Oil Catch Can Splatter

[Graham Hutton]

I wonder if anybody else suffers from the same issue as me with my catch can. I built my 310R just over a year ago and routed the outflow pipe from the catch can down so it exits below the bottom chassis cross member. But ever since the start it has always splattered a bit of oil down the underside of my car and there is always a little drip when I park up. It is not much but enough to be irritating.

There is also always a little bit of oil that splutters from the vent hole in the rubber plug on the top which makes the inside of nearside chassis skin get misted in oil.

I reficed it with the internal pipes cut short as I was worried that the breathing was causing some sort of bubbling in the little bit of oil which is in there but it has made no difference.

Any thoughts from anyone on this. Perhaps I am being a bit anal about it but I don't like things being oily. The Sigma engine is running fine, with no oil consumption and has only done 3000miles.

All thoughts welcome.

[GulfSeven]

On my 2020 Factory 310R the outflow hose goes back into the inlet manifold. I guess on the Ford Sigma install (on a Fiesta or Focus) there is just a direct hose between the crankcase and the inlet. I don't get any oil coming out of the breather plug on the top of the can either.

I actually fitted an oil catch can to my Fiesta ST, replacing the PCV hose between the crankcase and the inlet. In that case the can isn't vented. It's actually a much neater install than on the Caterham, with a very small aluminium can containing baffles and a bronze filter. It's a lot more expensive than the system fitted to the Caterham though.

[Graham Hutton]

Thanks Tim, that's very interesting. It does seem quite unsophisticated on the Caterham (perhaps not surpisingly) and I guess all engines have slightly different crank case pressure etc. Maybe mine is bit higher than most.

 

[GulfSeven]

If you want a look at mine you're welcome. I've actually got the bonnet and nose off at the moment, so if you wanted to compare we could do a video call today. Direct message me if you want to have a look 

[Graham Hutton]

Thanks Tim, that's very kind. I'm not at home at the moment but could be around later? Alternatively, could you send me a pic of the route of the pipe from the outflow to the inlet manifold? Top man

[Beagler]

I had my 270 uprated to 310 when having some warranty work done at CC. They fitted a catch can. There are two pipes going in and none exiting. I think the idea is you empty it when getting full. I prefer to this rather than have oil dripping on the ground. 

[GulfSeven]

Here you go.

I've marked the hose going from the crankcase to the can as C, and the hose going from the can to the inlet manifold as I.

You do indeed empty the oil out of the can, but as far as I understand, the air goes from the crankcase to the inlet manifold via the can. With a catch can the oil gets (mostly) removed before the air goes back in to reduce carbon deposits on the inlet valves.

[Beagler]

Mine looks like that that CC fitted.

[Graham Hutton]

Tim - That is so very helpful, much appreciated!

On my car, the setup is identical except the rubber bung in the middle of the top of the catch can has a pipe coming out of it which drains out the bottom of the engine bay. Looks like all I need to do is replace the drain with a bung. Does your bung have a breather hole in it or is it literally a bung in the top which you remove when emptying the can?

Thank again - looks like I'm off to get oily!

[Graham Hutton]

This is the offending item on my car 

https://caterhamparts.co.uk/oil-system/361-catch-tank-1-litre.html?search_query=catch+can&results=46

I had to drill the holes for the two breather pipes to go into it.

[GulfSeven]

The bung on mine has a few very small breather holes in it. It also doubles as a drain plug which you remove when emptying the can.

[SLR No.77]

My catch tank was originally the standard "race" setup, ie. engine vented to catch tank, open breather vented in the engine bay. Not great for a road car though because you're breathing in the vented fumes which I believe can be carcinogenic and you're spending much longer in the car that you normally would in a race car.

I've found that running with a sealed catch tank, venting from the engine to the tank then venting from the tank to under the car improves this dramatically. Even better when I ran the tank vent fully to the rear of the car.

