The end of the 2007 racing season is in its last throes. I have had several 998-based race engines returned for their post season post-mortem, and I have very good news to report.

The most arduous scenario the 998 engine could possibly see is that of the Class One Grass Track racing fraternity. Conducted round a 1/4-mile dirt-ridden field, flat out in second gear for three laps at a time between three and five times in a day it really tests the resilience of the components used.

Essentially these are bog-standard, unmodified 998 engines. No balancing allowed, no fettling of any sort. Only standard components allowed, or those allowed by the governing bodies. No magic cams, no offset cam keys or adjustable cam gears. No stage one kits. Just a bog-standard 998 engine, gearbox, induction and exhaust system. So the 'secret' to maximum performance – if there is one, especially over a years-worth of racing (anyone can build a grenade motor that is fast for one meeting) - must be down to piston/ring performance and reducing any drag/power comnsumption.

I have used these excellent pistons in various magazine project engines and other customer road performance engines and they proved fantastic. So at the end of last year I got these new Mini Spares replacements for the AE Hepolite 998 'Cooper' flat top pistons passed for this discipline of motorsport. More than anything because of the lack of availability of any other durable 998 piston. The most recently available 998 pistons from AE being the 'slipper' type pistons that are press-fit in the rod suffer badly from premature ring land degradation – seen after barely half a seasons racing. Plus the ring land in the piston is prone to cracking/collapsing. This makes them an expensive component to use since leaving them in a motor for a year is likely to seriously erode performance. Piston ring seal is EVERYTHING. Let alone the piston remaining in one piece. So at the beginning of the year I was at liberty to use these MSC pistons in several 998 engines I build for this formula.

The end of this year is the first time I have been able to properly assess the long term performance of these pistons – and the news is all good. Not only have the ring lands survived, the rings are also in pretty good condition. They will need replacing and the bores re-honing but at least performance will have been still pretty consistent at the end of the year.

Add to this that I have had very positive reports from folks using them in everything from fast road units to turboed ballistic missile applications – they are certainly proving their worth. And the good news is – they are soon, hopefully, to be available in +0.100 oversize! How good is that? I can't wait to build another road-sports 998 using them and a suitably modified 12G202 head casting!

Part numbers -
P20950-20 - +0.020” flat top 998 piston
P20950-40 - +0.040” flat top 998 piston
P20950-60 - +0.060” flat top 998 piston
P20950-80 - +0.080” flat top 998 piston