Catch tank and breather system

winkle · Post by **winkle** » Wed Jan 30, 2008 6:07 pm

Regulations state that I need to fit an oil catch tank for competition use.

Ok, each rocker cover has a breather hole I did away with the small sponge filter thingy and have a hole there now!

The catch tank would have 2 openings drain plug and sight guage.

Because Rovers have 2 breathers would I need 2 catch tanks?

My understanding is, 1 opening in the catch tank takes the breather pipe and the catch tank holds the oil mist that escapes when the engine breathes and the other opening is then fed back to the inlet manifold. Is this right or is there another way that would not require 2 catch tanks, 1 for each rocker cover in other words!?

Hope Im making sense here

kiwicar · Post by **kiwicar** » Wed Jan 30, 2008 8:20 pm

on my first range rover there was also a breather in the back of the block opening into the valley, don't know if it is on all rovers.......
Mike

winkle · Post by **winkle** » Wed Jan 30, 2008 8:40 pm

Theres not one on mine Mike...I dont think

Two is enough of a problem!

Steve

Post by **katanaman** » Wed Jan 30, 2008 9:08 pm

There will be a small hole at the back of the block going into the valley area. If the engine is of the square rocker cover era the hole will have a core plug type bung in it as it isn't needed. The later square covers had this built into the covers (white plastic filter thing) and its to let air in.
One catch tank will do fine for both breathers, think of it as a 2 into 1, 2 into the tank and one out to the inlet.

chodjinn · Post by **chodjinn** » Thu Jan 31, 2008 11:20 am

No you will only need a single catch tank!

There are many different configurations about. You dont necessarily need a sight gauge, or even a drain plug. The most basic catch tank has a single inlet and a breather - just needs checking regularly.

On my engine, I have made two adapters; one for each rocker cover. These have braided connections, both of which go to a single catch tank. The catch tank has a single large breather filter on the top, and a drain plug on the bottom.

It is not necessary to route anything to the inlet manifold etc.

SO for your engine, you could have a similar set up to mine. Just need to find a catch tank with two inlets and a breather. Worst case you could T the two breather connections together from the rockers to a single inlet on a catch tank.

In fact there is a good catch tank here with two inlets, a breather filter, drain plug and sight gauge, sorted! They are nice chaps here as well, chatted to them once or twice

http://www.nor-mal.com/43201.html

Lewis · Post by **Lewis** » Thu Jan 31, 2008 12:14 pm

I found it necessary to run a 'closed' catch tank, i.e. it didn't vent to atmosphere, it was routed back into the intake manifold - because loosing that little bit of crankcase vacuum promoted an oil leak from the front area of the engine.

It's there for a reason, that breather system, barring emissions.

chodjinn · Post by **chodjinn** » Thu Jan 31, 2008 12:19 pm

I run forced induction so plumbing it into the inlet manifold would be a very very bad idea!! Plus I dont like the idea of having gobs of oil burning inside my engine. Not been run yet so it might leak though lol!

Andy515666 · Post by **Andy515666** » Thu Jan 31, 2008 10:15 pm

Lewis wrote:I found it necessary to run a 'closed' catch tank, i.e. it didn't vent to atmosphere, it was routed back into the intake manifold - because loosing that little bit of crankcase vacuum promoted an oil leak from the front area of the engine.

It's there for a reason, that breather system, barring emissions.

Hi. I too would like to know what the purpose of the breather system is.????
I have replaced my one with a K&N filter. However on the other side (oil fill side) there is a small pipe sticking up which i am considering closing up.

Post by **katanaman** » Thu Jan 31, 2008 10:41 pm

the breather system allows gasses that leak by the rings to escape and also allows the crankcase to breath with all the things moving around inside it. Don't block any of it up or you will blow all the oil seals and you could also suffer from poor ring sealing.

Andy515666 · Post by **Andy515666** » Thu Jan 31, 2008 11:16 pm

katanaman wrote:the breather system allows gasses that leak by the rings to escape and also allows the crankcase to breath with all the things moving around inside it. Don't block any of it up or you will blow all the oil seals and you could also suffer from poor ring sealing.

ahhhh excellent! Well consider it not blocked! last thing i need to so have things going wrong after the hours i have spent on it!

Cheers mate

Wotland · Post by **Wotland** » Fri Feb 01, 2008 6:00 pm

I don't know the regulation here but why not use Evacupan system ?
Also Morosso sells an system with auxillairy vacuum pump.

CastleMGBV8 · Post by **CastleMGBV8** » Fri Feb 01, 2008 6:25 pm

I found it essential to maintain positive crankcase ventilation or you will run into problems such as oil leaks and oil being blown down the valve guides and possibly ring seating problems as mentioned above.

You need to keep one rocker cover vented to air with a decent size filter if using car for competition to allow scavenging, then one hose from the other rocker to the catch tank and then a return hose with the PCV valve to the the vacuum source, either carb or EFI. Make sure you use the rocker cover with the oil baffle as the feed to the catch tank as this will reduce the amount of oil mist being vented to the tank.

Kevin.

winkle · Post by **winkle** » Fri Feb 01, 2008 7:26 pm

Cheers guys.

Havnt got the baffles in the covers Kevin because they foul on the roller rockers

Steve

CastleMGBV8 · Post by **CastleMGBV8** » Fri Feb 01, 2008 8:23 pm

Steve,

I wouldn't worry about the baffle then, just check the tank a little more often, not as if you are going to do 24hrs du Le Mans!!!

You can't be far off getting it going, when's it likely to happen?

Regards,

Kevin.