Bought myself a cheap oil catch can off ebay for £24 instead of having the crankcase pipe going to the floor, got it all fitted today. Looks good but I'm not to happy with where it is, relocating the battery to the boot tomorrow so may fab a bracket up to sit where the battery was somewhere.

Really need to get mine in, had it about 6 months now

Really need to get mine in, had it about 6 months now

like a half hour job maybe not even that if you know where it's going

Yer know where i want it and i have the elphant mod done so be 10mins but keep forgetting and when i remeber its always rubbish weather.

Do i spot 15mm fittings on catch can?

Standard is 19mm so you may well be adding pressure to crankcase

Do i spot 15mm fittings on catch can?

Standard is 19mm so you may well be adding pressure to crankcase

they are indeed on the look out for some 19mm ones at the minute, it was a lot more money for the 19mm outletted one :(

I've got the 15mm connectors on mine and having read about adding pressure to the crankcase, i'm wondering if that's why my cam cover gasket gave up at Castle Combe.

Time to run my elephant mod to the floor until i can get some 19mm connectors, just to be safe.

Get a blue one, pink's for gurls!

I've got the 15mm connectors on mine and having read about adding pressure to the crankcase, i'm wondering if that's why my cam cover gasket gave up at Castle Combe.

Time to run my elephant mod to the floor until i can get some 19mm connectors, just to be safe.

any idea where to get them from dude?

Get a blue one, pink's for gurls!

it's red, nice try thow

Why would the smaller connectors add pressure to the crank case?

any idea where to get them from dude?

No idea. Had a quick look on eBay but couldn't find any, so will need to check out a few other places or get some made up if i want to keep the can. Haven't heard of anybody else having issues though.

No idea. Had a quick look on eBay but couldn't find any, so will need to check out a few other places or get some made up if i want to keep the can. Haven't heard of anybody else having issues though.

i can't imagine it making a huge difference to be honest or surely it would just blow the pipe off? Either way ill go to a fittings shop tomorrow maybe find something from a kitchen or plumbing shop, will keep you posted.

Cheers mate.

I'm not sure it would make much difference either but does throw a little doubt in your mind.

Why would the smaller connectors add pressure to the crank case?

Well its a crank case vent to relieve pressure

Skoda designed it needing a 19mm vent, so to fit a 15mm catch can your reducing the vent diameter by 4mm!

Im no scientist but a difference in 4mm seems miniscule but infact 4mm is a massive reduction

Well its a crank case vent to relieve pressure

Skoda designed it needing a 19mm vent, so to fit a 15mm catch can your reducing the vent diameter by 4mm!

Im no scientist but a difference in 4mm seems miniscule but infact 4mm is a massive reduction

But the Diamter of the exit on the crank case is still 19mm, so the pressure is already vented. I can see it possibly having an effect if the diameter of the pipe on the crank case was reduced.

Mines been something similar to the above for quite a long time without any adverse affects?

Yes exactly its 19mm for a reason!! You've reduced it by 4mm so it cant vent as it was designed to do so.... Its like fitting a smaller diameter exhaust... The car can't breath aswell reducing bhp!

This increases pressure which cant be a good thing! 4mm over 19mm will reduce flow by something crazy! Possibly by upto 50%

Wheres the mathematicians when you need them

Well its a crank case vent to relieve pressure

Skoda designed it needing a 19mm vent, so to fit a 15mm catch can your reducing the vent diameter by 4mm!

Im no scientist but a difference in 4mm seems miniscule but infact 4mm is a massive reduction

BigJase is entirely correct, a 19mm orifice has a cross-sectional area of 283mm and a 15mm orifice has a CSA of 176mm, which is a 38% reduction in flow capacity.

Looks nice though.

Wheres the mathematicians when you need them

In the Fabia Mk2 section and getting ready for the 'How Fast' event.

pie arrr squared....

15mm = 177 mm^2

19mm= 284 mm^2

177/284 *100 = 62%

A 15mm diameter would allow significantly less peak flow. And that's before you ask the gasses to do a U turn in the can.

In theory the lower the crankcase pressure the better. The more gas/fluid in the crankcase, the more of it has to be displaced or pressurised every time a piston goes up/down. i.e. increase the crankcase pressure and engine power goes down.

J.

pie arrr squared....

15mm = 177 mm^2

19mm= 284 mm^2

177/284 *100 = 62%

A 15mm diameter would allow significantly less peak flow. And that's before you ask the gasses to do a U turn in the can.

In theory the lower the crankcase pressure the better. The more gas/fluid in the crankcase, the more of it has to be displaced or pressurised every time a piston goes up/down. i.e. increase the crankcase pressure and engine power goes down.

J.

I rounded down in case I got screamed at by a pub genius for exaggerating.

Just run the pipe to atmosphere, that's what trucks and buses do.

Does it matter if you go from 19mm to a 15mm and vent to atmosphere? My pipe wasn't long enough so put some air line tube inside to run to the bottom of the car

Does it matter if you go from 19mm to a 15mm and vent to atmosphere? My pipe wasn't long enough so put some air line tube inside to run to the bottom of the car

I have had mine vented to atmosphere by 1" fuel hose as the crank case vent was approx. 23mm. Places where it gets much below freezing I see it's better to have big ID hose to prevent it from freeze and clog. Makes me hard to believe that there could be so much cylinder blow by gases that couldn't get handled by 15mm hose. But still I'd say go ahead and buy 1meter 25mm ID hose and route the hose under the car.

I see this very important for turbo life and intake manifold cleanliness. Once that crap hits turbo impeller blades when it's spinning over 100 000 rpm it must not be a good thing even though the drops are not that big. Next that crap goes to intake manifold and EGR lets hot exhaust gases in it gets burned on the walls of manifold and over time restrict airflow resulting in clogged intake manifold..