For the Lotus owner who finds its necessary to rebuild their water pump, then installing a universal drive flange is a direct replacement that is guaranteed to fit first time.
Unlike our competitors offerings, the steel billet flanges supplied by Lotus Marques are manufactured with an OKUMA CNC machining centre.
This approach produces high quality parts with a consistent interference press fit.
The universal drive flange has been inspired by rebuilding numerous water pumps and having the original flange fail on final installation.
The primary component that fails is the later type flange (Lotus part number A907E6295Z) that has a sintered metal construction.
The surface at the point of failure has a typical granular/crystalline structure (similar surface appearance to cast iron when broken).
Whilst powdered metallurgy is an economical way to mass produce automotive components, they often lack tensile strength.
The dual bolt pattern flange provides easy installation across various water pumps fitted to normally aspirated Lotus 907, 911, 912 and Lotus Esprit turbo-charged engines 910, 920.
Water pump drive flange to suit Lotus Esprit, Elite, Eclat, Excel and Jensen Healey
Applicable Lotus vehicles and water pump part numbers are as follows-
Elite, Eclat and Jensen Healey D907E0743W
Elite and Eclat C907E0878J
Excel SE and SA 912 HC A912E9055J
Esprit 83-87 M.Y (low compression + remote thermostat) Carb Turbo B910E9001J
Esprit 87 M.Y. on (high compression) Carb Turbo B912E9021J
Esprit 88-92 Injected Turbo A912E9055J
Esprit 93-97 Injected Turbo A912E9277J
Rebuilt Lotus Esprit water pump B912E9021J
The water pump in the above photograph has been fully rebuilt and is ready to be returned to a Lotus Esprit owner in Germany.
Recommended dismantling notes
Before dismantling any water pump, it is important to measure the distance from the back of the existing drive flange to the alloy bearing housing (typically 0.275")
This critical measurement is required so the new flange can be pressed on the bearing spindle to the exact same position.
The position of the flange and V-pulley ensures the drive belt is in alignment with the crankshaft pulley etc.
Recommended installation notes
Just because you may have purchased a water pump overhaul kit or components from different suppliers, this does not automatically result in a quality rebuild.
Blindly assembling various components such as the hub and bearing does not take into account manufacturing tolerances.
It is absolutely essential to measure mating parts where an interference fit is involved.
A recommended interference of 0.00075" to 0.0015" is designed to achieve a medium drive fit for a 0.625" diameter shaft (relevant to this particular application)
With all Lotus 900 series water pumps, the outer bearing spindle which the drive flange locates on should measure 0.625" in diameter.
The internal bore of the drive flange supplied by Lotus Marques should measure 0.6235" to 0.623" but might vary slightly due to the zinc electro-plating.
From experience, the soft zinc coating may peel ever so slightly when pressed onto the hardened bearing spindle - this is normal.
It is useful to apply Loctite 668 or Loctite 620 which are medium strength retaining compounds.
Loctite 668 is a semi-solid stick and should be applied to the bearing spindle where it cannot run off the contact surface (unlike Loctite 620)
Both retaining compounds initially behave as a lubricant and provide a useful reduction in friction as the drive flange is pressed on.
The drive flange must be pressed on absolutely square to the bearing spindle and this is best achieved with the aid of a hydraulic press.
Press on the centre boss of the flange to minimise distortion during the installation process when using a hydraulic press.
NOTE CAREFULLY - The correct press tools are required to avoid component damage and personal injury!
Drive flange weight is 190 grams
Reference and further reading
1) On-line calculator to determine correct type of fit - http://www.amesweb.info/InterferenceFit/InterferenceFit.aspx
2) Engineers Black Book (1st Edition) ISBN 0 - 9580571 - 0 - 9
Chapter - Fits for Shafts and holes, pages 55, 56 and 57
Price $35.00 each excluding GST ($38.50 each including GST)
Please note carefully, pricing above does not included postage and packing.
Postage (economy air-mail) and packing costs for a flange be sent to the United Kingdom is $20.00
Drive flange plus postage costs to the UK is a total of $55.00 which is approximately GBP27.50
Overseas customers, please note advertised pricing is shown in Australian dollars.
Pricing information is correct as of 9/4/2016 but may alter with time and currency exchange rate fluctuations.
