Regarding 'running in' during the first 1000 miles the M-type Manual states on Page Ten of Section I -
A little engine oil mixed with the petrol assists running in;it should be mixed in the proportion of a quarter of a pint of oil to a gallon of petrol ...
Do people do this today ? While this would be a ratio of 32:1 (Imperial Gallon) high performance oils are now used in Stihl chainsaws for example (Stihl Two-stroke Oil) and other devices in the proportion of 50:1 .
Is the Manual right ?
If the manual is correct, would the use of a modern additive (such as is used in modern two strokes) be a useful and desirable alternative and even an improvement on the oil in the sump ?
The engine need to be run gently for the first 500-1000 miles - no heavy loads in high gears - avoid steep hills and sustained periods in low gears. Also avoid high revs where possible - but the engine will tell you as you drive. I tend to change the oil at 500 miles and then again at 1000 miles - just to make sure everything is clean and there is nothing going awry.
In truth though an engine that runs well at first will keep going for ages - problems surface in the first few minutes running.
The running in thing is important though and a carefully run in engine will last longer. Avoid long sustained periods in high load and let the car tell you when it is happy!
The oil in the petrol comes I think from a time when fuels and oils were of worse quality than they are now. Certainly the engineers of the time were great believers in "upper cylinder lubrication" which is still in vogue among some but in truth contributed to the engines needing a de-coke every 3000 miles in the 1930's in my opinion.
Hope this helps - maybe others will have other views.
Although in principle I agree with your sentiments regards modern methods for running engines in - I think it fair to point out that most of the modern techniques are NOT relevant to MMM type engines.
Most of the ideas promoted on the first page or so are based on modern motorcycle and race engines. These engines are lighter in construction and use wider tolerances than MMM engines and are therefore less inclined to require running in.
Always best to talk to the man who builds the engine - I doubt any of them would encourage full throttle high load dyno runs on a J2 or F type engine. Maybe my thinking is old fashioned - as I have said before I am out of practice (on anything other than NA0307) but I think I am probably speaking sense?
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Posted - 11/07/2008 : 14:33:24
