Crankcase Pressure ruins my evening...
05-27-2002, 09:00 AM
#1
Crankcase Pressure ruins my evening... On my new 434ci setup, I went ahead and had the PCV system plugged to prevent oil from entering my intake, which is very common on our cars. All I had in place of the PCV system is one of the small K&N breathers coming off of the PCV line.
This was not nearly enough to vent the Crankcase.
Last week at the track, I was getting some oil blowing out of the PCV line just before the valve itself. The valve had a somewhat weak push-in fit into the rubber hose. So, before racing the car today I put a screwband on that hose to help seal the PCV line.
I guess I fixed the leak, but instead I blew a valvecover gasket out of the entire topside of the driver's valvecover on the first pass (10.92 @ 128.3 (1.65) spinning). The entire engine was covered in oil, and the valve cover O-ring gasket was sticking out about 2".
That sucked! I did what I could and yanked off the cover and started trying to get the O-ring back in place. Dennis brought some brake cleaner and RTV to help attempt to seal it back up. It must have wiggled out of the groove when I reinstalled it, because it blew out the backside of the gasket on the next pass. Again, coating my firewall with oil. It was the NineBall smokeshow yesterday!
Today I'll work on sealing those gaskets better, might have to use RTV all the way around them. Then I'll use some more vent filters all around the valvecovers.
Anyone else have an electric vacuum pump setup working properly? You'd be amazed at how much oil comes thru the PCV system and typically goes into our intakes.
Tony
This was not nearly enough to vent the Crankcase.
Last week at the track, I was getting some oil blowing out of the PCV line just before the valve itself. The valve had a somewhat weak push-in fit into the rubber hose. So, before racing the car today I put a screwband on that hose to help seal the PCV line.
I guess I fixed the leak, but instead I blew a valvecover gasket out of the entire topside of the driver's valvecover on the first pass (10.92 @ 128.3 (1.65) spinning). The entire engine was covered in oil, and the valve cover O-ring gasket was sticking out about 2".
That sucked! I did what I could and yanked off the cover and started trying to get the O-ring back in place. Dennis brought some brake cleaner and RTV to help attempt to seal it back up. It must have wiggled out of the groove when I reinstalled it, because it blew out the backside of the gasket on the next pass. Again, coating my firewall with oil. It was the NineBall smokeshow yesterday!
Today I'll work on sealing those gaskets better, might have to use RTV all the way around them. Then I'll use some more vent filters all around the valvecovers.
Anyone else have an electric vacuum pump setup working properly? You'd be amazed at how much oil comes thru the PCV system and typically goes into our intakes.
Tony
05-27-2002, 09:02 AM
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Re: Crankcase Pressure ruins my evening... I would setup a "baffled" catchcan and throw a restrictor inline. Then plug it into its normal position and hook back up the fresh air line. That isn't too healthy on the motor <img border="0" title="" alt="[Sad]" src="gr_sad.gif" />
Cheers,
Chris
Cheers,
Chris
05-27-2002, 11:17 AM
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Re: Crankcase Pressure ruins my evening... If your not going to run a pcv system or any other sort of evac system, you should install at least 2 large K&N breathers in the valve covers and change the oil very often.
I still use the pcv system but made a very good oil separator as I certainly can't have oil going in the intake with a blower.
I made a canister from some stainless stock, filled it with K&N open cell air filter foam, wrap the foam with terry cloth and baffled the exit.
Flows 100% free and 0 oil gets into the intake and just coats the filter foam and terry cloth.
I clean it maybe once a week.
Steve
I still use the pcv system but made a very good oil separator as I certainly can't have oil going in the intake with a blower.
I made a canister from some stainless stock, filled it with K&N open cell air filter foam, wrap the foam with terry cloth and baffled the exit.
Flows 100% free and 0 oil gets into the intake and just coats the filter foam and terry cloth.
I clean it maybe once a week.
