and for use in high inertia force conditions. For example, a high performance engine speed may peak at approximately 9200 revolutions per minute. This engine speed corresponds to a valve system actuating at 77 cycles per second. These high engine speeds cause very high inertia forces and high amplitude vibration forces to react on rocker arms and valve system components.

Rocker arms manufactured for performance engines generally have a common design basis. The common design consists of a rocker arm beam body having a needle bearing pressed centered in the beam body. The rocker arm pivots on a shaft that is rigidly fastened by 2 bolts through the shaft located one on each side of the beam fastened to a mounting base attached to the engine cylinder head.

Engines using push rods to actuate valves often have the push rod skewed in an oblique movement direction offset from the plane of rotation of the pivoting rocker arm, opening and closing the valve. This condition results because engine block and cylinder head castings are complicated with structure in the path areas where push rods operate. The resulting skewed push rod path applies a twisting torque to the rocker arm beam that tends to deform the rocker arm beam and the supporting pivot bearing and pivot shaft mounting. FIG. 1A is a rear elevation view of a conventional high performance rocker arm system. Illustrated is the skewed offset push rod 17 and rocker arm 10 arrangements often found in performance engines. The push rod offset connection 19 and resulting offset force OPF is illustrated by arrows at an angle to rocker arm pivot path 22. FIG. 1B section view illustrates the effect of push rod inertia force inducing torsional twisting TT to rocker arm 10, impacting edge loading EL to needle bearing rollers NB within housing NBH that serves as an outer “race”. The centered, narrow bearing width is not sufficient to stabilize and distribute high impact force. Needle roller elements and fixed shaft FS are very hard steel, much harder than housing NBH and rocker arm 10. Conditions occur where bearing edge loading cause material to yield a slight amount, enough to increase bearing radial clearance, allowing excess looseness, known to increase vibration amplitude, inducing discord of valve timing lift and performance. The torsional deformation of the rocker arm increases stress within the rocker arm body. Indeed, crack failures are common in the beam area near the push rod connection. These described conditions require precautionary and costly rocker arm replacement after a short service time in performance engines. Providing stable rocker arms is a needed improvement provided by the present invention.

The first improvement area: A stabilized rocker arm pivot having different concepts to correct conventional rocker arm deficiencies is provided. The improved rocker arm system eliminates bearings located centered within the rocker arm beam that develop excess looseness and instability. A replacement complete rocker arm system innovation having wide spaced bearing journals extending from each side of a rocker arm beam mounted and supported by bearing mounts each side of the rocker arm beam is provided. The system provides improved wide spaced rigid stabilized mount system with short direct load paths to a precision tolerance positioning system and mounting providing a means to stabilize deflecting high load forces.

The second improvement area: Reducing rocker arm beam mass is practiced by engineers in order to control inertia effects on the valve system. The purpose is to (1) achieve high engine speeds and aggressive valve actuation and lift rates to increase cylinder filling with air and fuel mixtures for applications requiring increased performance and (2) reduce rocker arm mass and inertia force. Thus reducing vibration amplitude input to valve springs to reduce valve spring vibration and surge issues is an important objective. Once initiated, spring surge creates valve movement disarray and failures.

The third improvement area: A system for precision geometry inter-reacting with valve motion and component dimensional manufacturing and positioning is provided. A further improvement is easily interchangeable rocker arm and mount assemblies having different valve lift ratios and retaining precise precision rocker arm geometry. This facilitates changing engine performance by altering valve opening to meet required performance conditions.

SUMMARY OF THE INVENTION

In one form of this invention, there is provided a rocker arm having a narrow low inertia mass beam body free of irregular form and assembly openings that disrupt and concentrate stress load paths. The beam body includes journals extending outward from each side being the pivot for valve actuation. The rocker arm beam and journals forming a single rocker arm, pivoting as a single whole structure. First and second bearing mounts are provided to support the journals. The bearing mounts are located one on each side of the rocker arm. The bearing mounts receive and rotatably support the rocker arm journals, transferring dynamic loads by direct short path to a rigid attachment mounting base that extends across the cylinder head.

Preferably, the rocker arm valve lift ratios may be changed quickly by exchanging rocker arm and bearing mounts as an assembly set on a mounting station at each valve position. Positional placement of the pivot axis and geometry alignment to the valve and actuation remains precisely as designed. Changing rocker arm valve lift ratios is often desired for performance or racing applications.

