01926 633211

mike@lotusbits.com

Engine Rebuilds & Development

Lotus Parts | Restoration | Upgrades

Much has been learned in the development of the 900 series Lotus engines from Lotusbits Rallying experience.

Whether you wish your engine rebuilt to original specification or are tempted by our upgraded Lotusbits 2.5litre 250bhp road-going engine, (Rally engines develop 320bhp), our approach and attention to detail, whether building a standard or racing engine is the same.

Dedicated engine builder Howard Potter assisted by Connor.

With over 25 years experience in engine performance development, EMS Calibrating, and building OEM engines, Lotusbits have become specialists in Lotus 900 series from standard rebuilds, 2.5 stroker engine to full historic specification Lotuses.

Contact Mike for all enquiries: 01926 633211 or email mike@lotusbits.com

Standard Engine Rebuild

At Lotusbits we have been building Lotus engines for over 20 years. Our inhouse engine builder is solely dedicated to the rebuilding of 907, 908, 910, 911, 912 and 920 engines.

As we have rebuilt many engines, including for competition, our experience has shown that a thorough and methodical approach is demanded. 

Details of Engine Rebuild

At Lotusbits we have been building Lotus engines for over 20 years. Our inhouse engine builder is solely dedicated to the rebuilding of 907, 908, 910, 911, 912 engines.
As we have rebuilt many engines, including for competition, our experience has shown that a thorough and methodical approach is demanded.

When your engine is received it will be steam cleaned prior to stripping and inspection. Once stripped all parts are vapour blasted then inspected as below:

  • Cylinder head – Hardness tested first – if soft it needs to be replaced.
  • All core plugs removed and oil gallery plugs removed, cleaned inside and out.
  • Inspected for damage from detonation and physical damage

Block

  • Corrosion in water jacket.
  • Snapped studs
  • Thrust washer damage
  • Liner seats
  • Uneven bearing wear indicating line bore issues

Cam carriers

  • Follower bores
  • Cam shaft bearing faces

Oil pump

  • Housing wear and scoring
  • PRV

Water pump

  • Corrosion on housing

Cam covers

  • Straightness of sealing face
  • Surface damage
  • Crankshaft Journals measured
  • Thrust washer damage
  • Evidence of previous failures

Cam shafts

  • Rust
  • Damaged noses
  • Damaged bearing surface
  • Pistons Measured
  • Scoring
  • Ring clearances
  • Det damage
  • Physical damage

Liners

Piston rings

Valves

Valve guides

Cam followers

Oil pump annulus and rotor

Water pump impellor, bearing, seal and drive flange

All gaskets and seals

All cam sprockets changed to HTD 

Stainless steel cam washers fitted

Cam belt and tensioner converted to HTD and offset dog

Spark plugs, plug leads, distributor cap and rotor arm

Exhaust and inlet manifold studs replaced 

Oil and filter

All external bolts replaced or re-plated

Crankshaft reground, balanced and fitted with new matching bearings with optimised clearances

Cam covers powder coated and finished to original spec

Head faces skimmed

Flywheel bolts inspected – replaced if damaged

Conrods – vapour blasted and inspected – little ends changed if required

Engine is built, shimmed, primed with oil and fitted to test stand

Distributor is cleaned and inspected

We treat each engine rebuild as bespoke. If, along the rebuild, there issues or areas that we feel need your consideration, we will inform you.

Further to ensure your satisfaction and our peace of mind each engine is run for a couple of hours to ensure quality of build and that there are no leaks.

Cost of above – £6600 normally aspirated engine – £6800 for a Turbo engine

2.5 ltr Lotusbits Engine

Background on the 2.5 ltr engine

Dyno Engine Testing

The Lotusbits 2.5 litre engine is the road going version of the Lotusbits Lotus Sunbeam Rally car successfully rallied by Mike Taylor and Cathy Sewart. The engine is the result of exhaustive testing and development in the harshest of environments, rallying. At the heart is Lotusbits own crankshaft designed by Mike and engineered in Warwickshire. Whilst 2 kgs heavier than the original, the design helps negate the imbalance of the original crankshaft, resulting in a smoother, higher revving engine with increased durability and reliability.

As part of a programme of continual developments, the Rally engine now puts out 320bhp. For road going use, a reliable 250 bhp and 210 lb ft is deemed sufficient, particularly when placed in a lightweight car such as an Esprit or Excel. On the road whilst this naturally makes for a quicker car it is the improved driveability due to the enhanced torque which really makes the difference.

“Racing improves the breed”

Upgrade options:

* Uprated clutch – required

* Exhaust manifold/exhaust

* Mapped ignition

* Fuel injection

Fuel Injection

The Lotusbits Fuel injection kit has been continuously developed over many years on the Lotusbits’ Excel and current Lotusbits Lotus Sunbeam rally cars.

This tried and tested package has been fitted to many of our customers cars, Esprits and Excels,

who have been delighted by the results.

Benefits:

* Improved cold start

* Enhanced driveability. Useable power feels stronger

* Diminish flat spots

* Removes potential hot start issues

* Increased fuel economy

* Base kit designed to work with all 900 series engines

* Base map supplied, although rolling road set up required

The Lotus 900 series fuel injection kit comprises:

* DTA S40 T2 engine management system and harness

* Jenvey throttle bodies

* Injectors and fuel rail

* Pressure regulator

* Fuel pump and filter

* Crankshaft sensor (including mounting bracket)

* Crankshaft trigger disc

* Coolant and air temperature sensor and wheel sensor etc.

Kit: £3600

Fully fitted: £7000 (engine out)

If you want further information or would rather we fitted the kit, please call. Mike to discuss.

Contact Mike for all enquiries: 01926 633211 or email mike@lotusbits.com