<div class='quotetop'>QUOTE (mylexicon @ Apr 19 2010, 06:58 PM)
<{POST_SNAPBACK}><div class='quotemain'>Check the rules. They can machine the cylinder head. I'm pretty sure last year that cylinder head mods were illegal and Hondas were garbage as a result (not the case in WSS).
WSS
2.5.8.2 Cylinder Head
Cylinder head must be as homologated. The following modifications are allowed.
1. Grinding of the cylinder head surface on the side of the gasket;
2. Modifications of the inlet and exhaust ports by taking off or adding material
(welding is forbidden);
3. Original homologated valves guides may be cut or modified, but only on the
intake or exhaust port side;
4. Polishing of the combustion chamber;
5. Original valve seats must be used, but modifications are allowed to the
shape;
6. Compression ratio is free, but the combustion chamber may be modified
only by taking material off.
. The
use of titanium valves is permitted only if the homologated machines are
equipped with such kind of valves.
Valve springs may be changed.
Valve spring retainers may be replaced or modified, but their weight must be theValves may be altered or replaced and the material may be changed, but
maximum diameters and minimum weights must remain as homologated
same or higher than the original ones
2.5.8.3 Camshaft
The method of drive must remain as homologated.
The duration is free but the lift must remain as homologated.
The cam chain or cam belt tensioning device(s) are free.
At the technical checks: for direct cam drive systems, the cam lobe lift is
measured; for non direct cam drive systems (i.e. with rocker arms), the valve lift
is measured.
DSB
5.8 Engine Modifications
a. Cylinder Head
i. Cylinders heads must remain as homologated with the following
modifications allowed:
1. Cylinder head, cylinder and crankcase gasket surfaces
only may be machined for increased compression. All other
surfaces of the cylinder head, cylinder and crankcases must
remain absolutely as homologated with no metal removal.
2. Light cleaning of gasket surfaces with steel wool, Scotch-
Brite®, etc. is permitted. Deburring radius of machined area
must not be greater than 0.020 inches or 0.5mm.
3. Valve seats may be machined or replaced. Replacements
must be of the same material and parts as the homologated
valve seat.
4. The cylinder head gasket may be changed.
d. Valves, Springs, and Retainers
i. The valves, valve seats, guides, springs, tappets, oil seals,
shims, cotter valve, spring base and spring retainers must be
as originally produced by the manufacturer for the homologated
machine. Valve spring shims are allowed.
e. Camshaft and Sprockets
i. No camshaft modifications are allowed.
ii. At the technical checks: for direct cam drive systems, the cam
lobe lift is measured; for non direct cam drive systems (i.e. with
rocker arms), the valve lift is measured.
iii. Cam timing other then stock is allowed.
iv. No cam sprocket dimensional modifications are allowed.
v. Cam sprockets may be slotted solely for the purpose of altering
cam timing.
vi. Press-on cam sprockets may be replaced with aftermarket steel
bolt-on cam sprockets and adapters.
vii. Aftermarket cam chain tensioners are permitted.
viii. The tooth count of the cam sprockets and cam drive sprocket
on the crank must remain as homologated.
ix. The cam chain style must remain as homologat