This is normal by combustion engines world wide. Engine producer which take care
that the engine have a right compression, control the distance between cylinder head
and piston in top. If the distance is too small need the engine 1 or 2 head shim.
Webra make here adjustment for a fuel with 0 % until 15% nitro, if there are a fuel with up
of 15% take 1 shim (or 1 shim more) between cyl. head and liner. Up of 30% we recommend
1 sometime 2 headshims.
No different in the technology - Blackhead comes from Horizon/USA.
Fuel is O.K., but you need not really 15% Nitro 10 - 12,5% is enough.
Don't change anything.
Best regards - Yours WEBRA-Service
Von: Luciano [mailto:firstname.lastname@example.org]
Gesendet: Dienstag, 11. März 2003 15:18
Betreff: Webra 91 heli version ???
I'm curious about one thing in this motor, i just bought one Webra 91 heli version and a guy at the field bought another one, When we open the head of both we saw the my motor has a shim and my friend's motor doesn't have a shim.
So my question is, there is some motor with shims and another ones without shims, what's the difference between them.
And other question, what's the difference between the black head and the aluminum color head...??
I want use this motor with 15% nitro(wildcat) 18% oil, do you think i need to use or not to use this shim???
My best regards...