madsteez

I have gone through like 10 pages of google and still can not get it straight.
How do you install a catch can,do you just run a hose from the back of the block,to the can insert,and then run a hose to intake manifold?

It seems really easy but the things being said in other diy installs is crazy.

So any input is well appreciated.thanks.

Fabrik8

An oil catch can I'm assuming?

With most engines the catch can goes inline between the crankcase vent (PCV often) and the intake manifold, or the intake itself depending on the car.
Usually it's just a matter of removing the short hose from the PCV to the manifold, replacing that with a longer hose to go to the catch can, and then adding another hose to go from the catch can to the intake manfold. So you've basically replaced the short hose with two long hoses connected by a catch can..

Google this: "oil catch can install".


Now for the "Don't spread misinformation from the internet" segment of my lecture:

I saw a number of installs that added steel wool to the catch can if it isn't baffled. All the installs claimed it was to "filter the oil vapors". It's actually to act as a baffle so the oil in the tank won't slosh around and get sucked into the hose ports. There is no reason to do this on a baffled catch can, because it's (obviously) already baffled. We put special fuel proof open cell foam in our race car fuel tanks for the same reason (to keep the fuel from sloshing and causing pump scavenging problems, but same idea). There will be a little help from the steel wool with getting the oil vapor out of the gases moving through the catch can, but it's still primarily for baffling.

madsteez

Thats what i was assuming,so it basically replaces the pcv with the catch can.Ive googled that several times but different websites would word it differently.

Fabrik8

No, not replaces, unless you remove the PCV. The PCV is still in there, you're just replacing the tubing to connect it to the manifold. You could replace the PCV, which is sometimes hard on some cars, but it won't necessarily net anything but less restriction in the tube. It's also technically illegal to remove the PCV, as it's an emissions device, but that's up to you. It won't really have any benefit to removing it is what I'm trying to say, and if I remember correctly the block side of the PCV has an O-ring seat, so if you discard the PCV you'll have to make a fitting that replaces that O-ring seat. All of the tube fittings you need are already there with the PCV in place, so keep it and it's a really easy install.

Oh, it's sometimes possible to have idle problems with the PCV removed too..

madsteez

OK now does it act as a filter for the pcv?Cause ive started to see oil build up in my pcv and hoses.Is the catch can there to prevent the built up?

Fabrik8

Yes, exactly. The oil is getting into you intake, which is what the catch can is designed to stop. And again, the steel wool will help a little bit..

dallasb84

on my ls there was a small catch can under the intake manifold.... which the pvc connects too....

my question is.....

if you install a catch can what do you do with the factory one... plug it up???? it would seem to be kinda stupid to route the pvc valve to a catch can and leave the factory one open venting to atmosphere...


on my turbo da i never had a catch can so its something i never thought aboot....


sorry to hijak

Fabrik8

I don't know that much about the specifics of stock LS stuff, but I'd check to see if that is a catch can or a charcoal filter. If it's a catch can, the aftermarket unit will directly replace it, and you can remove the stock one. Honestly though, if there is a stock one already, just keep an eye on the oil level in it and don't bother putting an aftermarket one in it's place. The only thing you'll gain by replacing it is more capacity, which you may or may not even need.

dallasb84

i believe its a charcoal guy

93turboeg

http://www.c-speedracing.com/howto/c...n/catchcan.php