tbi pcv and breather caps? need some schoolin' plz

[Swims350]

Ok I just got some new chrome valve covers for my 88 k1500, it's got tbi, well stock the DS VC has the oil fill cap, and a tube that goes to the spacer ring under the air cleaner, called a fresh air tube I think. PS has the pcv only. Ok new VC's got 2 holes in one and 1 hole in the other, just as it should but 1.25 holes or 1-1/4, still not a problem since I can get the grommets. Ok some say not to run a breather style cap with pcv system, I can understand that i guess, says it makes it not do it's job as good cuz it bring out or puts out the fresh air. I think it would bring it in cuz it sucks, but others I read online were talking other junk. Well I assumed the fresh air tube going to the tbi spacer ring sucked air into the air cleaner and burnt fumes or whatever. They were saying it pushed fresh air thru the VC's and out the pcv? How the crap does that happen is what I'm thinking, but maybe I'm wrong.

So to avoid any screw ups unless somebody can convince me or edumacate me in this crap, this is what I'm thinking of and hope it works...

getting a push in cap pcv, for the PS VC and work pcv as normal, this..

http://www.amazon.com/Spectre-4284-..._8?s=automotive&ie=UTF8&qid=1294286474&sr=1-8

Now that one has the ball thing for the pcv in it. So it should work just like a reg. pcv I'd hope and guess.

Now for the other hole, the tube for the spacer ring,
http://www.amazon.com/Spectre-4279-..._2?s=automotive&ie=UTF8&qid=1294286474&sr=1-2

now that looks to me like the only way in and out for air or fumes would be up the bottom and out the tube/nipple since it doesn't have holes, like this one..

http://www.amazon.com/Spectre-4300-..._5?s=automotive&ie=UTF8&qid=1294286474&sr=1-5

That way it's not a breather, or I'd think. SO with those I'd think it'd be just like stock, a pcv path to a port in front of the tbi and the other w/o pcv would be a direct path for whatever to flow in/out to the spacer ring and VC.

The other part will just be my push in oil fill cap.
http://www.amazon.com/Spectre-1738-..._2?s=automotive&ie=UTF8&qid=1294286818&sr=1-2

the valve covers..

http://www.amazon.com/Spectre-5260-..._2?s=automotive&ie=UTF8&qid=1294286847&sr=1-2

Then of course those caps, the pcv one and non pcv no holy underside one, one says 3/4 and one says 1 inch, and the grommets I was going to get have one of each, and the oil fill cap has it's own made on it.

So should those 2 caps work like I'm thinking? I mean they don't take in or let out air/fumes any other way without having other holes, and they don't(other then the pcv one) have like a one way valve or something? I just want some other opinions on this before I order the caps and fill plug, bolts etc.

 

[GreaseDog]

not real sure where you're going with that, and your choices are a little confusing.

you need a PCV in one cover, and a breather in the other. the PCV will suck the crankcase fumes into the intake and burn them, creating a slight vacuum in the crankcase, where the breather filters new air coming into the engine.

 

[Swims350]

ya just disregaurd that, they had the info screwed up and I get confused easy.

I was going to do the pcv cap in the PS, it looks like a reg. breather cap but has a replaceable pcv in it. Then on the back one I was gonna use a breather cap with no holes but a nipple to hook a hose to. The one that goes to the tbi spacer ring.

I think now I'll just get a reg. breather, loose the air hose that goes to the tbi ring, loose the ring all together unless I need it for a spacer, and then put my pcv back in the ps like stock and be done.

 

[Swims350]

one other thing though, it'd be kinda stupid to just use 2 breather caps in the DS valve cover? Reason: the oill fill cap is $5 and the breather is only $3. It would save a couple bucks but I think it would be kinda pointless or maybe I dunno just dumb? harmful? no real reason all that only then being cheaper.

 

[89Suburban]

one other thing though, it'd be kinda stupid to just use 2 breather caps in the DS valve cover? Reason: the oill fill cap is $5 and the breather is only $3. It would save a couple bucks but I think it would be kinda pointless or maybe I dunno just dumb? harmful? no real reason all that only then being cheaper.

Well, then you are dropping the vacuum and intake point for the motor. Figure the oil cap is solid and doesn;t vent. And the breather is filtered vent. What i mean is, I would stick wit just one nreather and one cap, just to keep things in balance, IMO.

 

[Swims350]

yea I was thinking that and plus it'd look funny.

 

[89Suburban]

yea I was thinking that and plus it'd look funny.

................

 

[skysurfer]

When I did the salad bowl mod I eliminated the tube that runs from the ds valve cover to the choke collar. I put an open breather in the valve cover (no hose) thinking it would draw fresh air in on that side because the opposite cover has the pcv valve connected to manifold vacuum. In my mind it would be in-on-one-side-out-on-the-other.

In reality, what happened was at high rpm's I was building crankcase pressure and it started forcing oil out the dipstick tube. I went back and added a tube to the salad bowl to mimick the stock setup, threw away the breather cap, and all was good.

The hose necessary to prevent crankcase pressure is under the right-side snorkel.

 

[89Suburban]

Not trying to make you repeat yourself, I musta missed it, but what is the salad bowl mod and what does it do? Like help with intake flow?

 

[skysurfer]

Yes. The choke collar and stock air cleaner setup is pretty restrictive. I don't have any before shots, maybe you could post a pic of your stock setup for comparison since we have the same trucks.

 

[89Suburban]

So you remove the stock collar? Wil the air cleaner still fit on the TB? Holy smokes. Please teach me. I will get a pic when I can. It's a stock single intake snorkel.

 

[skysurfer]

I made it so the bowl is the same finished height as the choke collar so the air cleaner still sits the same as original. The second snorkel was added by cutting up a donor air cleaner off ebay for ten bucks. The bowl was from the .99 cent store, and the tube adapter was from the hardware store. Total cost was less than $14.00.

 

[89Suburban]

Oh, so the air cleaner sit's on top of the bowl, no ****? Cool mod man. How did you cut the bowl to the right size at the bottom and keep it square/level?

 

[Swims350]

usually an angle grinder. It's pretty common on tbi's I think it's one of the ultimate tbi mods. That's what I was worried about though was it doing something it should not but I figured a breather cap would work too. Maybe not lol.

 

[89Suburban]

usually an angle grinder. It's pretty common on tbi's I think it's one of the ultimate tbi mods. That's what I was worried about though was it doing something it should not but I figured a breather cap would work too. Maybe not lol.

I can;t believe I never heard of that. Does it make a noticeable difference? Does it help mileage?