CPR offers full Engine Rebuilding Services ranging from Mild Internal Upgrades to Full Bespoke Race Engines, and with over 15 years collective experience building engines used in Motorsport application, we pride ourselves in offering the highest level of quality and attention to detail in all of our Engine Building Services.

Specialising in 4G63 and 4G64 Mitsubishi Engine's, we are also able to build many other Engines for
other Import Sports Cars.

Engine Stripping is an important process, often overlooked by many inexperienced Builders. Extremely subtle irregularities, damage or imperfections must be closely studied for, to avoid engine failure at a later date.

Photo above shows a Rival Competitor's Engine, bought by one of our customers. This engine was sold as Brand New, Freshly Rebuilt, but as we discovered when the owner requested an inspection prior to installation, we discovered marks in the bore, which would have lead to Piston Ring Failure shortly.

Previous failures on Engines must be carefully diagnosed (and rectified) where a multitude of imperfections can re-occur if not identified at this stage.

Every component that is to be re-used is examined, compared to the manufacturer's tolerances and tested where available, prior to thorough cleaning via our parts cleaner.
Typically our engine builders will spend a full day ensuring every component is checked and cleaned meticulously. We believe that Preparation is one of the most important stages, and should never be rushed.

Bottom-End Rotating Assemblies can be Dynamically Balanced in high hp/rpm applications. The balancing procedure is a lengthy process, but ensures maximum reliability and reduced inefficiency of the engine. The entire rotating bottom end (normally comprising of Clutch Cover, Flywheel, crankshaft, Front Pulley's/Belt Gears and all bolts) is expertly balanced up to 13,000 rpm.

Cylinder Block Boring is performed by our local Machinists, that we have worked with for over 10 years, having developed the most ideal procedure for ensuring a perfect cylinder bore and hone is achieved.

Unlike the majority of other engine builders, we use our own Bore Plate on every Evo engine we build. The Bore plate is used to simulate the attachment of the Cylinder Head. When a block is has a cylinder head attached and torqued down, it will change shape considerably. To bore a block without a Bore Plate attached and torque to specification, it will mean the bores will never be truly parallel, which will result in engine inefficiency, excessive wear, or increased oil consumption. Our Bore Plate ensures our Bores are parallel and true to how they should be when the Cylinder Head is re-attached. Our experience in building engines allows us to ensure the correct finish is left on the Cylinder Walls. Having built up a solid relationship with CP Pistons over the years, we have ensured the correct finish is applied to ensure correct ring bedding-in, and final sealing. Our machinist has worked with us, to ensure the exact grade of abrasives are used, and replaced regularly to ensure excellent repeatability.

Further specialist machining is sometimes required in some race applications, when using stroker crankshafts, where clearancing is required. This is performed by CNC, to industry leading quality. Many processes are carried out during this phase, most of which are closely guarded by our engine builders, where our trade secrets allow the highest level of quality and durability is passed onto our customers.

After final Decking and Honing, all blocks are re-measured and examined by ourselves to meet our Quality Control Requirements.

All Engine Assembly is performed in a clean, clutter-free room devoted to Engine Builds.

The photo above shows a competitor's engine assembled with incorrect water pump and no gasket. Silicone Sealant is noted to seal the pump, which is to be avoided at all costs (sealant will break away eventually and be carried away in Coolant/Oil System. CPR will always use a genuine Mitsubishi Gasket where available

We only use Genuine Mitsubishi Belts, Gaskets and Seals in our engine builds, where zero compromise to longevity or quality is permitted. Where aftermarket items are used (i.e. Metal Multi-Layer Headgaskets), we will have always tested these components in a racing environment.

Uprated Bolt & Fastener Hardware is often used in our high performance builds, particularly for the Cylinder Head Bolt, where we either offer an ARP Stud Kit, or the CPR Race Stud Kit, as used on our Circuit Cars in the highest hp (850hp+)/boost (3.0bar+) environments.

Every step of the engine build is performed to the manufacturer's tolerances and specifications, and our Quality Control Procedure ensures that no area of the build goes overlooked/unchecked.

Balancer Shaft's are typically removed from the 4G63/64 Motors for racing application, where the engine does not require vibration dampening. Removal of the Balancer Shaft will help to reduce parasitic power losses and the risk of Balancer Shaft Belt failure, which can cause engine failure. Upon removal of the Balancer Shaft,
we will install the CPR Balancer Shaft Eliminator Kit which uses Genuine Mitsubishi parts.

Cylinder Head, Camshafts and Valvetrain.

The entire top-end assembly is performed to the same attention to detail and quality as the Bottom End, where all re-used components such as retainers, valve springs, rockers, valves etc are examined and compared to manufacturer's tolerances. The majority of valvetrain builds will involve upgrading valvetrain components to ensure maximum reliability, where we will typically introduce an uprated aftermarket Single or Dual Valve Spring, Seal and Retainer Kit.

Cylinder Head Modification Services are available at CPR, where any Port Re-Shaping or Oversizing of the Valves is carried out by an Industry Leading Race Cylinder Head Specialist that we have worked with for over 5 years. Our specialist has over 30 years experience working on and developing Cylinder Heads for Racing Application.
This service is highly labour intensive, where every Cylinder Head is individually treated to many hours of processing. This Race Porting Service is therefore reserved to customers seeking the absolute highest level of quality and performance from their engine, and will understand not only the labour involved, but also the experience required to excel in this area of engine building. This level of quality is reflected in the cost and lead time, where no cylinder head is released for inclusion onto the engine until our specialist is happy to release it.

For more information about our Engine Building Services, please call us to discuss your requirements.