Valve cover breather on NA 1SS??

Rhobz · 02-11-2021, 01:13 PM

Hi everyone,

I rarely create new threads because I can usually find answers to my questions via search however my searches regarding valve cover breathers mostly resulted in conversations regarding boosted cars.

So, simple question I hope: Is there a benefit to running a valve cover breather (like the Metco that replaces the oil cap) on a NA 1SS that already has a Mishimoto Catch Can? Few minor mods, stock tune for now. I plan to do some track days this year but am not building a race car and plan to stay NA. I also hope to keep this car for a good long time.

Thanks!

BDPhoto519 · 02-11-2021, 02:54 PM

The valve covers are already vented from the factory to a catch can mounted near the front of the passenger side head. Both are routed to there, and the 3rd hose goes to your intake tube.

Drags1998 · 02-11-2021, 03:26 PM

The simple answer is NO.

BlackbeastSS2 · 02-11-2021, 04:02 PM

The more complex answer is yes. You could run both breather caps to a Y fitting and into a breather tank then into an oil separater. Then run that line into your valley cover to deposit it there. Pro’s you avoid dirtying your throttle body and looks cool. Drawl back, expensive compared to the system you already have. The current system is more for the environment and EPA regulations. You can vent a the valves in a street car with no problems but with a performance engine at WOT that requires a positive seal crankcase to seal the rings. Plus if you go that route it will effect the vacuum pressure and you might need a brake booster especially if you add a cam. Both systems work. You would need to adjust your AFR so a tune for performance, idle, fuel consumption would be needed. Your tuner could set your car up the right away if you wanted to go that route. Keep your oil clean and change earlier then recommend. I ran valve cover breathers back in he 70’s all the time but that was on a carb set. This camaro set up the in the gen6 seems almost like a closed system, I would be worried if I had a supercharger that can effect the positive venting system to a critical point where you blow your rings.

LT4Greg · 02-11-2021, 04:36 PM

Not a good idea for your 1SS.

Rhobz · 02-11-2021, 05:03 PM

Thank you everyone for your answers. I appreciate both the short and sweet and the detailed answers.

I guess I won't be buying a breather anytime soon.

Now to find somewhere else I can spend that money.

02-11-2021, 01:13 PM	#1
Rhobz Drives: 2018 Camaro 1SS 1LE Join Date: Feb 2020 Location: Colorado Springs, CO Posts: 186	Valve cover breather on NA 1SS?? Hi everyone, I rarely create new threads because I can usually find answers to my questions via search however my searches regarding valve cover breathers mostly resulted in conversations regarding boosted cars. So, simple question I hope: Is there a benefit to running a valve cover breather (like the Metco that replaces the oil cap) on a NA 1SS that already has a Mishimoto Catch Can? Few minor mods, stock tune for now. I plan to do some track days this year but am not building a race car and plan to stay NA. I also hope to keep this car for a good long time. Thanks!

02-11-2021, 02:54 PM	#2
BDPhoto519 Drives: 2018 Camaro 2SS A8 Join Date: Dec 2019 Location: Windsor, Ontario, Canada Posts: 90	The valve covers are already vented from the factory to a catch can mounted near the front of the passenger side head. Both are routed to there, and the 3rd hose goes to your intake tube. __________________ 2018 Camaro 2SS A8 Redline Edition

02-11-2021, 04:02 PM	#4
BlackbeastSS2 Drives: 2019 Camaro 1LE Shock Candy Join Date: Mar 2016 Location: Garage Posts: 1,757	The more complex answer is yes. You could run both breather caps to a Y fitting and into a breather tank then into an oil separater. Then run that line into your valley cover to deposit it there. Pro’s you avoid dirtying your throttle body and looks cool. Drawl back, expensive compared to the system you already have. The current system is more for the environment and EPA regulations. You can vent a the valves in a street car with no problems but with a performance engine at WOT that requires a positive seal crankcase to seal the rings. Plus if you go that route it will effect the vacuum pressure and you might need a brake booster especially if you add a cam. Both systems work. You would need to adjust your AFR so a tune for performance, idle, fuel consumption would be needed. Your tuner could set your car up the right away if you wanted to go that route. Keep your oil clean and change earlier then recommend. I ran valve cover breathers back in he 70’s all the time but that was on a carb set. This camaro set up the in the gen6 seems almost like a closed system, I would be worried if I had a supercharger that can effect the positive venting system to a critical point where you blow your rings. __________________ LT4 1.7 Supercharger snout ported & Meth 103 Katech TB, KATECH Custom Heads, DSX In-line fuel TSP Headers, Spec P Super Twin Clutch, TSP EL C7 CAM Diamond Piston & Manley Rods, Roto Fab Big Gulp BTR Push Rods,LS7 Lifters, ARP, FI Chiller, Kirkey Seats SJM Line Lock, Hurst Pistol Grip. 747/739 RWHP street tune - 821/794 RWHP track tune 101 octane. 2014 Mini Cooper countryman S All4 M6 daily driver

02-11-2021, 04:36 PM	#5
LT4Greg Drives: 2017 Camaro ZL1 Coupe Join Date: May 2016 Location: Georgia Posts: 5,813	Not a good idea for your 1SS. __________________ ZL1 Coupe, PDR, Exposed carbon fiber hood insert, My Link with Nav, M6 6 speed and Silver Ice Metallic. Mods done: ceramic window tint, GM Accessories Camaro floor mats and Roto-Fab CAI.

02-11-2021, 03:26 PM	#3
Drags1998 Drives: 15 SilveradoLTZ,162SSVert BlazerRS Join Date: Dec 2015 Location: Minot,Maine Posts: 644	The simple answer is NO.

02-11-2021, 05:03 PM	#6
Rhobz Drives: 2018 Camaro 1SS 1LE Join Date: Feb 2020 Location: Colorado Springs, CO Posts: 186	Thank you everyone for your answers. I appreciate both the short and sweet and the detailed answers. I guess I won't be buying a breather anytime soon. Now to find somewhere else I can spend that money.

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