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The latest product updates to the 4stHEAD and 4stSOFT software are detailed below. The complete information on each of these products and their respective sub-programs are on their respective pages.

New 4stHEAD Product Updates March 2008
The following 4stHEAD software upgrades were introduced in March 2008:
INTEGRATION OF SIGNIFICANT ELEMENTS OF 'CAM DESIGN/MANUFACTURE' AND 'VALVETRAIN DYNAMICS' INTO 'VALVE LIFT PROFILE DESIGN' Upon completion of a design in the 'cam design and manufacture' program when it comes to 'creating the manufacturing output' data there, a further option has been added to the 4stHEAD software. This option permits the export of all of the valvetrain data, i.e., its type of cam follower mechanism, the detailed geometry of that cam follower mechanism, the mass of each component of that cam follower mechanism, the masses of the valve springs, the preload applied to the valve mechanism by the valve springs, and the stiffnesses of the valve springs at both the preload level together with any progression of that stiffness towards maximum valve lift (to record the effect of a progressive spring). This entire valvetrain data is exported as a data file which can be subsequently imported into all three 'valve lift profile' design program options (HMB, GPB and GPBv2) where not only can a static and a dynamics analysis of the valvetrain be conducted at each stage of the design process for a valve lift profile but the output also graphs the radius of curvature of the ensuing cam profile and numerically displays the minimum positive (and also negative if applicable) radii of curvature of that cam profile.

New 4stHEAD Product Updates February 2008
In CAM MANUFACTURE:
Upon completion of a cam design, the following standard manufacturing grinding files have now been added as output data; (a) for NTC grinding machines in either Taiwan or the USA, (b) for Schaudt grinding machines and, (c) for a prototype cam grinding machine manufactured in-house by one of our user-clients, as CNC machine code in 0.1 deg intervals. We have enhanced the accuracy of, and simplified the data entry to, the "dynamic" model which computes the Hertz stresses and cam follower forces and oil film thickness.
In VALVETRAIN DYNAMICS:
We have very significantly upgraded the model for hydraulic tappets with pushrod followers. You may observe the detail of this model here in the 4stHEAD section of this website which elevates our model as being not only for analysis but is also for the design of hydraulic tappets. We have added triple coil valve springs to be used in the software. Quite a few of our clients are in the (American) NHRA drag racing business and triple valve spring installations with pushrod follower mechanisms are very common in that application. In all previous iterations of 'valvetrain dynamics' the detail of the valve seat dynamic model during valve bounce and re-seating was 'hidden' from the user's input perspective. This has now been opened up to the user and the model significantly enhanced in that the user can now select the material of the valve seat insert and also the valve seat angle both of which have a profound effect on the stiffness and damping coefficient between valve and valve seat.

WEBSITE Update December 2007
Site redesigned. Also now includes 4stSOFT.

New Product Updates November 2007
Introduction of second product, 4stSOFT. In December 2006 (see below) we reported an upgrade to the 4stHEAD software to include an expanded and enhanced version of the software package formerly sold by SAE as reference R-186SW to accompany the textbook "Design and Simulation of Four-Stroke Engines" (SAE reference R-186 at www.sae.org) authored by Professor Blair. The bundling of the 'old with the new' revealed possible long-term programming confusion and so it was decided to make the included software into a stand alone software suite which is automatically supplied to all perpetual 4stHEAD licence holders. We were further encouraged to do so, and make it available more widely, by the popular demand for this 4stSOFT software as expressed in many private communications to us from those who had bought the book and were frustrated to find that the 'accompanying software' described in it could no longer be obtained from SAE. Hence this introduction of the 4stSOFT software and more details of its contents are to be found within its page on this website

New Product Updates September 2007
In our 'VALVETRAIN DYNAMICS' computation procedures before September 2007, all cam tappets for a pushrod follower mechanism have been assumed to be 'solid tappets' having a mass, a stiffness, and internal and guide damping coefficients. With this update, users can now opt to employ a hydraulic cam tappet where the input data required is extended from the above to include the detailed physical geometry of the internals of the hydraulic tappet and the properties of the oil being supplied to it. From this extended data, the computation for the dynamics of the entire engine and pushrod mechanism can proceed with the inclusion of accurate data for the stiffness of the hydraulic cam tappet at the actual setting of its drylash position between minimum and maximum drylash. An explanatory picture of this input data process can be found within the 'valvetrain analysis' area of the '4stHEAD' section in this website.

