LC tech

For Sale





The contents of this page has been lifted straight from Dave Evan's website with

his permission. Lots of very useful info here !!


Engine: Lotus-GM
Cylinders: 6
Fuel supply: Electronic MPFI (GMP4),
Twin Garrett T25 turbochargers
Water/Air Charge cooler
Bore × stroke 95.00mm × 85.00mm, 3.74 in × 3.35 in
Bore/Stroke ratio 1.12
Displacement 3615 cc (220.601 cu in)
Unitary capacity 602.5 cc /cylinder
Compression ratio 8.20:1
Max. output 382.2 PS (377.0 bhp) (281.1 kW) @5200 rpm
Max. torque 568.0 Nm (419 lbft) (57.9 kgm) @4200 rpm
Maximum rpm 6253 rpm
Specific output 104.3 bhp/litre 1.71 bhp/cu in
Specific torque 157.12 Nm/litre

Max power (bhp/rpm): 377/5,200
Max torque (lbs ft/rpm): 419/4,200
Transmission (ratio/mph per 1,000rpm)
1st 2.68/8.2, 2nd: I .80/12.2
3rd: 1.29/17.0, 4th: 1.00/22.0
5th: 0.75/29.4, 6th: 0.50/44. I
Reverse: Final drive ratio: 3.45:1

Wheels & Tyres (F/R): Alloy, 17x8.5ins 235/45ZR17 Alloy, 17x9.5ins 265/40ZR

Offset ET 28mm Front,  ET 7mm Rear



Brakes(F/R): I 2.9/11.8ins ventilated discs. ABS
Steering: Re circulating ball, power-assisted.

ABS sensor check at the abs connector to abs ecu under passenger seat
Front Left: 4-6
Front Right: 11-21
Rear Left: 8-9
Rear Right: 24-26
Sensor resistance should be between 500-2000 ohms
Pins 1 to 18 is in one row, pin 1 at left facing (female cable) connector
Pins 20-35 (less pins than above) are in lower row

Lock-to-lock: 2.6, Turning circle (ft): 32.6

Measurements (ins)
Length: 187.7
Width: 76. I
Height 56.5

Wheelbase: 107.5
Track (F/R): 57/58
Ground clearance: 7
Kerb weight (Ibs): 3,641

Front Independent, MacPherson struts, coil springs,twin-tube dampers, anti-roll bar Rear Multi-link,
semi-trailing arms, progressive rate coil springs, twin-cube dampers, self-leveling

Performance figures (mph/secs)
0-60: 4.8
0-100: 10.1
1/4-mile (secs): 13.5
Max speed (mph): 186
Average mpg: 22.3


What are the differences between a 3.0L 24V and the 3.6L 24V?

Inlet Manifold

Same injector rail and the same lower half

Exhaust Manifold

Completely different

Cam shafts, valve gear, timing gear

The Same

Head Bolts (Updated Jan2009)

C30SE 8.8 grade M12 (1.5mm)
C36GET Lotus 10.9 grade M12 (1.5mm)  

Update Jan2009

Stud: ARP-AU4800-1LUB
Nut: ARP-300-8307 12 point standard style.
Washer: ARP-200-8500 aprox 3mm thick.
Length: 120mm long and has 30mm base thread and fits the threads in the block perfectly. 1.5 threads.
Top threads length 30mm, 1.25 threads.
Nut has 1.25 threads.
About 12$ at summitracing in the US. All ARP sellers should be able to order it in.

Big thanks to Johan Nilsen


Cylinder Head

The cylinder head is basically the same!
The C36GET head has a extra cooling outlet/inlet at #6 on the inlet manifold side.
The piston crown recesses have had a minor but significant amount of alloy milled away.
A standard head can be converted by a competent machinist.
Cracks that don't cause a problem are not unusual.

Head Gasket

The head gasket is very similar between the two engines, I've never seen a new original head gasket from the early 90's, it's thought that the ones sold now are not the same as they were then
Material and thickness (1.3mm) is the same
Extra 12 holes of which only 11 are needed in the Lotus version and cost nearly twice as much as 3.0L 24V version!
A 3.0L 24V gasket can be converted with care and a reference gasket,


The Block is basically the same far) the Lotus version has extra webbing, holes for fitting a piston cooling spray bar
The 3.6V version has 3.6 cast on the side of the block
Oil flow through the block has been reversed.
The 3.6L version has a larger thread for fitting the single knock sensor
A standard 3.0L 24V block would probably last quite well but you take your chances and at your own risk!
Some Lotus blocks develop cracks between water and oil, and between head bolt holes and water channels.




