Catch can question

[GeminiZ06]

Is a catch can on a N/A LS7 Z06 effective?

I had one on my big-turbo vehicle (STi) and it was fantastic. It definitely worked well and was quite simple in design. It caught all the nasty oil and water vapors and kept them out of the intake tract.

I would check the return line back to the intake during every oil change and that end of the tube was always clean as a whistle and bone dry. The can, however, needed emptying. Removing that stuff alllowed the intercooler to remain effective as the car aged.

Since water is a by-product of combustion and oil vapors are also present in any engine, I would think there would be value in making sure that stuff didn't make its way back into the engine - especially for those folks trying to run a lot of miles between oil changes.

The real benefit probably comes from keeping the intake clean.

Anyone w/o a catch-can take off their intake after some time? and if so, did you find the inner walls to be "slimy" and dirty? The one on the STi was smooth and clean even after 36K miles of hard driving.

Are those products out there for the LS7? Do they invalidate warranty?

[RoHo]

I ran on on my C5Z after seeing oil in the intake and it worked very well, not a drop of oil in the intake after the install.

For some reason I haven't seen anyone using them on the C6Z yet, and I have heard more than one story about oil in the intake after some track time.

[GeminiZ06]

I would assume I'd set it up just like any car - pulling vacuum from the intake and hooked into the PCV line.

Can someone shed some light onto this?

[DJWorm]

The PCV system has been redesigned on the LS7.

In an attempt to solve the "oil behind TB syndrome", Chevy engineers vented the RT & LT valve covers to the Dry Sump oil reservoir tank and then to the TB as a vacume source. They also redesigned the PCV system under the Valley Cover but it is atill vented to the TB. So now there are 2 vent circuits to the TB/Intake as a vacume source. The theory was to reduce the top end pressure in the valve train and so reduce the amount of pressure in the PCV circuit to the TB.

See the diagrams and instructions below:
http://www.corvettels7.com/technical...case_vents.PDF
http://www.corvettels7.com/technical...s_PCVDIRTY.PDF

This does work when the car is driven normally on the street. However the problem still exsists when in competition. The Reservoir tank becomes overwelmed with high oil flow at high RPM and vents to the TB/Intake. The PCV system still "spits" excess oil into the TB. Note the the new ZR1 will have a larger reservoir tank boosting the total oil capacity to 10.5 qts. from 8 qts. The ZR1 will also have higher flow oil pumps and a revised Dry Sump oil pan with integral oil cooler.

There are a number of options:
- Install 2 oil catch cans, one for the valve cover vent circuit and one for the PCV circuit.
Other considerations are to:
- Install a larger aftermarket reservoir tank (Peterson)
- Install the larger ZR1 tank when it becomes available

[GeminiZ06]

DJ-W:"- Install a larger aftermarket reservoir tank (Peterson)
- Install the larger ZR1 tank when it becomes available"

That was exactly my next thought after reading about the initial issue.

Great info - thanks.

I've read quite a few times to not let the oil level go above the mid-point of the cross-hatched area.

Is Peterson the best tank? I think we can ignore waiting for an upgrade to the ZR1 version, which I don't know if its compatible. I'm just curious as to what's proven.

Thanks again

Originally Posted by DJWorm

The PCV system has been redesigned on the LS7.

In an attempt to solve the "oil behind TB syndrome", Chevy engineers vented the RT & LT valve covers to the Dry Sump oil reservoir tank and then to the TB as a vacume source. They also redesigned the PCV system under the Valley Cover but it is atill vented to the TB. So now there are 2 vent circuits to the TB/Intake as a vacume source. The theory was to reduce the top end pressure in the valve train and so reduce the amount of pressure in the PCV circuit to the TB.

See the diagrams and instructions below:
http://www.corvettels7.com/technical...case_vents.PDF
http://www.corvettels7.com/technical...s_PCVDIRTY.PDF

This does work when the car is driven normally on the street. However the problem still exsists when in competition. The Reservoir tank becomes overwelmed with high oil flow at high RPM and vents to the TB/Intake. The PCV system still "spits" excess oil into the TB. Note the the new ZR1 will have a larger reservoir tank boosting the total oil capacity to 10.5 qts. from 8 qts. The ZR1 will also have higher flow oil pumps and a revised Dry Sump oil pan with integral oil cooler.

There are a number of options:
- Install 2 oil catch cans, one for the valve cover vent circuit and one for the PCV circuit.
Other considerations are to:
- Install a larger aftermarket reservoir tank (Peterson)
- Install the larger ZR1 tank when it becomes available