Hey everybody,
My name is Curtis, I'm from Saskatchewan, Canada
I'm new to the forum and I have a couple of what I think will be easy questions for you all.

I have a 1986 Camaro Z28 with a 305 engine.
I've always loved cars and I figured it was time I got myself a project that will teach me more about car engines and so on.

Here's my questions.



In the pictures above I have a couple things marked off and numbered.
Item 1. Can sombody tell me what these flaps are for and when are they supposed to open. I know about reving up the engine from under the hood and when I do that, even when revving it pretty high, These flaps do no open. Should they be opening? and if they are supposed to be but aren't, What do I do?

Item 2. What is this thing and what do I do with it when I put on a chrome air cleaner that I already have waiting to go on the car? (I've done my reading on the open aircleaner and the pro's and con's of it and I have decided to go with one)



In the picture above I have something circled, It's not even hooked up to the thing in the aircleaner very good. Just a loose piece of hose holding the thing in the aircleaner to this metal pipe.
What do i do with this thing when i install my open air aircleaner?
I've seen in some pictures that some people have some small thing plugged into the valve cover and they no longer have this metal hose going to their air cleaner.


If anybody could take the time to answer these questions it would be very much appreciated.

Thanks guys.

Curtis.

 

That's the secondary air valve. They don't open when you just blip the throttle. They'll open when the demand for air through the secondaries overcomes the spring tension holding them closed.

That's the fresh air source for the PCV system. Some open element air cleaners have a provision for it on the bottom, some people just replace it with a breather filter plugged into the valve cover.

 

Welcome to ThirdGen.Org!

Im glad you chose an F-body to learn on.

The #1 pic.
Those are the "choke plates" on a 4bbl carbuerator.
(thanks Apeiron, haha)

#2 picture.. Im not quite sure, Im a TPI guy..
Someone should chime in on that question.

The tube you circled is part of your PCV system.
(Positive Crankcase Ventilation, PCV) It can be removed
and replaced with a open-air element filter for the valve
cover. I wouldnt tear it off.. until you run a cold air
induction setup with a new filter element.

Looks like a nice car, Best of luck!

**Disregard, as ApeIron beat me to the punch!

 

Those aren't the throttle blades. The throttle blades are in the base of the carb. The flap over the primaries is the choke plate.
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I missed this one. That's the TVS for the Thermac system. An open element air cleaner doesn't have a Thermac valve, so it won't be needed anymore.

 

Thanks a Ton guys, for the welcom and the info. Can't believe how quick I got replies on this.
Figured this would be easy stuff for you guys.

Ok,
So those flaps over my other 2 barrells absolutetly will not open just by "Blipping" the throttle right?
So there is no realy way to make sure that they are working?

- I can get a "open air elemement filter" to replace that metal pipe, AFTER I put on the open air aircleaner.

APERION,
You said:
"I missed this one. That's the TVS for the Thermac system. An open element air cleaner doesn't have a Thermac valve, so it won't be needed anymore."

So what do I do with the hoses (comming from the Carb) that are sucking in air that go to that piece that I will no longer need?

 

Right

No, but they're such a simple thing that there's not much that can go wrong with them. If the air valve didn't open, your car would be a complete dog at WOT.

It'll actually be called a PCV breather. Or, if your new air cleaner has a provision for it, you can run a hose to it.

You'll have to plug the unused port on the carb.

 

Thanks Again

I find that If I unhook even one of those hoses (there are 2 going to it) and plug it with my finger that my engine seems to have a harder time running....

 

----------

I was close, hahaha

Thanks for the clarification

I dont know what I was thinking, completely
forgot they are at the bottom of the unit.

"Think before you speak/type" ...hehe

 

It's actually very easy to tell if your secondaries are working. When you floor the gas, and you hear the pitch of the engine change to a nice, low roar, that means your secondaries just opened up. That's why I've always called the Quadrajet carbs "Quadraflush" instead. Lol. When you open up the secondaries, it's like flushing the toilet, especially when you see that your gas gauge never quite recovers all the way afterwards. When it comes to plugging your unused vacuum ports, the easiest way to do it is to leave the unused hose connected to the port on the carb and find a bolt or screw that screws firmly into the other end of the hose. That'll prevent you from having vacuum leaks, which will make your motor run erratic. You can also go to just about any parts store, look in the "help" section, and buy an assortment of vaccum line plugs. That's the cleaner way of doing it, but a bolt or screw in the end of the hose always does the job in a pinch.

 

Thanks for the Info. You guys sure are Great here. Hopefully one day I can learn enough to help out other as well.

One problem with plugging those Vaccuum lines, When I inplugged one of those lines and plugged it with my finger the engine didn't seem to like that very much and it sounded like it was working way harder and the idle dropped, Any idea why this is?

 

Don't worry about it. You might need to do some minor adjustments on the carb, but leaving the vacuum port open is certainly the wrong thing to do.

I'm more of a fan of dual snorkel air cleaners than open element. The single is certainly restrictive, but the thermovac system helps prevent a wicked dead spot when the engine isn't quite warmed up, and an open element will suck in hot engine air that cuts power and can really make life "interesting" when in stop & go traffic in hot weather. Been there, done that; have a dual snorkel that I've been running for years and wouldn't trade it for any open element.

 

Thanks,
I wouldn't leave the Vacuum port open as I can see how it could potentially suck in bad things.
I'm sure it would be easy to drill two holes in a open-air aircleaner to mount that TVS, or is that not recommended?

I obviously don't know anything about carb adjustments but I will check out the autowreckers around here to see if maybe by chance I can find a dual snorkel aircleaner for cheap.

 

There'd be no point. It's there to control the opening of the Thermac valve in the snorkel that five7kid mentions, but an open air cleaner doesn't have a snorkel or a Thermac valve to control.

 

Gotcha,
Thanks.

When I tried plugging just one of those hoses going to TVS I still had the other hose hooked to the TVS so maybe that is why the engine was bogging.

Thanks again guys. Much appreciated.