Scavang Tank

[clivegto]

Is it really necessary to vent a scavang tank underneath a turbo for an electric scavang pump is my question as I see people do both. 

[jonny1bump]

Clive i could not see why up would want to vent scavenge tank at end day the pump always needs a head of oil to work there best, mechanical pumps certainly need this why wouldn't the little electric pumps be the same.

[clivegto]

Personally I don't think it needs to be vented but some people say they do. I know Mr Dunlop tanks are not vented but hears one that is. 

[Gixer1460]

I suppose it depends on how efficient the pump is and what turbo bearings are fitted!  A average pump and ball bearing cartridge will be running mostly dry due to low flow requirements, whilst a good pump and trad. plain bearings having lots of oil flow could drain the sump and, without a vent, try to suck oil from the turbo bearings. Maybe unlikely, but the addition of a vent breaks that suction risk I guess?

[clivegto]

I was also told that with the breather it can drain after the engine is turned off. With my electronic pump when I turn the ignition on I just wait until I hear it clicking then I know its cleared itself then press the go button. I havet had a tank on my 3 turbo bikes I just had a big pipe going into a smaller pipe which in my head is the same as a tank. 

[clivegto]

One without a breather. 

 

Edited April 10, 2022 by clivegto

[jonny1bump]

Got to say Clive thats looks awful.

At end of day the scavenge tank needs to be big enough for when you shutdown as there is still pressure in the system that pushes into turbo for quite some time. I used check valve on flow pipe and along with sump stopped any smoking on start up.

I'm totally impressed with my home made mechanical pump too.

Happy days.

Edited April 11, 2022 by jonny1bump

[clivegto]

Started to make this as a catch tank. 

[jonny1bump]

That looks good.

[clivegto]

Not going to put a breather in it. 

[clivegto]

1 hour ago, jonny1bump said:

That looks good.

Bit of scaffold pipe