all 2v new and old
Standard £499 or Ultimate £639
2v cylinder heads are very time consuming to get right. The port shape
has to be extensively changed.
Please be aware the older heads non (DS) only have the option of the
Ultimate version because of seta/guide reliability reasons. The newer
heads if guides are not requested or needed can benefit from performance
seat cutting to bring the head up to near Ultimate spec but minus the
guides. Guides £18 each - Seat cutting £18 per seat.
head has boosted a high compression 900cc long manifold bike into the
88hp range (see project 90hp superlight) and a 900cc fuel injected
version to 97 hp. Both bikes do not use big bore kits. This head
has extensively re-shaped intake and exhaust ports, new 3 angled valve
seat profiles, uses new Colsibro valve guides and your original valves
which are restored modified and polished. Sometimes the valves are very
worn meaning they cannot be restored. If your valves cannot be restored
they can be changed for 1 piece stainless items at extra cost. This head
definitely has a bang for buck rating being much more than a spit and
shine job. 2v bikes have poor valve
guides too that leads to smoking and poor oil consumption. Colsibro guides correct this problem giving greater reliability
of the valve stem to guide clearance giving a more reliable cylinder head. Big valve versions are
available on request. You will
need to phone for pricing and details as extensive flow bench testing
and even more re-shaping of the port is needed to perfect.