CHADisBAD

i know this subject has been beat to death in different threads in the past, but are most of you guys venting your PCV lines to a catch can and then venting the can to the the atmosphere, or are you returning it to your throttle body?

i do not have emissions checks were im located, so im gauging the idea of just putting a breather on my catch can, and capping off the return in the throttle body

CHADisBAD

Anyone? Thoughts/opinions?

sircl55amg

no return for me...all to atmosphere. so far so good

cij911

I run the the lines to catch cans and then back to the throttle body...(I would not recommend venting to atmosphere for a variety of reasons, none of which are emission related...)

You want vacuum to help relieve the pressure...If you really want to gain some hp, you can actually vent the oil fill cap to the exhaust, but only if you are not running cats...

CHADisBAD

What are some of the other reason you choose not to vent to the atmosphere?

cij911

Chad - I am really sorry, but I don't want this to get into yet another "I know more about cars than you" thread...

Some people vent to atmosphere and others use vacuum to help relieve pressure (and gain hp). If you look into what some of the pros do, you may learn a few tricks - google crankcase vacuum pumps. Here is a good link: http://www.dragstuff.com/techarticles/vacuum-pumps.html

It really depends on what your goals are : (1) looks, (2) performance, (3) solving a problem. I generally focus on (2) & (3) and use catch cans in all of my street cars (often saikou michi brand) and run back to the intake. For a street car, the other issue could be spraying a fine film of oil all over the engine bay, so if you do vent to atmosphere make sure you use a catch can (like dc3). On my e55, I just used two fuel filters (connected to the stock lines) and then routed back to the intake. I drive the car a fair bit in vacuum (not WOT all the time) and find the filters to catch a decent amount of oil. For race cars, it is different and depending on the rules, often use vacuum pumps, exhaust, or similar. Good luck

Hulk

This explains a bit more although it's a diff car

http://media.wix.com/ugd/dddf24_90f7...6e93194093.pdf

Shifter

For those with a larger TB, where do you connect back to the intake at? My 80 does not have the nipple the stock TB does.

CHADisBAD

Thanks for the info guys.

AgSilver

This is a very well made unit that is small enough to fit between the firewall and the engine shroud (next to the aux battery). My TB is bone dry.

http://www.customcorvetteaccessories...lcatchcan.html

Hulk

If you don't have a hole on your tb like the stock mb tb then you need to have a catch can with a breather I think or you can make a fitting in your intake

Exotic-metal55

It is more than just to vent or not to vent, it is to have extra crank case pressure or not. Our crankcase lines pull vacuum on the crank, and reduces pressures on the pistons as they travel , among other things. If you notice on the V12`s, thay have a pump to actually create large amounts of vacuum on the crank case and one reason many race cars also use vacuum pumps to reduce this pressue. This is even more important on boosted engines. Removing crankcase vacuum, can alow for more oil to be pushed into the oil catch can by distrupting the crankcase vacuum. Just something to look at and research before you go back to late 60`s muscle car catch can technology

Hulk

Do you have a vacuum pump on your car?