I had a 1988 305 TPI/ lb9 with the P1SC. Procharger say- snip the PCV line, vent to atmosphere and vent the other valve cover to atmosphere. Job done.
But I liked the idea of keeping the PCV operational, at least at idle and non-WOT drives. So, following great advice did this-

PCV>Catch Can>One way check valve> vacuum source on the plenum.
Passenger side VC- open breather/ filter

Remember I cant run clean air from the throttle body as it would pressurise the crank- so the filter is a vacuum leak that the MAF hasn't allowed for. The car ran great like this for many miles.

Now I have a forged 355 with new/ different valve covers from an 82 Vette. For the first 1000 miles I was using 1 quart every 100 miles. I thought it could be the rings seating or just the general running in of a new motor- but it never got better. I was getting a puff of smoke on startup, so for a while I thought valve stems in my new AFR heads! Every so often when I went WOT there would be a definite cloud of oil smoke- really quite bad- but the car ran really well.

Then I thought maybe it was the PCV. I simply plugged the plenum vacuum source and vented to atmosphere and voila- no more oil consumption! It appears that the new valve covers are not baffled and the PCV was just taking the oil from the rocker it sits over and shoving it down the plenum and into the combustion process!

So currently it is PCV>atmosphere on the drivers side and open vent passengers. It makes a bit of mess under boost but no oil out the mufflers! Happy to be at this stage!
Here is my question, Do I-

1/ Keep it as it is?
2/ Run the PCV>catch can> to atmosphere, saving a bit off mess under the hood and maybe using a 2nd catch can for the breather
3/ Get PCV working again as it was but this time I will have to somehow baffle the valve covers. You can buy external baffles as well like https://www.summitracing.com/parts/nal-88962074

What are your thoughts everyone? Love to get your advice

I also noticed the idle is a bit richer without PCV operational / vacuum. Makes sense.

 

Despite what some may say i would just vent both covers to a catch can and live with it. Ive done this on all my boosted engines. I change oil somewhat often however especially on the more racey stuff.

you can try to configure it with baffles again and check valves. You can try air oil separators. Some ppl run the fresh air line to the supercharger air intake side. But not sure how much vacuum is there. Or to throttle body with another one way valve. Up to you if you want to go thru the work and money

 

Thanks, I will change my oil every 2/3k or annually anyway so should be good. The catch cans, as you suggest, just prevent mess really and that's definitely a goal here.

 

Ironically, I'm at this stage as well. I was thinking of capping the factory 3/8 vent nipple and pcv on the LS valve covers and tig welding some 1/2" nipples to my motion catch can and just calling it a day. That's acceptable?

Right now my passenger cover has a 3/8" vent nipple to atmosphere, and when under boost I get stinky oil mist / smoke out of it.

 

I mean alot of guys do it. Crankcase pressure can def be high, sometimes even vacuum pumps dont pull much on FI engines. So idk what a pcv valve is gonna do. They arent real big and idk how much they can flow with something with a good bit of crankcase pressure/flow. Its only good for cruising and to me a well tuned car with oil changes wont need one. A good size vent line and catch can with breathers helps. Bad ring seal or a leak into crankcase will result in alot more air and oil goin to the cans and can spit out the breather occasionally.

 

I'd probably go a little bigger on those nipples to get at minimum -10an line off each cover. That little bit of smoke is normal.

I currently run -12an lines off each cover to a single catch can and I also get a little bit of smoke but no oil mist and pretty much nothing is in my catch can

 

Which can are you running? This one has two 3/8" NPT ports. Typically 3/8 NPT has about the same ID as -6.

You guys concur to just run both valve covers into a can with a filter and call it a day, don't bother with a vac source ?

I had bought a GM vac pump (from like a 09+) but it's loud AF.

 

I'm running a cheap eBay can that has 2 -12an fittings and a filter top. I'm using Motion Raceworks bolt on valve cover breathers with a line from each cover to the can. Nice and simple and no issues @ 20 psi

 

Would that not mean the engine is breathing in the toxic nonsense from the can? Better to have clean air through one and separate one for the other VC?