Preferably, a spring rate function is developed for rocker arm beam portion on either side of the pivot portion. Initiating defection of rocker arm portion late in the valve opening sequence, storing energy like a spring, released as the cam opening is completed, in effect lofting the valve, increasing airflow into the cylinder. This is a potential benefit to valve actuation in certain applications.

Preferably, there is provision for setting valve lash clearance by means of a shim and/or spacer; eliminating the inertia mass of a screw adjustment fitting to the rocker arm body making connection with the push rod. Screw adjustments remain the most common alternative system in general use.

Preferably, the rocker arm beam is hollow. The hollow form provides a structural beam component having the least mass ratio to strength and overall rocker arm stiffness. Manufacturing hollow rocker arms presents particular difficulties and manufacturing costs.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings constitute a part of this specification and include the embodiment of this invention.

FIG. 1A is a rear elevation view of a prior art complete rocker arm system and components illustrating valve actuating systems manufactured for common use and illustrating skewed oblique push rod movement direction offset to rocker arm plane of rotation.

FIG. 1B is a sectional view of the top portion of FIG. 1A.

FIG. 2 is a plan view of a rocker arm assembly illustrating a system of one embodiment of the present invention.

FIG. 3 is a side elevation view of the trunnion rocker arm assembly illustrating the embodiment of the FIG. 2 invention.

FIG. 4 is a side elevation view of a whole single rocker arm arrangement illustrating another embodiment of the present invention.

FIG. 4A is a plan view of the embodiment of FIG. 4.

FIG. 5 is a side view of rocker arm support mounts installation and force load paths illustrating another embodiment of the present invention.

FIG. 5A is a section view of the embodiment of FIG. 5.

FIG. 6 is a view illustrating exchangeable rocker arm and support mounts with different rocker arm valve lift ratios and valve lash shim embodiment of the present invention.

FIG. 7 is a side elevation view illustrating a rocker arm having a spring rate embodiment of the present invention.

FIG. 7A is a section view of FIG. 7 taken through section line A-A.

FIG. 8 is a side elevation view illustrating a hollow rocker arm embodiment of the present invention.

FIG. 8A is a top view of the embodiment of FIG. 8.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The improved system embodies a rocker arm beam having journals, (cylindrical pivot projections, one each side), extending from each side of the rocker arm body making a single whole structure, supported and pivoting in outboard bearings and bearing mounts to guide the pivot motion of the rocker arm and journal as a whole. The improved rocker arm embodiment with journals and outboard bearings embodies a widely spaced dual bearing support, thus eliminating common installation of a pivot bearing or bearings centered within the rocker arm beam body. This improvement provides wide stable resistance to rocker beam deforming torsional forces. The improved stability provides a rocker arm pivot system having accurate and precise valve actuation. Improving valve system stability and precision leads to higher potential engine speed and improved engine performance and reduced or eliminated unwanted valve train excitation caused by vibration amplitude excesses.

A detailed description beginning with reference to FIG. 2 and FIG. 3 of the drawings illustrates rocker arm 10 and mounting system. Referring to FIG. 2, a plan view of the improved rocker arm system is illustrated incorporating a rocker arm 10 beam body having rocker arm journals 20 (cylindrical projections) illustrated as dark-dashed lines, extending from each side as a single whole, forming rocker arm 10 which is supported and pivots within outboard bearing mounts 11, having bearing bores, one at each side of rocker arm 10. The bearing mounts 11 being wide spaced provide stabilized support to rocker arm 10 from torsional offset push rod force OPF and twisting TT as noted in FIG. 1. The rocker arm 10 and the bores of the bearing mounts 11 are aligned with pivot axis PA dimensionally by geometric planes (discussed below) to the valve being actuated, positioned at a mounting station 25, as shown in FIG. 2, on or located from surface plane SP as shown in FIG. 3. The surface plane SP and connection alignment at each valve mounting station 25 provides precision attachment of rocker arm and bearing mount assemblies. A feature is an exchangeable rocker arm ratio set disclosed with FIG. 6. Rocker arm whole component 10 and bearing mounts 11 are fastened to each mounting station 25, being a portion of mounting base plate 12 which is fastened with bolts 13 (or studs) 2 at each bearing mount 11 to provide aligned positioning and a rigid mounting structure with high clamping force. Approximately 3,700 to 5,200 lbs. clamping force for each of the 4 fasteners is normally required for a rigid non-flexing system. Thrust bearing 24 as shown in FIG. 2, having a first side interfacing with a rocker arm 10 thrust face bearing surface 29, shown in FIGS. 4 and 4A is located on each side of the rocker arm 10 beam body. Thrust bearing 24 has second side interfacing between bearing mount 11. Thrust bearing 24 reduces friction and restricts axial movement thrust between these components. Mounting base plate 12 is in turn fastened across cylinder head 14 of an engine.

