Every now and again Lotus Marques is presented with Lotus vehicles that have been privately imported from the UK.
This article shows how some Lotus Esprit's have extreme corrosion problems and what is required to rectify the damaged components.
Every component of the brake system had been attacked by salt corrosion and all solid brake lines plus flexible hoses needed to be replaced.
A routine safety check reveals a number of items need attention, including the top front ball joints
The exhaust waste-gate adapter manifold could not be re-used so a replacement was obtained.
If you are contemplating importing a Lotus Esprit into Australia, then you might want to look for a locally delivered vehicle that is relatively free from corrosion
The valve seat located inside the waste-gate adapter manifold shows its cracked and has sections missing from it.
A concealed and damaged valve seat like this one will constantly allow exhaust gases to bypass the turbocharger and will significantly reduce the boost.
Anyone contemplating changing the waste-gate diaphragm, then this is the opportunity to examine the condition of the valve and its mating seat.
Changing the waste-gate diaphragm without removing the waste-gate body ignores the opportunity of inspecting other vital components.
The left hand photograph shows the corroded external waste-gate after it was removed from the exhaust adapter manifold.
A complete second hand unit was sourced by the owner but this proved to have problems despite being recently rebuilt.
The standard Lotus Esprit turbo-charger is a non-water cooled unit and has experienced a hard life.
The intake side of the turbo-charger has residual oil that indicates worn seals and refurbishment is required.
At some stage the waste-gate signal tube has been broken and someone has carried out repairs by installing a flexible braided hose.
Reducing the waste-gate signal tube bore from 0.25" to 0.128" is restrictive and will dampen the waste-gate response time.
A blown head gasket requires the cylinder head to be removed so the problem can be investigated further.
A heavily corroded radiator and poorly functioning fans caused the engine to over-heat.
Radiator and fans were rebuilt and re-installed with a brand new fibreglass shroud to replace the cracked plastic item.
After any engine experiences over-heating problems, the radiator and water pump need careful examination.
This Lotus Esprit water pump has extensive corrosion inside and out, indicating it is in need of repairs.
Despite this Lotus Esprit water pump being in poor condition, Lotus Marques is able to carry out a successful repair in-house.
For comprehensive details regarding Esprit water pump repairs and options, view the article here.
This Esprit has received an HC engine upgrade but the inlet cam cover is off a normally aspirated engine.
The thread detail different and external diameter of the oil filler cap is too large to provide clearance at the turbo outlet pipe.
All the tired paintwork gets stripped and new wrinkle paint applied by the owner - teamwork here!
Both Dellorto carburettors are dismantled and placed in a solvent filled ultra-sonic bath to make sure every component is clinically clean.
After the carburettors are reassembled, the accelerator pump jet delivery systems are calibrated in-house to ensure the volumes are identical.
As all the components get returned to the engine bay, everything is first dummy installed to ensure it fits correctly.
Silicon high temperature heater hose is used to provide coolant to the turbo-charger body.
Orientating fittings, various pipes and hoses is critical to the future operation of the engine and cooling system.
Stainless steel lock tabs are installed to prevent temperature cycling and vibration from loosening nuts and bolts.
A new signal pipe fabricated so its the correct bore size that runs from the turbo outlet to the external waste-gate.
Anti-seize compound is applied to all the stainless steel studs and nuts to prevent galling when tensioned.
From experience, galling is cause by a combination of friction and adhesion between the male and female thread surfaces.
This aluminium alloy pipe usually lives in the right-hand front wheel arch and contains the Otter thermostatic switch that controls the radiator fans.
Discovering heavily corroded, paper thin coolant pipes creates challenges because these components are obsolete.
The above replacement pipe has been fabricated in stainless steel and bronze to eliminate the possibility of future corrosion.
The bronze housing has been threaded to accept a screw-in switch which in-turn provides the choice of three switches with different operating temperatures.
The thermostatic switch is orientated downwards which is the correct position per the Lotus TSB.
The orientation of the switch has been revised to ensure the switch is always in contact with coolant when there is a chance of air in the cooling system.
BE AWARE - On other Lotus Esprit related web sites, the Otter thermostatic switch orientation is shown incorrectly pointing upwards.
Both of the above coolant pipes were found to be badly corroded so new replacement components were fabricated in-house.
Assembling and then testing the waste-gate on the bench revealed it was capable of delivering approximately 5psi of boost pressure.
Dismantling the waste-gate, then checking the spring on a valve spring machine confirms its badly fatigued and out of specification.
