Oil Catch Tank Filling Up Quickly

[rob_mitch 0 1 Cars]

Hi,

 

I have bought a tarmac rally-prepared 1.9 to use for sprints and trackdays.

 

I did an autosolo recently as a bit of a shake-down trial and the oil catch-tank filled up very quickly.

 

The only connection to the catch-tank is from the oil-filler cap.

 

When the engine is revved there is a quite a lot of vapour coming out of the oil-filler and perhaps more worrying a lot of oil drops come out of the cam cover breather outlet when the hose is removed.

 

I have put a baffle plate underneath the outlet to stop oil having a direct path out in case it was been flung out by the camshaft lobes.  But still getting large drops of oil coming out of cam cover outlet.

 

I have seen the article from Burton Power recommending having a drain from the catch-tank back to the sump and it certainly seems worth a try.

 

Or is the there just too much crankcase pressure due to ring failure and the engine needs a re-build?

 

The engine appears to run fine and there is no smoke from the exhaust at all.  When engine is running at idle there is a regular pulse of pressure felt form the oil-filler, could that be ring-failure on one cylinder?

 

Any help or suggestions would be much appreciated including any others tests I could do.

 

Thanks,

 

Rob

[Tom Fenton 1,525]

I’d put the breather back to standard and all your problems will go away. Why folk are obsessed with catch tanks I’ve no idea.

[calvinhorse 870]

I had the pipes going into the filler tower the wrong way round, caused the same problem.

 

the top 2 that are one above the other if that makes sense 

[Lilsandy 1]

i've just started running the attached photo setup... early days but we should compare notes when I have put some miles in...

[calvinhorse 870]

That’s another point, you need to make sure your catch tank is as high up as you can get it so the oil drains back into the engine rather than being pushed into the catch tank 

[rob_mitch 0 1 Cars]

On 10/30/2018 at 9:40 PM, Lilsandy said:

i've just started running the attached photo setup... early days but we should compare notes when I have put some miles in...

 

Thanks for photo of your setup, my catch tank is in similar position.

 

I found this diagram of breather system on web which has been useful.  It looks like when the car was converted to Webers, whoever did it decided to delete the hose shown in green.  The connections were capped off at either end with silicon caps.

 

 

I haven't found any description of the purpose of this hose but Peugeot did go to quite a bit of design effort to include it so it must have a purpose.  I did a temporary connection with some heater hose and ran the engine.  With oil filler cap off there was no sign of any oil droplets  escaping when the enine was revved heavily which was a definite improvement.

 

I have now fitted the proper replacement silicon hose from BakerBM. so cross-fingers this will fix it.

Edited November 15, 2018 by rob_mitch

[mollisk 2 1 Cars]

I have had a similar problem in the past and did some research in the French build book for the 1.6 group A rally cars.

 

What they recommended was the following

 

Baffle plate under the cam cover outlet ( as you have done )

Re-route the cam cover breather hose to the rear of the block, using the existing plugged tapped hole to drain the oil back to the sump.

Block off the original, lower,  connection for the cam cover breather hose.

The drain has to pass between the primaries on the exhaust manifold, so I used stainless steel tubing from the block to above the manifold, attaching the hose to the stainless tubing.

Although not entirely eliminating oil collecting in the catch tank, it did make a big difference and is no longer a problem.

 

The engine is revs to 7750 rpm and is regularly used above 6000 rpm in competition.

 

Mollisk

[rob_mitch 0 1 Cars]

Hi Kevin,

 

Thanks for this info, having seen the size of the droplets which originally came out of the cam-cover outlet, this makes good sense to drain back into sump.

 

I haven't run the car yet in competition to check the current setup but is really good to have a Plan B.

 

Thanks,

 

Rob