Question for Vettrdstr

Besides, I'd like to get more information on fixing the PCV system since I need to do this mod soon, so it's good that this was posted instead of IMed.
Besides, I'd like to get more information on fixing the PCV system since I need to do this mod soon, so it's good that this was posted instead of IMed."
Ditto!
:lurk:
[Modified by drcoffee, 6:26 PM 2/12/2004]


Look in the sig pic and you will see it to the RH side of the Throttle Body. Funny thing is that I have an extra new one sitting on my desk and I am looking at it now. Boosting the crank case is not a good thing and this will take care of it for you. :yesnod:
VR :cheers:
[Modified by vetterdstr, 8:02 PM 2/12/2004]


VR :cheers:
On my '99 is see a similar setup as yours. I have the two Vac ports on the TB as you do. The silver upper port vents the crankcase. The lower one that you have the new check valve on powers the brake booster. What did you do with the crankcase line. The upper line on your car seems to have a solid metal line where I have only a nipple that has a rubber tube that goes to the forward nipple on the valve cover. Would I need two check valves?
:confused: Or did you just plug the upper vac port with a bolt?
Correction: I see the lower vac line is the vac line from the PCV. and the upper line is fresh air to the crankcase.
Is the Brake booster check valve strong enough or is another check valve needed there as well?
Thanks
[Modified by drcoffee, 12:26 PM 2/13/2004]


VR :cheers:
[Modified by vetterdstr, 6:44 AM 2/13/2004]
The Best of Corvette for Corvette Enthusiasts
Besides, I'd like to get more information on fixing the PCV system since I need to do this mod soon, so it's good that this was posted instead of IMed.
:lurk:
[Modified by SideStep, 10:18 AM 2/13/2004]
On my '99 is see a similar setup as yours. I have the two Vac ports on the TB as you do. The silver upper port vents the crankcase. The lower one that you have the new check valve on powers the brake booster. What did you do with the crankcase line. The upper line on your car seems to have a solid metal line where I have only a nipple that has a rubber tube that goes to the forward nipple on the valve cover. Would I need two check valves?
:confused: Or did you just plug the upper vac port with a bolt?
Thanks
[Modified by drcoffee, 7:46 AM 2/13/2004]
Why not just tap into the the air inlet between the air filter and the intake of the blower?
This is how my ATI is set up and I've had "0" problems with it, and it will still evacuate the crankcase under boost.... :D Something that is not done with a check valve in the system. :eek:
On my '99 is see a similar setup as yours. I have the two Vac ports on the TB as you do. The silver upper port vents the crankcase. The lower one that you have the new check valve on powers the brake booster. What did you do with the crankcase line. The upper line on your car seems to have a solid metal line where I have only a nipple that has a rubber tube that goes to the forward nipple on the valve cover. Would I need two check valves?
:confused: Or did you just plug the upper vac port with a bolt?
Thanks
[Modified by drcoffee, 7:46 AM 2/13/2004]
Guess I'm kinda :confused: why do you need a antiboost valve in your PCV line?
Why not just tap into the the air inlet between the air filter and the intake of the blower?
This is how my ATI is set up and I've had "0" problems with it, and it will still evacuate the crankcase under boost.... :D Something that is not done with a check valve in the system. :eek:
I'm confused as well, that's why I hope to clear it up here.
On my '99 is see a similar setup as yours. I have the two Vac ports on the TB as you do. The silver upper port vents the crankcase. The lower one that you have the new check valve on powers the brake booster. What did you do with the crankcase line. The upper line on your car seems to have a solid metal line where I have only a nipple that has a rubber tube that goes to the forward nipple on the valve cover. Would I need two check valves?
:confused: Or did you just plug the upper vac port with a bolt?
Thanks
[Modified by drcoffee, 7:46 AM 2/13/2004]
Guess I'm kinda :confused: why do you need a antiboost valve in your PCV line?
Why not just tap into the the air inlet between the air filter and the intake of the blower?
This is how my ATI is set up and I've had "0" problems with it, and it will still evacuate the crankcase under boost.... :D Something that is not done with a check valve in the system. :eek:
In theory that is accurate. But the air bridge between the MAF and SC will have serious vac pressure almost always and this will power-vent the valve cover on the air inlet nipple sucking all the oil layden crank fumes thru the compressor and into the intercooler and into the intake ultimately reducing the octane of the charge in the cylinder, leading to poor ignition. You need a heavy duty check valve between the intake and PCV because the PCV valve is not sufficient to stop the boosted air, leading to boost pressure in the crankcase and seal failure.
I'm confused as well, that's why I hope to clear it up here.
And the line is before the MAF sensor right behind the air filter.
I think your running the risk of more engine damage with a check valve because your not venting the crankcase when it needs it the most under boost.
Back in my drag racing days we used to run the PCV line down to the header collector to evacuate the crankcase at WOT.
Unless you have excessive blowby I would look at plumbing it into the air intake right behind the air filter.
When I refer to Vac pressure I mean "negative pressure". If you suck the vapors into the intake with the suction that the blower can produce, you will draw vapor, liquid, etc down that line. I would think you would not want to risk ingesting oily crank vapors into the engine when you need clean air-fuel mix at WOT. I am wrong here? I have a NA car right now and the draw thru the air cleaner is pretty strong. The SC would certainly best that. Besides that, the crankcase gases will leave an oily mess thruoghout the IC, intake, etc. It would be best to vent it out of the engine altogether.
If we are worried about crankcase pressure (positive boost) then a breather on the oil filler tube will work well. But this may make any vac of the crankcase null and void.
Crud! :banghead:
What works best? Stock install instructions with the Procharger is wrought with issues so the stock instructions are not reliable. I'm sure Andy will help me thru this issue when the time comes.
[Modified by drcoffee, 1:49 PM 2/13/2004]


VR :cheers:
Now on your boosted car you are drawing off a 3" dia pipe with a 3/8 or smaller orifice parallal to the intake charge.
You may draw some small amount of vapors out of the crankcase but I bet the most you will do is reduce some pumping loss's. :cool:
In a healthy engine without excessive blowby the following is true. The amount of air flow out of the crankcase is directly porportional to the amount of air flow across the TB same as a NA engine.
Vapor or liquid can only be drawen up the line by air flow, if your rings are sealing correctly there will be little or no air flow.
And I have 14,000 miles on my ATI and had the airbridge off last week for installation of headers and it was clean as a whistle......
If it ain't broke don't fix it!!! :D :)
If thats the case then say at 5-6k rpms your making say 8# of boost,the check valve will stop boost from surging into the crankcase.But at high rpm and boost,there is alot more blowby.And in order for the crankcase gases to escape,it has to overcome 8#'s ofboost in order to vent into the t/body.Therefore you still have at least 8# of pressure in the c/case for a short while..I think the best setup is the pcv line venting just after the air filter w/ a oil separator.I'm doing this soon on an ati'd vette and I'll post pics.At high rpms and having a vacuum in the c/case,you get a better seal on the p/rings.
Frank
I've talked about this PCV stuff in several posts, so you might want to dig around for more info. It bascially comes down to tradeoffs. There is no perfect answer. If you have a motor that does not have much blowby you can get away with the check valve and the basic setup that ATI suggest.
Most people who really run the car hard just removed the entire PCV and vent the crankcase to catch cans. JBsblowc5 said he tired everthing and that is all that would work on a road course (he has had boost on an ls1 longer than just about anyone here).
If it ain't broke don't fix it!!!
[Modified by QuickSilver2002, 1:36 AM 2/14/2004]













