no boost

[Radcat]

Originally posted by Mighty Thor:

With my stock TB, I usually don't blow my dipstick at 6-7 psi. But at 9 and over it does it.

I have been running 10psi and haven't drilled mine and have never blow my dipstick.

[Wicked 3800 V6]

Think about it -- the PCV is designed to vent out pressure out the valve instead of out the valve covers. The PCV vents only through that throttle body tube. By blocking the hole, you've forced the air to go out the valve covers (after going past the rings, etc). The idea behind the block / drill is to get the pressure outside of the boost side -- the tb tube lets out back into the boost area, and since boost can't enter boost, it backs up and blows the dipstick.

So you drill the TB to let boost enter normal air. The PCV is a check valve, so the hole in your tb is a bit of weight savings at other times.

The valve cover breather is just a nice add on to the whole setup above. The PCV is the workhorse of the venting, though. I'd be cautious about a block without a drill!

[blackFbird_98]

alright well ty guys and sorry for starting an
argument

[Teufel Hunden]

I didn't drill my TB either.... never have blown out the dipstick, and i've seen 15 psi on several occasions.

[Wicked 3800 V6]

No sweat blackFbird_98, I'm just feeling passionate tonight about a few grams of aluminum!

[grayman]

Originally posted by Wicked 3800 V6:
Think about it -- the PCV is designed to vent out pressure out the valve instead of out the valve covers. The PCV vents only through that throttle body tube. By blocking the hole, you've forced the air to go out the valve covers (after going past the rings, etc). The idea behind the block / drill is to get the pressure outside of the boost side -- the tb tube lets out back into the boost area, and since boost can't enter boost, it backs up and blows the dipstick.

So you drill the TB to let boost enter normal air. The PCV is a check valve, so the hole in your tb is a bit of weight savings at other times.

The valve cover breather is just a nice add on to the whole setup above. The PCV is the workhorse of the venting, though. I'd be cautious about a block without a drill!

Ok, here is where you are getting it wrong. The PCV pressure does not exit past the piston rings to escape. Once gases are blown (from compression or ignition of cylinder) into the crank case they vent from the PCV valve. Older cars have the PCV valve on the valve covers. Or even one breather on each valve cover. The inside of crankase has the crank, oil pan, etc. There are BIG oil channels and holes in the heads that mate with the block. This is where oil travels as well as positive PCV pressure. The two heads (valve covers) are not seperate from each other. The inside of crankcase is open to either side...head...valve cover.

From reading this quoted post it sounds like you think the inside of the crank case is 'locked down'....but it is not. Oil and gaseous build up can travel from side to side...and will exit from the point of least resistance...in my case a valve cover breather on the passenger side. If our stock PCV valve can release crankcase gases from EITHER side of engine....so to can a breather on one valve cover vent the gases for the entire engine. There is no double blow by through the piston rings. Just gases getting in the oil pan and then exiting up through either side...wherever the vent hole is. Further, If there was PVC gases blowing back through the piston rings that gas would then be UNDER the cylinder head combustion chamber. It would then exit through the A) exhaust valve or B) get stuck inside cylinder and reburned...(which is what emissions goal is) or C)
try and push it's way past the incoming air fuel mixture through the intake valve and then into the intake manifold and then what? it would get sucked back into the next open intake valve geting ready for its related cylinders compression stroke.

Go out and take a look at the small block chevy motor in your 1970 GMC pick up and you will see a PCV valve on ONE of the valve covers. It has a hose that leads to a 1/4" fitting on the base of your edelrock 625 cfm 4bbl carb....or its stock equivalent. Even my 1977 cordoba ghetto sled has just one pcv valve on the passenger side valve cover.


I do appreciate and respect your concern that we perform proper and safe mods to our cars. Your thoughtfulnes for others and willingnes to take the time to share your knowledge and mechanical insight with us here is awesome.


Hey, how many posts are going to show up in a search (staring us) concerning PCV bypass in the FI forum next year when a member gets interested in installing a SC or turbo? ;)

[Turbo V6 Camaro]

Originally posted by grayman:
</font><blockquote>quote:</font><hr />Originally posted by Wicked 3800 V6:
Think about it -- the PCV is designed to vent out pressure out the valve instead of out the valve covers. The PCV vents only through that throttle body tube. By blocking the hole, you've forced the air to go out the valve covers (after going past the rings, etc). The idea behind the block / drill is to get the pressure outside of the boost side -- the tb tube lets out back into the boost area, and since boost can't enter boost, it backs up and blows the dipstick.

