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what external breathers to fit

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  • T4
    T4
    1 year ago
    Ya, the catch can is vented. 

    As you say, these hoses and stuff are to allow the motor to breathe. Two big pistons thundering up and down simultaneously create a lot of air displacement under them which has to go somewhere. If the umbrella valves in the rocker covers are not serviced and go hard the engine will breathe out any casket or seal it can, usually but not restricted to the base gaskets (have got this issue with my 95 Sportster at the moment).

    I have been thinking about drilling and tapping the rocker covers while they are off when I do the base gaskets and screwing in two large brass fittings with clear hoses going up just like your set up Bluey. The engine can breathe and the oil will gravity feed back into the motor.

    Cheers, Will
    Catchcanvent.JPG
  • 408
    408
    1 year ago
    Quoting T4 on 10 Jan 2024 09:05 AM

    Ya, the catch can is vented. 

    As you say, these hoses and stuff are to allow the motor to breathe. Two big pistons thundering up and down simultaneously create a lot of air displacement under them which has to go somewhere. If the umbrella valves in the rocker covers are not serviced and go hard the engine will breathe out any casket or seal it can, usually but not restricted to the base gaskets (have got this issue with my 95 Sportster at the moment).

    I have been thinking about drilling and tapping the rocker covers while they are off when I do the base gaskets and screwing in two large brass fittings with clear hoses going up just like your set up Bluey. The engine can breathe and the oil will gravity feed back into the motor.

    Cheers, Will

    Catchcanvent.JPG

    So, the oil you drain from the catch can is clean, no moisture, condensation,....
  • blueystar
    blueystar
    1 year ago
    Quoting T4 on 10 Jan 2024 09:05 AM

    Ya, the catch can is vented. 

    As you say, these hoses and stuff are to allow the motor to breathe. Two big pistons thundering up and down simultaneously create a lot of air displacement under them which has to go somewhere. If the umbrella valves in the rocker covers are not serviced and go hard the engine will breathe out any casket or seal it can, usually but not restricted to the base gaskets (have got this issue with my 95 Sportster at the moment).

    I have been thinking about drilling and tapping the rocker covers while they are off when I do the base gaskets and screwing in two large brass fittings with clear hoses going up just like your set up Bluey. The engine can breathe and the oil will gravity feed back into the motor.

    Cheers, Will

    Catchcanvent.JPG
    Quoting 408 on 10 Jan 2024 12:19 PM


    So, the oil you drain from the catch can is clean, no moisture, condensation,....

    thats why  dont use catch can have a breather hose going higher moisture and condensation will vapour off and go up the hose and clean oil can run back Were you born after 1984
  • Daz666
    Daz666
    1 year ago
    Quoting T4 on 10 Jan 2024 09:05 AM

    Ya, the catch can is vented. 

    As you say, these hoses and stuff are to allow the motor to breathe. Two big pistons thundering up and down simultaneously create a lot of air displacement under them which has to go somewhere. If the umbrella valves in the rocker covers are not serviced and go hard the engine will breathe out any casket or seal it can, usually but not restricted to the base gaskets (have got this issue with my 95 Sportster at the moment).

    I have been thinking about drilling and tapping the rocker covers while they are off when I do the base gaskets and screwing in two large brass fittings with clear hoses going up just like your set up Bluey. The engine can breathe and the oil will gravity feed back into the motor.

    Cheers, Will

    Catchcanvent.JPG
    Quoting 408 on 10 Jan 2024 12:19 PM


    So, the oil you drain from the catch can is clean, no moisture, condensation,....

    Quoting blueystar on 10 Jan 2024 03:14 PM

    thats why  dont use catch can have a breather hose going higher moisture and condensation will vapour off and go up the hose and clean oil can run back Were you born after 1984

    Been following and listening to all the back and forth about the oil... only problem is, when the water and oil mix in the breather, what you get is that creamy sludge, not clean oil as is being said, which then runs back down into the crankcase unless it is routed down to something, thats what I have noticed with all my bikes over the 30 plus years of riding them... sorry for stirring the hornets nest yet again 🤣🤣
  • perthhog
    perthhog
    1 year ago
    This was my point the hoses are going up hill  so any dirty oil shit,water,byproducts of the combustion 
    Cycle will end up back in the engine from gravity so basically a waste of time  but bluey keeps going on about being people being born after 1984 😳 
  • T4
    T4
    1 year ago
    Quoting 408 on 10 Jan 2024 12:19 PM


    So, the oil you drain from the catch can is clean, no moisture, condensation,....

    Quoting blueystar on 10 Jan 2024 03:14 PM

    thats why  dont use catch can have a breather hose going higher moisture and condensation will vapour off and go up the hose and clean oil can run back Were you born after 1984

    Quoting Daz666 on 10 Jan 2024 08:04 PM

    Been following and listening to all the back and forth about the oil... only problem is, when the water and oil mix in the breather, what you get is that creamy sludge, not clean oil as is being said, which then runs back down into the crankcase unless it is routed down to something, thats what I have noticed with all my bikes over the 30 plus years of riding them... sorry for stirring the hornets nest yet again 🤣🤣

    Ya, agreed about the creamy sludge in some instances, though by using the 'as specified' clear hose of a large diameter I will be able to monitor what comes out. By going up without too many bends or kinks the air will/should go up the middle and any (heavier) oil drops will/should stick to the sides. Usually the sludge is caused by short runs and once the motor is at temp it is not so much of a problem. The other thing is the lines normally used are usually smaller and generally run down on the hope (I think) that any sludge gravity feeds out the end, or into the catch can. The old Triumphs I grew up on had a line that followed up and over the line of the rear mudguard and we never had an issue with them.

    No Bluey, my youngest daughter was born in 1985; been riding since the very early '70s
  • Grease Monkey
    Grease Monkey
    1 year ago
    My only concern with upward hoses is "if" it causes any restriction at all my dipstick will hit me in the leg again, it happened tuning the 110 in one of its first iterations, I ended up drilling out the breather bolts as much as I dared and increasing the size of the hoses and T, hasn't done it since and to be fair that was at 6000rpm sustained so unlikely many will see it, gravity is omnipresent however.
  • WideglidingNZ
    WideglidingNZ
    1 year ago
    I have my trask tranny cover which ventilates the crank case(engine) with the filter mounted on the lower frame, Trask recommends to mount it upwards, I didn't like the idea of condensation going back into the engine, I keep an eye on the breather filter for signs of oil but so far next to nothing, So far no oil mist in the intake at all, this includes about 12 passes down the strip
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