Valve cover breather experiment. Interesting results.
10-19-2009, 06:48 PM
#21
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I left everything intact and just added a breather where the oil fill cap is. Didnt get any results, didnt expect any either. I did it to see if it would help with the small oil leak I had.
Plus mines a 93, no MAF so I think you can get away with more as far as unmetered air goes.
If anything it looks pretty lol.
Plus mines a 93, no MAF so I think you can get away with more as far as unmetered air goes.
If anything it looks pretty lol.
10-19-2009, 07:10 PM
#22
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I've had one on my 96 Impala for years.It idles better.I still have the pcv but instead of puting oil residue back through the t-body I vent it out.This keeps the IAC and TPS alot cleaner and makes the idle better.
10-19-2009, 08:33 PM
#24
I think you may have stumbled upon another problem rather than a valve cover breather actually causing a better idle. My bet is that the hose going to the throttle body is old and cracked or just plain clogged. If it is like the ls1, I believe the throttle blade is downstream of the throttle and therefore a vacuum leak... which causes idle problems.
10-19-2009, 08:39 PM
#26
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I used a push in breather but instead of just a filter it is a pcv style filter that connects to the T-body like stock, similar to this but cheaper from the local parts store.
http://www.summitracing.com/parts/BS...0/?image=large
http://www.summitracing.com/parts/BS...0/?image=large
10-19-2009, 08:47 PM
#27
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so my question is how do we keep oil out of our intake tract? I cringe at the thought of my new intake manifold looking like my old one on the inside when i pulled it off. IMHO the air/oil separator looks like crap. I would like to also clean up the engine bay as much as possible. I was going to cap off the PCV system and run a breather off the valve cover but apparently that's incorrect.
10-19-2009, 08:53 PM
#29
TECH Veteran
10-19-2009, 09:01 PM
#30
Im running a breather on both VCs with baffles to keep the oil off the motor, and ran a new PB. With that said, the car was down on the dyno but I figure most of that if not all is the heavy street twin clutch.
I did track test (back to back runs) with a single breather back in 97 on my basically stock car. The car ran better without a breather and with the oil cap back on. Maybe 1-2 tenths.
I did track test (back to back runs) with a single breather back in 97 on my basically stock car. The car ran better without a breather and with the oil cap back on. Maybe 1-2 tenths.
10-20-2009, 06:29 AM
#31
TECH Enthusiast
I am more curious is to why you are getting such horrible mileage in the first place. Your cam is small enough to where gas mileage should be that much different from stock, though I don't know if you are manual/auto and what gears you run. Though my car is stock gears and cam, I still get an average of 19-21 with mostly city driving.
10-20-2009, 04:15 PM
#34
My $0.02... (At the risk of getting jumped on by individuals who think that ALL stock is the only way to go...)
Yeah, I added two of those to my 96. First I took an extra Pass side valve cover and put it on the DR side, then added two breathers.
Now, my car is boosted (STS kit running 11 psi) and even with the STS check valves in place on the stock PCV system, oil would blow up the dipstick tube, so this was a "solution" to excessive pressure in my crankcase when under boost.
After I modded my PCV system, my engine's oil consumption (which was a problem BEFORE I installed my STS) dropped by 67% as well, so I could not be happier.
Having said all that, Yes - I know that a PCV system does indeed have a specific purpose - to ensure that all emmissions produced only exit via the tailpipe. FYI - I am a mechanical engineer who worked for 20 years in Detroit.
However, don't jump all over HitmanWS6 just because of an observation he made while trying to solve a problem on his car. If you must jump on the "Stock ROCKS!" / GM-put-everything-there-for-a-performance-reason bandwagon, then give him a few good reasons for retaining / fixing his car's faulty PCV system.
(It's not like he's the first guy here to remove this Appendix-like growth on the engine of a DD.)
Yeah, I added two of those to my 96. First I took an extra Pass side valve cover and put it on the DR side, then added two breathers.
Now, my car is boosted (STS kit running 11 psi) and even with the STS check valves in place on the stock PCV system, oil would blow up the dipstick tube, so this was a "solution" to excessive pressure in my crankcase when under boost.
