Reluctantly joining the catch can club

[1991 Corvette ZR-1]

have had some spirited drives in the Z and noticed I get a decent puff of smoke on an aggressive downshift sometimes. Any other time, no smoke even on WOT without downshifts. Well after a few romps to near redline on one trip and off throttle coasting down to a stop at a light, I noticed the engine was running rough. This was after I looked in my rear view mirror around 4K rpm during the off throttle deceleration and saw a big puff of oil smoke. Not constant, just a decent quick cloud almost like the engine took a teaspoon gulp of oil in the cylinders. Pulled into a parking lot and the car recovered from the rough idle. The first thing that popped in my mind was O2s or spark plugs got saturated with burned oil and this caused the rough running condition.

I have had a few more trips to the 6-7K rpm area since and no issues but I also didn?t get off the throttle completely on those for decel. Looking inside the plenum and it is the usual shiny wet appearance that is what we have come to expect from the LT5. Driver side PCV valve is new while the extremely rare passenger side valve is still the original. Both valves rattle freely. There was noticeable oil volume collected below the pcv valves when removed. As expected, the tips on the Corsa are black after a few drives. So I am going to try a catch can and see if this provides something of value.

This always felt like an LS band aid and the idea of one is not great to me. However, the idea I may be slowly strangling spark plugs or O2 readings with burning oil also does not sound great either. Did a compression check a few years ago and all cylinders were great. Also, I am wondering if the after fires I sometimes get on decel are due to oil smoke in the exhausts messing with the O2s and making them enrich the combusion.

Anyway, the can I went with was an ADD W1. They come in lots of colors but I went with black to try and not draw the eye to it versus some bright purple or blue. The internal baffle design looks good and there is no Brillo pad style filter. Even has a little dipstick to check how much oil is in it if needed. I guess I will see how this works out and follow up with results good or non eventful.

Also as a side note, Dorman makes a hood prop clip assortment with a decent replacement for the passenger side fuel vapor hard line retainer if you need a new one. Stumbled on it while at the parts store for pcv hose. Dorman 45396

[1991 Corvette ZR-1]

Alright, if I remember an old diagram I found from Jerry posting on here I did this right. Inlet into the can is the hose connected to the pcv valves assembly at back of plenum. The outlet from the can is hose going to the pipe coming off the front of plenum just behind the throttle linkage. A few pics. I?ll take it for a test sometime today or tomorrow. I tried to keep this as clean an install as possible.

[HAWAIIZR-1]

Thanks for sharing. Very nice and clean install. I bought a catch can years ago and it?s still in my closet waiting install. I had good results with one I installed on my 90Z. It?s amazing how much oil it caught. I hope you find it worthwhile and can?t wait to hear your thoughts.


Sent from my iPhone using ZR-1 Net Registry (http://r.tapatalk.com/byo?rid=90383)

[dredgeguy]

Been thinking of this mod for a while and looking forward to hearing your results.

[DRM500RUBYZR-1]

Nicely done!
Factory looking.
Keep us posted on effect.
Thanks!
:cheers:
Marty

[Paul Workman]

The LT5 tends to need a 'BANDAID" too.

I installed mine (a Moroso) on my '90 and it seems to have cured that oil issue recovered from the PCV loop.

I used metal braded lines following the stock route and then wrapped to the catch can return line to the catch can placed in the well in front of the left front tire.

It actually looks good (once I finished routing the braided lines to the stock route, except for the detour to the catch can and back). And, the Moroso can has a dump valve on the bottom. I routed the dump outlet hose to a opening in the wheel well. Works good!

[Dynomite]

I used metal braded lines following the stock route and then wrapped to the catch can return line to the catch can placed in the well in front of the left front tire.


I did very similar :handshak::thumbsup:

Post 148 - Elite Engineering Oil Catch Can (http://forums.corvetteforum.com/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-8.html#post1587644228)

Post 242 - Installation of Elite Oil Catch Can (https://www.corvetteforum.com/forums/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-13.html#post1592505469)

The PCV hose connected under front of plenum (Vacuum source) is connected using SS braided hose to an Oil Catch Can external to the engine which Oil Catch Can is connected using SS braided hose to the dual PVC valves hard line located at the rear of the plenum. The Oil Catch Can is located on the drivers side under the drivers side head light.

https://cimg6.ibsrv.net/gimg/www.corvetteforum.com-vbulletin/800x600-1/80-7cf29450_2dcc_422a_a473_5f05bca4234a_1__796e3a5140 a2d96e62e57d1b58493cbe2e565cc9.jpg
https://cimg8.ibsrv.net/gimg/www.corvetteforum.com-vbulletin/400x450-1/80-ba5010c3_1fa7_4e37_b571_3e4229d3b12c_1__d9a3a2c843 2ead07650ffa998e61b983dada7bfc.jpghttps://cimg9.ibsrv.net/gimg/www.corvetteforum.com-vbulletin/400x450-1/80-59f7c74a_e643_462c_a97c_ef0fb87b0677_1__e6df38448f 47e6f8b0e3c9c57eeb9e7ac77d260f.jpg

[W i l l]

I've got catch cans on one of my cars, but a racer told me I should go back to PCV to get the vacuum on the inside of the motor and avoid the pressure buildup that will cause gaskets to leak, etc. I told him I didn't want to be burning oil back through the intake but he said in a street-driven car the horsepower loss is very minimal.

