Regarding Catch Cans - ZR-1 Net Registry Forums

XfireZ51 · 05-04-2015

Earlier last week I happened to be looking at the catch can I installed last year. Underneath it I noticed what looked like an oily looking area. I reached under the can and felt an oil film that looked like it originated from one of the site tube fittings. So I removed the can from the car to use some plumbing tape to seal it. The can also has a bottom lid that screws into the can and I noticed it was not torqued. At this point I was pretty certain this may also be causing a vacuum
leak to the manifold. Although the motor idles well, I had noticed some slight surging at idle. More so when freewheeling while decelerating from speed. I made sure I sealed and tightened things down reinstalling the can. Actually my catch can is an oil separator and does not use any medium to trap the oil. Oil drops out of suspension as the air cools and oil collects at the bottom. Had 1-2 tablespoons of oil after 1500 miles. I can also tell there's less oil in exhaust because tips stay much cleaner and clean up much easier than before.
Took car out yesterday to a C&C. I immediately noticed how much smoother the idle was and how much less the motor oscillated when freewheeling.
The leak wasn't enough to be OBVIOUS but once tightened down, the difference was very noticeable.

Karl · 05-04-2015

Same thing happened to mine. The John Guest fittings began to leak so I plugged and sealed them up.

Paul Workman · 05-04-2015

Hmmmmm....

Veddy Intorestink!

bradley · 05-05-2015

what catch can do you guys use . I want to get one

Dynomite · 05-05-2015

Quote:

Originally Posted by bradley

what catch can do you guys use . I want to get one

Elite Engineering Oil Catch Can

Paul Workman · 05-06-2015

Quote:

Originally Posted by bradley

what catch can do you guys use . I want to get one

I use the MOROSO, mounted in the driver's headlight well.

Billy Mild · 05-06-2015

What benefit does a Catch Can provide? Seems like a lot of GM guys run one.

I have never seen a catch can on a 928 or 944 Turbo unless it was a very high HP build and they were trying to prevent all sources of pre-ignition.

Dynomite · 05-06-2015

Quote:

Originally Posted by Billy Mild

What benefit does a Catch Can provide? Seems like a lot of GM guys run one.

I have never seen a catch can on a 928 or 944 Turbo unless it was a very high HP build and they were trying to prevent all sources of pre-ignition.

Suppose to be an oil separator for the PCV system minimizing the amount of oil being sucked back into the Plenum.
The Oil Catch Can minimizes the amount of oil burned by the engine. There are other ways that oil is burned (bad valve guides, bad rings) but with the Oil Catch Can oil is not burned through the PCV system.

05-04-2015	#1
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,660	Regarding Catch Cans Earlier last week I happened to be looking at the catch can I installed last year. Underneath it I noticed what looked like an oily looking area. I reached under the can and felt an oil film that looked like it originated from one of the site tube fittings. So I removed the can from the car to use some plumbing tape to seal it. The can also has a bottom lid that screws into the can and I noticed it was not torqued. At this point I was pretty certain this may also be causing a vacuum leak to the manifold. Although the motor idles well, I had noticed some slight surging at idle. More so when freewheeling while decelerating from speed. I made sure I sealed and tightened things down reinstalling the can. Actually my catch can is an oil separator and does not use any medium to trap the oil. Oil drops out of suspension as the air cools and oil collects at the bottom. Had 1-2 tablespoons of oil after 1500 miles. I can also tell there's less oil in exhaust because tips stay much cleaner and clean up much easier than before. Took car out yesterday to a C&C. I immediately noticed how much smoother the idle was and how much less the motor oscillated when freewheeling. The leak wasn't enough to be OBVIOUS but once tightened down, the difference was very noticeable. __________________ [SIGPIC][/SIGPIC]Former Membership Chairman Former ZR-1 Registry - BOD 1972 Corvette 4speed base Coupe SOLD long time ago 1984 Corvette Z-51/4+3 SOLD 1992 Corvette ZR-1 Aqua/Gray #474 SOLD 1992 Corvette ZR-1 Black Rose/Cognac #458 2014 Honda VFR Interceptor DX Last edited by XfireZ51; 05-04-2015 at 04:48 PM.

05-04-2015	#2
Karl Join Date: May 2013 Location: Chicago Posts: 974	Re: Regarding Catch Cans Same thing happened to mine. The John Guest fittings began to leak so I plugged and sealed them up. __________________ 1993 ZR-1 #211 Yellow On Beige Beast #2 1992 ZR-1 #427 Black On Black Sold 1985 L98 Blue On Blue Sold

05-04-2015	#3
Paul Workman Join Date: Nov 2007 Location: Squires (near Ava MO in the Mark Twain N'tl Forest) - Missouri Posts: 6,493	Re: Regarding Catch Cans Hmmmmm.... Veddy Intorestink! __________________ Good carz, good food, good friendz = the best of timez! 90 #1202 "FBI" top end ported & relieved Cam timing by "Pete the Greek" Sans secondaries Chip & dyno tuning by Haibeck Automotive SW headers, X-pipe, MF muffs Former Secretary, ZR-1 Net Registry

05-05-2015	#4
bradley Join Date: Aug 2013 Location: ridgecrest ca Posts: 104	Re: Regarding Catch Cans what catch can do you guys use . I want to get one

05-06-2015	#7
Billy Mild Join Date: Aug 2014 Location: Kansas City, MO Posts: 838	Re: Regarding Catch Cans What benefit does a Catch Can provide? Seems like a lot of GM guys run one. I have never seen a catch can on a 928 or 944 Turbo unless it was a very high HP build and they were trying to prevent all sources of pre-ignition. __________________ Looking for a ZR-1 1985 Yamaha RZ350-NOT STOCK 1971 Yamaha AT1-Middle of a restoration