Different.... to allow for the extra stroke which gives the engine the torque and capacity!


Same ish... Its the same basic sump but has extra baffles and take off pipes.

Timing Cover


Water pump

Different... has a larger impeller

Golden Nuggets!

Make sure that the engine cooling system works correctly, if you don't it could be a very costly decision.

Electric Auxiliary Water pump:

Located to the left of the engine this water pump deals with the immense amount of heat that the engine dissipates after the engine is switched off, if this pump fails potentially you risk the head/ block cracking, head gasket failure, turbo failure every potential scenario is very expensive.

Electric Fan:

The Fan should come on when your A/C does, this shares the same fuse as the electric suspension, if that doesn't work then it's likely your fan doesn't either. The Fuse is located in the engine bay fuse box. Failure of the this component can assist in the worst possible failure scenario as itemized above.

Self Leveling suspension:

The LO/LC is fitted with self leveling suspension it's intended purpose is to keep the car to a set level as much as possible when traveling at high speed and when carrying extra load, this is intended to make sure the suspension operates in it's best operating window. If shortly after you switch the ignition on you don't hear the sound of a air compressor then chances are the pump is not working and needs investigation. If the pump is working then you need to check the link arm that connects from the suspension to a level sensor attached to the car. Failure of the link arm fixing can cause the rear suspension to jack up, your unlikely to notice this whist driving along until you attempt drive around a bend at which point you'll either come to grief or get lucky!

Should you ever have to remove the gear box:

Replace the spigot bearing in the end of the crank and whist the box is out verify that the breather located on the top of the gear box is working, to check unbolt and shake, if it rattles then it works if it doesn't you will have to carefully remove the cover and clean the bearing.

Before you refit the pivot pin:

Have a very close look at the bell house where the pivot pin fixes, if the bell housing is cracked then you need to fix it otherwise you'll be looking again in the very near future! whilst your there mate the pivot pin to the fork using grinding paste, this will give the clutch the best chance of giving failure free service.

Rear Shock absorbers:

Should you ever purchase new rear Air shock absorbers, check that the valve for the air supply clears the body of the car, if it doesn't then you will have to press the bottom bush out and reverse it.

Annoying Tapping from the front of the car:

A light tapping from the front of the car when going over small bumps is likely to be a washer at the top of the front strut, the strut needs to be removed to replace, these washers are very expensive from Vauxhall/Opel.

Crank Case alignment:

When refitting the crank case do exactly what it says in the manual with regards to the alignment of the crank to cam sensor drive, when you have it right, sighting down through the top of the crank case you will see the alignment marks lined up.


The knock sensor has a 1/4" NPT ((USA) National pipe thread).


The Lotus Carlton fuel injection system uses a GM P4 (1228331) engine control module to inject fuel sequentially via six Ac Rochester injectors (9260 17101598).

These are of Ball type they have excellent atomisation and a wide spray pattern but are prone to partial plugging by varnish deposits.These injectors use 14mm O-rings.

38 #/Hr @ about 300 kpa, 12.2 ohm (4.75gm/s according to the manual)

JPG: Injector Side View

JPG: Injector Nozel View

GIF: Injector Cut Away



The ZFS6-40 is a constant-mesh parallel-axial fully synchronized synchromesh transmission. The design incorporates an input/main shaft, a countershaft, and the output/main shaft. The input shaft and main shaft are located on the same axis. The counter shaft is on a parallel axis with the main shaft at a 95mm separation distance. The 1st, 2nd and 3rd idler gears are assembled on the mainshaft. 4th gear is part of the input shaft and is the driving gear. The 5th and 6th idler gears are assembled on the countershaft. All forward and reverse gears are fully synchronized. 1st and 2nd have dual cone clutch synchronizers. 3rd through 6th and reverse have single cone synchronizers.

