Catch can or not?
Thread Starter
Race Director
Joined: Sep 2007
Posts: 16,557
Likes: 2,106
From: Peoria/Phoenix AZ
C6 of Year Finalist (performance mods) 2019
Catch can or not?
With two threads currently discussing/cussing the virtures and pointing to all the really bad things when you don't use a catch can, I decided to check it all myself.
Here's some pics of my pistons, intake ports, and a sample valve from my original LS3 with 71K miles. It's a bolton car that has seen ~300 passes at the drags and probably twice that many WOT occasions on the street up to the speed limit.
I never changed oil before the DIC read 3% and I never was down even a 1/4 qt before any change. Oil changes ranged from 11K to 16K. Prior to 56K, I used Mobil 1 5W-30. At that change, I then started using 4.5 qts of Mobil 1 0W-30 and 1 qt of Mobil 1 0W-30 racing. I always used an AC PF48 filter.
I have never used a catch can, yet have no carbon buildup (I did wipe a small spot on the lowest piston just to read the numbers), and no oil deposits in the heads or on the valve heads. Actually, it's pretty clean for the mileage.
So what makes my car different than the ones in those other threads?
Here's some pics of my pistons, intake ports, and a sample valve from my original LS3 with 71K miles. It's a bolton car that has seen ~300 passes at the drags and probably twice that many WOT occasions on the street up to the speed limit.
I never changed oil before the DIC read 3% and I never was down even a 1/4 qt before any change. Oil changes ranged from 11K to 16K. Prior to 56K, I used Mobil 1 5W-30. At that change, I then started using 4.5 qts of Mobil 1 0W-30 and 1 qt of Mobil 1 0W-30 racing. I always used an AC PF48 filter.
I have never used a catch can, yet have no carbon buildup (I did wipe a small spot on the lowest piston just to read the numbers), and no oil deposits in the heads or on the valve heads. Actually, it's pretty clean for the mileage.
So what makes my car different than the ones in those other threads?
Track Junky
Joined: Jun 2007
Posts: 4,074
Likes: 36
From: Orlando Area
Tech Contributor
From what I understand, the PCV setup in our cars is only an orifice, not an actual valve. Could tolerances in machining contribute to the amount of oil in the intake? I don't know the answer to that.
My pistons at 38k looked considerably worse than that. Up to 1/16" thick of carbon at some points and plenty if oil in the intake. I figured a catch can can't do any harm.
Just my $0.02
Sean
My pistons at 38k looked considerably worse than that. Up to 1/16" thick of carbon at some points and plenty if oil in the intake. I figured a catch can can't do any harm.
Just my $0.02
Sean
Tech Contributor
Joined: Jul 2002
Posts: 14,950
Likes: 264
From: St. Louis, MO
St. Jude Donor '08
Yours were a lot cleaner than mine Tom.
It's hard to see from this picture but I probably had twice as much build up as you, likely more. My build up was solid across the piston.
Not sure what, if anything this proves however! I've got a catch can and it works, I have to empty it from time to time. And before I had the can, the intake was sopped with oil, it isn't anymore. I seldom add oil between changes and change it at 10% on the DIC or so.
You drive your car for long periods of time at a stretch...I do also in my daily drive....but not long stints like you do. We both race. I've got 55,000 miles We use our cars similarly, and mine with the can has more buildup than you! :toe tap:
Some facts, but no conclusions in this post. What do you think Tom?
It's hard to see from this picture but I probably had twice as much build up as you, likely more. My build up was solid across the piston.
Not sure what, if anything this proves however! I've got a catch can and it works, I have to empty it from time to time. And before I had the can, the intake was sopped with oil, it isn't anymore. I seldom add oil between changes and change it at 10% on the DIC or so.
You drive your car for long periods of time at a stretch...I do also in my daily drive....but not long stints like you do. We both race. I've got 55,000 miles We use our cars similarly, and mine with the can has more buildup than you! :toe tap:
Some facts, but no conclusions in this post. What do you think Tom?
Race Director
Joined: Aug 2005
Posts: 13,592
Likes: 187
From: Hudson WI
NCM Sinkhole Donor
From what I understand, the PCV setup in our cars is only an orifice, not an actual valve. Could tolerances in machining contribute to the amount of oil in the intake? I don't know the answer to that.
My pistons at 38k looked considerably worse than that. Up to 1/16" thick of carbon at some points and plenty if oil in the intake. I figured a catch can can't do any harm.
Just my $0.02
Sean
My pistons at 38k looked considerably worse than that. Up to 1/16" thick of carbon at some points and plenty if oil in the intake. I figured a catch can can't do any harm.
Just my $0.02
Sean
Plus it is a good conversation piece at shows.
Instructor
Joined: Sep 2010
Posts: 219
Likes: 1
From: Winnipeg
I purchased an EliteEngineering CC after doing some research. Thinking about all that oil going throught the engine can't be could as mentioned in their thread. For a little over 100$, I'd say it's not going to hurt. Just do it!