New Product Updates August 2007
A selection of the enhancements which have been added to the software in the period March to August 2007, and which have been supplied to all user clients, are described below:
Users can create cam tappet lift files for a pushrod mechanism where the valve follower pad is either 'normal' with a roller or a radiused pad, or is a perfectly centred valve follower pad. The output data yields a cam tappet lift file which can be taken directly to cam design and manufacture where a further manufacturing enhancement now outputs correctly-formatted cam grinding data for Okuma cam grinding machines, as it did previously for many others. Much clarity has now been implemented for all cam tappet lift files (of the .DES. S96, etc, type) in that the file title now encapsulates the base circle and cam tappet radii information, such files not normally holding this critical information, and also permits the creation of alternate cam tappet lift files for the same cam lobe but with differing cam tappet radii. This latter feature is particularly important for finger and rocker mechanisms where a conventional cam tappet lift file used for cam manufacture has no physical meaning.
Valvetrain dynamics computations are mathematically complex and can often seem slow to compute, even on the fastest computers. Much time can be wasted by a user waiting for a computation to complete. Batch programming has now been implemented so that the user can load up a series of input data and then let the computation for all of them operate in the background while proceeding with other duties.
In the 'valvetrain dynamic analysis input data page' the user must insert 'measured' data for the camshaft mass and stiffness as 'measured' at the relevant cam lobe of the actual camshaft in-situ in the engine. Clearly, this is difficult data to acquire. The users are now supplied with a simplified version of an FEM-type analysis in which they input the geometry of the camshaft and the camshaft lobe and the materials of that camshaft and its housing and the analysis produces the relevant camshaft mass and stiffness to be inserted as input data.
Significant enhancements have been made to the already-sophisticated valve lift profile design programs where the users can see immediately the design differences between their previous design iteration or that of an imported valve lift profile design file. The comparison data they can scrutinise is also more extensive than previously provided, particularly in the area of Fourier analysis.

New Product Update March 2007
METAL MATRIX COMPOSITE PUSHROD IN 'VALVETRAIN DYNAMICS'
In 'VALVETRAIN DYNAMICS' the users will now find within the input data section for the pushrod of a pushrod follower system that they can select the material for a pushrod as a 'metal matrix composite' material as well as for steel (Cr-Mo), aluminium and titanium. This material has properties which approximate those of steel but the density of the material is about 50% that of steel. This permits considerable weight reduction for a given pushrod design. Should you wish to know more about this material, and its supplier, then you can contact Prof Blair & Associates.

New Product Update March 2007
USING .des FILES AS CAM PROFILE DATA WITHIN PROGRAM No. 8.
In the 'CAM MANUFACTURE' program, one of the standard manufacturing outputs is the so-called cam design file, a .DES file, which can be in metric (mm) or in imperial (inch) units. It is composed of 360 rows of data of the actual cam tappet lift with the nose of the cam set at row 180. Each row contains the row number followed by a space and the cam tappet lift. It is quite different from a 'cam profile' where the measuring 'roller', or 'flat' measuring device, has dimensions that has no, or little, relevance to the dimensions of the cam tappet.
In program no.8, titled as 'CREATE MEASURED VALVE LIFT FROM A MEASURED CAM PROFILE', the cam profile data is normally read in as input data, together with the cam follower geometry, to create 'measured valve lift' (a .MVL file). The 'measured valve lift file' can then be mimiced in any of the 4stHEAD programs numbered 3-6 to determine the valve lift characteristics of that design.
With this upgrade, these design data files (.DES) can also be directly read in as input data to program no.8, together with the cam follower geometry, to create the 'measured valve lift' output data. Many of our clients are camshaft manufacturers, with vast libraries of these design (.DES) data files, and this upgrade saves them much time in the conversion of their 'cam design' data to the much more important and infinitely more relevant 'valve lift files' (.MVL).

