When I searched the forum, a lot of guys were discussing ways to route PCV to compressor intake. I want to have my pcv routed to theexhaust before the cat. Will this cause my cat to fail, or will any oil vapor that remains after going through the catch can burn up either in the exhaust stream or once it hits the cat?

Also, what check valve are people using for the exhaust? Where can i get one? Thanks

 

anybody?

 

you can go to the parts store and ask for a Ford style check valve, just pick an early 80's Ford app with an air pump, one word of caution though, the threads on the valve might be odd ball.

 

cool thanks. I'll see if i can weld it or something if it doesn't want to fit. Thanks again!!

 

keep us updated, ive been contemplating doing the same setup for a while now. I was thinking about just drilling a hole into the downdown pipe, weld in a slash cut tube at an angle, connect some high temp tubing w/ a check valve inline... what do you think?

 

that's what I'm planning. there's a local shop that has a racecar (civic) set up like that. I asked him whether or not it would affect the cat and he said that the cat would just burn up whatever ended up going there... I just hope it doesn't coat the cat right away. Its brand new and I need to pass emissions...

 

http://www.moroso.com/catalog/...13023
Sell half of it to friend.
glenn

 

I think I've got a new solution for people looking for PCV E-vac check valves.

http://www.circle-seal.com

Look at the 800 and 8500/8800 series of check valves.
- http://www.circle-seal.com/pdf...s.pdf
- http://www.circle-seal.com/pdf/800_series.pdf

I'm still undecided as to which one to get until I talk to a local distributor.
The literature says that the 8800-series is the same as the 800-series with the exception that the 8800-series are slightly reduced in weight (see specs in .pdf's above for each). The weight reduction difference isn't much.

The biggest worry I have is the maximum operating temperature thresholds of the check valves since they weren't originally designed for exhaust temps.
The 8500/8800-series offers a teflon o-ring that is rated for temps up to 450 deg F and the 800-series silicone o-ring is only rated to 400 deg F. It might be a non-issue tho.

The other concern is cracking pressure, the amount of pressure required to open the valve.
In the specifications, the range of available cracking pressures is lower on the 800-series (as low as 2" H2O = .147" Hg). Even a standard cracking pressure of 8" H2O = .5884473" Hg isn't much in required pressure to open the valve.

The check valves are vibration-failure resistant, have zero-leakage to any reverse flow, and are full-flowing to minimize pressure drop across teh valve.

I also considered the 200-series, but the pressure drops were too large to be considered for PCV E-vac use.

Both are offered in a wide range of pipe, hose, and tube (w/ and w/o flare) ends to facilitate a wide variety of plumbing.

They're available in a small range of aluminum and stainless steel materials.

 

Nevermind that idea. I called Circle Seal and the pricing is rather high. We're talking around $200 for an 800-series (or 200-series) 3/4" check valve -12AN tube ends with Viton o-ring in T6 aluminum body, and then another +20% or so to specify a 2" H2O cracking pressure.

It's definitely not an affordable solution for everybody...even myself.

 

Yeah Im gonna do the exhaust set up w/45deg slash cut soon. Im just running hollowed out PVC dumped to ground and breather on valve cover. The car likes to puff white smoke at stop lights running like this. does anyone else have this problem too.

 

just wondering exactly why you'd wana run your pvc to your cat?(performance/tunning?) I worked for emissions in AZ and we checked all connections depending on the yr of the car. PVC and EVAP canister must follow OE specifications on the cars diagram.. Not sure if your state is the same but probably not, but if your putting it on a machine that usually read(NOX, CO, HC) etc .. it may increase your risk of failing(NOX/CO), even if the gases are burning in the cat. just .02

 

ive been running the slash cut for about 2 weeks now, right off the stock PVC valve. Today i went and looked at Fram pcv valves just to compare with the stock, and the Fram seems to have a larger inside diameter so i bought it. it seems to be working great, i pulled it off after a couple of hours that included some hard runs and some watery substance dribbled out as i pulled the tube off the PCV.

most deffinately not safe for emissions though.

 

I wouldn't use a PCV valve, they are pretty restrictive.

I made a setup on my 240 using a large 300ZX PCV valve and got absolutely no vacuum by the time the line reach my pressure gauge. Had I run that setup too long, it probably would have built up pressure up to the line and then caused issues with the PCV system.

Once I switched to an actual check valve (pulled the brake master cylinder valve off my totaled teg, idea from someone on this board and TOO) I am getting steady vacuum from idle to redline.

If you are really concerened, the moroso kit is like $60 and fits two cars. Thats $30 a person if you go in on it with someone.