Karting NSW has made changes to the technical regulations for the Vortex Mini ROK engine, including the rollback of the mandated spark plug rule and an increase of the maximum restrictor size.
from Karting NSW:
Upon review of recent changes to the homologations used by other sanctioning bodies we have updated some of the technical specifications for the Mini Rok engine. The main reason for this change is to ensure cost effective and fair racing for competitors and to eliminate the need to have multiple engines setup to different technical regulations.
We released this change to KNSW Clubs two weeks ago and the updated homologation document is available on the KNSW website. After some feedback we have decided to roll back the mandated Spark Plug criteria. Initially with these changes the mandated spark plug was NGK-B10EG or NGK-B9EG. This spark plug is cheaper than the more expensive options available in the market. We felt this was a small step towards helping to make karting as affordable as possible. It has come to our attention that there are supply issues with these two sparks plugs and this, combined with feedback that people would like to use the spark plug of their choosing means we have taken the decision to revert back to the original rule which is that any brand of eligible spark plug may be used.
We have also had some queries as to why the restrictor size has changed. It is now maximum 16.05mm. It has come to KNSW attention that there is a batch of standard un-modified restrictors being purchased from suppliers that are over our previous maximum 16.00 limit. It is unfair to punish someone for unknowingly purchasing a totally standard part from a supplier that does not conform to the regulations. Therefore, to alleviate any issues like this occurring the maximum size has changed to 16.05mm. (Competitors are reminded it is not permissible to modify restrictors in any way.)
These new specifications come onto effect from 1st July 2023 to give competitors and engine builders time to make the required changes.
The updated Technical Specifications can be found HERE.