Valve lash adjuster and lock nut assembly 15, shown in FIG. 2 and FIG. 3, provides adjustment of valve clearance between rocker arm roller 16, providing a radial contact surface, or a rocker arm having a radial tip 34 in contact with valve 17 as illustrated in FIGS. 2-4. Valve clearance (lash) is required to accommodate and allow for engine thermal expansion provided by valve lash adjuster 15. Valve lash adjustment is possible by other means such as valve lash shim 23 which is illustrated and discussed in reference to FIG. 6. A partial view is included in FIG. 2 illustrating a typical skewed oblique offset push rod 18 making connection 19 to rocker arm 10 at valve lash adjuster 15.

FIG. 3 a side elevation view illustrating a complete rocker arm system, depicting the rocker arm 10 and system of the present invention. Continuing with FIG. 3 general components not visible in FIG. 2 are shown. Rocker arm 10 has extended journals 20 each side of the rocker arm body that fit into outboard bearing mounts 11 at each side of rocker arm 10. Pivot bearing 21 illustrates a rolling element bearing, however pivot bearing 21 could be a monolithic low friction bearing element. Rocker arm mounting and positioning are geometrically located on and from pivoting axis PA and planes illustrated in FIGS. 2 and 3.

FIGS. 4 and 4A illustrate top and side views of rocker arm 10 of the present invention. Typical are components making a single whole rocker arm structure 10 include a first component beam body 30, having a first portion 31 providing engine push rod connection 19 and offset 39 from pivot plane PP, illustrating a common offset condition, a beam body radial portion 32 location for pivot axis PA and journals 20, and a second body portion with a valve contact beam portion 30, having a radial surface 34 making contact with valve 17, and a tip end to actuate opening and closing of valve 17 through arc motion at pivot axis PA and pivot center PC. Beam body 10 having a continuous curvature form 33 is uninterrupted by irregular projections, structure openings or abrupt surface transitions. FIG. 3 illustrates rocker arm 10 making contact with valve 17 tip having a radial contact surface by means of roller 16. Another form of a radial surface is illustrated in FIGS. 4 and 4A. Surface 34 is a hardened insert 36. Radial surface 34 may also be machined or ground to a radial form to contact valve 17 tip end. Rocker arm 10 beam body radial portion 32 diameter extends outwardly from each journal 20 and includes thrust face bearing surfaces 29 with each side interfacing thrust bearings 24 one each side, illustrated installed in FIG. 2.

FIG. 4A, showing a beam body 30 cutaway view illustrates another embodiment. Inward lowered surface 36 is a depressed surface which is depressed to a depth predetermined distance allowing a solid mid-section thickness. Outer projected flanges, include upper flange 38 and lower flange 37. Configuration and depressed area dimensions are formed by removing mass from the beam and may be determined by using Finite Element Analysis Software (FEA). The defined depressed areas are a feature to reduce total inertia mass imparted into the valve spring and maintain rocker arm structural stiffness.

FIGS. 5 and 5A are side and section views illustrating wide spaced bearing mounts 11, each side of rocker arm 10, and indicates load path LP transferring rocker arm twisting torque TT from offset push rod forces OPF to wide spaced edges at journals 20 and bearing mounts 11. There is defined a wide radial circumferential contact bearing surface approximately 0.50 inch width at each bearing mount 11 limiting journal 20 twisting reactions by providing widely spaced width and radial clearance distribution. Clamping force CF connection provided by bolts/studs 13 react load path directly through bearing mounts 11 lower mounting surface. This is purposely made the shortest direct possible undeviating load path distance LPD. Load path distance LPD should not exceed 0.75 inch to mounting plate 12 and has a high bolt clamping force CF (approximately 3,700 to 5,200 lbs.) to maximize a rigid non-flexing mounting structure.

