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Hurley Engineering
"The UK's Leading Rotary Engine Specialists"
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« Rotary Engines

Re-Engineered and Modified Mazda 12A Rotary Engines

Engine Specification & Modification


New tip seals with corner pins and plugs

New bearings

New oil seals - oil pump

New gaskets with stainless steel seal protectors

Side housing reground and lapped for better oil retention and sealing


Engine Guarantee

All engines are guaranteed for 12 months, or 12,000 miles provided that the engine has been fitted and maintained to our specifications and serviced by us.

Engines built with new motor housings will be guaranteed for 24 months or 24,000 miles

Exchange units must be serviceable


Performance with Economy Conversion

Carburettor Conversion

Twin 1 3/4" HIF SU carburettors with modifications

Special HME inlet manifold

GTI Megaflow air filter system

12A Complete Exhaust System

HME super-flow exhaust system and extractor manifolds give 15%-20% more BHP and a pleasant sounding exhaust tone.

The combined conversion gives an incredible 30 MPG at 70/80 mph motorway cruising and 0-60 mph in 7 seconds.


250 BHP RX-777
Tripple Rotor Engine Conversion

Triple rotor engine

Triple 1 3/4" HIF SU carburettor

Special HME inlet manifolds

Exhaust manifold and free flow exhaust system

Heavy duty clutch assembly and bearing

Triple rotor distributor

Rev-counter conversion

Drive in / Drive out

The RX-777 conversion gives 160 mph performance combined with an economical 24 MPG at 70/80 mph motorway cruising.



Specification Set Price
12A Rotary Engine (Exchange) $2.00
Mazda 12A Sports Rotary (Exchange) $2.00
12A/13B Sports Rotary (Exchange) $2.00
New Rotor Housing $883.30
12A Engine Fitting $503.48

Specification Set Price
12A Carburettor Conversion $971.63
12A Complete Exhaust System $874.47

Specification Set Price
12A Tripple Rotor RX-777 $9.00




Tripple Carburettor
After ten years of development HME are now proud to offer our multi-rotor engine conversions, the first triple engine was built three years ago and has been tested by many magazines in the United Kingdom, Europe and Australia, all of which have been impressed with the performance and fuel economy. To date 25 engines have been built for road and racing.

The turbine smooth and refined performance of the triple rotor cannot be compared with a ported and tuned twin rotor giving the same max. power output.
For example the acceleration time from 40-60 MPH in fifth gear is only 6.5 seconds as compared to the standard time of 10.5 seconds = 40% faster, and a 0-60 in a little over 5 seconds while still returning 25 MPG+ motorway driving, and an added bonus of the triple rotor is the truly magnificent exhaust note. The engine has excellent low speed torque which makes it very easy town driving.

The total weight of the Triple Engine is 315 lbs. together with carburettor and exhaust system, is in fact 15 lbs. lighter that the standard RX-7 engine, with carburettor and exhaust system and is only 4 3/4" (120mm) longer.


...for the ultimate in performance

600 BHP Hurley Quad Rotor Engine P.O.A.
900 BHP Hurley Six Rotor Engine Seeing is Believing !