Bearing failure k series

[PACR]

I found some slivers of metal in my sump. On stripping the engine the no 1 and 2 big end bearings look heavily fatigued. The no 3 and 4 look ok, bit scuffed like the mains. Is this an oil starvation issue? Is there some feed to 1&2 that is shared and possibly blocked? Any suggestions to prevent reoccurrence when I rebuild are most welcome. Photo of the offending bearings

[Ivaan]

Do you have dry sump, Apollo, or standard wet sump set up?

If you've got decent tyres, with just standard wet sump, you can easily get oil starvation on roundabouts, if pushing on.

Still have the foam in the sump?

[oilyhands]

If 1&2 are damaged, 3&4 are less so then that is classic oil starvation.

Oily

[oilyhands]

If 1&2 are damaged, 3&4 are less so then that is classic oil starvation.

Oily

[rj]

Oily,

Have you any idea why it only applies to 1&2?

[oilyhands]

The shortest route is to bearings 1&2 so they run dry first , the pump is not efficient at pumping air so there is then a pressure drop, this slows delivery to bearings 3 and 4 which have a longer run to them so they remain lubricated for longer, albeit at lower pressure.

Oily.

[rj]

Thanks.

[ECR]

That's interesting

As 4 is furthest away from the pump, I would have expected that to fail first ....

[PACR]

The engine is normal wet sump. There had been an oil leak so it’s possible that the level dropped even more than I realised between checks and top up. I should have kept an eye on how much oil I had to add, and not just the drips in the tray perhaps.

[SLR No.77]

Do you have an Apollo fitted?

Stu.

[rj]

Just what I thought.

I heard the tappets ratteling when I first time was on a track with my car. Since I've run it with wet sump and it has seen significant abuse, even sometimes with dropping pressure at a high speed left-hander when the oil level has been low. However the bearings were still fit for fight after 15k track miles. The apollo must have done something good.

[PACR]

No Apollo fitted. Road use only mainly with Yoko 48s. The Apollo isn’t on the Caterham parts web store - just a bracket at a discount. Where’s a good source for these and the fittings?

[CageyH]

The Apollo is on the Caterham parts store. https://caterhamparts.co.uk/oil-system/258-cylinder-oilair-separator.html

[rj]

There is a chance I can dig up a complete (brand new) kit in my garage. Just need to check with someone before I promise.

[rj]

Complete kit here

https://caterhamparts.co.uk/oil-system/3068-oilair-separator-package-lhd-not-r500.html?search_query=Separator&results=8

albeit LHD. The only difference is the hose that connects the tank to the cam cover.

[CageyH]

Try Redline as well.

Think Automotive will sell all the hoses and fittings.

 

I think I still have my old Apollo kit in the garage somewhere.