Crankcase Evacuation with the LT1 smog pump. How To:

[Hock]

Ok.

So would I leave the PCV systems as is?

If so what do I do with the outlet after I run it to the catch can?

The reason I ask this, is that it would seem to me the without some how returning the air pulled from the engine back to it that would be the equivalent of a vacuum leak since the air is metered before it goes to the VC vent tube. I'm thinking that I would just want to run it back to that vent after the catch can.

 

[oldtimer]

you're relieving pressure in the crankcase, not vacuum. the vacuum pump will only work upon boost conditions determined by your Hobb Switch setting. Dump tank collects any oil/fumes that might be sucked out. Highly unlikely much oil with an LT1 air pump. not enough vacuum.

 

[Hock]

Well the factory breather pulls from the inlet tube, which is metered. This system will end up pulling air through that tube as well.

 

[WSLN 6]

If you are talking about the factory tube that goes from the valve cover to the turbo inlet bell, that should have been removed a long time ago.

 

[oldtimer]

"Quote" If you are talking about the factory tube that goes from the valve cover to the turbo inlet bell, that should have been removed a long time ago.
__________________

Absolutely !:wink: I didn't think anyone had that breather left on there valve cover anymore.

 

[Hock]

If you are talking about the factory tube that goes from the valve cover to the turbo inlet bell, that should have been removed a long time ago.

Take that off and you have yourself a vacuum leak. Remember, the pcv runs off the intake and all the air coming to the pcv has already be metered by the maf so for me its gonna stay.

I think what I'm gonna do is just run a hose from the catch can back to the turbo inlet, just to keep things in check.

 

[WSLN 6]

I know how it works, took it off 10 years ago......
You cap off the turbo inlet bell, remove the hose, and install a breather on the front of the valve cover. Has nothing to do with the pcv valve. That is a whole other can of worms.
For the pcv valve I put a check valve inline and installed a catch can on that line to stop all oil from entering the intake.
Now back to the purpose of this thread, vacuum pumps.....

 

[Hock]

I know how it works, took it off 10 years ago......
You cap off the turbo inlet bell, remove the hose, and install a breather on the front of the valve cover. Has nothing to do with the pcv valve. That is a whole other can of worms.
For the pcv valve I put a check valve inline and installed a catch can on that line to stop all oil from entering the intake.
Now back to the purpose of this thread, vacuum pumps.....

Thats the purpose that I am here and thats what I'm trying to do. I know the PCV works while under vacuum and when the intake is pressurize its acts as check valve (at least the one I have does) to help keep boost pressure out of the crankcase. Now that breather tube is also part of that system and if I remove it and put a filter in it place like is being suggested I will end up drawing unmetered air into the intake while under vacuum through the PCV.

Now I would like to retain the PCV system and have the crankcase evac system for when the engine is under boost, so that is what I am trying to figure out.

Now just incase it was missed this is for an Eagle Talon TSI which is my daily driver, not a Grand National. I would ask on the DSM board I am registered on but the last few times I asked questions there I got absolutely no good answers so I decided to ask you guys about this particular mod because I know for a fact that you guys would be able to give me a better answer then most anyone over on those boards.

So I think the question I really need to ask is if the PCV system can be retained as it was designed or do I have to get rid of it? If it does have to go how do you guys handle crankcase evac when not under boost?

 

[WSLN 6]

Oh ok that explains some things. You should put that in your sig perhaps....lol
I wil pm you the name of a guy I race with that is big into Buscher racing engines and Talons.

 

[Pablo]

I covered this I don't know how many times already in the thread.

let me make it simple

in this order
For the pcv:
engine-pcv valve-moisture seperator-check valve(I use an aux check valve since the pcv is actually really crappy at sealing)-manifold vacuum port

For the pump
Engine - moisture seperator- pump - pump outlet to atmosphere OR back to your inlet bell.

If you don't run it to your inlet bell (I wouldn't unless I had to for emissions or something) I would plug the port on the inlet bell.

It's not rocket science.

And since I'm sure someone is wondering; you retain the pcv in line even with a check valve because the PCV serves to limit the amount of air flow through the pcv hose. Without it you would have a very large vacuum leak, or, if your engine was well sealed, you'd pull the same amount of vacuum on your crankcase as what you see in your manifold which is more than likely too much.

PCV functions under vacuum to pull vacuum from the crank case. As you hit boost the pcv side seals and the pump kicks on so your crank case is always under vacuum.