So you drill the TB to let boost enter normal air. The PCV is a check valve, so the hole in your tb is a bit of weight savings at other times.

The valve cover breather is just a nice add on to the whole setup above. The PCV is the workhorse of the venting, though. I'd be cautious about a block without a drill!

Ok, here is where you are getting it wrong. The PCV pressure does not exit past the piston rings to escape. Once gases are blown (from compression or ignition of cylinder) into the crank case they vent from the PCV valve. Older cars have the PCV valve on the valve covers. Or even one breather on each valve cover. The inside of crankase has the crank, oil pan, etc. There are BIG oil channels and holes in the heads that mate with the block. This is where oil travels as well as positive PCV pressure. The two heads (valve covers) are not seperate from each other. The inside of crankcase is open to either side...head...valve cover.

From reading this quoted post it sounds like you think the inside of the crank case is 'locked down'....but it is not. Oil and gaseous build up can travel from side to side...and will exit from the point of least resistance...in my case a valve cover breather on the passenger side. If our stock PCV valve can release crankcase gases from EITHER side of engine....so to can a breather on one valve cover vent the gases for the entire engine. There is no double blow by through the piston rings. Just gases getting in the oil pan and then exiting up through either side...wherever the vent hole is. Further, If there was PVC gases blowing back through the piston rings that gas would then be UNDER the cylinder head combustion chamber. It would then exit through the A) exhaust valve or B) get stuck inside cylinder and reburned...(which is what emissions goal is) or C)
try and push it's way past the incoming air fuel mixture through the intake valve and then into the intake manifold and then what? it would get sucked back into the next open intake valve geting ready for its related cylinders compression stroke.

Go out and take a look at the small block chevy motor in your 1970 GMC pick up and you will see a PCV valve on ONE of the valve covers. It has a hose that leads to a 1/4" fitting on the base of your edelrock 625 cfm 4bbl carb....or its stock equivalent. Even my 1977 cordoba ghetto sled has just one pcv valve on the passenger side valve cover.


I do appreciate and respect your concern that we perform proper and safe mods to our cars. Your thoughtfulnes for others and willingnes to take the time to share your knowledge and mechanical insight with us here is awesome.


Hey, how many posts are going to show up in a search (staring us) concerning PCV bypass in the FI forum next year when a member gets interested in installing a SC or turbo? ;) </font>[/QUOTE]why do you think no longer uses the system in the covers??? umm maybe cause it don't work that well...

but your wrong about one thing...... Where do you think the gas's in the crank case come from?
its the blow bye from the comp stroke.... some stuff does get buy the rings and in boosted cars even more gets by cause the crank to pressureize.

if it was "ok" to just vent the vavle cover 1) i think gm would have done it to save monye. and 2) the GTP's would come stock with a vented cover and no the weird system they have that i still can't figure one how it works. .

AND
mod the TB, and is the best way = free to 5$
beather that WORKS = $40-50

[John_D.]

Originally posted by viper04af:
why do you think no longer uses the system in the covers??? umm maybe cause it don't work that well...

...I think gm would have done it to save money.

They can't do it because of emissions... Same reason they can't have vented gas caps anymore. They used to do it back in the 60's though.

Also the longer the path, the less likely it is for oil to escape. It's pretty easy for oil to get blown out through an opening in the valve cover especially with the rocker arms slinging it around. It's a lot harder for it to wind it's way up through a narrow opening in the lower intake, upper intake, and on out the tb channel.

[grayman]

come on Viper,
Lets not mis-quote each other. The least we can do if we are having a discussion is read the other persons post before replying. I don't need to go on and on about this because I am not the person telling people who have never even changed a starter before to drill holes in their engine. Don't mis-quote me though, ok?
"but your wrong about one thing...... Where do you think the gas's in the crank case come from?
its the blow bye from the comp stroke.... some stuff does get buy the rings and in boosted cars even more gets by cause the crank to pressureize. "

Read my post again if you care. I said there was blow by and that is where crank case gases come from. I also said that there is no REVERSE blow my in response to Wicked's post....when it looks like he is saying that crank case pressure is relievd by REVERSE Blow by of piston rings.
"Think about it -- the PCV is designed to vent out pressure out the valve instead of out the valve covers. The PCV vents only through that throttle body tube. By blocking the hole, you've forced the air to go out the valve covers (after going past the rings, etc). The idea behind the block / drill is to get the pressure outside of the boost side -- the tb tube lets out back into the boost area, and since boost can't enter boost, it backs up and blows the dipstick."

