Buell Thunderstorm Heads

- increased power through the whole RPM range
- increase in compression ratio depending on piston choice and cc volume
- heads are fully ported, resurfaced and have had a radius valve job
- contains new valves (1.840” & 1.625”), guides (manganese bronze), springs (titanium top retainers) and special seals (Viton)

These heads are best when used with the Wiseco 1200cc domed pistons.

With these pistons, we can adjust the compression ratio anywhere from 10.5:1 to about 11.5:1.

The ready to run Thunderstorm heads have a cast combustion chamber and squish (quench) area that is nowhere near concentric to the piston dome. This causes a lot of problems with detonation. Notice how we cure this problem by machining the squish area concentric to the piston. We have a special fixture that enables us to do this work on a lathe. This is a very important step!