SYNCHROMESH MECHANISM: Unlike a dog clutch, a cone clutch can progressively increase or decrease its level of torque transfer. Motion is transferred through the shift linkage to the shift fork and then to the sliding collar of the synchronizer hub. Synchronizer hubs are located aft of the reverse idler gear, between 1st and 2nd, between 3rd and 4th, and between 5th and 6th idler gears. As the sliding collar starts to move, pressure pieces momentarily exert pressure on the synchronizer ring forcing it onto the conical binding surface attached to the idler gear. This momentary binding force causes the idler gear to synchronize its rotational speed with the planetary shaft beneath it. As the sliding collar continues to move toward the idler gear, pressure is released off of the binding ring while both sets of dog teeth self align and interlock with each other. Proper sliding collar-to-idler gear dog tooth alignment prior to interlock engagement is provided by 3 evenly spaced sets of 5 dog teeth which protrude further from the remaining dog teeth. These are the preemptive dog teeth located only on the sliding collar. The design of the dog teeth provide a positive lockup at engagement disallowing disengagement until the sliding sleeve is retracted by the gear shifting system. Power loading through the engagement gear further enforces this self-locking effect.

SHIFTER: The shifter selection-rod system is responsible for the tactile sensation for most of the lateral shifter movement and some of the fore-aft movement. The remaining tactile sensation is induced by the detentes on shift rails. A series of locking pins and a ball restrict shift selection to allow for only one rail to move at a time. If you desire more tactile feedback, adjustments can be made by shimming the shifter selection detent springs or driving the shift rod detent spring caps (10mm) in just a hair at a time. Do not exceed 1/8 inch recessed on the 10 mm detent spring expansion plugs. Loctite 609 Retaining Compound will seal them nicely.

DRIVELINE: Torque flows from the engine to the transmission input shaft driving-gear at the front of the gearbox, through the driving gear down to the countershaft, through the driven gears up to the main/output shaft at the rear of the gearbox and down the drive shaft to the rear axle. Fourth has a 1:1 direct torque flow from the input shaft to the output shaft.

LOOK OUT FOR TROUBLE: The preemptive dog teeth are most susceptible to damage when the clutch hydraulic system becomes degraded. The sensation of notchy shifting is more prevalent when the sliding collar's preemptive dogteeth become worn or badly deformed. Advanced stages of preemptive dog tooth wear may result in gear engagement difficulty due to metal burrs restricting normal movement of the sliding collar. This condition can also cause partial engagement of the dog teeth resulting in unexpected gear disengagement. In any such circumstance, discontinue use of the problematic gear until necessary repairs can be performed. This may save lots of money in additional parts when repaired.

Technical Data:

Oil: HD-engine oil SAE W/20 or SAE30 / Castrol Formula RS racing syntec 10W60 / Castrol syntron 10W/60 / Castrol R synthetic 5W50

Oil capacity: .55 gallon (2.1L)

Gear Ratio :1(2.68) 2(1.80) 3(1.29) 4(1.1) 5(0.75) 6(0.5) R(2.5)

Maximum torque: 610Nm

Weight : 135 pounds (63.5Kg) approx.

JPG: Left Front Cut Away  


Input (propshaft) seal, that's still available from VX - 90393408.
For recons are DOME motorsport in Bromsgrove. Dennis Osborne - the owner. 
Prices to have your diff re-conned range from £250-£500, depending what needs doing.


2 Garrett T25's

Part numbers:
TB2544 (Garrett#) 452038-0001 (Lotus PartNumber) P530.4021.851AF
TB2545 (Garrett#) 452039-0001 (Lotus PartNumber) P530.4021.852AF
GIF: Compressor Section
JPG: T25 exploded view
JPG: Turbo Cutaway



Fuel Filter

Lotus P530.4403.601AF
Vauxhall/Opel 90393166
Bosch 450905002
OEM 771.

