I-Rotary Steel Apex Seals Review by Green Brothers Racing Ltd
Recently we inspected the first set of I-Rotary apex seals to come into NZ back in early 2017. Fitted to Ryan Dorricott’s FD drift engine this was always going to be a good severe conditions test. 13B REW, very 2nd hand rotor housings, Borg Warner EFR9180 at 30psi, E85 fuel, 650RWHP. Over the last 2.5 years the car has completed many meetings and events. It has not been treated nicely! When the engine came apart recently I took the opportunity to inspect the apex seals. Considering 2nd hand housings and E85 fuel, seal wear rate is the best we’ve seen from a metallic seal. The wear rate is as good, and possibly even better than stock Mazda seals. Average wear is 0.04mm (less than .002″) The seals are perfectly straight and very consistent. Apart from some rust pitting along the beam (common in E85 engines that don’t get started for a month or more) the seals are in excellent condition. Based on the wear to date this same set of seals could theoretically run for another 10+ years at the same power level and still be within spec. The photos do most of the talking. Note – these seals have not been cleaned in any way, apart from the oil residue wiped off.
The rotor housing surface had superficial marks (common with E85 fuel). These were not scratches and easily removed with sand paper or a diamond drum. With petrol I’d expect there to be minimal or no marking – similar to stock Mazda seals (based on what we’ve seen in the past).