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New Carb, what to do with the hole in the Rocker Cover ?


Iain
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Hi Guys

Apologies if this is a stupid question but....

I've removed the old carb from my Manta B and replaced it with a Webber

The old Air Filter Housing had a pipe that connected to the top of the Rocker Cover which i have had to remove as its now redundant

I've blocked the hole in the cover with a rubber bung, the issue Im having now is the pressure build up is causing oil to leak from the Rocker Cover Gasket, if I remove the bung all is well ( no leaks ) as the pressure escapes through the hole in the top but I cant leave it this way as oil escapes through it when driving ! 

I assume that I need some sort of catch can that prevents the oil escaping and allows the rocker to breathe or is it just a case of replacing the Gasket ?

Many thanks in advance

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Hi lain

I think you've found out that the engine has to breath so you can't just block off the breather pipe as the air will build up and find another escape route ie the leaky rocker cover gasket.

Before this was fed back into the induction system it used to vent to atmosphere, so all you need is a filter connected to let the air out and keep the oil in.  Search crankshaft breather on eBay 

You could go the catch tank route which is a lot more involved and used more on performance engines. 

 

 

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Hi Mick

Yes the pipe originally fed back into the air filter recirculating through the induction system.

As many early B owners would have replaced the varajet carburettor I wondered what they had done as a solution ? 

I have now ordered a breather and 90deg solid plastic pipe that i will fix into the rocker cover so it sits upright.

I will muddle through and see what I can cobble together when the parts arrive. 

Thanks for your help,

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Hi Sam, cheers buddy thats what I was after.

Just one question, when I run mine with the hole open quite a bit of oil splashes out, with just a pipe running to the back of the engine and down to the crossmember doesnt it  just drip oil all the time ?

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6 hours ago, Iain said:

Hi Sam, cheers buddy thats what I was after.

Just one question, when I run mine with the hole open quite a bit of oil splashes out, with just a pipe running to the back of the engine and down to the crossmember doesnt it  just drip oil all the time ?

Have you checked that your filter gauze is not all gummed up?

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 obviously it’s worth cleaning the gauze filter anyway( not designed to be an easily serviceable item but can be removed by bending back the tabs and pulling gauze out)as this will be why its spitting oil and not just air but when you just vent the pipe to the atmosphere it lets all the engine fumes out and to any following car will stink. this gives classic cars a bad name . I know people do this and I know people also fit catch tanks which as far as I know are perfectly legal ?  .but the perfect solution would be to incorporate the breather back into the air filter correctly by adding a stub if there’s room.

this is my opinion only.many will disagree but gm designed it this way for a reason.obviously it wont affect exhaust emissions as such but I wonder if there are any environmental laws ? ?

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