[Graham Hutton]

Thanks everyone, I'm just going to get rid of the breather pipe and put a bung in the top with a little breather hole like Tim's and see how it goes. Awesome!

[Shortshift]

"Even better when I ran the tank vent fully to the rear of the car."

This is exactly right.  And easy to do with an appropriate length of 1/4" (or whatever) oil resistant tubing.  Mine vents behind the rear axle.

Another problem with allowing the can to vent/breathe underbonnet is that everything ends up covered in a thin, slimy film of oil mist.  Yukky-pooh...

Venting rearwards (is there any other way?) avoids this, as well as the ingestion of carcinogens.

James

 

[Graham Hutton]

Is it really necessary for the can to be vented at all? If the crank case pressure is simply fed into the inlet manifold surely it'd all equal out....or would the catch can explode??? I take James' point about routing the pipe to the back of the car though

[7 wonders of the world]

I use one like this

https://www.ebay.co.uk/itm/362906628652?mkevt=1&mkcid=1&mkrid=710-53481-19255-0&campid=5338703917&toolid=20006&customid=s%3AGS%3Bgc%3AEAIaIQobChMIr4O-9MnB9wIVz9vVCh0fUgDnEAQYASABEgKu9PD_BwE

Theres an internal baffle, and you can offset the inlet and oulet, I run mine on the same side, the outlet is vented along with the gearbox roughly half way along the gearbox, no issue with nasty niffs.

although these come with different sized barb fittings You can easily get adaptors to enable you to couple to JIC ot BSP if you run a DS set up.

Drain either by the drain plug or with a syringe if your restricted for height on your installation.

[Beagler]

Thought I would replace the plastic bottle with one of these. Anyone fit it.

https://www.amazon.co.uk/gp/product/B01L3M8L86/ref=ox_sc_act_title_1?smid=A3P5ROKL5A1OLE&psc=1

 

Mishimoto Compact Baffled Oil Catch Can 

Defend Your Intake 

The internal air diverter turbulates the air longer and ensures all the oil sinks to the bottom of the can, leaving nothing but clean air to pass through the 50 micron bronze filter to the intake. 

Safe for pressurized applications 

Internal air diverter turbulates air longer to improve oil separation 

Includes 2 plastic barbed 1/2" hose fittings 

Universal mounting bracket for different configurations 

Filter and can are both fully serviceable

 

[GulfSeven]

It's very similar to the one I have on my Fiesta ST (this one).

It's unvented though, so I'd want to know why the Caterham needs a vented one before I fitted something different.

[Graham Hutton]

Another possible solution, which may be even easier is to stick a K&N crank case breather filter like this one on the outlet pipe. That should stop the splatter I guess.

https://www.demon-tweeks.com/k-n-filters-breather-filter-244153/?sku=K/N62-1000&istCompanyId=a2904180-3a7d-4e56-b876-cf81c9512180&istFeedId=6fbc4b04-fd28-4ce1-8513-835c8f118690&istItemId=wptwlplqx&istBid=t&gclid=EAIaIQobChMI_pi14uDC9wIVi7TtCh0L8guNEAQYAiABEgLM0PD_BwE&gclsrc=aw.ds

Mind you a nice piece of alloy bling for a catch tank is quite appealing.

[Beagler]

I think the brass filter insert and good circulation within the unit filters out splatter and retains it in the can so very efficient filtering means no external splatter hence no vent required.

[Beagler]

Ended up ordering this,

https://www.amazon.co.uk/gp/product/B07LGGY4NF/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

[GulfSeven]

I think all the fittings for that one are Fiesta ST specific.

[Beagler]

I will just link the existing hoses to new ones. ( liked the quick release). Attaching can wont be a problem.

[GulfSeven]

Fair enough. It's a really nice part. Show us what it looks like when you've installed it.

[Beagler]

There are two tapped holes at the upper front of the engine and the bracket may go on them. Will have to wait and see when it comes. The connecting hoses will just be joined to the hoses fit by CC to the plastic Catch can.