Let me also add that you are always drawing unmetered air through your pcv. That's why there isn't just one generic pcv valve for all cars. The little pintle inside is weighted and sometimes sprung specifically for your application and is accounted for in the initial factory tune.

 

[1fastII]

Bumping this thread up for another non-Buick owner! I'm about to put this setup together in my Mustang SVO but I can't find a moisture separator with 3/4" inlet/outlets (both my crank vent and the inlet on the pump require me to use a big hose) that are less than $100. Where did you get your moisture separator? I like the 928 separator, but I'd rather not spend $145 (but I will if I have to).

 

[TURBOPOWERED68]

i am tired i just read this thing start to finish.
thanks for the write up dude.

and it seems that my engine is a candidate for this set up (165K miles) making good power and No leaking gaskets (knock on wood) put i always have a mess of oil on top of my valve covers. i did just replace the PCV with a new ACDelco one and i am also going to a check valve on it.

I recently added a second Driver side Valve cover replacing the passenger side cover and was going to put two straight up breathers. But this system seems like a better idea.

Sorry for the stupid questions.
is it better to pipe off of the two valve cover breathers?
or just one?

What application pump do i look for?
years?
makes?
models?
engines?

thanks

 

[siguy]

hey guys i am new here but got my idea to run a Lt1 smog pump on my supercharged lt1 ... i tossed my stock smog pump years ago (yea stupid move) and recently bought one from a 94 corvette stupid me thought they are all the same or at least similar mistake number two... ok all that said can i use something like this or should i toss it and just pick up a lt1 style pump

check out the pictures and let me know what you think thx

 

[1fastII]

LOL! It's an electric turbo!

 

[siguy]

LOL! It's an electric turbo!

lol yea i know i did not realize this when i bought it because the intake was covered

 

[KEVINS]

I'm bring this thread back up from the dead.

I did this mod and it has been working perfect up to around 26psi of boost. No oil leaks at all. LOVE IT!

But once I start pushing it beyond this I get slight amount of leaking from somewhere but I haven't had the time to search for it.

For this mod I have my PCV vented into air only which isn't good for around town driving but I rarely drive it anyway and that's only a couple miles at a time so it's been fine so far. But since I want to run 28-30psi of boost I'm thinking about installing a second electric pump and just keep it running at all times while I'm driving to replace the PCV valve altogether. Then under boost both motors will be running.

Has anyone had any of the motors burn up from running them all the time? Are they made to run all the time or only occasionally?

thnx
KS

 

[Racetronix]

I'm bring this thread back up from the dead.

I did this mod and it has been working perfect up to around 26psi of boost. No oil leaks at all. LOVE IT!

But once I start pushing it beyond this I get slight amount of leaking from somewhere but I haven't had the time to search for it.

For this mod I have my PCV vented into air only which isn't good for around town driving but I rarely drive it anyway and that's only a couple miles at a time so it's been fine so far. But since I want to run 28-30psi of boost I'm thinking about installing a second electric pump and just keep it running at all times while I'm driving to replace the PCV valve altogether. Then under boost both motors will be running.

Has anyone had any of the motors burn up from running them all the time? Are they made to run all the time or only occasionally?

thnx
KS

Continuous duty would burn them out.

 

[KEVINS]

How are they designed to work on the GM cars that they come standard on?
What activates them if they are not running all the time?

KS

 

[ttypewhite]

Mine is set to run off of a hobb switch. I still run a PCV valve with a one way check valve on it. I have had my pump for years now and still running strong. Get yourself a Racetronix harness with the hobb switch and call it a day. 2 pumps are overkill. I only run one.

Link is below

http://www.racetronix.biz/customkititems.asp?kc=CEPH&eq=

Just a fyi, my pump has been in the car running flawlessly for 7 years now, going 8 in the Spring.

 

[KEVINS]

Mine is set to run off of a hobb switch. I still run a PCV valve with a one way check valve on it. I have had my pump for years now and still running strong. Get yourself a Racetronix harness with the hobb switch and call it a day. 2 pumps are overkill. I only run one.

Link is below

http://www.racetronix.biz/customkititems.asp?kc=CEPH&eq=

I already have one but over 26psi I still get some minor leaks so I already know that one pump is not enough for my application.

My motor is still stock with 86k miles on it so the rings are not sealed as good as a fresh motor so I don't expect one pump to keep up with the blowby so I will run two for the higher boost levels.

ks