Historic Formula Ford 2000 Association

Hi all,

I decided to change the engine oil owing to a quiet period between Christmas and New year.

I have previously changed the oil on a 30 to 40 mile basis and always used Mobil products.

Because I had plenty of time on my hands, I decided to remove the dry sump tank and clean it out thoroughly.

To my horror, I discovered a 6 to 8 mm thick layer of filthy oil clogged with rust flakes and thick carbon muck stuck to the bottom of the tank.

I can only presume that this is from a previous engine as the one installed is, to use a well used adjective, Spotlessly clean.

In fairness, I have never bothered to strip out the oil tank due to the extra complication involved. I have like many of us, simply drained the oil, and refilled with clean oil and carried on.

This is an omission I will not be guilty of in future.

Fortunately the oil pick up in the oil tank welded in about 1/2" up the side of the tank and therefore is raised above the bottom of the tank The engine has been fed on clean oil as a result.

I have had a careful look inside the engine and there is no evidence of any of the rust flakes etc having been sent into the oil ways or being stuck in any of the flat areas in the top of the cylinder head.

I imagine that this is not a situation unique to me. I am hopeful that this will save me suffering a costly engine bearing failure or the oil pump seizing etc.

My cleaning plan is to boil wash the tank in an industrial engineering process local to me.

You have been warned!

Greg, you'll probably find that what you refer to as rust flakes are actually the copper parts of someone else's failed big end shells. We take our tanks off each winter and wash them out with paraffin until the bottom is clearly visible, for all the reasons you have said. In addition, when ever a sump is removed we give it the same treatment until the paraffin comes out clean.
In our Renault days we bought a rebuilt engine from a well known French engine builder. We put it in the car as bought and ran it for a few seasons with no problems. We decided to treat it to some new big end bolts just to be safe and while the sump was off we removed the demountable windage plate to find the level of destroyed big end shells in there was so high it must have only just been scaveging enough to keep up with the feed. I guess the message is, it's not only us amateurs who make these mistakes.