New Product Update February 2007
DESIGN OF VALVE FOLLOWER PADS WITH LOW/ZERO ECCENTRICITY
In program no.7 of the 4stHEAD suite (create Cartesian geometry for all followers) a new sub-program has been added to the selection list entitled "design a centred valve follower pad". Actually it is two sub-programs as one has both input and output data in metric (mm) units and the other has the same functionality in imperial (inch) units. This permits the design of a valve follower pad for either finger or rocker followers where the contact point of the valve follower pad can be maintained almost precisely on the valve stem centre-line. If the valve follower pad contacts the valve stem centrally then the valve is not pushed sideways against the valve guide which thereby reduces the friction force to lift the valve, decreases valve guide wear, increases the friction force to return the valve follower and cam, and lowers the power required to turn the camshaft. The design process yields a valve follower pad profile which is not a radius but a scroll and the output data from the computation provides the manufacturing data for the profile of this scroll. Naturally, there are some minor penalties to pay for this centralised valve follower contact point. Firstly, it is not always possible to have the full extent of the valve lift accommodated by the scroll pad and so some of it must be accomplished by a conventional radiused pad segment, which inherently gives an eccentric motion to the point of contact between pad and valve stem. However, much of the valve lift can be attained with the scroll profiled pad and here the eccentricity will vary with valve lift between zero and a typically negligible 0.1 mm (0.004 inch). Also, there is a lift error involved in the design process for the scroll pad by comparison with using a pad with a single fixed radius, but even here that lift error is also negligible being typically on the order of some 0.15 mm (0.006 inch) for even the most extreme valve lift/follower design combinations. Further pictorial information on this design and computation strategy is given in the Cam Follower Geometry section of this website.

New Product Updates January 2007
USEFUL ADDITIONS TO VALVE LIFT PROFILE DESIGN
The 4stHEAD software suite contains six programs relating to both valve lift profile design and to the analysis of measured valve lift data to determine their valve lift profile characteristics. In these programs two useful sophistications have been added. One is the ability to instantly mimic the closing flank of any lift or acceleration profile with the opening flank. The second is the ability to change the standard (and probably the most sophisticated available anywhere) PBA profile smoothing characteristics to (a) a minimal or almost non-existent level or (b) an even heavier than standard level. It is not that we recommend our users to use either 'minimal' or 'heavier' smoothing characteristics for design purposes, but it aids our users to more accurately mimic the lesser or even non-existent smoothing levels which appear in the production designs of others. Hence, our clients can now more accurately assess the real dynamic performance of such production designs within our valvetrain dynamics software.

USEFUL ADDITION TO THE VALVETRAIN DYNAMICS PROGRAM
The output of the valvetrain dynamics program includes the dynamic lift profile of the valve, bounce, under-lift, lofting, and all. In this software upgrade, it is now possible to edit this dynamic valve lift file on-screen to tailor it more precisely and more logically for export to an engine simulation. The editing process permits the user to note the location of maximum dynamic lift of the valve with respect to its static maximum lift location (in the crankshaft angle diagram) and to decide how much and to what extent the valve lift bounce(s) are to be included in the export process. The output filing process is now tailor-made for the immediate direct export of this edited dynamic valve lift file (or indeed the static valve lift file instead) in the correct input data format to each of the major commercial engine simulation packages, i.e., OPT Virtual 4-Stroke, GTPower, Ricardo Wave, AVL Boost, and Lotus Engine Simulation. This was always possible in previous versions of the 4stHEAD software but this upgrade now greatly simplifies the process for our users.

New Product Updates September - December 2006
MAJOR ADDITION OF TEXTBOOK RELATED SOFTWARE
The 4stHEAD software caters for the design of all cylinder head related components. As you may well know, Prof Blair has written a textbook on the "Design and Simulation of Four-Stroke Engines". Almost all of that book is about the thermodynamics and gas dynamics within the cylinder head and within the components and ducts attached to that cylinder head. It is published by SAE as reference R-186. At one time, from 1999-2006 but no longer, it was accompanied by both software (SAE reference R-186SW) and a single cylinder engine simulation model (SAE reference R-186M). These have now been withdrawn from sale at SAE. The copyright for the R-186SW software has now been returned to Prof Blair and has been re-written in the PBA house-style and much sophisticated to boot, and is now added to the 4stHEAD software suite. Apart from many educational programs to explain textbook theory relating to both engine thermodynamics and the unsteady gas dynamics of pressure wave flow in engine ducting, several fully professional analytic programs are included as well. One refers to the analysis of an experimental cylinder pressure diagram to acquire the combustion or burn rate (Vibe exponents) for that combustion process. Others refer to the analysis of steady flow bench test data for the discharge coefficients (Cd) of poppet valves, within-pipe throttles or restrictors, and pipe end 'restrictions' such as bellmouths, plain pipes, or turbocharger nozzle rings. These Vibe combustion and Cd flow data parameters are required as input data to an engine simulation program and it is clearly not only essential they are accurately measured but also that such test data is accurately analysed.

