LS2 breather system?

[ultimagtr-ger]

Hi Guys,

I had to install my LS2 motor in my Ultima GTR without any help from the supplier of the motor.
I’ve build the following breather system based on my own ideas:
1. One pipe from crank case and right rocker cover to an oil catch tank
2. Pipe from oil catch tank to the airbox
3. Small pipe from left rocker cover to the airbox

Please see pictures:
http://thumbsnap.com/Qmry88oW
http://thumbsnap.com/qjChDXtk
http://thumbsnap.com/G34Z00XQ

Is a PCV necessary?
How should it be changed?

Any help is much appreciated.

Thanks

Regards
Oliver

[SchimmS]

Hey Oliver,

the right side to the tank looks ok, I would change the left side in such a way that it also goes into the tank. A PCV is not necessary unless you`re keen on meeting the latest emission standards. The "problem" with a connection to the intake is that the engine sucks in the oil vapors and burns them. Over time it`ll leave a mess in the intake manifold which will be covered in sticky oil residues.
Before people had the urge to save the polar bears the vapors were simply let in the environment, which on the other hand could result in an oily smell in the cabin or the engine compartment. On some engines you can see small filters on top of the valve covers to prevent the smell.
So you don`t really need to route a line to the intake as there`s enough pressure on the lines to blow the air outside, you could connect all the lines to the catch tank and put a small filter on top of it - and you`re done.

[ROWDYRENAULT]

wet sump or dry sump? Dry sump you need filtered air into the engine which is eventualy sent to the breather can and exhausted. A dry sumped motor should run with a slight vacum in the crankcase, that air has to come from somewhere and go somewhere else. In the early development of the wet sumped LS motor the motor built up to much positive presure in the block and they cracked a block. Notice as you go from LS1 forward to latter versions that the bay to bay circultion holes get bigger and bigger. Another reason why I think that dry sump is the only good answer for these motors in this application. Lee
The ref. on the bay to bay breathing is Chevy LS1/LS6 V8S by Will Handzel page 16

[ultimagtr-ger]

Hello,

I have a standard LS2 which is wet sump.
Do I need a dry sump system for sportive road use (Michelin PS2 tyres)?

Regards
Oliver

[SchimmS]

ultimagtr-ger said:

Hello,

I have a standard LS2 which is wet sump.
Do I need a dry sump system for sportive road use (Michelin PS2 tyres)?

Regards
Oliver

No, you don`t. You could install one which on the other hand brings you a greater complexity (more connections) but no further advantages on the road. There are also LS7 installations on the road (and track) that use a wet sump systems and never had an issue.

[ROWDYRENAULT]

An LS7 without dry sump? My uncle was an engineer for G.M. one of the truths about OEMs that he taught me is they don't spend a dime on the construction of a car unless its needed. Chevy dry sumps every LS7 Corvette they build. They don't do that to be cute. Talk to the folks at ARE and they will site instances when even the LS7 Vette has had problems with the stock dry sump pan on the track. Take a look back through the different threads on main bearing failures in SBC Ultimas. Main bearing failures are primarily caused by lack of oil. Those Vettes and Ultimas have one thing in common, lots of G loading. Yes you have a much greater chance of running into this problem on the track, but most of you guys did'nt build a Ultima because you have a huge respect for speed limits. At least here in California I know of several roads that allow fairly safe 20-80 mph blasts at your limit for 15 or 20 minutes at a time. G loads are G loads doesn't matter where they happen. Go ahead build your $20-$30K motor and skip the dry sump to save money, your engine builder needs the work. Lee

[UltimaCH]

ROWDYRENAULT said:

Go ahead build your $20-$30K motor and skip the dry sump to save money, your engine builder needs the work. Lee

And your banker may not be too happy either.

[ultimagtr-ger]

Hello Lee,

I have a LS2 motor (not LS7). Do you recommend a dry sump system for the LS2 motor for road use?

Thanks

Regards
Oliver