FIG. 6 illustrates a quick-change rocker arm system having means to change valve lift by exchanging rocker arm ratios as a set. This system includes a rocker arm and support mount having predetermined ratio and positioned pivot axis providing correct geometric alignment of rocker arm arc path to valve and valve tip contact position made by radial roller 16, or a rocker arm having a radial tip. Positioning is determined using geometric embodiment of the present invention.

FIG. 6 illustrates means to provide exchangeable rocker arm valve lift ratio sets. View A shows the primary rocker arm set, rocker arm 10A and support bearing mounts 11A having pivot axis PA-A positioned for rocker arm ratio set of 2.00 to 1 and is attached to mounting station 25 positioned by precision geometric alignment of located surface plane SP (discussed below) and stud/nut 13 positions. Spacing 40 accommodates geometrically correct positioning of required pivot axis, PA-A and PA-B, for rocker arm ratios illustrated. This method easily accommodates exchangeable ratios of 1.5 to 3.0 to 1. Precision placement of support bearing mounts 11A to station 25, for a 2.00 to 1 ratio valve lift of 0.800 inch is initially provided.

FIG. 6, View B shows the exchangeable rocker arm ratio set having pivot axis PA-B positioned correctly for rocker arm 10B ratio illustrated as rocker arm ratio 2.30 to 1 set, providing 0.920 inch valve lift for this example. Stud nuts 13 are removed and the rocker arm and mount assembly with a predetermined ratio set is reassembled. Correct geometric alignment is provided using distance D2 from valve tip end to bottom surface of support bearing mounts 11A and 11B providing support mounts having identical fitting dimensions 39 (noted in Views A and B). Push rod connection 19 to rocker arm 10A and 10B may remain in positional alignment, which is an objective for exchangeable rocker arm range. In the selected example (2.00 to 2.300 to 1), valve lift exchangeable increase of 0.800 to 0.920 inch and using existing push rod 18 length is enabled. Below is a table to predetermine exchangeable rocker arm ratios and valve lift.

RATIO FOR VALVE LIFT
CAM LIFT * RATIO = VALVE LIFT
0.400 IN. * 2.00 = 0.800 IN. VALVE LIFT
0.400 IN. * 2.30 = 0.920 IN. VALVE LIFT

Referring to FIG. 3 and View A of FIG. 6, a valve lash adjustment system using valve lash adjustment shim(s) 23 is illustrated being applicable to lash adjustment of rocker arm 10 in applications without valve lash adjuster and lock nut assembly 15 as illustrated in FIG. 3. Referring to View A of FIG. 6, rocker arm 10A lash shim 23 thickness provides a predetermined lash (a clearance to allow for thermal expansion change). Valve lash shim 23 raises the rocker arm set providing design lash clearance distance in combination with an optional spacer 26.

Spacer 26 provides mounting surface height adjustment where there is a need to accommodate variations in valve assembly components, such as valve 17 stem length variations. Mounting station 25 has surface plane SP located to provide for a spacer 26 with the thickness varied as required to position the pivot axis PA the distance D4 in combination with D2 and D3 from valve 17 tip end as illustrated in FIG. 3. Lash shim 23 is added after determining spacer 26 thickness.

FIG. 7 and FIG. 7A illustrates a “spring rate rocker” arm embodiment, which provides a function to the rocker arm beam portion from pivot portion 32 to valve 17 contact or to beam portion to contact 19 of a push rod. The beam body has a solid form shown in FIG. 7A. This embodiment provides a rocker arm deflection to impart additional valve opening energy after the cam lobe has opened the valve fully for increasing mixture flow into the combustion chamber for performance increase. This embodiment also reduces valve spring mass and spring closing force requirements by accommodating a portion of the valve spring function. By reducing valve spring mass and load force requirements, a potential benefit to reduce valve spring vibrations and surge dynamics is provided.

Preferably the rocker arm is made from high strength alloy steel. The side of the rocker arm tapers from the body radial portion 32 to the valve 17 contact area, defining a spring rate portion of the beam. Spring portion taper profile and dimensions required for strength and preferred deflection involves correlation between opening deflecting force applied by the cam lobe and resistance of valve opening force and spring force. Stress and deflection factors are difficult to calculate in most cases. Finite Element Analysis (FEA) is a most convenient accurate method to model distribution of stresses and deflection in combination with functional testing. Predetermined static spring rate function is illustrated by a simple example resolved using FEA. Starting with a valve lift design of 0.800 inch at a valve spring force of 500 lbs., a spring rate is modeled to provide predetermined deflection close to 0.030 inch deflection at a reduced spring closed force of 400-450 lbs. force and is accomplished within allowable tensile stress design limits. This is illustrated in the table below.