Steve
05-27-2002, 02:33 PM
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Re: Crankcase Pressure ruins my evening... A belt drive vacuum stystem would be best.
i have been working on an electric system with mixed results.
The two K-N filters are only a band aid for the problem.
We really need a REAL fix.
Anyone else?
i have been working on an electric system with mixed results.
The two K-N filters are only a band aid for the problem.
We really need a REAL fix.
Anyone else?
05-27-2002, 02:39 PM
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Re: Crankcase Pressure ruins my evening... The REAL fix is an engine that is built properly and doesn't experience blow by. If you're running low tension oil rings (like the Pepper), an electric vacuum pump will help, but for the rest of us with stock like rings I don't think it makes any difference.
Right now I have the stock PVC setup. I've tried running an "open" PVC system with no improvement in oil consumption or power. In my case oil is coming past the rings, about 1qt every 500 miles.
Right now I have the stock PVC setup. I've tried running an "open" PVC system with no improvement in oil consumption or power. In my case oil is coming past the rings, about 1qt every 500 miles.
05-27-2002, 03:12 PM
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Re: Crankcase Pressure ruins my evening... Electric vacuum pump isn't a power adder (well, not much of one) - but it is good for improved oil control.
I have had one working fine on my LT1 for agest - jMX tried out the same pump on his LS1 and it couldn't keep up at WOT though.
If you are trying to use stock air pumps you will be outta luck - they don't move enough volume.
Worst case you could use two pumps - this should work, even on a LS1. There is also a different pump now we are using than the caddy crankcase pump I use/jmX tried. It pulls a little more vacuum, is quieter, and is internally regulated at 10" - prevents you from getting to much vacuum (really 15" or more could be bad - if you run a dual pump setup this could be an issue at lower rpm).
I wouldn't just run breathers though - as you will have problems like you mentioned.
Chris
I have had one working fine on my LT1 for agest - jMX tried out the same pump on his LS1 and it couldn't keep up at WOT though.
If you are trying to use stock air pumps you will be outta luck - they don't move enough volume.
Worst case you could use two pumps - this should work, even on a LS1. There is also a different pump now we are using than the caddy crankcase pump I use/jmX tried. It pulls a little more vacuum, is quieter, and is internally regulated at 10" - prevents you from getting to much vacuum (really 15" or more could be bad - if you run a dual pump setup this could be an issue at lower rpm).
I wouldn't just run breathers though - as you will have problems like you mentioned.
Chris
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05-27-2002, 03:31 PM
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Re: Crankcase Pressure ruins my evening... tony, I had a helluva time getting a "bad" gasket to stay in the grooves. best solution is to use a new GM gasket which will stay in the grooves better. You can also use a bit of weatherstrip adhesive to keep it in place.
Have you considered a LS6 valley cover as your new PCV location? It seems like the true "fix". I have one sitting here and it definately should help (pickup is away from moving oil towards the center of the engine <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> )
Have you considered a LS6 valley cover as your new PCV location? It seems like the true "fix". I have one sitting here and it definately should help (pickup is away from moving oil towards the center of the engine <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> )
05-27-2002, 04:06 PM
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Re: Crankcase Pressure ruins my evening... </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by ChrisB:
<strong>If you are trying to use stock air pumps you will be outta luck - they don't move enough volume.
</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Nope, I disagree. I have the single AIR pump running in reverse and I get 0 blow by and 0 oil in my intake. I have a tube coming fromboth valve covers tying in to each other and running to the AIR pump. It vents out to atmosphere. I also have a K & N brather on the passenger valve cover. No it doesn't create a big vacuum, but it eliminates the oil in the intake while venting the crankcase. At WOT instead of a positive pressure in the crancase, I have exactly 0 pressure and 0 vacuum. Been running this for 2 years with no problems. I now have the same setup on the wifes LT1.
Tim
<small>[ May 27, 2002, 04:08 PM: Message edited by: Tim98TA ]</small>
<strong>If you are trying to use stock air pumps you will be outta luck - they don't move enough volume.