 

This is the question and so far, majority suggests 'Yes'/ Let's see

 

No it's not breathing anything from the can. Air is being pushed thru the piping into the motor. If the BOV is open air is pushed out there's no vacuum

 

I've vented both sides to atmos. Smoke through PCV has gone, which is excellent.

I'm getting a few oil drips if I leave the car sitting after a run. Anyone else that vents- how much oil do you get?

 

I was having the same issue so I basically did the same vent to atmo but I do really like the might mouse can that uses the pcv but vents when in boost it’s just to big to fit under my hood and we wouldn’t do a custom one for me.

 

You can piece stuff together as you like on his website.

 

yes I know you can piece his parts but the canister itself just isn’t small enough to fit under my hood, I asked him if he could make me like a 3” by 6” but no luck.

This is what I’m working with, this was like two years ago so it’s a little different now, I did a custom 4” can that I had a friend fabricate, and yes I know it’s a lot of sh*t under the hood.

 

I recently installed a Vortech V3-Si on my 305TPI using the universal SBC kit (I had to modify the supercharger mounting brackets to fit it under the stock hood). I've had no issues with oil consumption through the PCV and I'm running a very simple setup.

• I removed the breather tube/hose that went from the throttle-body to the passenger valve cover; installed a K&N filter
• Cut the PCV valve hose that went to the intake manifold and spliced in a check valve. The check valve is pointed towards the intake manifold. This is so that the supercharger cannot pressurize the crankcase, but only pull crankcase gases back into the manifold. I am using the stock 89 valve covers that have the built-in oil baffle. It seems to work well.

I am currently only running 4 PSI with the included kit and my intercooler piping. I'm looking to go from a 6" crank pulley to a 7"/7.8" crank pulley (keeping the 3.33" supercharger pulley) to bring the boost up a bit.

 

You can't hide that canister in front of the radiator and run your lines??

 

I think the key is 'stock valve covers' mine were butchered L82 Vette covers. Butchered meaning just the baffles.

 

I wish, so left side up under the bumper is my engine oil cooler with fan, left side is trans cooler with fan, front has my 3gal water tank with electric pump for my water to air heat exchangers, heat exchanger radiator in front of the condenser oh and my receiver drier for my custom a/c setup.

 

The factory PCV valve already does that, if you remove the stock valve from the grommet and blow into it you will feel the restriction. Adding an additional check valve in front of it won't hurt, of course. How do your brakes feel immediately after boost? Consider splicing and installing a similar check valve into the brake booster's vacuum line to the plenum because the fitting on the booster is very weak, I've had a few bust on me...

- Rob

 

Not trying to hijack ZZ42 thread but I agree with street lethal the stock pcv valve is a check valve so technically in boost it should not be pressurizing the crank case via pcv line and a stock motor with stock ring gaps with only 4psi I wouldn’t expect you to have too much blow by, with my setup I’m at about .030 cause I was planning on running like 30+ boost but when I started off with 15 I was like oh sh*t this is too much for this car so keep it between 7 to 10, okay sometimes like 12 if I want to scare myself, anyway I attribute my blow by because of the ring gaps.

 

i Ran 14psi out of a procharger D1SC on my stock cast lb9 that i rebuilt for years. i used the factory PCV and an open breather on the passenger valve cover.

 

Good to know in regards to the brake booster check valve... I'm still running the stock brakes (which have a lot to be desired) and haven't had any issues thus far. Adding a check valve into the booster line isn't a bad idea.

I'm aware that the factory PCV valve is a check valve, but I've read mixed information on the pressure rating of the stock PCV. This was the reason I added the additional check valve. Does it need it? Maybe not. Does it hurt anything having it? Not at all.

I did have a lot of oil consumption issues before replacing my intake gaskets and valve seals. As in it would smoke a good amount at idle (worse at WOT). I contributed this to the lack of miles on the car as it likely sat for a while and dried out all of the seals.