		ROCKER
	OPENING	ARM	TENSILE
	FORCE	DEFLECTION	STRESS
	450 LBS.	0.026 IN.	93,950 PSI
	400	0.024	83,520
	300	0.018	62,640
	200	0.012	41,180
	100	0.006	20,880

The deflection stores energy in the beam, like a spring, releases stored energy to accelerate the valve opening, a lofting motion, increasing mixture flow into combustion chamber after cam reached maximum lift.

For certain applications reducing and sustaining a minimum pivot bearing radial clearance is desired for maximum precision. This is accomplished by eliminating the pivot bearing 21 and using specially prepared bearing mounts. The special bearing Mounts 11 and journals 20 consist of treated surfaces to the parent material, accomplished by applying selected surface materials, hardness and finish selections. Available material coating such as diamond like carbon (DLC) produced by plasma source ion implantation (PSII) is a preferred technology embodiment of the invention.

Geometric alignment of the rocker arm arc path and forces opening and closing the valve must align closely with the valve center axis (VCA). This is required to reduce valve stem deflection and friction that affect performance and reliability. Location of the rocker arm pivot, the pivot center (PC), defines rocker arm path geometry in relation to the valve opening and closing requirements and valve center axis VCA. The embodiment of reference planes provide a mechanism to establish precise rocker arm arc and pivot dimensional geometry and to dimensionally define component orientation with the engine cylinder head and for manufacturing, assembly and adjustments.

FIG. 2 and FIG. 3 disclose specification for reference planes and placement. Referring to FIG. 2, illustrated is the primary geometric reference plane, identified as reference pivot plane (PP). This is the plane were rocker arm and motion geometry is defined the plane that orientates valve system component alignment to the cylinder head and valve. Reference plane PP is joined collinearly to the valve center axis VCA, establishing a first reference plane in alignment with the valve center axis. Directional alignment of reference plane PP provides a means to locate components and surfaces from the valve center axis VCA and reference plane PP within the engine cylinder head. Subsequent reference planes are generated relative to plane PP and a reference normal plane (NP). Referring to FIG. 3, normal plane (NP) is specified as being normal to plane PP and normal to the valve center axis VCA. The rocker arm pivot center (PC) and pivot axis (PA) are defined as lying on plane NP. The locating position coincide on pivot plane PP as illustrated in FIG. 2 and FIG. 3. Referring to FIG. 3, pivot axis PA is illustrated offset at distance D1 from the valve center axis VCA. Distance D1 is determined from rocker arm geometry. The linear dimension D4 from the closed valve tip end position to plane NP and is also determined by rocker arm arc geometry that considers valve lift design requirements and is dimensioned from the bottom of bearing mounts 11 by D2 and D3.

Referring to FIG. 3, mounting plate 12 is manufactured having surface plane SP parallel to plane NP. One purpose is to position components such as bearing mounts 11 and valve lash shim 23 in linear, direct line location, dimensioned from a manufactured surface plane SP. Another purpose is to insure that rocker arm pivot center PC and pivot axis PA remain in geometric alignment with the valve center axis VCA for assembly and adjustments. Surface plane SP is specified parallel to the normal plane NP. Dimension D2 locates bearing mount 11 base surface at a defined linear distance from the closed valve tip. Dimension D2 is complementary to establishing surface plane SP by including initial design shim thickness 23. Dimension D3 locates the pivot center PC and plane NP and the base of bearing mounts 11.

In another embodiment of the present invention illustrated in FIGS. 8 and 8A, the rocker arm beam 41 is hollow. The hollow beam form may be produced by two means. A machined hollow beam 41 having an open section for machining and a closure cover 42 may be welded or fused in place or a cast hollow beam 41 such as investment casting process with a core process may be used. FIG. 8 illustrates a hollow rocker arm body 41, and FIG. 8A, a section view with closure cover 42 prior to welding process.

Although preferred embodiments have been specified in the detailed description, there are system variations and combinations of the disclosed embodiments not shown that may be used. Combinations using the disclosed embodiments are applicable arrangement combinations. Reference planes and surface planes specified in the detailed description as a preferred embodiment are an appropriate application to rocker arm valve systems. The specified detailed embodiments of the present invention are especially noted to be applicable to requirements of the general field of internal combustion engines. While certain embodiments of the present invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention as defined by the following claims.

