: Hmm, Breathers, new valve covers, and pressure?
Chirp08 Jan 15th, 05, 6:58 PM Ok, my engine developed a miss as most of you know, and we are looking at all the changes that were made, and have came up with a few questions.
I had old plain chrome valve covers on the engine, when looking at it from the front the left side had a breather, the right side had hte pcv valve.
We got new edelbrcok classic valve covers and put the breather on the ride side, with the pcv valve going into the breather (looks very clean).
We are wondering if the fact that there is no breather/pcv on the left side would cause any problems with the engine. Is it supposed to be divided, or are there suppose to be breathers on both sides if you put the pcv valve into the breather?
Wolfplace Jan 15th, 05, 7:35 PM Not sure what you are saying??
Is the breather open to atmosphere or sealed to the PCV valve??
If you put the PCV into the same place as the breather it ain't doin' much but pulling in fresh air from the breather, it's not pulling on the crankcase.
It should be on the other side of the engine from the breather.
And you need a breather along with the PCV or it won't work properly.
Also, at anything but hi vacuum conditions you need a breather, there is no vacuum at heavy load or WOT & this is when you have the most crankcase pressure :(
Chirp08 Jan 15th, 05, 8:35 PM Ok it used to be this way:
Left Side of motor: breather
Right Side of motor: PCV Valve
NOw its:
Left Side of motor: nothing
Ride side of motor: Breather with pcv valve attached to it.
The breather is this one:
http://www.carshopinc.com/images/EDE/4201.jpg
The Back side (not visible) is flat, so after reading online that you can have a pcv valve on a breather we drilled a hole, and put a rubber seal on it and put the pcv valve in it.
So im guessing that the pcv is pulling mostly fresh air, what kind of problems can this cause?
Wolfplace Jan 15th, 05, 8:45 PM Not much I guess, as long as the carb is calibrated for a continuous fresh air leak ;)
It should help keep the crankcase fumes in the engine at idle I suppose but it isn't going to work as intended.
Chirp08 Jan 15th, 05, 8:47 PM would this affect how the end is running though? I guess i need a new breather without a hole, and move hte pcv valve to the other side.
BillK Jan 15th, 05, 8:53 PM Chadwick,
If I am reading this correct, you have the pcv valve going into one valve cover, and the other valve cover is sealed up. If that is the case it will not work. The pcv valve has to be able to draw fresh air in from somewhere. That somewhere should be a breather in the other valve cover.
Hope this helps,
Wolfplace Jan 15th, 05, 9:18 PM Originally posted by Chirp08:
would this affect how the end is running though? I guess i need a new breather without a hole, and move hte pcv valve to the other side. If you like the way it looks why not just seal the breather you have the PCV hose hooked to on the top so it pulls on the crankcase & put another breather just like it on the other valve cover that is open??
Chirp08 Jan 15th, 05, 10:27 PM The current setup is this:
Left side valve cover, totally sealed, nothing coming from it.
Right side has hte breather attached to it, and hte pcv valve goes into the breather.
Wolfplace Jan 15th, 05, 11:16 PM Originally posted by Chirp08:
The current setup is this:
Left side valve cover, totally sealed, nothing coming from it.
Right side has hte breather attached to it, and hte pcv valve goes into the breather. I am aware of how you have it hooked up & it is wrong.
Read my above post again :(
There are a couple of options,,
I will repeat this,,, if you like the way the breather looks then,,,
1, Add another breather just like the one you have on the other valve cover.
That will be the Left side.
2 Leave the PCV hose hooked up to the side of the breather as you have it but take the top off of the breather with the PCV hose & make a plate to seal it so it does not go to atmosphere.
Atmosphere is the air outside of the engine.
You want the PCV to pull a vacuum from the valve cover not to pull air from outside.
Or, option 2,,
You can just use the breather you have in the right side & hook the PCV to the Left side without a breather.
This is really very simple, you want the breather on one side & the PCV valve on the other side with no breather on the PVC side that is open to atmosphere
BTW, do you have the other end of the PCV hooked to the base of the carb or to the intake manifold?
It has to go to the base of the carb or to the plenum under the carb.
If it goes to a single runner that goes to a single cylinder it will cause a miss.
Chirp08 Jan 16th, 05, 9:37 AM Explain hte single runner to a single cylinder please, because we do have a miss. The hose goes from the breather to the carb, but not sure exactly what its hooked up to.
Also with these valve covers i must put hte pcv valve in the side to get a good seal, is there anything i should know when it comes to placement, should it be in between cylinders, etc. ?
Wolfplace Jan 16th, 05, 1:22 PM Originally posted by Chirp08:
Explain hte single runner to a single cylinder please, because we do have a miss. The hose goes from the breather to the carb, but not sure exactly what its hooked up to.
Also with these valve covers i must put hte pcv valve in the side to get a good seal, is there anything i should know when it comes to placement, should it be in between cylinders, etc. ? In the side of what?? the carb or the valve cover??
If the hose goes from the valve to the carb you are fine.
It doesn't make any difference where it is hooked to the valve cover except you do not want it directly over a rocker & you want some kind of baffling in the valve cover or you will end up with raw oil being pulled into the hose.
It is the other end of the hose that goes to the carb I am talking about.
You cannot hook the PCV to the intake so it draws from a single runner which is like in the back or front of the intake that goes to a single cylinder.
This is a runner & if you look into the intake with the carb off it will be very obvious.
The plenum is the area directly below the carb & is either a single area for a single plane or two areas for a dual plane & the runners are the individual divided parts that direct the plenum to each cylinder.
It really sounds like you should have someone take a look at what you are doing as this is a bunch simpler to explain in person & really is very simple once you are shown ;)
Why don't you post where you are & maybe someone can come by & give you a hand,, lot's of good folks on here & a pretty fair chance someone is close by graemlins/thumbsup.gif
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