AN ADDITION TO THE VALVETRAIN DYNAMICS PROGRAM
The valvetrain dynamics program in the 4stHEAD software suite caters for a computation under firing as well as motoring conditions. Under firing conditions, the valve head is exposed to gas forces from the cylinder and the duct. Until now this has been done by logically tweaking a stored cylinder pressure profile and inferring intake and exhaust duct pressures to compute the force on the valve head in both directions. This software upgrade permits our clients to import both the cylinder and the (intake and exhaust) duct pressure data emanating from an engine simulation. This leads to much greater accuracy of computation of valvetrain dynamics under firing conditions. A wide selection of relevant pressure data files are supplied to our clients such as for NASCAR pushrod engines, turbocharged spark-ignition WRC engines, turbo-diesel car engines, 3 hp industrial weed-eater engines, 800cc MotoGP engines, 450 Motocross engines, etc., etc. However, it is also possible for PBA to rapidly produce bespoke engine-simulation-created pressure data files specifically for our clients.

New Product Update August 2006
UPGRADE TO THE CAM MANUFACTURE PROCESS. The 4stHEAD software caters for the design of all cam follower mechanisms, including finger followers. However, for the design of high performance engines there has been an increasing use of compound shapes for the cam follower pad. Hence, in the 4stHEAD software the design for manufacture of a cam follower pad with a double radius has been added to the software suite. It is not just a simple two radius design where the confluence of the two radii meet on the base circle, but is a more complex design where the confluence point of the two radii can be offset making it into a compound cam follower pad design yet one which is readily amenable to accurate manufacture. Accurate manufacture of the cam follower pad, and the finger, is just as essential as accurate cam profile grinding if accuracy of the valve lift profile is to be attained in practice. More detailed geometrical information on this update can be found in the CAM MANUFACTURE section on this website.

New Product Update July 2006
UPGRADE TO THE CAM MANUFACTURE PROCESS. In the 4stHEAD software in the "cam manufacture" program the software automatically outputs many standard manufacturing files for the grinding of the cam for many standard production grinding machines. It also puts out the cam measurement checking files for the post-machining quality control of the cam grinding process. It also puts out the manufacturing data for "master cams" for "cam copying" grinding machine tools. All of this data is set at 1.0 degree cam angle intervals in the "cam manufacture" program. A new program has been added to the software which takes any or all of the above cam manufacture data and re-computes it at cam angle intervals down to 0.05 deg (one can select cam angle intervals of 1.0, 0.5, 0.2, 0.1, or 0.05 degrees) to include the data input of the precise diameter of the grinding wheel or the cutter, so as to predict the motion coordinates of the grinding wheel during the cam grinding process. The above procedure can also be conducted from cam tappet lift files supplied externally by design software other than 4stHEAD.

New Product Update February 2006
UPGRADE TO THE CAM MANUFACTURE PROGRAM. In the manufacture of hollow flank cams it has been requested by users to provide a rough machining profile for such a cam where the hollow flank(s) is replaced by a flat side(s). This easily permits the machining of the cam as it now has a 'convex' profile. The hollow flank(s) can then be finish ground with the correct diameter of cutter at the correct cutting speed while the convex part of the profile can be conventionally ground with a suitable large diameter grinding wheel. The software now outputs all of the machining data for all of these operations, and on-screen graphics of the 'flat-sided' cam rotation with a flat tappet ensure that the mathematics correspond to the manufacturing reality.

New Product Update February 2006
UPGRADE TO THE WEDGE HEAD DESIGN PROGRAM. A neo-classic wedge head has been added to the wedge head design program which previously featured both classic and modified wedge head designs. The neo-classic wedge head is a viable, and potentially higher output, design to the modified wedge layout and the standard numerical data in the software features almost identical designs for a NASCAR engine so that this contention may be examined with numbers rather than opinions. The identicalities include common data for valve lift diameters and valve lift profiles, compression ratio, bore and stroke, yet the piston crown pockets are shown to be considerably reduced, the combustion space will arguably provide superior combustion and air/exhaust breathing characteristics, and the pushrod, rocker, and tappet layouts are manifestly simplified.

