|
|
|
|
|
|
|
|
Starting head modifications
) Those
modifications aim at improving the engine breathing. The matter is to port
and polish the valves bowls, intake and exhaust ports. As the engine is
for street application, I must avoid to enlarge too much the ports. Port
enlargement improves high revs but hurts low and mid revs.I use different
carbide burrs on a flexible shaft connected to
a electric engine running up to 7000RPM and a small 1/8 grinder. |
|
||||||||
) Modifications
on the right head (2-4-6-8) are in progress.
It is already dark; I didn't see how time flies. That reminds me the "LEGO" syndrome, when I was kid, I forgot even to eat when playing with those Lego. |
|
before
after
) )
Exhaust ports are matched to the gaskets: |
) ) The
bowls under the valve in porting progress.
Lots of metal is gone, I hope that the port volumes does not increase too much... |
|
|
|
(by Rick Voegelin) |
|
|
|
|
||
|
|
|
|
) |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Back-cutting the exhaust
valves:
|
I also polish all the valves, what doesn't hurt.
|
) ) The
left head (1-3-5-7) is now dismounted. |
|
before
after, but not finish yet
) ) |
|
|
|
|
)
)
)
)
)
)
)