</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Nope, I disagree. I have the single AIR pump running in reverse and I get 0 blow by and 0 oil in my intake. I have a tube coming fromboth valve covers tying in to each other and running to the AIR pump. It vents out to atmosphere. I also have a K & N brather on the passenger valve cover. No it doesn't create a big vacuum, but it eliminates the oil in the intake while venting the crankcase. At WOT instead of a positive pressure in the crancase, I have exactly 0 pressure and 0 vacuum. Been running this for 2 years with no problems. I now have the same setup on the wifes LT1.
Tim
<small>[ May 27, 2002, 04:08 PM: Message edited by: Tim98TA ]</small>
05-27-2002, 05:06 PM
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Re: Crankcase Pressure ruins my evening... I've had an electric evac. system on my car for ~6 months or so. However, I haven't really had an opportunity to completely test it yet. It does seem to work well, though. All of the stock fittings are blocked off, and I have a baffled crankcase evacuation breather in each valvecover. They both T together and are fed into the electric pump. The output of the pump goes into a breather tank.
05-27-2002, 05:12 PM
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Re: Crankcase Pressure ruins my evening... As far as the motor on my setup, it's a modified LT1 AIR pump. Some place in TN makes the kit, and it's primarily used on alcohol dragsters to suck condensation out of the crankcase, but it serves the purpose I'm using it for as well also...
05-27-2002, 05:25 PM
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Re: Crankcase Pressure ruins my evening... Tony,
If you want to try a catchcan, I've been using the GReddy version (Link: http://www.roadraceengineering.com/i...dycatchcan.htm ) for almost a year now with good results. In my case I installed it upstream of the PCV an my oil-in-the-intake problems are all but solved. Granted I probably don't have the kind of crankcase pressure you do, but if you're interested I'd be happy to email you some pics of my installation.
Good luck <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
If you want to try a catchcan, I've been using the GReddy version (Link: http://www.roadraceengineering.com/i...dycatchcan.htm ) for almost a year now with good results. In my case I installed it upstream of the PCV an my oil-in-the-intake problems are all but solved. Granted I probably don't have the kind of crankcase pressure you do, but if you're interested I'd be happy to email you some pics of my installation.
Good luck <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
05-27-2002, 05:57 PM
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Re: Crankcase Pressure ruins my evening... one of my friends had a 355 with 15lbs of UN-intercooled boost on a TPI motor....
what he did for crankcase evac was he used solid valvecovers and installed a -12an bulkhead and used a moroso -12an catch can
he told me it worked perfect and never had any pressure in the crank
maybe you can use that...
OR
there was a post in the FI section a while where a buick guy explained a system he used that worked great
what he did for crankcase evac was he used solid valvecovers and installed a -12an bulkhead and used a moroso -12an catch can
he told me it worked perfect and never had any pressure in the crank
maybe you can use that...
OR
there was a post in the FI section a while where a buick guy explained a system he used that worked great
05-27-2002, 06:09 PM
#14
Re: Crankcase Pressure ruins my evening... All of this PCV discussion leads me to a question. My PCV sucks a lot of oil and I have put a breather cap on the oil neck filler and put filters in my PCV line that leads to the intake manifold. It still sucks oil! I am thinking about removing the PCV line altogether and just putting in breather caps on both valve covers. What are the pros and cons of this system and why? I know others probably want to know this info too. Thanks!
(sorry to ***** the post)
(sorry to ***** the post)
05-27-2002, 06:43 PM
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Re: Crankcase Pressure ruins my evening... </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Nine Ball:
<strong>
Anyone else have an electric vacuum pump setup working properly? You'd be amazed at how much oil comes thru the PCV system and typically goes into our intakes.
Tony</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I am running a vacuum pump (part # is from 85 caddy diesel) and small breather. no probs so far.
<strong>
Anyone else have an electric vacuum pump setup working properly? You'd be amazed at how much oil comes thru the PCV system and typically goes into our intakes.
