Here at BSD we build an awful lot of GSX-R engines. Mainly the injected ones, though we still work on carb’d versions now and again. With the later injected motors some remain in a bike chassis, but a lot are for racing cars.

The rebuilds focus on cylinder head work. Depending on what condition the head’s in we might have to re-face the valve seats; if we’re adding compression we’ll skim the head (all done in-house here).

Now the problem with the GSX-R lump is when it’s got older, and had some heat into it the exhaust valve seats sink in the middle, near the spark plug so you can’t lap in the standard valves as they’re composite titanium. Essentially you take off any surface coating and the valves will then burn out. So we re-face the seat then lap in with an old valve, so the new one has a good seat to go in to.

On leak down tests, on a fresh engine we’ve built post Dyno run we’ll see maybe 3% leak down, compared to 8-10% on the same engine as it came in. So we know what we do with these things works, and works well…