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This partnership was established to create and distribute software relating to the design of reciprocating internal combustion engines.

Tribute to Prof Blair

Prof Blair & Associates present valve-spring design
paper at
SAE 2010

Now over 70 client users worldwide

RET Article
June 09

The prime objective is to utilise existing expertise in this field to produce a suite of programs that are user-friendly, have a short learning curve, yet deliver comprehensive in-depth engineering know-how and results to engine designers.


This product is a software package for the design, and design for manufacture, of components within or attached to the cylinder heads of four-stroke engines. This product is a software package to accompany Prof Blair's book, "Design and Simulation of Four-Stroke Engines". It is an enhanced and expanded version of the original SAE-marketed software.

This site contains information on both software products, 4stHEAD and 4stSOFT. It contains information on the variety of users of our software. It also contains many technical articles that we have written on both engine and valvetrain design and manufacture that can be directly downloaded. There is also information about those who link with our site and how to contact us.

©Prof Blair & Associates 2020