[Burly]

Originally Posted by PRAY

I will tell you that without a doubt a properly functioning PCV system with a catch can will make more power. 34rwhp and 63rwtq to be exact in one case. Actually more because we went from 3.42 gears to 3.90 gears between dyno runs. Same dyno. There was an ill working "catch can" that wasn't catching anything. This put oil on the back of the intake valves that caked up. The motor only had 8,500 miles. I flowed the heads all nasty and caked up. I then cleaned the heads up and reflowed them. Just cleaning them up was worth 140cfm throughout the lift curve. The head didn't even catch up till .600" lift. Multiply that by 8 cylinders and you have 1,120cfm of air not getting to the motor. This motor had the benefit of fuel going through it helping clean the oil. Power went from 511/445rw to 545/508rw. These flow numbers are off my SF110 bench with a 4" bore. The gap would have been much worse on a SF600 at 28". These heads went 380cfm@.700 at 28".

..........Dirty.....Clean
.100.....68..........86
.200....137........154
.300....208........228
.400....268........275
.500....310........316
.600....341........340
.700....351........353

Yes GM did put a "catch can" on the CCV side of the Camaro's. Why they didn't do it on the PCV side is kind of baffling. They ran the dirty air right into the manifold. If you don't limit that oil by using a catch can and an auxiliary PCV valve, oil is getting into the system. No if's, and's, or butt's about it. Oil vapor does not combust in the combustion cycle. I turns hard, causing detonation and sticks to everything in the intake and exhaust tract. The missing key is a check ball breather for the valve cover. You could also dual vent your catch can to the manifold and CAI. If you can't vent enough crank pressure under WOT you will get oil in the mix no matter what. DI motors are more susceptible to detonation and power loss due to the higher compression, and no cleaning effects of fuel passing over the valve. Fuel passing over the valve and sitting behind the valve helps cool the valve as well helping to stave off detonation. Caked up oil below the valve also raises compression again leading to more detonation. The motors are on the ragged edge with timing from the factory. Only time will tell. Wait till guys really start camming these things and you have real overlap. It's going to get worse.

Very interesting and thanks for real world information.

[SS 1LE]

Originally Posted by PRAY

I will tell you that without a doubt a properly functioning PCV system with a catch can will make more power. 34rwhp and 63rwtq to be exact in one case. Actually more because we went from 3.42 gears to 3.90 gears between dyno runs. Same dyno. There was an ill working "catch can" that wasn't catching anything. This put oil on the back of the intake valves that caked up. The motor only had 8,500 miles. I flowed the heads all nasty and caked up. I then cleaned the heads up and reflowed them. Just cleaning them up was worth 140cfm throughout the lift curve. The head didn't even catch up till .600" lift. Multiply that by 8 cylinders and you have 1,120cfm of air not getting to the motor. This motor had the benefit of fuel going through it helping clean the oil. Power went from 511/445rw to 545/508rw. These flow numbers are off my SF110 bench with a 4" bore. The gap would have been much worse on a SF600 at 28". These heads went 380cfm@.700 at 28".

..........Dirty.....Clean
.100.....68..........86
.200....137........154
.300....208........228
.400....268........275
.500....310........316
.600....341........340
.700....351........353

Yes GM did put a "catch can" on the CCV side of the Camaro's. Why they didn't do it on the PCV side is kind of baffling. They ran the dirty air right into the manifold. If you don't limit that oil by using a catch can and an auxiliary PCV valve, oil is getting into the system. No if's, and's, or butt's about it. Oil vapor does not combust in the combustion cycle. I turns hard, causing detonation and sticks to everything in the intake and exhaust tract. The missing key is a check ball breather for the valve cover. You could also dual vent your catch can to the manifold and CAI. If you can't vent enough crank pressure under WOT you will get oil in the mix no matter what. DI motors are more susceptible to detonation and power loss due to the higher compression, and no cleaning effects of fuel passing over the valve. Fuel passing over the valve and sitting behind the valve helps cool the valve as well helping to stave off detonation. Caked up oil below the valve also raises compression again leading to more detonation. The motors are on the ragged edge with timing from the factory. Only time will tell. Wait till guys really start camming these things and you have real overlap. It's going to get worse.

All very well said. I have a Mishimoto catch can waiting to go on mine after I get it...

[PRAY]

Thanks guys. The last 15 or so LS's that I have built all had the same issues until I completely redesigned the PCV system to what I use now. Oil control is no longer an issue for my builds. Unfortunately the key piece to my system hasn't been built yet for the LT platforms as far as I know. I have to get ahold of the manufacturer to see if he has any plans to build something for us. If he does, I will put up a post about how to run it all and make it work.

[PRAY]

I am not fond of where the Mishimoto sits. They did their homework and have a nice product but there is a much cheaper and faster to install option. It literally took me 10 minutes to install mine and I used a bolt that was already there. I had to remove just the MAF sensor plug and the Camaro cover on the drivers side. The can in basically hidden.

[Burly]

Originally Posted by PRAY

I am not fond of where the Mishimoto sits. They did their homework and have a nice product but there is a much cheaper and faster to install option. It literally took me 10 minutes to install mine and I used a bolt that was already there. I had to remove just the MAF sensor plug and the Camaro cover on the drivers side. The can in basically hidden.

Hidden? Doesn't that make it harder to check and empty? I think I'm going with the Mishi setup.

[PRAY]

Originally Posted by Burly

Hidden? Doesn't that make it harder to check and empty? I think I'm going with the Mishi setup.

No not really, You unscrew the top barb fitting to the can and unscrew the top of the can. Take a Windex or like spray bottle and pump out the oil. Takes less than 10 minutes. Nothing to really remove and disassemble. I am not trying to sell you anything. Just pointing something out.

[PRAY]

These pics are from when I still had the stock CAI on. The RF pretty much covers it up now. Still very easy to get to. If it was black you probably wouldn't notice it. I am probably going to add a barb that will go to the CAI and put PCV valves in both of the hoses. That may help the situation until I can get a valve cover breather built.

[Burly]

Ha! Hard to call that hidden with the red can! I get it and like your setup because the hoses are way shorter than Mishi.

[PRAY]

Originally Posted by Burly

Ha! Hard to call that hidden with the red can! I get it and like your setup because the hoses are way shorter than Mishi.

True, but if it was black it would be better. It is more "hidden" with the RF.

[Ponyeatr16ss]

$350 I can spend elsewhere. If you "needed" it, GM would have put one on it.

[PRAY]

Originally Posted by Ponyeatr16ss

$350 I can spend elsewhere. If you "needed" it, GM would have put one on it.

You can get the catch can I run for $100 from many sources. Cheap insurance.

[JFM-jr]

Originally Posted by PRAY

You can get the catch can I run for $100 from many sources. Cheap insurance.

You can lead a horse to water . . . . . .

[Atra]

The Mishi setup looks way better and imo in a better spot >.>

[PRAY]

Originally Posted by Atra

The Mishi setup looks way better and imo in a better spot >.>

To each his own. That is why there are a bunch of company's that make them. I personally don't like stuff that clogs up the engine bay and makes it hard to get to plugs and wires. The Mishi set up is a nice piece though. Just not for me.