NEW LKE KZ: PERFORMANCE AND RELIABILITY

Max Bernardi

26 September 2016

TYPE
Like most kart engines on the market, the RKZ is a 2-S. 4-stroke engines are still a small niche

125 CC

DISPLACEMENT
125 cc has been the standard for some time now, while in the past it used to be 100 cc

PUSH

START
Push-mode as in all KZ engines, with hand-release clutch and neutral to 2nd gear shifting

GEARBOX

TRANSMISSION
The RKZ belongs to the gearbox “family” of karting engines.
It has a 6 gear manual transmission

HOMOLOGATION
Certified under KZ homologation, just renewed and valid for the next 9 years, beginning in 2016

The new engine developed by LKE for the KZ class is called the LZ1. It is not a revolution compared to the previous approval, even if there are important changes, in particular the cooling system and cylinder

The LZ1 is the new engine for the KZ classes of the company LKE, the brand dedicated to the engines of the Sicilian company Lenzokart. The result of a completely computerised design using CAD software was then the protagonist of a refined development on the company’s engine benches.
At first glance, compared to the previous approval, you immediately notice the difference in the cylinder, whose mould has also been completely redone for the OK and OKJ engine versions that LKE manufactures.
In particular, the cylinder area underwent major external dimeter shrinkage, while maintaining the width of the water ducts unchanged.
Externally, they were placed in the front part of the flaps that improve the cooling, in addition to improving its aesthetics.
One of the LZ1’s most substantial differences with respect to its predecessor can be seen above the exhaust manifold, where the cylinder is increased in size by exploiting the position that the exhaust valve has in the OK engine, and an “add-on bag” that allows a greater flow of water was developed, and therefore, an improvement in decreasing temperatures.

The new LKE LZ1 engine is much more compact than the previous model thanks to the angle of the gear change axis and the new water cooling system.

The comparison between the 2007 crankcase (below) and the new one shows the great development that has been accomplished. More compact in length, it has an outer passage of water that provides better cooling of the area where parts are in friction.

The cooling water passes in the outer area of the crankcase by dissipating the heat due to friction better and the rolling of the bearings, it rises to the cylinder and out of the head.

The head and its inner insert were restricted following the cylinder, and even the water flow was enhanced by working on the interior cavity. As regards cooling, if you analyse the crankcase you will appreciate LKE’s idea to exploit the outer water passage between the engine compartment and the gearbox, in addition to the water ducts which pass externally, cooling the clutch and bearing roll area, friction elements area that are therefore subject to high temperatures.