Page last modified: 05/07/13
The history of the GS engine
Initially, the basic GS engine design underwent a few stages:
the quintessential GS, an air-cooled, two-valve-per-cylinder DOHC engine, which set Suzuki off as a serious competitor in the UJM market, and a good one to boot! This design was first introduced in the late 70's.
the 4-valve-per-cylinder GS, introduced in 1980, which had basically the same air-cooled engine, but with another cylinder head, featuring 4 valves per cylinder and a reworked combustion chamber (TSCC). In Europe and Japan, these models were known as the GSX's.
It's these two engine types that this magazine is mainly concerned with... and which this website/magazine will refer to as the GS.
Later on, Suzuki took the 4-valve-per-cylinder GS(X) series into a completely new oil/air cooled engine, which was called GSX the world over. These engines carried large oil coolers, since the oil played an important part in cooling the engine (the SACS system). On the sports series (GSX-R), this system was later abandoned for proper liquid cooling, since it appeared that under stress the SACS bikes lost power as opposed to true liquid-cooled designs.
Sidenote: the only bike which debatably still carries the GS signature is the GS500E, which is said to be a development of the GS450S. I may look into that once, but for now I'll leave it to this.
The 2-valve-per-cylinder-powered bikes are recognized by experts as the most reliable, bulletproof engines the world has ever seen, closely followed by the air-cooled 4-valve-per-cylinder-GS's.
These classic engines have True Grit: no matter what happens, they will take you home.
Why is the GS engine so utterly bullet-proof?
Basically, there are three aspects that set the GS engine apart from its contemporaries:
The first is the fact that the crankshaft runs in roller bearings, which is quite complex (and expensive) to build, and which caters for a long engine life and for high resistance to uneven or higher load on the crankshaft. (Note: this goes for most models, but the GS450 engines are a noted exception, they aren't blessed with roller bearings)
The second is that the lubrication is basically designed as a low-pressure job, which does not suffer as much from poor
pressure, cold engine oil and clogged channels.
The third is that, contrary to contemporary habits, there is a lot of reserve built into the design. The market demand for space and weight saving was not as large as it is in these FireBlade and GSXR750W days, and so the engineers of these bikes didn't have to drill iron out of the design to make the bikes marketable...
Written By: Peter Huppertz
An article on the history of the classic GS motorcycles that "The GS Resources" concentrates on.