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Sumping explained......sort of

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  • 98fxstc
    98fxstc
    5 years ago
    I wondered if he really did have an M8 or was mistaken.   ????
    Sometimes doesn't pay to be the first to find something wrong.
  • R2D2
    R2D2
    5 years ago
    Quoting 98fxstc on 07 Aug 2018 12:03 AM

    I wondered if he really did have an M8 or was mistaken.   ????
    Sometimes doesn't pay to be the first to find something wrong.

    There's plenty of fake news about the M8 guys , I reckon it was just that.
    I know we disagree 98 but that's the way it is.
    Cheers.
  • Proffesor
    Proffesor
    5 years ago
    Quoting 98fxstc on 07 Aug 2018 12:03 AM

    I wondered if he really did have an M8 or was mistaken.   ????
    Sometimes doesn't pay to be the first to find something wrong.

    Quoting R2D2 on 07 Aug 2018 01:18 AM

    There's plenty of fake news about the M8 guys , I reckon it was just that.

    I know we disagree 98 but that's the way it is.
    Cheers.

    Not sure where you were given the figure of 1.2% but I must just be unlucky then. 2017 stage 1 Road King 107, engine sumped may 2018, dealer voluntarily replaced complete motor and explained the sumping problem to me.
    October 2018 traded the RK in on a Street Glide 107 stock, with 6000 kms on it it sumped today, no oil in tank, smoke pouring out of exhaust, happy to know I am in the 1.2%, let's see what the dealer says tomorrow
  • Baloffski
    Baloffski
    5 years ago
    Quoting 98fxstc on 07 Aug 2018 12:03 AM

    I wondered if he really did have an M8 or was mistaken.   ????
    Sometimes doesn't pay to be the first to find something wrong.

    Quoting R2D2 on 07 Aug 2018 01:18 AM

    There's plenty of fake news about the M8 guys , I reckon it was just that.

    I know we disagree 98 but that's the way it is.
    Cheers.

    Quoting Proffesor on 17 Feb 2019 04:35 AM

    Not sure where you were given the figure of 1.2% but I must just be unlucky then. 2017 stage 1 Road King 107, engine sumped may 2018, dealer voluntarily replaced complete motor and explained the sumping problem to me.

    October 2018 traded the RK in on a Street Glide 107 stock, with 6000 kms on it it sumped today, no oil in tank, smoke pouring out of exhaust, happy to know I am in the 1.2%, let's see what the dealer says tomorrow

    Pro

     You have to be kidding us..................................
  • DocGreen
    DocGreen
    5 years ago
    Quoting R2D2 on 07 Aug 2018 01:18 AM

    There's plenty of fake news about the M8 guys , I reckon it was just that.

    I know we disagree 98 but that's the way it is.
    Cheers.

    Quoting Proffesor on 17 Feb 2019 04:35 AM

    Not sure where you were given the figure of 1.2% but I must just be unlucky then. 2017 stage 1 Road King 107, engine sumped may 2018, dealer voluntarily replaced complete motor and explained the sumping problem to me.

    October 2018 traded the RK in on a Street Glide 107 stock, with 6000 kms on it it sumped today, no oil in tank, smoke pouring out of exhaust, happy to know I am in the 1.2%, let's see what the dealer says tomorrow

    Quoting Baloffski on 17 Feb 2019 09:14 AM

    Pro

     You have to be kidding us..................................

    Balof, I really hope Professor is joking, but somehow doubt it unfortunately.

    Professor, can you give us anymore info on what happened?

    DocGreen
  • Nutty
    Nutty
    5 years ago
    Simple question: 
    If the sumping issue is confined to 1% of all M8s, why would both Fuelling and S&S spend a small fortune on R&D, tooling and development of twin-scavenge pumps if the market truly was so small?
    A few weeks ago I was explaining the M8 scavenging system to an Engineer who developed dry-sump small-block Chevs for GMs marine and racing division. His first words in reply were "that won't work". 
  • DocGreen
    DocGreen
    5 years ago
    Quoting Nutty on 18 Feb 2019 07:47 AMedited: 18 Feb 2019 07:47 AM

    Simple question: 

    If the sumping issue is confined to 1% of all M8s, why would both Fuelling and S&S spend a small fortune on R&D, tooling and development of twin-scavenge pumps if the market truly was so small?
    A few weeks ago I was explaining the M8 scavenging system to an Engineer who developed dry-sump small-block Chevs for GMs marine and racing division. His first words in reply were "that won't work". 

    Nutty, I don't think the reason S&S and Fueling made their pumps and plates has much to do with sumping - they see a market and make a product, they did the same for the TC. S&S have even been quoted as saying their pump won't prevent sumping.

    I am interested to hear more of the thoughts of your engineering mate though - does he have suggestions or ideas you could share. 

    DocGreen

  • Nutty
    Nutty
    5 years ago
    Quoting Nutty on 18 Feb 2019 07:47 AMedited: 18 Feb 2019 07:47 AM

    Simple question: 

    If the sumping issue is confined to 1% of all M8s, why would both Fuelling and S&S spend a small fortune on R&D, tooling and development of twin-scavenge pumps if the market truly was so small?
    A few weeks ago I was explaining the M8 scavenging system to an Engineer who developed dry-sump small-block Chevs for GMs marine and racing division. His first words in reply were "that won't work". 

    Quoting DocGreen on 19 Feb 2019 08:34 AM

    Nutty, I don't think the reason S&S and Fueling made their pumps and plates has much to do with sumping - they see a market and make a product, they did the same for the TC. S&S have even been quoted as saying their pump won't prevent sumping.

    I am interested to hear more of the thoughts of your engineering mate though - does he have suggestions or ideas you could share. 

    DocGreen

    It was a long discussion Doc. His basic thrust was that looped-scavenge systems don't work and that each area to be scavenged should stand alone with its own separate pump. The reservoirs' venting should be totally separate to the motors venting. The factory Chev race motors had 3 separate pumps and a stand-alone tank with its own vent. I'm doing a mates Stage 2 107 this very minute with a S&S pump, H-D bearing seal and the tank independently vented. This one sumps about 400ml/2500km so it'll be a good test. This same engineer sussed out the HD gearbox transfer issue with me and also designed the water-rejecting airbox for Maddo's record-breaking 'waterbike'. He's a clever man. 
  • Hoodeng
    Hoodeng
    5 years ago
    You have my full attention, i need to have the failure of a system that has successfully been in place for twenty years now explained to me .As for  the oil tank needing to be vented to atmosphere that is also new to me as the engine and tank as installed operate in a vacuum. The line between the tank and cases is an internal air transfer as the pump always returns more by volume than it feeds .

    In Harley engines the pistons virtually travel up and down together much like a big single ,so whatever the capacity of the engine is this is the same capacity displaced in the bottom end hence breather valves to keep it in vacuum.

    As an aside, I have experience with the old F5000 Holden version [collectively manufactured by Bartz Chev, Morand Chev and Holden-Repco V8]engine that had a number of  scavenge pumps and one feed pump ,the number of scavenge pumps varied over the engines development ,i think the last version of scavenge went one in the rear of each side of the valve covers,one in the valley and one each end of the crank cover [i will stand correction on this ,i have not seen the inside of one for near 35 years] ,these systems were vented to atmosphere due to the depression they could develop  in the engine.The V8 engine can not make a vacuum , as one piston is on the way up there is always a piston on the way down so internal displacement is almost constant, much like an even fire four, it will always have a degree of blow-by [although preferably near to zero].


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