In the world of uncompromised racing engines, few people outside of the manufacturers have real knowledge- this certainly is the case for Cosworth engine conversions covered in Des Hammill's book. Having spent plenty of money in my own dyno sessions, Mr. Hammill got to the point of real working engine packages nicely with head porting, cam, and carburettor specifics; he could have saved me plenty of time and money in development had I known of his work earlier. What he describes can be extrapolated to other Cosworth conversions including Formula Atlantic (Ford), Cosworth-Vega, and Cosworth-Pontiac engine street/race tunings. It's indeed a rarified atmosphere at this level, only recently broached by Honda with their S2000, and you won't find Steve Jennings writing about his top-flight engine tuning/tricks anywhere! Its a world where 2-valve motor rules-of-thumb and assumptions don't apply: just ask David Vizard. Complaints? I do wish the DOHC section had been more than just a single chapter, but what's there is gold!