Oil Filter

Vauxhall/Opel/GM 25011122 Rock Auto
Ac-Delco AC PF897
BALDWIN B7839-10
NAPA 1551
WIX 51551

Engine Oil

Vauxhall/Opel No longer sold
ELF Classique 20w/50 same as OEM Elf competition order from Cromwell-Tools Part# ZZ20062936 (20L)  

Millers CSS 20W50 is an alternative now that elf have discontinued the classique


Vauxhall/Opel 90393267
Jabsco 9200-0021 (cheaper) Jabsco

Ignition Plugs

Vauxhall/Opel 90393137 (NGK BK6E)
OEM 1989579  

A tip from Joe Ellis
Just for your info, I spoke to NGK and learnt a lot about spark plugs. Both listed plugs 
(BCP6ES and BK6E) are exactly the same except that the BK6E is 2.5mm shorter 
which probably makes it more difficult to get the plug lead caps on. They also suggested 
that their latest iridium plugs will offer better performance and suggested the BKR6EIX 
as worth trying. For those with higher boost a colder plug is advised so substitute the 6 for a 7

Air Filter

FRAM CA5107 Vauxhall/Opel/GM 25062406

Transmission Oil

Vauxhall/Opel 90393527
Castrol RS 10W60

Differential Oil

Vauxhall/Opel 90393473 NLS
Castrol SAF-XJ 75W140

Aux Ribbed V-belt

designation 6K2230


Fuel Pump
Vauxhall/Opel 90393163
Bosch 580254937  
same as fitted to renault 5 turbo ?


Aux electric water pump

Vauxhall/Opel 90393380 12L/min @ 0.12Bar
Lotus A100K6018K(motor agp 12v)
Jabsco 59500-0012 Jabsco
Bosch 130002066  



1. Bosch fuel pump for LC

2. Bosch Electric Water Pump

…from Germany, not available in UK takes 3-4 days

Ask for Shaun

Name A P D Ltd (Norwich)
Address 3 Spar Road
St Faiths Industrial Estate

Phone 01603 486020

Fax 01603 417105

Email norwich@apd.co.uk

Website http://www.apd.co.uk/

1. £109.92 incl. VAT (May 2006)

2. £98.16 incl,VAT (Feb.2008)

Updated 04.02.08


Rocker cover filter (internal) crank case vent

Vauxhall/Opel 90393235
Lotus P530.4007.103B(AF/BF)
OEM mil-b-83054B polyester foam (60/41/32mm)
Seems to be the same as fish tank filter?

Electric Water Pump Vacuum Solenoid  

Mark up your parts calalogue (PS 925 - page 8-7) with these alternatives:- 1. 90393254 - vacuum valve, Esprit no. A082M6421F £11.70 plus VAT 2. 90393255 - solenoid, turbo Esprit no. A082M6420F £13.95 plus VAT It appears these parts fail and are not always detected as having done so but can affect performance and cooling!! I recommend purchasing a spare - not really expensive. I was helped by a chap called Russell at my local Lotus dealer:- Stratton Motor Company (Norfolk) Ltd. 01508 530491 (FAX 01508 531670) email: parts@strattonmotorcompany.com Mention they are for a Lotus Carlton and my name and ask for Lotus Club discount and you may get them for £10.53 & £12.55 plus VAT each!
AutobahnStormers View topic - LC Aux-Water-Pump problem

Vacuum solenoid for water ewp valve 
Vauxhall/Opel 90393254
OEM DR189 (0170)  
Esprit no. A082M6421F £11.70 plus VAT
Contact Russell at Stratton Motor Company (Norfolk) Ltd. 01508 530491
 (FAX 01508 531670) email: parts@strattonmotorcompany.com


Vacuum Solenoid part no 214-615 for ewp valve
Desc:- Valve with red dot / 1997225 lotus carlton £38.92
AC Delco Ltd (London)
OCW 19 Wandsworth Rd
Unit 14
Neil  tel 0208 8104595

Turbo Boost Solenoid
Vauxhall/Opel 90393255
OEM DR1997194  
Lotus dealership,used on the Espirit.
Part No:- A082M6420F--Price approx-£13.95 + Vat
Contact Russell atStratton Motor Company (Norfolk) Ltd. 01508 530491 
(FAX 01508 531670) email: parts@strattonmotorcompany.com


Idle Air Control Valve
Vauxhall/Opel 90393250
OEM 17059523

Ignition coil  

GM 10472401- D555 delco-remy $58.59??
Get from the USA

Coil Carrier

Vauxhall/Opel 10462702
OEM 10467202- D1998A delco-remy
Get from the states, buick V6?


