Sales are going well.　H1/H2-ICBM®

Among them, the LOC machine of Over Racing's Chairman Kensei Sato (who seems to be touring with a number plate after winning the LOC) and the machine of 2-Stroke Magazine's Editor-in-Chief Takeshi Goto, who recently won the TOT and LOC, are being tested on the track, not on the street.

In addition, Moto Maintenance's Editor-in-Chief Katsumi Taguchi actually started the engine in front of audiences interested in the H1 at the BB Festival the other day, and experienced the quiet engine with only exhaust sound, free of piston slap and ring noise, and has received high praise from a number of distinguished people.

Now, the advantages of ICBM® are not limited to its ultra-high durability.

1. Lightweight

First of all, it's light! This goes without saying. The weight of the aluminum-plated sleeve alone is only 1/3 that of a cast iron sleeve. The fact that the weight of the relatively upper parts of the engine can be reduced by several kilograms is particularly significant for racers, not only in terms of the acceleration of the bike, but also in terms of the reaction of the motorcycle body when cornering.

2. Heat dissipation

Aluminum has excellent thermal conductivity compared to cast iron. This makes the cylinder excellent at dissipating heat. This effect is particularly significant in air-cooled engines. In old bikes, the material deterioration of aluminum engine parts progresses, but in this respect, aluminum-plated sleeves with excellent heat dissipation have a great advantage. Subsequent engines have evolved in the direction of cooling the cylinders, even to the point of installing radiators and using water, but aluminum-plated sleeves can be said to be an unparalleled effective means of cooling the engine while keeping it air-cooled.

3. Uniform expansion

The piston is made of aluminum. Also, the genuine cylinder and head are made of aluminum. However, if a cast iron sleeve is inserted into the cylinder, the expansion rate is completely different in this part, and there is less expansion. If that only cast iron part is aluminum plated, the engine will be made entirely of aluminum, and it is possible that the clearance can be significantly reduced. Even if it is not reduced that much, there are various benefits to having the expansion rate of each part of the engine be almost the same.

Whether the engine is not very warm or it gets hot, the change in clearance will be minimal.

4. Resistance to seizure

iB has been accepting re-plating of NSR cylinders for a long time, and when we lightly hone the inner diameter of a cylinder that arrived for re-plating request, it is not uncommon for an undamaged plated inner diameter to appear under the aluminum that has melted and stuck to the cylinder wall. That is how strong the plating is, but I think that the great merit of the plated surface is that it is slippery and resistant to seizure, combined with its good heat dissipation.

ICBM® has various advantages beyond simply being hard and not worn down.

Still, why did KAWASKI stop using the INTAKE port pillars that were on the early model of the H1? There are no pillars on the ports on the later H1 and the subsequent H2, or any other mid-mach models.

Next time I'll give you my theory on why this is the case.