My catch cans were installed by Lingenfelter and have the brillo pads vents. Are the catch cans you guys are using sealed? Probably not if they have a dipstick. But why not get a baffled and sealed catch can and put the catch can downstream of the PCV valves and get the best of both worlds?

[1991 Corvette ZR-1]

I've got catch cans on one of my cars, but a racer told me I should go back to PCV to get the vacuum on the inside of the motor and avoid the pressure buildup that will cause gaskets to leak, etc. I told him I didn't want to be burning oil back through the intake but he said in a street-driven car the horsepower loss is very minimal.

My catch cans were installed by Lingenfelter and have the brillo pads vents. Are the catch cans you guys are using sealed? Probably not if they have a dipstick. But why not get a baffled and sealed catch can and put the catch can downstream of the PCV valves and get the best of both worlds?

The ADD W1 is sealed. The little knob for the dipstick is threaded to screw into its hole and it also incorporates an O ring to help seal it when fully threaded in. It is a nice little feature.

[Young1]

19059

19060

19061
I joined the Catch Can Club to eliminate oil in plenum and octane reducing oil vapor. I experience pinging only when hot on the track and the can should fix that. I purchased one with a valve on the bottom to drain it. I made a bracket to attach it to the nut on the brake booster. The nipple under the plenum is 3/8 and I inserted a 3/8 hose barb in the pcv collector at rear of plenum. Easy.

[1991 Corvette ZR-1]

Nicely done. I am happy to report that the catch can has reduced the soot on the tips tremendously. Since I installed this can, I have cleaned the tips once. Cleaning the tips used to be every weekend after a few drives.

[dredgeguy]

NIce mod Steve and well done! Let us know the end results.

[Young1]

I am now ready for MR9 snd BG.

[BlackZR1]

Steve,
My setup is very similar to yours using the booster studs. I strived for a clean approach keeping line lengths short using stainless tubing and printed pipes for the bends. The tubing brackets have a bushing in the them so that I can torque the plenum without crushing the plastic brackets. Here are a few pics.

https://zr1.net/forum/picture.php?albumid=536&pictureid=5080
https://zr1.net/forum/picture.php?albumid=536&pictureid=5081
https://zr1.net/forum/picture.php?albumid=536&pictureid=5083
https://zr1.net/forum/picture.php?albumid=536&pictureid=5084

It definitely works - there are usually a couple of tablespoons of oil in there when I empty it.

[AndrewL]

Nice install BlackZR1! I just ordered my catch can yesterday and was planning on making custom hard lines (albeit routed differently) like you've done. I'm looking forward to seeing if it makes a good difference.

[1991 Corvette ZR-1]

Figured I would do a follow up on finally emptying my catch can after getting some interesting readings on the little dipstick. Oil level was over two inches deep. No wonder the exhaust tips stay clean now. No more big puffs of blue smoke when an aggressive downshift occurs. Both PVC valves rattle freely when you shake them. So far, the catch can has done its job perfectly and I will keep it in place.

[XfireZ51]

BlackZR1,

Is that a custom setup or where can you get it?

[BlackZR1]

BlackZR1,

Is that a custom setup or where can you get it?Hey Dom,
Yes, a custom setup I fine-tuned over the course of a couple weeks. I am happy to share my gcode for the printed parts and a picture of my cardboard template for the bracket if you or anyone else is interested.

Thanks,
Roger

Sent from my SM-F721U using ZR-1 Net Registry mobile app (http://r.tapatalk.com/byo?rid=90383)

[XfireZ51]

Hey Dom,
Yes, a custom setup I fine-tuned over the course of a couple weeks. I am happy to share my gcode for the printed parts and a picture of my cardboard template for the bracket if you or anyone else is interested.

Thanks,
Roger

Sent from my SM-F721U using ZR-1 Net Registry mobile app (http://r.tapatalk.com/byo?rid=90383)

Excellent work Roger. Don?t have knowledge of 3D printing nor a machine but I appreciate the offer. I think its a very clean install. If u decide to do a few more, please put me down for one,