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Additional crankcase breather

Posted: Wed Jul 29, 2015 9:24 pm
by Slugger
Hi guys.
I am considering adding additional crankcase breathing on my 1300 Ital engine via the blanking plate that covers the old mechanical fuel pump. I'm intending to drill the plate, weld a pipe on and then run a small hose up to a mini k & N type filter under the bonnet..
Has anybody got any advice please? I have seen an article on this years ago, but can't remember where?

Re: Additional crankcase breather

Posted: Wed Jul 29, 2015 10:06 pm
by philthehill
I have recently fitted a breather to the fuel pump aperture of my 1275cc 'A' Plus engine.
Not because it needs extra breathing but because the front breather tends to collect condensate and eventually rust through the bottom of the breather canister
It is better with the breather listed as it does restrict the oil vapour exiting the engine and it is easily removed for cleaning.

http://www.mmoc.org.uk/viewtopic.php?f=4&t=60692

Re: Additional crankcase breather

Posted: Wed Jul 29, 2015 10:42 pm
by Slugger
Thank you Phil. That's ver useful.

Re: Additional crankcase breather

Posted: Thu Jul 30, 2015 9:24 am
by bmcecosse
DO NOT connect to a 'breather filter' - it will spew out oil fumes that you will then breathe... It must be connected to the inlet system to suck away, and burn, the nasty fumes.

Re: Additional crankcase breather

Posted: Thu Jul 30, 2015 9:58 am
by philthehill
I agree with bmc.
Where ever possible the crankcase and rocker cover breathers (if fitted) should be connected to the inlet manifold or carb so as to enable (as stated above) the crankcase fumes to be consumed/burnt in the combustion chamber.
Phil

Re: Additional crankcase breather

Posted: Thu Jul 30, 2015 4:26 pm
by Slugger
Thanks to both of you. Must admit that I was intending to attach the normal front outlet to the carb as usual, and the second one to a small filter up under the bonnet, but I think you've just changed my mind.
Is it ok to connect both breathers (via a tee piece) to the carb then? or would that be too much going into the carb?

Re: Additional crankcase breather

Posted: Thu Jul 30, 2015 4:32 pm
by bmcecosse
You can only try...

Re: Additional crankcase breather

Posted: Thu Jul 30, 2015 5:35 pm
by philthehill
Joining the two breathers together should be no problem - no matter how many breathers you have you will still get the same amount of blow past (engine fumes). Instead of passing through one breather it will now pass through two and still end up in the same place i.e. the carb/inlet manifold. If you have so much blow past that it overpowers the carb/engine there is something seriously wrong with your engine and your engine will need urgent and serious attention.

Re: Additional crankcase breather

Posted: Thu Jul 30, 2015 11:29 pm
by Slugger
Yep, will do that then guys. The engine only has very few miles on it, so that should be no problem. Thank you both.