If that is realy what he meant to say and indeed thinks....then read my earlier post again, please.
There is no reverse blow by when there is also a low pressure vent hole such as a valve cover breather or a sealed PCV system such as ours which is located in the upper manifold. it is there because it is easier to CONTAIN it...for emissions requirements. Think about that one a moment...the valve cover method works so well that emissions standards were changed in order to better contain the PCV system.

what concerns me the most is that a couple of you are telling some VERY green, hard headed, don't listen the first 5 times you tell them, don't even own $100 worth of tools, have never heard of 'PCV' and we don't know their level of mechanical ability - to drill holes in there TB. Come on...that write up I copied onto my site is not even very clear....especially for a rookie. I can follow it but it is only three or four sentences. My site is intended for intermediate and above home mechanics...to share specific 4th gen v6 info and techniques. It is not completely comprehensive nor oriented towards teaching a novice mechanic how to fix and mod their car. I don't understand how you feel confidant in telling people of questionable mechanical abilities that they MUST drill their TB. That is too scary. Maybe one of you 'drillers' can make a better, more comprehensive write up for this mod...something that will help keep the noobies safe.

We are mechanics. We look at our engine bay and know what is going on. Other people...they call AAA when they get a flat tire.
We don't want those people drilling holes in their engine, do we?


Hey, I see a book coming...instead of 'greasers' and 'soches' it will be about 'drillers' and 'breathers.'

"Stay golden, Fireboy"

[img]graemlins/popcorn.gif[/img]

[Wicked 3800 V6]

Fack you $100 of tools. Your coming off a little aggressive grayman, even if you do host some technical documents.

And you've misquoted me. Now, it's one thing if I don't understand, but it's another if you are misunderstanding me.

Let me say my point again:
NA: The PCV collects pressure from the crankcase, and vents it to the vacuum of the post-plate TB.
FI: The PCV collects pressure from the crankcase, and tries to vent it to the pressure of the post-plate TB, but pressure can't go into pressure, so the dipstick blows out.
FI Fix: The PCV ... and vents it to the outside air. No air is sucked in through the hole, since it is only in the tube connected to the checked side of the PCV.
NA Using FI Fix: ... vents to outside air. Ditto.

So you're saying that the pressure will make its way to the valve covers? &lt;sarcasm&gt; Maybe I'm confused on what the crankcase is ... or how pressure gets there ... or where the dipstick goes ... or where the pcv attaches to &lt;/sarcasm&gt;

1. Where does the PCV go to? Lets settle that issue first.

2. Also, I don't understand why you are against the TB drill, but for the plug at the same time. I argued in an above post that by plugging without drilling, you've disabled the PCV system. Is that acceptable with a breather?

3. Besides, it's only the TB. John_D can cut his in half and run fine!

Lets see who has the $100 of tools. [img]graemlins/popcorn.gif[/img]

[ March 23, 2005, 05:07 PM: Message edited by: Wicked 3800 V6 ]

[Wicked 3800 V6]

Another note: I'm not sure where you were going with the "reverse blow by" or something. The extra pressure in the cylinders makes more air pass the rings out of the combustion chamber into the crankcase.

[1DangerousV6]

over the years i have drilled my TB 3 times for nitrous nozzles..so i can see both sides..it is definitely relatively easy to do as long as you have the tools..and it really should be removed instead of stuffing a rag in there or something..but i'll admit i've done it both ways..if you have the tools and you're gonna do it then simply do this..CAREFULLY FOLLOW DIRECTIONS!..if you really dont feel comfortable doing it yourself..just have a local performance shop do it..it really shouldnt cost much even if they do fully remove the TB (which they should) [img]smile.gif[/img]

[Mighty Thor]

Ok Viper, you better step in. Things are getting out of hand. I don't think the TB was the concern anyway. How it got to be is weird.

[Turbo V6 Camaro]

jeez is it really that hard to

1) remove TB
look in it.. you see the ONLY hole you can see light in on the other side (other then the big one in the middle [img]graemlins/rofl.gif[/img] )

plug the side thats in the TB with quick steal you get at auto zone....

then look at the back of it..... see the hole ? yup there it is see hoe the "vien" in the TB stick out just for that hole?

yup
use a small drill bit and dril into it..... then after you know your in the right spot make then bigger and drill a few more......

install TB....

any one that knows how to use a drill can do this mod.... and i bet you could it with out even removing the TB on a 1999 and up f-body....