Engine Oil for Break In

[DJThom]

Hello All:

I'm getting very close to starting my Elan for the very first time. Once I get the temp bulb in and fill the coolant, I'll be ready to go.

However...I have filled it with Mobil 1 synthetic and have been reading in my MGB driver and on the MG forums about the reduced Zinc complex additives in many oils. Several people have had huge problems with camshafts being destroyed at only a few thousand miles.

Recommendations are to use diesel rated oil like Rotella, Castrol HD30 or redline synthetic. Other suggestions are to use additives available from Crane Camshafts or GM EOS additive.

Any experience or suggestions specific to the twink?

thx
Darren

[redskatejbf]

Suggest you go to the search window (top right hand) and type zddp a lot of info. there.
Regards John.

[Hamish Coutts]

Darren,

From previous threads on this site Mobil 1 is, perhaps, not the best choice!

I used Duckams Q20/50 when starting up after a rebuild; on advice from the engineering guys who rebored my engine.
They also said to make sure the filter was full of oil and that the oil galleries were well primed.

Another thing to do before running the engine is to turn it over on the starter with the plugs out to make sure there is oil pressure.

Regards,

Hamish.

[types26/36]

I would not use a synthetic oil after a rebuild as the engines were never designed for it, my own preference is for a straight SAE 40 oil for the first 500 miles and then a change to a 20/50 as Hamish suggests.
If the engine was rebuilt and the cams/valves/bearings etc coated in a cam lube, the filter filled,the pump primed and again as Hamish suggests turned on the starter until oil pressure is achieved then you should have no problems.
http://www.ar-sheldon.com/acatalog/Cast ... _Oils.html

[rgh0]

Darren

I would use a specific running oil. Penrite Oil who are an Australian company make it here but I am sure there will be equivalents elsewhere.

The running in oil has extra levels of extreme pressure lubricants ( eg ZDDP ) to help the bedding in of new rubbing surfaces such as piston rings to bores and cams to tappets and prevent premature failure. It also has no anti friction addiitives contained in normal use oils which would slow the bedding in process.

Make sure the oil system is properly primed and up to pressure when cranking with the plugs out before starting the engine. Also ensure lots of moly assembly lube ( I use Redline assembly lube) on the cams and tappets. If the cam has been rebuilt using a steel spray process to build it up or if you are using steel cam tappets then wise to also have them phosphate treated.

I run for the first couple of hours on this oil while bedding in the rings and other engine components. I do the run in by cycling the engine between around 1500 and 3500 rpm at full throttle under full load slowing down and then accelarating again for about an hour and then for a second hour at around 2500 to 4500 rpm. The high cylinder pressure during full throttle acceleration ensures the rings bed in rapidly and do not glaze the bores. After that its change the oil to a top quality synthetic ( i use redline in my competition engines and Mobil1 or Valvoline synthetic in my road engines) and onto the track and flat out. For a road engine I would be a little more gentle for the first couple of thousand km's !

regards
Rohan

[mopho]

So am I reading this correctly that this issue with the oil is only a concern with the running in of the engine or is it a long term issue as well?

[rgh0]

My experience is that modern normal synthetic or mineral oils are fine for twin cams that have been properly built and properly run in using an oil suitable for running in, which most modern normal oils are not due to low anti scuff / extreme pressure additives ( eg zddp) and high levels of antifriction additives.

Once an engine is run in for a couple of hours minimum for a race engine and maybe 1000 miles for a road engine a change to a modern synthetic has never caused me any problems.

I believe most of the fuss around low ZDDP levels in modern oils creating problems for flat tappet engines relates to poorly designed mods ( high lift cams and heavy valve springs ) poor material selection ( incorrect hardness differences and changes from cast iron to steel tappets and cams) or poor fabrication and assembly ( incorrect tolerances, poor grinding and surface finishes) or using these low ZDDP oils for running in and not using phosphate coatings or assembly lube when required during the engine build.

Just my personal opinion and if you use a higher ZDDP synthetic such as Redline after the run in period you also avoid the risk that that added protection is actually critical after running in. Personally I dont see the need for a road engine and are comfortable using Mobil 1 in my Esprit and plus 2 and have done so for lots of years without any problems.

cheers
Rohan

[bcmc33]

Rohan,

I?m interested in reading that you use fully synthetic oil in your Lotus cars. It has been my understanding that seal manufacturers had to design new sealing systems and develop new materials specifically to address problems that arose when synthetic oils were used with the old type of seals as used in the twink.
?Synthetic oil would p*ss out of every seal? was the phrase used by the technical manager of Europe?s biggest seal manufacturer when I asked him if it would improve the lubrication in the twink or MGB.

I?ve taken advice from my local Lotus Specialist and use semi-synthetic oil from Millers.

So Rohan, I?m interested to know if the advice not to use fully synthetic oil was good advice or have you used modern seals in your engines?


Brian Clarke
(1972 Sprint)

[DJThom]

thanks all! I'll definitely be taking the advice and dumping the oil. No hard done, as I've just turned the engine with the starter a couple of times to ensure I have good oil pressure, which I do.

[rgh0]

Hi Brian

I have never had any problem with oil leaks using synthetic oils since they became available maybe 20 years ago in either the engines or gear boxes of all 3 of my Lotus. Lots of ther people I know have also used sytetics in their Lotus without problems.

There may have been some seal rubber formulations that did not react well to synthetics but I have never come across them and I would think that all seal manufacuters today would make suitable seals for synthetic oils.

A more likely explanation for where this urban myth of synthetic oils and older cars come from is that synthetic oils tend to clean up the insides of your engine better than mineral oils and this may have removed crud and vanish that had built up on seals in old engines that was helping them seal.

regards
Rohan