K-Series Sump Foam Check Today

[21jigsaw]

 The K series installation  was designed with a shallow sump to fit under bonnet. The consequence being a low shallow volume of oil which was susceptible to aeration - tiny bubbles suspended in the oil. This was amplified buy the high lateral g forces generated by the cars. The aerated oil would circulate to the hydraulic tappets acting as a spring the valves bounce resulting in  loss of control, the valves would touch the pistons bending them, eventually with a bending fatigue the valve heads would drop off resulting in total engine failure. The tiny bubbles suspended in the oil  need to be burst or be purged .  Air is  removed / bubble burst if the oil hits a solid surface / object ie baffle, foam, block or sump.

The sign off test devised by Caterham for a 1400 Supersport was 1st gear (5 speed box) max revs three figure of eights as fast as possible brake to a stop idle the engine and listen to see if the tappets rattled / aerated. The  foam arrangement gave the required results.

Further development mainly for track competition resulted in the Apollo tank, solid tappets, purple pump dry sump leading to much higher performance  gold pump dry sump package.

To run an  Apollo with the increase in oil  volume and the centrifugal purging of air from the system would probably negate the use of the foam.

I have  run the same foam for some 27k miles 13 years without issue. There have been  failures of the foam leading to engine failure possibly due to :-

 1) bad batch of foam material

 2) fuel contamination

3)Oil  compatibility / contamination

4) engine temperature etc.

 There is no clear reason as to the cause of failure of the foam.

Hope this helps

Dave

[Skipper555]

So wouls a logical upgrade be the Apollo tank, removing the need for the foam, and the maintenance that goes with it?

[TomB]

You need a dry sump. Like mine.  😜 

[oilyhands]

Just my two-penneth,

My experience of many, many engines has shown that engines with no Apollo tank and wet sump show distress on the big end bearings to a greater or lesser degree in around 80% of cases, those with factory fitted Apollo tanks rarely show any issues (less than 5% of cases) so the Apollo would seem a good halfway house towards the merits of a dry sump, mitigating against the effects of oil surge but nor eradicating the cause. I have seen 20+ engines seriously compromised by blocked pickups due to disintegrated sump foam. I have been advocating the removal of sump foam and drilling of the sump gasket since around 1999 and all the engines built or rebuilt here will have that modification undertaken.

I would recommend that you ditch the foam, drill the gasket and if you can, fit an Apollo tank.

Oily

Edited April 23 by oilyhands