Craig Riley and his red 1989 Esprit are no strangers to Lotus Marques.
Craig initially brought his Esprit to us for a face lift by installing a later bumper bar and new air-dam.
However, on moving the Esprit into our workshop we discovered all was not well with the Lotus 2.2 litre engine.
The engine did not start easily, it did not idle and it appeared to run on three then four cylinders (depending on the rpm)
A quick diagnosis with the leak-down tester revealed the Esprit engine had a burnt out exhaust valve.
Subsequently the cylinder head was removed to confirm exactly what had been diagnosed.
The above right-hand photograph shows there is material missing from the exhaust valve.
During the cleaning process a thorough inspection of all the components was carried out that revealed something a lot more sinister than a burnt out exhaust valve.
With more than 30 years of experience working with these engines, Lotus Marques routinely crack tests all cam followers
The above photographs show one of the cam followers in this engine that has cracked right through and is close to failure.
Ignoring the routine crack testing of cam followers nearing the end of their design life is a recipe for disaster!
A decision was made to replace the original chilled cast iron followers with light weight steel followers
The burnt out exhaust valve was removed from the cylinder head to be replaced by a high quality component.
The Esprit cylinder head was totally dismantled so all the valves, guides and valve springs could be checked.
Afterwards, the valve seats, valve faces and valve tips were carefully machined so as to remove the minimum of material.
This resulted in the valve tip height being restored to within 0.002" deviation across similar valves when checking and adjusting the tappet clearances.
It is critical the valve seat heights be synchronised during this routine and the valve tip heights are identical.
Synchronised valve seat and valve height ensures the combustion chambers volumes and resultant compression ratios are identical across all four cylinders.
Lotus Marques recommends upgrading the exhaust manifold fasteners to include stainless studs, nuts and lock tabs.
This simple and cost effective upgrade prevents the exhaust manifold fasteners from working lose.
Upper left head gasket is the original Lotus laminated type head gasket removed during this exercise.
The standard Lotus replacement head gasket (Lotus part number B912E7029Z) is a superior composite construction but much thicker.
Whilst Lotus promote the new cylinder head gasket assisting with poor quality fuel, it has a detrimental effect on engine performance.
From experience gained in our workshop, we have observed a 15 to 20 horse power reduction on turbo charged engines.
To over-come these problems and restore engine power, Lotus Marques stocks and fits new thinner composite head gaskets.
If you are looking to undertake a similar project on your Esprit, then Lotus Marques would be pleased to help you by providing quality parts, technical support and special tools if required.
Before purchasing parts from another another Australian based Lotus parts specialist or club ask yourself - exactly what am I purchasing and what qualified support can I expect if I encounter problems?
For valued customers who purchase quality parts from Lotus Marques, we provide technical support via phone or email (this includes trade and over-seas customers).
The advice provided is based on operating a full-time workshop and 30 plus years experience working with the Lotus Esprit and other Lotus vehicles.
If you desire a quality and lasting result, then it is wise to deal with a qualified operator who understands engineering is a precise discipline.
Copyright © 2011 Lotus Marques
Craig initially brought his Esprit to us for a face lift by installing a later bumper bar and new air-dam.
However, on moving the Esprit into our workshop we discovered all was not well with the Lotus 2.2 litre engine.
The engine did not start easily, it did not idle and it appeared to run on three then four cylinders (depending on the rpm)
A quick diagnosis with the leak-down tester revealed the Esprit engine had a burnt out exhaust valve.
Subsequently the cylinder head was removed to confirm exactly what had been diagnosed.
The above right-hand photograph shows there is material missing from the exhaust valve.
During the cleaning process a thorough inspection of all the components was carried out that revealed something a lot more sinister than a burnt out exhaust valve.
With more than 30 years of experience working with these engines, Lotus Marques routinely crack tests all cam followers
The above photographs show one of the cam followers in this engine that has cracked right through and is close to failure.
Ignoring the routine crack testing of cam followers nearing the end of their design life is a recipe for disaster!
A decision was made to replace the original chilled cast iron followers with light weight steel followers
The burnt out exhaust valve was removed from the cylinder head to be replaced by a high quality component.
The Esprit cylinder head was totally dismantled so all the valves, guides and valve springs could be checked.
Afterwards, the valve seats, valve faces and valve tips were carefully machined so as to remove the minimum of material.
This resulted in the valve tip height being restored to within 0.002" deviation across similar valves when checking and adjusting the tappet clearances.
It is critical the valve seat heights be synchronised during this routine and the valve tip heights are identical.
Synchronised valve seat and valve height ensures the combustion chambers volumes and resultant compression ratios are identical across all four cylinders.
Lotus Marques recommends upgrading the exhaust manifold fasteners to include stainless studs, nuts and lock tabs.
This simple and cost effective upgrade prevents the exhaust manifold fasteners from working lose.
Upper left head gasket is the original Lotus laminated type head gasket removed during this exercise.
The standard Lotus replacement head gasket (Lotus part number B912E7029Z) is a superior composite construction but much thicker.
Whilst Lotus promote the new cylinder head gasket assisting with poor quality fuel, it has a detrimental effect on engine performance.
From experience gained in our workshop, we have observed a 15 to 20 horse power reduction on turbo charged engines.
To over-come these problems and restore engine power, Lotus Marques stocks and fits new thinner composite head gaskets.
If you are looking to undertake a similar project on your Esprit, then Lotus Marques would be pleased to help you by providing quality parts, technical support and special tools if required.
Before purchasing parts from another another Australian based Lotus parts specialist or club ask yourself - exactly what am I purchasing and what qualified support can I expect if I encounter problems?
For valued customers who purchase quality parts from Lotus Marques, we provide technical support via phone or email (this includes trade and over-seas customers).
The advice provided is based on operating a full-time workshop and 30 plus years experience working with the Lotus Esprit and other Lotus vehicles.
If you desire a quality and lasting result, then it is wise to deal with a qualified operator who understands engineering is a precise discipline.
Copyright © 2011 Lotus Marques