Water and Oil venting

[nike 5]

I have a LS2 crate engine (so no plumbing to work from).

STEAM VENTS
Has a cross over at the front of the engine, linking the two heads, with a pipe to vent.
- What's the purpose, release pressure or means of getting rid of air at top of engine.
- The vents at back of engine are blocked off with bolts (engine slightly higher at front) so is this ok, or should there be a cross over at rear too.
- should it be vented directly to radiator, header tank or water pump which looks neatest (or anything other than catch tank will encouraging airlocks).

VALLEY COVER has a vent
- Is this an oil vent.
- Should I just loop it 180 degrees, and connect a T-piece to rocker cover vent which leads to dry sump tank.
- is the valley cover fitment directional, can it be spun 180 degrees as this would be neater solution.

[stevieturbo]

1. Whilst they are called steam ports, they are basically just an air vent to prevent air locks there.
Early engines used all 4, GM later changed to just the front.

A lot depends on usage...mild road car, no big deal. If it's something that will get used hard or making decent power, all 4 make sense.

This is a vent port so it must remain within the sealed system. As it is there to vent air and prevent air locks, yes it should route to a high point in the system, ideally a remote header tank.

2. Dry Sump matters......what you do with any engine breathers, depends on the abilities of the dry sump.
If this is a full on proper dry sump that will evacuate the system, then you'd likely block all engine breathers, fit a pressure/vac limiting breather and have the dry sump system cover all breathing aspects back at the tank.
If it's only a baby dry sump that would not pull crankcase vacuum, then crankcase venting will need to be addressed up front via some sort of catch can type setup. Up to you to decide routing and overall setup, and where any vents may be used.

[nike 5]

With the Steam venting thank you, that makes sense.

With the Dry sump, the engine has not been started yet, so I do not know.

What signifies it as a PROPER dry sump system.
PRESSURE, ie the pump - I have is an external pump (2scavenge in 1scavenge out and a pressure in and out), which was sold as LS suitable (DRYSUMP.COM).
or
VOLUME or the drysump tank.Which maybe on the small size? at 2 gallons.
Looking at their website, this is 3inches shorter than the tank they supply for use on their 7litre engines (mine is a 6litre LS2)
https://www.drysump.com/images/PDF/2GallonOilTank....

[stevieturbo]

nike 5 said:

With the Steam venting thank you, that makes sense.

With the Dry sump, the engine has not been started yet, so I do not know.

What signifies it as a PROPER dry sump system.
PRESSURE, ie the pump - I have is an external pump (2scavenge in 1scavenge out and a pressure in and out), which was sold as LS suitable (DRYSUMP.COM).
or
VOLUME or the drysump tank.Which maybe on the small size? at 2 gallons.
Looking at their website, this is 3inches shorter than the tank they supply for use on their 7litre engines (mine is a 6litre LS2)
https://www.drysump.com/images/PDF/2GallonOilTank....

A 2 stage scavenge would be smaller than some options, so there may not be much expectation of it being able to pull vacuum in the crankcase. So you may still need some form of cranckase breather at the engine.
Presumably the supplier of the dry sump kit could advise better in this regard ?

And the LS9,7 etc came with what people call a dry sump. Except it isnt really, it's a sort of hybrid, with an external tank, and like a 2 stage crank driven pump where the normal pump resides.