Cylinder head
Original top cover for the B18 / B20 as follows.
B18 has a standard height of approximately 88.1mm.
Valve size 40mm in and 35mm out.
The length of the combustion rooms is approximately 85mm.
The valve locks are single-track and the valve seal is mounted on top of the valve plate.
External differences to B20 are as follows.
At the bolt for the generator, there is a bending missing on all B20.
The valve guide diameter is 15mm.
The valve shaft are about 8,64mm compared to the B20 which is about 7,96mm.
B20A / B through -1971 has a total height of about 86.7mm and 42 / 35mm valves.
The length of the combustion chamber is approximately 90mm.
The valve on all B20 is three-track and the valve seals are mounted on the valve guides.
Valve valve guide diameter is 13.5mm.
B20A / B from 1972- has a total height of about 87mm and 44 / 35mm valves.
The length of the combustion chamber is approximately 92mm.
External differences to B18 and early B20 are as follows.
The manifold packing area is much wider on the B20E and reinforcement plates are embedded on the suction ducts.
B20E has a total height of about 85.5mm and 44 / 35mm valves.
The intake ducts are slightly larger just at the beginning of the duct, otherwise it is like an "A" cylinder head from 1972-.
This cylinder head can not be compared to a machined and ported top, as it is only bigger at the beginning of the channel.
Original top cover for the B18 / B20 as follows.
B18 has a standard height of approximately 88.1mm.
Valve size 40mm in and 35mm out.
The length of the combustion rooms is approximately 85mm.
The valve locks are single-track and the valve seal is mounted on top of the valve plate.
External differences to B20 are as follows.
At the bolt for the generator, there is a bending missing on all B20.
The valve guide diameter is 15mm.
The valve shaft are about 8,64mm compared to the B20 which is about 7,96mm.
B20A / B through -1971 has a total height of about 86.7mm and 42 / 35mm valves.
The length of the combustion chamber is approximately 90mm.
The valve on all B20 is three-track and the valve seals are mounted on the valve guides.
Valve valve guide diameter is 13.5mm.
B20A / B from 1972- has a total height of about 87mm and 44 / 35mm valves.
The length of the combustion chamber is approximately 92mm.
External differences to B18 and early B20 are as follows.
The manifold packing area is much wider on the B20E and reinforcement plates are embedded on the suction ducts.
B20E has a total height of about 85.5mm and 44 / 35mm valves.
The intake ducts are slightly larger just at the beginning of the duct, otherwise it is like an "A" cylinder head from 1972-.
This cylinder head can not be compared to a machined and ported top, as it is only bigger at the beginning of the channel.