First, I just want to express my sincere thanks and gratitude to all the helpful folks on C3VR! I find it VERY informative to see the issues others are having and read all the responses...

Second, I want to replace the dual snorkel air cleaner housing on my '79 L48 with an open element setup. However, the factory air cleaner includes a fitting for the PCV from the passenger side valve cover. I am not clear how to route the PCV with a new air cleaner. Do I simply drill a hole and install some kind of fitting so I can attach the hose from the valve cover? One person told me to re-route the PCV to either a carburetor or manifold vacuum port, rather than the air cleaner housing. Are all vacuum ports the same so I could just pick one and fabricate a connection?

Also, some folks have told me to be careful with the aftermarket air cleaners as they do not always correctly work with the Q-Jet; they fit too tightly and block some arm which prevents the throttle plates from opening fully.

Anyway, I appreciate any help anyone can offer!
Thanks!

The PCV hose to the air cleaner is a filtered air intake for the engine crankcase. The flow out of the engine goes through the PCV valve. All you need is filtered air. You can install a filter in the new housing, or you can go to a speed shop and get a filter that plugs into the grommet where the hose goes into the valve cover. Just pull out the hose and pop it in. Of course it has to be the correct size. These can be chrome and very attractive in the valve cover.

If you push the secondary air flap open you will see a lever or arm raise up in between the two large flaps. This raises the needle valves for the secondaries. Just make sure it can raise up all of the way with you air filter. Most designs are not a problem, it doesn't like that far.

Just keep in mind you may need to do some choke adjustments. With the present setting it depends on the hot air into the snorkle for cold operation. An open design can create a cold hesitation or bog. It may not, but often does. Just richening up the choke a bit will usually cure it.
Ken Styer

|UPDATED|3/11/2004 9:47:53 AM (AZT)|/UPDATED|

Why would you want to replace your dual snorkel cold air induction with an open style air cleaner that will be sucking in hot underhood air? Performance will suffer.

My thought exactly. Every bit of air your carb breathes will have been preheated by the 200 degree radiator since that will be the only source of fresh air. There's a reason GM went to enclosed air cleaners, ducting, and even cowl induction!

Guys, from reading your previous posts, it is obvious that you are way more knowledgeable than me. I understand the theory behind what you are saying, but let me explain my experience with this situation. I was working on my 79 L82 one Saturday and had to take off the ducts to the snorkles. They were in the way for whatever I was doing. Before I got too involved I had to run out. I jumped in my car, without replacing the ducts, and took off. The increase in power was dramatic, even after the engine warmed up. So much so that I have not replaced them. The only reason I can come up with that explains this is that the ducts and collector(?) resistricted the air flow to such an extent that the negative effect was greater than that of the hot air. Hot air is better than no air. Does this make any sense to you? If I could route the ducts to allow greater air flow, I would. My gut feeling is that the collector is inadequate to supply enough air. It sits on top of the radiator. It's a narrow housing with an opening of about 1"-1.5" high and about 24" wide. Do you have any thoughts on this? Thanks.
Hank

Do your snorkels have a vacuum operated damper that ports preheated air from the exhaust manifold? Might check to see that they aren't stuck shut or otherwise causing a restriction when the engine is fully warmed up as they should be fully open by then. That is if it has them.

Good luck. Open element looks good, especially with chrome lid.

Marc

The open element air cleaner on "The Toy's" 350 has a port on the bottom of it where the hose from the valve cover connects.