Tony</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I am running a vacuum pump (part # is from 85 caddy diesel) and small breather. no probs so far.
05-27-2002, 09:48 PM
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Re: Crankcase Pressure ruins my evening... </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">
Nope, I disagree. I have the single AIR pump running in reverse and I get 0 blow by and 0 oil in my intake.
</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Your car is so slow you probably wouldn't notice extra crankcase pressure @ WOT, but its likely the air pump can't keep up. If it doesn't pull vacuum what's the point? You're no better than a traditional breather (and around 8# heavier at that).
Nope, I disagree. I have the single AIR pump running in reverse and I get 0 blow by and 0 oil in my intake.
</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Your car is so slow you probably wouldn't notice extra crankcase pressure @ WOT, but its likely the air pump can't keep up. If it doesn't pull vacuum what's the point? You're no better than a traditional breather (and around 8# heavier at that).
05-27-2002, 10:19 PM
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Re: Crankcase Pressure ruins my evening... Sounds like a lot of crankcase pressure to be pushing a valvecover gasket out. Are you sure you don't have a ring issue?
05-28-2002, 02:11 AM
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Re: Crankcase Pressure ruins my evening... </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Tim98TA:
<strong>Nope, I disagree. I have the single AIR pump running in reverse and I get 0 blow by</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif"></strong>
How have you determined/quantified this? Even a stock vehicle has an amount of blow by?
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"><strong> and 0 oil in my intake.</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif"></strong>
That is because you block off the pcv. Removing the pcv and running breathers, or even worse, leaving the crankcase unvented will achieve the same result. The fact that you have no oil in the intake reflects a lack of a pathway for the oil to travel. It does nothing to quantify the viability of the air pump in reverse.
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"> I have a tube coming fromboth valve covers tying in to each other and running to the AIR pump. It vents out to atmosphere. I also have a K & N brather on the passenger valve cover.</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">
With this setup you are not creating any vacuum. You can only do this with a sealed crankcase - which your breather works in counter to.
I believe my original statement - that the stock air pump will not move enough volume to create a vacuum still stands.
If you wish to quantify the effectiveness of your setup you need to hook up a vacuum gauge to the setup and monitor your pressure at WOT. Any positive values (pressure relative to atmospheric) indicate that the setup is not working. The best your setup can do is atmospheric (since it is vented).
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"><strong>
At WOT instead of a positive pressure in the crancase, I have exactly 0 pressure and 0 vacuum.
</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Have you verified this with a vacuum gauge? If so where did you plumb it?
Chris Bennight
<strong>Nope, I disagree. I have the single AIR pump running in reverse and I get 0 blow by</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif"></strong>
How have you determined/quantified this? Even a stock vehicle has an amount of blow by?
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"><strong> and 0 oil in my intake.</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif"></strong>
That is because you block off the pcv. Removing the pcv and running breathers, or even worse, leaving the crankcase unvented will achieve the same result. The fact that you have no oil in the intake reflects a lack of a pathway for the oil to travel. It does nothing to quantify the viability of the air pump in reverse.
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"> I have a tube coming fromboth valve covers tying in to each other and running to the AIR pump. It vents out to atmosphere. I also have a K & N brather on the passenger valve cover.</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">
With this setup you are not creating any vacuum. You can only do this with a sealed crankcase - which your breather works in counter to.
I believe my original statement - that the stock air pump will not move enough volume to create a vacuum still stands.
If you wish to quantify the effectiveness of your setup you need to hook up a vacuum gauge to the setup and monitor your pressure at WOT. Any positive values (pressure relative to atmospheric) indicate that the setup is not working. The best your setup can do is atmospheric (since it is vented).
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"><strong>
At WOT instead of a positive pressure in the crancase, I have exactly 0 pressure and 0 vacuum.
</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Have you verified this with a vacuum gauge? If so where did you plumb it?
Chris Bennight