Copyright © 2013 Lotus Marques
This article shows how some Lotus Esprit's have extreme corrosion problems and what is required to rectify the damaged components.
Every component of the brake system had been attacked by salt corrosion and all solid brake lines plus flexible hoses needed to be replaced.
A routine safety check reveals a number of items need attention, including the top front ball joints
The exhaust waste-gate adapter manifold could not be re-used so a replacement was obtained.
If you are contemplating importing a Lotus Esprit into Australia, then you might want to look for a locally delivered vehicle that is relatively free from corrosion
The valve seat located inside the waste-gate adapter manifold shows its cracked and has sections missing from it.
A concealed and damaged valve seat like this one will constantly allow exhaust gases to bypass the turbocharger and will significantly reduce the boost.
Anyone contemplating changing the waste-gate diaphragm, then this is the opportunity to examine the condition of the valve and its mating seat.
Changing the waste-gate diaphragm without removing the waste-gate body ignores the opportunity of inspecting other vital components.
The left hand photograph shows the corroded external waste-gate after it was removed from the exhaust adapter manifold.
A complete second hand unit was sourced by the owner but this proved to have problems despite being recently rebuilt.
The standard Lotus Esprit turbo-charger is a non-water cooled unit and has experienced a hard life.
The intake side of the turbo-charger has residual oil that indicates worn seals and refurbishment is required.
At some stage the waste-gate signal tube has been broken and someone has carried out repairs by installing a flexible braided hose.
Reducing the waste-gate signal tube bore from 0.25" to 0.128" is restrictive and will dampen the waste-gate response time.
A blown head gasket requires the cylinder head to be removed so the problem can be investigated further.
A heavily corroded radiator and poorly functioning fans caused the engine to over-heat.
Radiator and fans were rebuilt and re-installed with a brand new fibreglass shroud to replace the cracked plastic item.
After any engine experiences over-heating problems, the radiator and water pump need careful examination.
This Lotus Esprit water pump has extensive corrosion inside and out, indicating it is in need of repairs.
Despite this Lotus Esprit water pump being in poor condition, Lotus Marques is able to carry out a successful repair in-house.
For comprehensive details regarding Esprit water pump repairs and options, view the article here.
This Esprit has received an HC engine upgrade but the inlet cam cover is off a normally aspirated engine.
The thread detail different and external diameter of the oil filler cap is too large to provide clearance at the turbo outlet pipe.
All the tired paintwork gets stripped and new wrinkle paint applied by the owner - teamwork here!
Both Dellorto carburettors are dismantled and placed in a solvent filled ultra-sonic bath to make sure every component is clinically clean.
After the carburettors are reassembled, the accelerator pump jet delivery systems are calibrated in-house to ensure the volumes are identical.
As all the components get returned to the engine bay, everything is first dummy installed to ensure it fits correctly.
Silicon high temperature heater hose is used to provide coolant to the turbo-charger body.
Orientating fittings, various pipes and hoses is critical to the future operation of the engine and cooling system.
Stainless steel lock tabs are installed to prevent temperature cycling and vibration from loosening nuts and bolts.
A new signal pipe fabricated so its the correct bore size that runs from the turbo outlet to the external waste-gate.
Anti-seize compound is applied to all the stainless steel studs and nuts to prevent galling when tensioned.
From experience, galling is cause by a combination of friction and adhesion between the male and female thread surfaces.
This aluminium alloy pipe usually lives in the right-hand front wheel arch and contains the Otter thermostatic switch that controls the radiator fans.
Discovering heavily corroded, paper thin coolant pipes creates challenges because these components are obsolete.
The above replacement pipe has been fabricated in stainless steel and bronze to eliminate the possibility of future corrosion.
The bronze housing has been threaded to accept a screw-in switch which in-turn provides the choice of three switches with different operating temperatures.
The thermostatic switch is orientated downwards which is the correct position per the Lotus TSB.
The orientation of the switch has been revised to ensure the switch is always in contact with coolant when there is a chance of air in the cooling system.
BE AWARE - On other Lotus Esprit related web sites, the Otter thermostatic switch orientation is shown incorrectly pointing upwards.
Both of the above coolant pipes were found to be badly corroded so new replacement components were fabricated in-house.
Assembling and then testing the waste-gate on the bench revealed it was capable of delivering approximately 5psi of boost pressure.
Dismantling the waste-gate, then checking the spring on a valve spring machine confirms its badly fatigued and out of specification.
Copyright © 2013 Lotus Marques
