QUESTION
I've had to change cam bearings on my current Lotus twin cam engine a couple of times due to scoring and wear.
Can you tell me what causes this problem?
M.H. - Sydney, Australia
ANSWER
If you experience camshaft bearing scoring, then there could be several things that can cause this.
Firstly, the Lotus twin cam engine has an inherent design flaw which is the catalyst of oil contamination problems.
The Lotus twin cam crank-case is positively pressurised by blow-by from the combustion process.
In most modern day engines the combustion bi-products and gasses are usually drawn off from the crank-case and absorbed into the induction system.
This constant scavenging of the crank-case significantly reduces the build-up and contamination of the engine oil.
As the Lotus twin cam engine is not equipped to do this, then its wise to change to oil more frequently.
Installing a magnetic sump plug will also remove tiny metal particles and prevent them being pumped up to the camshafts.
I assume the engine your refer to is dry-sumped and has a remote oil filter??
Whatever type of oil filter that is installed, it would be prudent to drain the oil into a large stainless steel tray whilst changing the filter at the same time.
The tray can then be gently rocked from side to side to inspect the oil for metal paticles.
At the same time, the filter should be cut open and inspected for metal particles.
You might try using a very high quality oil filter that is capable of filtering down to one-micron.
Most commercially available filters in Australia are only capable filtering at about the 35 micron particle size.
Lotus Marques stocks a wide range of AMSOIL filters that filter to 1 micron and will fit most engines, including the Lotus twin cam.
Using AMSOIL filters means your precious oil stays cleaner for longer and helps to reduce wear!
The other area where carbon deposits and debris can lurk are in the cylinder head and camshaft oil galleries.
Have you any idea when these oil galleries where last scrubbed with a bottle brush and solvent?
It might be worth carrying out this exercise to eliminate the possibility of sludge and harsh debris hiding in these hidden galleries.
Copyright © 2012 Lotus Marques
I've had to change cam bearings on my current Lotus twin cam engine a couple of times due to scoring and wear.
Can you tell me what causes this problem?
M.H. - Sydney, Australia
ANSWER
If you experience camshaft bearing scoring, then there could be several things that can cause this.
Firstly, the Lotus twin cam engine has an inherent design flaw which is the catalyst of oil contamination problems.
The Lotus twin cam crank-case is positively pressurised by blow-by from the combustion process.
In most modern day engines the combustion bi-products and gasses are usually drawn off from the crank-case and absorbed into the induction system.
This constant scavenging of the crank-case significantly reduces the build-up and contamination of the engine oil.
As the Lotus twin cam engine is not equipped to do this, then its wise to change to oil more frequently.
Installing a magnetic sump plug will also remove tiny metal particles and prevent them being pumped up to the camshafts.
I assume the engine your refer to is dry-sumped and has a remote oil filter??
Whatever type of oil filter that is installed, it would be prudent to drain the oil into a large stainless steel tray whilst changing the filter at the same time.
The tray can then be gently rocked from side to side to inspect the oil for metal paticles.
At the same time, the filter should be cut open and inspected for metal particles.
You might try using a very high quality oil filter that is capable of filtering down to one-micron.
Most commercially available filters in Australia are only capable filtering at about the 35 micron particle size.
Lotus Marques stocks a wide range of AMSOIL filters that filter to 1 micron and will fit most engines, including the Lotus twin cam.
Using AMSOIL filters means your precious oil stays cleaner for longer and helps to reduce wear!
The other area where carbon deposits and debris can lurk are in the cylinder head and camshaft oil galleries.
Have you any idea when these oil galleries where last scrubbed with a bottle brush and solvent?
It might be worth carrying out this exercise to eliminate the possibility of sludge and harsh debris hiding in these hidden galleries.
Copyright © 2012 Lotus Marques
