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
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.
2.5 ltr Lotusbits Engine
Background on the 2.5 ltr engine
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.
When we fit this kit in our workshop, the engine requires to be removed
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