Claims

1. A rocker arm assembly comprising:

a single whole rocker arm including a beam body having a first body portion; said first body portion having an actuating end adapted to be connected to an engine push rod; said beam body having a second body portion including a radial surface for actuating a valve stem end tip; said beam body consisting having journals projecting outwardly one from each side of said beam body; said journals being a pivot axis for said single whole rocker arm; said single whole rocker arm pivoting at said pivot axis as a single load carrying unit for actuating an engine valve;

said journals having radial portions extending outwardly one from each side aligned with said journals pivot axis; said radial portions having diameters greater than said journal diameter thereby providing a thrust face bearing surface on each side of said beam body; at least portions of the sides of said rocker arm beam body having a continuous curvature form uninterrupted by irregular projections, openings or abrupt surface transitions; a mounting base having at least one mounting station; first and second support bearing mounts having bearing bores aligned with said pivot axis for receiving and supporting said rocker arm journals attached to the mounting station on the mounting base;

said support bearing mounts having aligned said bearing bores defining a circumferential contact bearing surface in which said journals pivot;

a pair of thrust bearings, one each side of said whole rocker arm, each having a first side interfacing with said rocker arm thrust face bearing surface a second side interfacing with side of said support bearing mount;

said journals each engage each thrust bearing without substantial restraint;

said support bearing mounts providing direct rocker arm load path from each bearing bore to said mounting station and said mounting base connection; said support bearing mounts each having a lower mounting surface; said lower mounting surface located a distance not exceeding 0.75 inch below said pivot axis of aligned bearing bores;

said support bearing mounts attach to said mounting station by plurality of positioning and fastening members;

said mounting base attached to a cylinder head of an engine extending across said cylinder head.

2. A rocker arm assembly of claim 1, wherein said support bearing mounts engage at least one valve lash shim and a spacer located between said support bearing mount lower mounting surface and matching surface of said mounting stations;

said spacer thickness adjusts said mounting stations surface height for said rocker arm assembly to said pivot axis position; said pivot axis and said lower mounting surface being perpendicular to said valve stem, positioned from valve tip; said spacer mounting surface once set, provides mounting surface for said valve lash shim; said shim(s) having thickness equal to the required valve lash.

3. The rocker arm assembly of claim 1 wherein said rocker arm and support bearing mounts at each said mounting station provide a exchangeable rocker arm valve lift ratio set.

4. The rocker arm assembly of claim 1 wherein said positioning and fastening members engage matching alignment holes within said support mounts for aligning and fastening to said mounting base station with the mountain base station surface being perpendicular to the stem of the engine valve.

5. The rocker assembly of claim 1 wherein the mounting base extends across the cylinder head providing a plurality of mounting stations across the cylinder head, one at each engine valve position.

6. A rocker arm beam body comprising:

a beam body with sides having an inward lower surface depressed to a predetermined depth on each side; said depressed area contour being offset inwardly a predetermined distance from the remainder of said beam body thereby leaving outer projected flange thickness above and below each side of said depressed area; said depressed area not being a through opening.

7. A rocker arm beam body comprising:

a beam body of solid configuration; said beam body having a pivot portion; one end of said beam body adapted to contact a valve stem tip and another end adapted to contact a push rod; said beam body tapering from said pivot portion decreasing thickness to said end having valve stem tip contact and tapering to said end having contact with push rod; said tapered beam body having a predetermined spring rate.

8. A rocker arm beam body comprising:

a beam body having a first hollow portion; said beam body having side walls separated and joined across a bottom; a closing cover fused to a portion of said side walls; said beam bodying having a first hollow portion extending from an end which connects to a push rod actuating to pivot axis portion; a second hollow portion extending from said pivot axis portion to an end having a radial surface contacting valve stem end tip.

9. A rocker arm system for internal combustion engines comprising:

a rocker arm; a journal attached to said rocker arm; portions of said journal extending outwardly from each side of said rocker arm; first and second bearing mounts for said journal;

said bearing mounts located on each side of said rocker arm;

said bearing mounts receive and rotatably support said journal;

a mounting base; said bearing mounts attached to said mounting base which locate and restrain said bearing mounts.

10. The system of claim 9 wherein said journal is connected with said rocker arm.