A light rotating assembly is essential in any high-power naturally-aspirated engine build and for those of you thinking about hardening up your K20A-equipped Honda, you might want to consider JUN’s newest releases.

JUN have two grades of piston for you to choose from: the lighter-than-stock Hyper Piston, and the featherweight Hyper Piston EX. Both are 86mm in diameter and come with gudgeon pins and K20A-specific valve reliefs, although you’ll need to provide your own piston rings.

JUN also have a set of lightened I-beam conrods to match those shiny new pistons. Made from SCM440 alloy steel and featuring ARP rod bolts, these conrods should definitely have the strength to deal with practically any NA Honda build.

The centrepiece of JUN’s K20 kit is without doubt their billet steel crankshaft. It maintains the stock dimensions, so don’t expect any capacity increases, but it’s lightweight construction is designed to provide a perfect match to JUN’s piston and conrods and keep your K20 revving high, while the SCM440 steel used guarantees strength. The crank is available from JUN Machine Shop for JPY 399,000. The Hyper Piston kit costs JPY 168,000, while the conrod set will set you back JPY 138,600.

Head over to JUN for more info.

[Source: JUN Machine Shop]
[Images courtesy of JUN, Honda]