New Product Update December 2005
UPGRADE TO THE CAM MANUFACTURE PROGRAM. Having completed a cam design the user finds under the ‘file cam manufacture output’ button there is now the ability to 'create a master cam' in either inch (imperial) or mm (metric) units.
Input data for the geometry of either a Berco or a Storm Vulcan or a Van Norman machine, or indeed any such machine, can be inserted and the master cam profile is not only calculated but the output data, in both inch or mm units, can be filed for the manufacture of that master cam.
The output data includes the actual profile of the master cam as both point profile data and as the motion coordinates of a cutter of a designated diameter. The graphics pages show both the complete motion of all components within the entire Berco-type machine during the manufacture of the cam and also the prior cutting of the required master cam. The information sketches which accompany these graphics make plain the geometrical significance of each data value employed as either an input or an output data.
This is a mathematically precise solution for the profile of a ‘master cam’ as it is clear that, due to the mathematical complexity of such calculations, that not all such which were previously employed within the cam manufacture industry were either truly precise or were actually capable of coping with all possible variations to the geometry of a particular cam grinding machine.

New Product Update December 2005
UPGRADE TO GPB VALVE LIFT PROFILE DESIGN. In the GPB valve lift profile design program one of the penalties of tweaking and dragging an acceleration curve is that the maximum lift value, upon numerical integration of the acceleration profile through velocity to valve lift, changes with each iteration of every tweak of the acceleration profile. This is no longer the case after this upgrade.
On the main input data page, after one has completed any ‘calculation’, i.e, by changing the shape, profile and magnitude of the entire acceleration diagram, there is a ‘control maximum lift value’ button which, when pressed, reads in your desired maximum lift value and proceeds to precisely control the entire profile to give that required value without changing the basic shape of the acceleration profiled.

New Product Update November 2005
In earlier versions of the Valvetrain Dynamics programs within the suite there were two separate programs for the coil springs and the gas springs. The one for coil springs was by far the more sophisticated as it incorporated separation and bounce of all components as well as handling all cam follower mechanisms (direct bucket, finger, rocker and pushrod).

The one for gas springs previously simulated only a direct acting tappet. Now, gas springs, with either an inside or outside piston, becomes just another spring element within the springs section where coil springs of every conceivable type can already be simulated as can every conceivable cam follower mechanism.

New Product Update August 2005
Viscous Friction, Turning Torque and Power Absorption are now calculated for the cam lobes for all cam follower mechanisms in the Cam Manufacture program within the 4stHEAD software suite.

In the Cylinder Head Design section of the 4stHEAD software suite previously Wedge Head Design only covered the Classic Wedge Head where the valves lie parallel to each other in the x-y plane. With this upgrade the Modified Wedge Head can be designed to cover all possibilities of valve-to-piston clashing and valve-valve clashing. This is important in the design of a Modified Wedge Head as the valves are usually canted in both the x-y and the y-z planes so that they have the potential of striking each other during the valve overlap period. This is a common cylinder head design for the 2-valve American v8 engine as seen in NASCAR and other forms of racing this engine. The standard demonstration data within the software and the valve lift files to drive it are from a (tweaked somewhat to hide its source) NASCAR engine and the movie (avi) supplied on the website for you to download is from this standard data set

New Product Update June 2005
In 3 programs within the 4stHEAD suite, Cam Manufacture, Valve Train Analysis, and Cam to Valve Lift, it is necessary to create the Cartesian geometry of complex cam follower mechanisms. The data preparation is somewhat awkward as it needs to be presented to these programs in a very precise manner. This new user-friendly program greatly simplifies this data creation exercise and, once done for a particular cam follower mechanism, the data can be saved and exported directly into all three of the programs listed above. This not only eliminates the tedious typing of the coordinate numbers into the geometry edit fields on three separate occasions but it eliminates the potential inaccuracy of typographical errors in doing so. Further, the direction of rotation of the cam is also exported/imported accurately and consistently, as is the base circle radius of the cam on the camshaft. While this is not a design program per se, it is an example of the continuous effort by Prof. Blair & Associates not only to to reinforce the user-friendly nature of the 4stHEAD software but also to assist its clients to eliminate errors in its design application

New Product Update May 2005
The new CREATE VALVE LIFT DATA FROM A MEASURED CAM PROFILE program in essence reverses the process in the Cam Manufacture program where a cam profile is provided as an output. Here an actual cam profile is measured using either a ball or a flat follower on a conventional cam profile measuring machine and its measured output data is used as input data to this program. The units of the input data can be imperial (inch) or metric (mm). The user must then have available the geometry of the entire cam follower mechanism as applied to this cam, which geometry and input data format is identical to that already employed in the Cam Manufacture and the Valve Train Dynamics programs. The output is a file of 'measured valve lift' in a format which can be directly analysed in one of the 3 Deduce Valve Lift programs in the 4stHEAD suite.