To order your water pump drive flange, send us your parts order today
Shipping from Australia to UK, USA, New Zealand, anywhere worldwide!
Contact Lotus Marques now for postal or courier shipping costs.
Unlike our competitors offerings, the steel billet flanges supplied by Lotus Marques are manufactured with an OKUMA CNC machining centre.
This approach produces high quality parts with a consistent interference press fit.
The universal drive flange has been inspired by rebuilding numerous water pumps and having the original flange fail on final installation.
The primary component that fails is the later type flange (Lotus part number A907E6295Z) that has a sintered metal construction.
The surface at the point of failure has a typical granular/crystalline structure (similar surface appearance to cast iron when broken).
Whilst powdered metallurgy is an economical way to mass produce automotive components, they often lack tensile strength.
The dual bolt pattern flange provides easy installation across various water pumps fitted to normally aspirated Lotus 907, 911, 912 and Lotus Esprit turbo-charged engines 910, 920.

Applicable Lotus vehicles and water pump part numbers are as follows-
Elite, Eclat and Jensen Healey D907E0743W
Elite and Eclat C907E0878J
Excel SE and SA 912 HC A912E9055J
Esprit 83-87 M.Y (low compression + remote thermostat) Carb Turbo B910E9001J
Esprit 87 M.Y. on (high compression) Carb Turbo B912E9021J
Esprit 88-92 Injected Turbo A912E9055J
Esprit 93-97 Injected Turbo A912E9277J

The water pump in the above photograph has been fully rebuilt and is ready to be returned to a Lotus Esprit owner in Germany.
Recommended dismantling notes
Before dismantling any water pump, it is important to measure the distance from the back of the existing drive flange to the alloy bearing housing (typically 0.275")
This critical measurement is required so the new flange can be pressed on the bearing spindle to the exact same position.
The position of the flange and V-pulley ensures the drive belt is in alignment with the crankshaft pulley etc.
Recommended installation notes
Just because you may have purchased a water pump overhaul kit or components from different suppliers, this does not automatically result in a quality rebuild.
Blindly assembling various components such as the hub and bearing does not take into account manufacturing tolerances.
It is absolutely essential to measure mating parts where an interference fit is involved.
A recommended interference of 0.00075" to 0.0015" is designed to achieve a medium drive fit for a 0.625" diameter shaft (relevant to this particular application)
With all Lotus 900 series water pumps, the outer bearing spindle which the drive flange locates on should measure 0.625" in diameter.
The internal bore of the drive flange supplied by Lotus Marques should measure 0.6235" to 0.623" but might vary slightly due to the zinc electro-plating.
From experience, the soft zinc coating may peel ever so slightly when pressed onto the hardened bearing spindle - this is normal.
It is useful to apply Loctite 668 or Loctite 620 which are medium strength retaining compounds.
Loctite 668 is a semi-solid stick and should be applied to the bearing spindle where it cannot run off the contact surface (unlike Loctite 620)
Both retaining compounds initially behave as a lubricant and provide a useful reduction in friction as the drive flange is pressed on.
The drive flange must be pressed on absolutely square to the bearing spindle and this is best achieved with the aid of a hydraulic press.
Press on the centre boss of the flange to minimise distortion during the installation process when using a hydraulic press.
NOTE CAREFULLY - The correct press tools are required to avoid component damage and personal injury!
Drive flange weight is 190 grams
Reference and further reading
1) On-line calculator to determine correct type of fit - http://www.amesweb.info/InterferenceFit/InterferenceFit.aspx
2) Engineers Black Book (1st Edition) ISBN 0 - 9580571 - 0 - 9
Chapter - Fits for Shafts and holes, pages 55, 56 and 57
Price $35.00 each excluding GST ($38.50 each including GST)
Please note carefully, pricing above does not included postage and packing.
Postage (economy air-mail) and packing costs for a flange be sent to the United Kingdom is $20.00
Drive flange plus postage costs to the UK is a total of $55.00 which is approximately GBP27.50
Overseas customers, please note advertised pricing is shown in Australian dollars.
Pricing information is correct as of 9/4/2016 but may alter with time and currency exchange rate fluctuations.
To order your water pump drive flange, send us your parts order today
Shipping from Australia to UK, USA, New Zealand, anywhere worldwide!
Contact Lotus Marques now for postal or courier shipping costs.