Question:
What are the differences between the Hayabusa Gen1 engine and Gen 2 engine?
Answer:
The Hayabusa Gen 2 engine 1340cc has been around now since 2008 and therefore more readily available. The earlier Gen 1 engines were discontinued at the end of 2007, this means that the engines are now getting quite old and in shorter supply because of its popularity.
The Gen 2 has quite a few advantages over the earlier engine; the gearbox was dramatically improved and some of the shortcomings in the original design and the weak output shaft were overcome. The slight increase in engine stroke gives a nice improvement in torque and the engine having a better design of piston and higher compression has allowed the engine to produce the performance in standard form of a reasonably tuned Gen 1 engine and with the added advantage of the increased torque, a nicer all round package. The cam profile are also slightly larger, which helps add to this.
The downsides to the Gen 2 engine is that the valves are now titanium and they have seen failures in motorsport applications. Also the valve springs are now a single valve spring where the Gen 1 has a double valve spring, so a common modification is to replace the valves with either the Gen 1 valve or a stainless steel high quality replacement and fit the Gen 1 valve springs.
The barrels on the Gen 2 engine are windowed, which is fine if the bore size remains standard but if the bore size is increased, they will quite often fracture, so it is recommended for big bore versions that the Gen 1 barrels are sourced because they are much stronger but they are becoming harder to find due to their age.
The crankcase of the Gen 2 has been thinned around the area where the head studs or bolts fit into, this is normally not an issue unless you are using a turbo application.
Category:
Hayabusa Specific