ORCi Ministox Sub Committee Statement

Last Updated: 01/04/2018 17:16

The ORCi Ministox Sub Committee wish to clarify the following items:
Following the publication of the 2018 specifications and having done checks over the 2017 season at the Championship events, we have clarified a number of issues that came to light. 

There was much talk following the British Championship held at Lochgelly, items under investigation were Rotor Arms, engine breathers, suspension components, rocker arms, Cylinder heads.  See findings below.

Cylinder Head

On the  Monday after mini British I read up on paperwork (Rule 4 )  mini engines it appears the latter  mini 998 had a head with the ND code up beside the  thermostat housing as the one on The winners car.  On  Tuesday  4 standard heads were stripped valves out them and one was the ND code type this was measured  and it came in with the same size valve seats ports  as the Winners; so after reading then seeing this I accept that the Winners head is ok and legal to the rules. Theses heads came standard on a mini 998.

Thomas McGarva (HRP).

MINI Rotor Arms

I have done a bit of research on the rotor arms fitted to standard 25D distributor. As below.

Most minis up to 1974 had the 25D type distributor fitted with side or top entry caps. This rotor arm fits both but for any sort of performance use they have failed because the contact blade on the arm is riveted and becomes loose, Because the blade is thin, or the rivet sometimes to long and not moulded correctly it becomes loose at the rivet and shudders or current can arch down to the distributor shaft causing electric engine failure. The material used on cheaper versions also contains more carbon blacking and is therefore more conductive again causing electrical shorting to take place.
The original blue rotor arm was fitted  and made stronger by moulding and riveting the contact plate to the arm, so for peace of mind the tried and tested red rotor arm was introduced.


If you have an original 25D type distributor this is an upgraded arm (blade moulded and riveted )for performance use because all the other types available now are likely to fail at higher revs. 
In essence these modification that have been made over the years are for reliability of performance not that they give you a bigger spark or other type of enhanced performance , if you go into your local parts distributor and ask for a rotor arm for a1000cc mini , chances are you will come out with a Red one.

2018 rule now rules rotor arms are free.

Dave Borthwick (GMP).

Suspension Components


“On the NSF you may lengthen the track control arm by up to a maximum of 20mm to give a maximum of 4o negative camber on the NSF wheel and 2o on the OSF wheel. The use of an after-market threaded adjustment type control arm is allowed, but must NOT when removed, be in excess of 20mm in length from a standard arm (i.e.310.5mm max). The modified components are not permitted to be adjustable on the car.”

When the NSF track control arm was removed from the winners car it measured correctly, the issue was around the welding of the arm so as not to make it adjustable, it does not say I the rule above that it has to be welded, the case with the arm in question was it had a piece of angle iron covering the two adjusters which was welded at one end, on checking we were happy that the angle iron prevented any adjustment being made to the arm on the car, without said angle iron being removed.

Engine Breathers

The only reference to Engine Breathers in the 2017 rules are as listed below.

“The engine must be fitted with a metal catch tank of 1 litre minimum capacity connected to the engine breather system. This must be fitted under the bonnet.”

Over the season we have found various breathers fitted, this has now been clarified in the 2018 specifications as to what is allowed.

Rocker Gear

Having checked rocker shafts we were happy that those checked complied with the rule as below.

“Rocker Gear: All factory types will be accepted with a ratio of 1.25 to 1”.

Finally, we trust that this has now clarified all of the perceived problems primarily with the stripped cars from the British Championship at Lochgelly last year.  

Whilst gallons of dirty water has flowed under the bridge since the British and a lot of hard feelings towards certain drivers and indeed Promoters, we sincerely hope that we can all move on from here.

Dave Borthwick (ORCi Mini Sub Committee)