The cut-off on the bridge
As you know, the H2R cylinders had bridges on both the intake and exhaust ports.
The intake port is not much of an issue, but the bridge on the exhaust port causes heat to concentrate and expand, which can lead to seizing.
Therefore, it is necessary to precisely create a cut-off on the bridge with the cross-section shown in the graph.
The upper graph shows work done by another Japanese company, likely by hand.
The lower graph shows work carried out by (iB) Inoue Boring using a machining center.
In the case of a plated sleeve, if the relief is not taken exactly the same before and after plating, the plating thickness cannot be maintained evenly.
We excelled in this technology, at a certain period, we were responsible for processing all of Honda’s two-stroke replacement cylinders.
