Help! 1981 pcv vacum from valve cover to ???

[samm]

Hello I have a 1981 small block modified with 750 CFM Four Barrel Race Carburetor but vacum hose from valve cover was not plugged.It just had pcv valve but no hose and the oil is slowly squirting everywhere making a mess.A corvette shop in montreal told me my carb is to big and to get a Demon carburetor 6282010VE Road Demon Jr. 625 cfm carburetor with electric choke and vacuum secondaries.Is this really the case or is he just trying to make a buck off of me? although it does run rich(dark smoke) when i drop the hammer....any help would be appreciated,I'm still waiting on my shop manual but dont know if it will help cause original pcv hose goes from valve cover to air filter housing.......I will try to get some clear pictures of modified engine posted(dont know if it will help).....thnks in advance

 

[bill81vette]

It goes into the side of the air cleaner..

 

[TimAT]

Samm, I think your shop is trying to seperate you from your wallet. I ran a 750 on a modded 350 for years with no problems. It was a little soft (low torque) off the stoplite, but made up for it in the mid and high RPM performance. Your dark smoke when you jump on it is 100% a tuning issue. maybe a different accelerator pump shot, power valve change or different jets.

Your PCV system is a pretty easy fix- there should be a hose from the base of the carb to the front of the left rocker cover with the PCV valve going into a grommet in the cover. On the right cover, at toward the rear, there is another grommet that has a simple tube going to the air cleaner and a small filter inside the base. If you don't have the tube to the air cleaner, you can get a push-in breather that will do just fine. You can see the tube in Bill's picture.

 

[Vettehead Mikey]

Samm,

Tell Paul (I'm guessing it's Paul) to get his hand out of your pocket. Your stock carb was 750cfm so yours is not too big, it sounds like it's incorrectly set up though.

This issue is unrelated to your PCV problems.

 

[gmjunkie]

It goes into the side of the air cleaner..

Thats not the PCV valve,it's the breather for the crank case, the pcv valve should be hooked on a big port somewhere under the carburetor!

 

[samm]

Can anyone point it out in this picture.

 

[samm]

??

The rear hose goes to booster.The front goes to tranny.Is there somewhere else and i cant connect to air filter.(I dont think so)

 

[gmjunkie]

Can anyone point it out in this picture.

Yeah,it the big one in the back where the brake booster is,you'll need to get a 2 port fitting!!

 

[samm]

But everyone is saying (Not) to connect with the brake booster.

I just dont want those embarrising oil stains that come from valve covers breathers.or the pcv that was not connected to any vaccum.

 

[gmjunkie]

But everyone is saying (Not) to connect with the brake booster.

I just dont want those embarrising oil stains that come from valve covers breathers.or the pcv that was not connected to any vaccum.

As long as the fitting is large enough to get enough vacuum volume to both of them it shouldn't matter as long as the booster has a working check valve!!Ford,Chrysler,and GM have been doing it for years on some models!
You might look and see if there is a plugged vacuum port in the rear intake runners,some aftermarket manifolds do have extras plugged!!!

 

[samm]

???

Could my real problem with oil getting out of breathers be i have no baffles under the valve covers ?