Engine Management Unit

Vauxhall/Opel/GM 16162329/16165499
OEM 1228331 Ac-Delco

esc filter code: 1070033
Vauxhall/Opel ????
OEM 16150306 Ac-Delco  

Suspension Pump
Vauxhall/Opel 90473498
OEM 22153583/22153582 Ac-Delco
Shock Absorber
Vauxhall/Opel 90393102
Lotus P530-3103-138
Starter Motor
Vauxhall/Opel 90277933
OEM 1108080


Vauxhall/Opel 90338188
Bosch 120469910

Fuel Injectors

Vauxhall/Opel 90393211
Rochester 10365

Positive Crankcase Ventilation (non return valve)

Vauxhall/Opel ???
PDF: Non return Valve Patent


Manifold Air Temperature Sensor

Vauxhall/Opel 90393161
OEM 2250 0 AC 12V

Manifold Air Temperature Sensor

Vauxhall/Opel 90393161
OEM 2130 0 AC 12V

2 Bar Manifold Air Pressure Sensor

Vauxhall/Opel 90393206
OEM GM 886 0143 AA-10
GM #16009886
Lotus A910E6961
AC DELCO 213-183 $85.00 ??  

Following source sell the map sensor @oct2007 £46
Product code PMAP3004


1 Bar Atmospheric Air Pressure Sensor

Vauxhall/Opel 90393237
OEM 16038591

Crankshaft Sensor
Vauxhall/Opel 1103703
OEM 10456257 delco-remy  
Changed to 213970 AC-Delco
(12567712 Delco Remy ?)
After some digging around the internet a part supplied by RockAuto was purchased.
ACDELCO  508 213-970 crankshaft position sensor (9031.80.3890)
This fits ok and works see here



Camshaft Sensor

Vauxhall/Opel 903933084
OEM 10096172 delco-remy

Lambda Sensor

Vauxhall/Opel 25312178 - AFS73 Rock Auto
OEM 25312178- AFS73 ac-delco was afs40

Knock sensor
Vauxhall/Opel 10497163
OEM 10497163 ac-delco  
Note at 09/03/06
10497163 has changed to 10456208
available from ACDelco (rockauto)
The knock sensor has a 1/4" NPT ((USA) National pipe thread).



Temperature Sensor
Vauxhall/Opel ???
OEM 25036979 ac-delco 


ECU Coolant temp sensor
Vauxhall Part Number - 15326386
RRP - £35.66 (£30.35 +VAT)

Lotus number A910E6928F
Available from www.sjsportscars.co.uk
Tel / Fax: 01363 777790
£17 odd incl delivery,
Contact Steve Roberts

Isuzu Part Number - 8-15326386-0
RRP - £61.24 (£52.12+VAT


Possible source of clutch slave cylinder seals
Bore of clutch slave cyliner 1"
Piston slot size: 0.28"/7.34mm
Pistion Seal ID: 0.262"/6.66mm
(used) Piston Seal OD:1.02"/26mm
DE seal


Clutch pressure plate release bearing same as Porsche 944 Turbo. 

It is a Sachs no. 3151-155 301



Throttle position sensor

Thanks to David Franczak

Part Number :- ETC6443

 http://www.motorcarsltd.com/?cookieID=1S10VPK131SM0XE4GM&clientid=motorcars and they also had the following REF numbers


XREF: IN102372, 73305, SEB201, ETC6443


Joe Ellis just found that '89 Land Rover TPS is the same as LC/LO.
 Intermotor part number 19971.


MAT is not scaled - it's just the value read from the Analogue to Digital
converter inside the ECU. There isn't a simple equation to convert the
value into an actual temperature, the ECU has the following table in it :

0 = - 40 Deg C
16 = - 7 Deg C
32 = + 6 Deg C
64 = + 24 Deg C
96 = + 37 Deg C
128 = + 50 Deg C
160 = + 64 Deg C
192 = + 81 Deg C
224 = + 109 Deg C
240 = + 138 Deg C
255 = + 196 Deg C

You need to interpolate between these fixed points to get the real




Imperial Green
ICI Paint Manufacturer

One Way Valve
Brake servo non-return valve, 
Vauxhall part number is 90498464 and retails at £3.82+VAT (£4.48 Inc)

It's a standard part on loads on Vauxhalls, old (Corsa B) and new (Vectra C).
Thanks to Keith Forrest for that info