We’d been floored by just how tight the flywheel nut was on this engine. We had to get pretty creative in order to remove the thing.



Literally nothing we’ve had to undo comes close to the amount of torque required to remove this thing. We had an 18stone man (me) jumping up and down on the end of a metre long breaker bar. In physics terms that’s over 1100 nM of torque. This nut wasn’t messing about. We had the thing sitting in an engine bay with a thick section of steel gas pipe jammed solidly between the inner wings and bolted into the flywheel (with fine gauge threads that were actually quite hard to find), with an extension on top of the breaker bar.


Eventually I had a Jack Bauer moment of grim choice and got out the oxyacetylene. and heating up something which I really didn’t want to warp anywhere if it could be helped. The crank shaft (eccentric shaft or ‘E’ shaft as it’s known) could take some heat but if you heat metal up enough then it will warp. That’s science. That just how it works.


There was also the issue of the nut itself. We’d had an issue or two before melting alloy stuff before realising the melting point is only 600⁰. The nut looked like brass and we estimated it’s melting point at around 1000⁰. Hopefully we wouldn’t find out.


All was well and we were back relatively plain sailing. Off came the flywheel and out came all 20 or so of the housing bolts which go right the way through the engine and screw into the front iron, followed by the first rotor and a handful of seals.


Immediately apparent was a possible reason for the overheating – the system was full of gravelly shiny granules reminiscent of Radweld. The water pump rotated freely and thermostat had been recently changed – for now this was the most likely cause.



As the for the rotors themselves, they didn’t look totally bollocks, which was a plus. The housings, however, had seen better days. The minimum allowable wear of 2mm from the edge had been exceeded and in places multiplied. Interestingly the wear wasn’t of the usual concentric style around the edges but a staccato chatter style mark which indicated that the seals had been bouncing across the surface.


After asking some adults on a rotary forum (RX7club.com – cheers guys!), the grim confirmation came home that the housings were indeed bollocks as previously assumed.


Curiously the apex seals and the side seals seemed to be in good condition. The rotors are sealed with metal seals – apex seals on each of the corners and side seals between the rotor and the irons. Behind these are springs which maintain a light pressure behind the seal to keep it sealing. These looked to be in okay nick although they’d need to be properly tested for clearance later.



Now all I needed was a car.

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