After I modded my PCV system, my engine's oil consumption (which was a problem BEFORE I installed my STS) dropped by 67% as well, so I could not be happier.
Having said all that, Yes - I know that a PCV system does indeed have a specific purpose - to ensure that all emmissions produced only exit via the tailpipe. FYI - I am a mechanical engineer who worked for 20 years in Detroit.
However, don't jump all over HitmanWS6 just because of an observation he made while trying to solve a problem on his car. If you must jump on the "Stock ROCKS!" / GM-put-everything-there-for-a-performance-reason bandwagon, then give him a few good reasons for retaining / fixing his car's faulty PCV system.
(It's not like he's the first guy here to remove this Appendix-like growth on the engine of a DD.)
Last week i decided to try an experiment with my PCV system. I removed the crankcase ventilation hose on the passenger side valve cover, put in a breather filter and capped off the intake port. The results were unexpected, but very good. Immediately following installation of the breather I could feel a smoother idle. The smell of fuel is now gone, so if you are running rich this will lean you out. Acceleration is smoother as well as faster, I attribute this to the adjusted A/F ratio. The oil leak I had had almost stopped, with only a few drops from time to time now. But the big surprise was at the pump. After mixing city/highway miles driving to the same places, it took 13.5 gallons of gas to make my tank full. This time around, after pushing my TA harder than the week before, it took just over 12 gallons to fill the tank. Both fill ups were done at 160 miles. IMO its not a bad mod for just under 20 bucks.
Here is the filter you will need, take the clamp off and push it in. Comes in blue, silver, red and if i remember correctly black. $9.99 at auto zone.
Here is the filter you will need, take the clamp off and push it in. Comes in blue, silver, red and if i remember correctly black. $9.99 at auto zone.
10-20-2009, 04:26 PM
#35
That's one solution... G/M -
The PCV system will indeed introduce oil vapors and burnt combustion gasses back into the intake, just as it is designed. So, while capping it off and adding vents is one solution, so is adding a catch can to the stock PCV system; but adding extra hardware will not "clean up the engine bay as much as possible".
At this time there only seems to be 3 options:
1) Leave it Stock
2) Cap it off and add Vents (my personal choice)
3) Add a catch can to the stock system
Someone else might have a revolutionary idea, who knows!
The PCV system will indeed introduce oil vapors and burnt combustion gasses back into the intake, just as it is designed. So, while capping it off and adding vents is one solution, so is adding a catch can to the stock PCV system; but adding extra hardware will not "clean up the engine bay as much as possible".
At this time there only seems to be 3 options:
1) Leave it Stock
2) Cap it off and add Vents (my personal choice)
3) Add a catch can to the stock system
Someone else might have a revolutionary idea, who knows!
So, my question is how do we keep oil out of our intake tract? I cringe at the thought of my new intake manifold looking like my old one on the inside when i pulled it off. IMHO the air/oil separator looks like crap. I would like to also clean up the engine bay as much as possible. I was going to cap off the PCV system and run a breather off the valve cover but apparently that's incorrect.
10-20-2009, 04:40 PM
#36
I think you may have stumbled upon another problem rather than a valve cover breather actually causing a better idle. My bet is that the hose going to the throttle body is old and cracked or just plain clogged. If it is like the ls1, I believe the throttle blade is downstream of the throttle and therefore a vacuum leak... which causes idle problems.
10-20-2009, 04:44 PM
#37
I am more curious is to why you are getting such horrible mileage in the first place. Your cam is small enough to where gas mileage should be that much different from stock, though I don't know if you are manual/auto and what gears you run. Though my car is stock gears and cam, I still get an average of 19-21 with mostly city driving.
10-20-2009, 05:26 PM
#38
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I added a jegs air/oil separator to my engine. It does a good job at keeping most of the oil out of the intake. I think replacing the pcv with a breather only allows unmetered air to enter through the valves and the unburned gases to vent to the air...which can't be good for engine idle or gas mileage. IMHO!
