Clio 2 and 3 RS PM 275 Competition Engine

This 2100cc F4R series engine produces 275bhp (205kW) and 200lbft (270Nm).  The engine design has been maximised to produce great midrange performance to make it suitable for a wide range of competition uses such as racing, rallying, hillclimbs and sprints.

The engine comes as a completed cylinder block with sump, and head assembly with a Pure Motorsport baffled breather plate, it does not include: any induction, throttle bodies, exhaust manifold, oil catch tank, ignition coil, plug leads, flywheel or auxiliary belt driven parts.  All of these extra parts can be supplied and we will offer advice as to the best parts to use.

The engine spec is as follows:

12.5:1 Compression ratio,
85mm bore
93mm stroke
2100cc displacement
275bhp output
200lbft torque

Cylinder head:

All engines utilise the Clio 3 RS cylinder head, heavily modified with solid tappets.

Hand ported head to ensure adequate thickness to the coolant circuit.
Valve seats cut with three angles blending into the combustion chamber and valve throat
New valve guides on all heads (these are not cut down when porting to keep maximum valve stability)
One piece uprated oversize valves
Uprated double valve springs and titanium retainers
Cat Cams with VVT
Vernier Pulley on exhaust
Solid tappets
Uprated cambelt kit with steel pulleys
Genuine Renault head gasket set and head bolts.

Bottom end:

Standard balanced crank, choice of crank for sprint/hillclimb or endurance/high mileage use
ACL or King racing tanged main bearings
ACL or King racing tanged big end bearings
New genuine Renault thrust washers
New genuine Renault larger capacity oil pump
Robson engineering custom con-rods 148mm long
Custom CP X Bridge pistons, three ring, 20mm pin and crown height to suit our con-rods, 85.0mm
Built with Recon block including: stripping, soda blasting, paint, skim sump face, hone, grind deck, new oil jets, new dipstick tube, new core plugs, new main cap bolts, modify main caps and block for race type tanged bearings
New piston cooling oil jets
Genuine Renault engine seal kit

Why is this engine different from building one using generic off the shelf components?  
The generic off the shelf parts are designed with many compromises so that they will fit lots of different engines.  Generally off the shelf pistons will have large valve cutouts to allow for the use of big valve lift cams - this lowers the compression ratio so the intruder dome height will be higher to compensate.  Off the shelf piston domes will be designed to fit the standard combustion chamber so take up a smaller area - the intruder needs to be higher still to raise the compression ratio.  The higher the dome is, the more of a barrier it produces to the flame front within the combustion chamber, so the lower the intruder height - the better!
We custom design our pistons to suit this engine configuration, so we don't have any compromises - we also use a superior quality manufacturer of our pistons by the name of CP Carillo in the USA.

The stroke of the F4R engine is very long compared to it's bore size and this causes the piston speeds to be very high.  This means we have to keep the maximum RPM down so tune the engine to work well in the midrange.  We also reduce the loads on the piston and rod assembly by using a longer than standard con-rod with a shorter piston.  The rods are very lightweight and beautifully designed and made in the UK from forged blanks.  They are considerably lighter than cheap rods and are very well designed with no stress raising sharp internal corners - all corners utilise a stress reducing radius.

The cam choice we use is surprisingly mild with moderate valve lift and a comparatively low duration and helps keep the engine ultra tractible and flexible at all engine speeds. 

The combination of many hours of design and testing, with a selection of the finest quality components means you can rest assured you are getting the best value for money, best reliability and best performance from your engine. 

Suitable donor engine must be supplied and should have a head in good condition, with matching cylinder head cover, small exhaust port, not modified in any way, have minimal or no scoring of cam journals and not having been skimmed. 

Running in procedure can be found here