New Product Update May 2005
In the Cam Manufacture program enhanced data output is available for the profile of the cam being 'designed for manufacture' in exactly the same format as if measured on a machined camshaft by commercial cam profile measuring machines. The check follower can be specified in the program data input as either a flat follower, or a ball (roller) follower of a specified radius. The cam profile output from the Cam Manufacture program is in both imperial (inch) or metric (mm) units. This permits the user to directly compare the profile of the manufactured camshaft with the profile that it was designed to have and so ensure the quality and accuracy of the manufacturing process.

New Product Update April 2005
The new DUCT DESIGN program is somewhat akin to a combination of the Exhaust Valve Design and Intake Valve Design programs. But it is much more than that as the intake duct and exhaust ducts can be empirically optimised as well to tune the engine at the selected engine speed of the target peak power characteristic. Further, imported static valve lift files can be manipulated internally in the new program with both lift and lift duration multipliers so that target specific time areas can be matched with some precision. Even the bellmouth at the end of the intake ducting is designed here and its manufacturing data can be filed as output. This is undoubtedly one of the most important and powerful design programs within the 4stHEAD suite.

New Product Update November 2004
In the DYNAMIC Valve Train Analysis program conical/tapered springs have been added to the simulation. This means that all spring types can now be analysed.

New Product Update September 2004
In the 4-Valve Head Layout program the design Pyramid Heads has been added to the simulation. A Pyramid Head is a 4-valve head where the valves may be canted as well as angled. This permits the creation of high compression heads above a flat-top piston for high bore-stroke ratio cylinders. This picture shows the computation output of a head profile to scale where a finite-element mesh is used to compute clearance volume and the surface area of the head.

New Product Update August 2004
In the DYNAMIC Valve Train Analysis program progressive springs have been added to the simulation.

New Product Update July 2004
In the DYNAMIC Valve Train Analysis program coil clash and binding has been added to the simulation. Also, several cosmetic features have been added to the output animation.

New Product Update APRIL 2004
The Piston Crown Valve Pockets program permits the input of the geometry of the size and location of the actual valve head within the cylinder and which also can be simultaneously canted with respect to the cylinder axis and at right angles to it. The intrusion of a valve, which has known actual head geometry, from a location in three dimensions above and into a moving piston crown can now be computed with accuracy. The program permits the dimensioning of a machining cutter to manufacture this valve pocket with specified side and axial clearances over the intrusion created by the valve head and to provide the orientation and location of this cutter for the manufacturing process

New Product Update FEBRUARY 2004
In the DYNAMIC Valve Train Analysis program a major upgrade has been added. Previously it was only possible to model the valvetrain as being motored, i.e., with no gas pressure forces on the valve and much as if it were running on a Spintron machine. It is now possible to consider the valvetrain dynamics where the valve can be an exhaust valve or an intake valve under firing conditions.

New Product Update FEBRUARY 2004
A NEW 2-Valve Cylinder Head Design Program has been added for the case of the two-valve engine where the valves are vertical (parallel to the cylinder axis) and the chamber can be designed as a ‘pancake’ type or a ‘compact’ type.

New Product Update FEBRUARY 2004
The DYNAMIC Valve Train Analysis program has been further updated to accurately simulate the 'BOUNCE' and 'SEPARATION' phenomena that can occur in all types of valve trains. A FULL Dynamic simulation of Direct-Acting/Bucket followers has been added.

New Product Update DECEMBER 2003
A new program on The Design of Cooling Fins for air cooled engines has been added to the 4stHEAD design suite.

New Product Update NOVEMBER 2003
The DYNAMIC Valve Train Analysis program has been updated to accurately simulate the 'BOUNCE' and 'SEPARATION' phenomena that can occur in all types of valve trains.
Of Particular interest is the NEW Dynamic PUSHROD Valvetrain Analysis which has been developed for the demanding NASCAR environment.