weber help again

[diamondjumper]

So im still getting terrible mileage, 15mpg. Granted im lifted 5 inches on 27 tires, but i know i should be getting better than this. Ive tried to find float specs online but i cannot find anything. What float specs do you guys run that you know works!?!? or any other things i should do? I was getting pretty good mileage with my old hitachi so i need to fix this i am a broke college student.

 

Also, another question, I hooked the fresh air supply for the cat up to the valve cover breathers routed to the air filter on the carb. I drove it for a couple days, came outside and there was a pretty good size oil spot below the drivers side of the motor, looked like it came from the breather, but i am not positive, could be unrelated. Anyways, should i leave it routed like this, or cap them off?

any help is great,

thanks

Jeff

[hatchsub]

Here is a diagram of how to set the floats on the weber. I found that right out of the box mine was incorrect so i reset mine.

 

http://www.racetep.com/weberX.html

 

Just make sure you do it for plastic or brass (whichever you have) There are two different settings depending on what you have.

 

As for the oil in the breather...how do you have your PCV hooked up? Did you basically imitate the factory setup with a smaller 1/4 inch line beteween the PCV and the passenger side of the motor? It needs this otherwise you will not get the correct flow characteristics and you will be blowing oil everywhere and possibly doing harm to the engine. GD stressed it enough in the past that i redid my lines and got rid of my oil blowing problem...but i think a bit too late since my motor went south a month ago. Here is a picture of how mine is hooked up for reference.

 

 

Note the 1/4" line that is between the passenger side head and the pcv/drivers side head. This is the important piece to get the proper flow.

 

A quote from GD explaining it better than i just did:

 

"The PCV system needs a directional flow - in one head and out the other then to the PCV valve. But you need a smaller diameter hose between the second head and the PCV valve going back to the air filter in order to break the high vacuum and prevent oil being sucked into the manifold."

Edited September 4, 2010 by hatchsub

[Psyko]

Note the 1/4" line that is between the passenger side head and the pcv/drivers side head. This is the important piece to get the proper flow.

Funny. I don't know what size I'm running, but I assure you it is larger than 1/4" and my Brat couldn't care less.

[hatchsub]

Funny. I don't know what size I'm running, but I assure you it is larger than 1/4" and my Brat couldn't care less.

 

It will run with it the other way sure. I ran mine for years like you probably have it hooked. But it would suck oil into the PCV and blow it out the tailpipe every once in awhile under good acceleration.

[diamondjumper]

All I have hooked up are the valve case breathers and the air supply for the cats, and the vac advance, all other vacuum hoses are capped, i dont have to pass emission so i figured i didnt need them..

[diamondjumper]

now that i think about it, did i accidentally take out the pcv valve? i have a hose running from the valve to the air filter from each valve cover. then the air supply for the cat on each side i just routed into the breather hoses with a t coupler....

[GeneralDisorder]

The air supplies for the catalytic converter? As in the Air Injection System??!?!

 

I have to ask:

 

1. Why would you think these should get crankcase air when they were hooked up to the air filter box orginally?

 

2. If you don't have to pass emisssions, why are you running the AIS anyway?

 

Pull that crap off and route your PCV as in the picture above. This is the proper way to run it and mimicks the factory setup RE: hose sizes and routing to acheive the dual purposes of properly evacuating the crankcase blow-by gasses and not sucking oil from the valve cover into the intake.

 

Do it the wrong way and you risk damage to the engine. Crankcase gasses are nothing to mess with - they will foul your oil and etch the metal in your engine leading to bearing failure.

 

GD

[GeneralDisorder]

Funny. I don't know what size I'm running, but I assure you it is larger than 1/4" and my Brat couldn't care less.

 

And how do you know? You been testing your oil for blow-by contamination? If you don't know the hose sizes then you obviously gave no thought to how this should be done so I'm doubting it.

 

Could just be you got lucky and the PCV lines are so plugged up that they can't flow enough to pull oil from the valve covers.

 

GD

[diamondjumper]

so how do I plug the ais system?

[GeneralDisorder]

Weld the pipes closed that run under the heads.

 

GD

[diamondjumper]

ok, so i tried to redo the valve cover breathers. does this look about right now?

[diamondjumper]

i did timing tonight, it was set at 12*. now what can be causing my mileage to be soo terrible. And i think i might have fixed my whole crankcase breather issues IF my pictures are right, hope you can tell if i am right or wrong by them.

[GeneralDisorder]

Yes - the breather/PCV routing looks good now. Should work much better for you.

 

As for the mileage - do you for-sure know the jetting?

 

GD

[hatchsub]

i did timing tonight, it was set at 12*. now what can be causing my mileage to be soo terrible. And i think i might have fixed my whole crankcase breather issues IF my pictures are right, hope you can tell if i am right or wrong by them.

 

12 degrees shouldnt be killing your mileage that bad. I had my car running at around 11 for 3 years and got 30mpg on the highway no problem. Ill second what GD said. What are your jets. Also when was the last time it had a tune-up (plugs, wires, rotor, cap)? Fuel filters? How are the wheel bearings? All these are things to consider when your getting bad mileage.

[diamondjumper]

yeah when I first got the weber i checked the jets, and they were 140 mains 160/170 air correctors and 50/60 idles.

One of the mains didnt screw in as easy as the other as i remember, and head was alittle chewed, but the hole in the jet was in good condition, and it seated fully, so i figured everythint was alright there. I have not done a tune to it, it does have fairly new ignition wires and new spark plugs though.

[kanurys]

Here is a diagram of how to set the floats on the weber. I found that right out of the box mine was incorrect so i reset mine.

 

http://www.racetep.com/weberX.html

 

Just make sure you do it for plastic or brass (whichever you have) There are two different settings depending on what you have.

 

As for the oil in the breather...how do you have your PCV hooked up? Did you basically imitate the factory setup with a smaller 1/4 inch line beteween the PCV and the passenger side of the motor? It needs this otherwise you will not get the correct flow characteristics and you will be blowing oil everywhere and possibly doing harm to the engine. GD stressed it enough in the past that i redid my lines and got rid of my oil blowing problem...but i think a bit too late since my motor went south a month ago. Here is a picture of how mine is hooked up for reference.

 

 

Note the 1/4" line that is between the passenger side head and the pcv/drivers side head. This is the important piece to get the proper flow.

 

A quote from GD explaining it better than i just did:

 

"The PCV system needs a directional flow - in one head and out the other then to the PCV valve. But you need a smaller diameter hose between the second head and the PCV valve going back to the air filter in order to break the high vacuum and prevent oil being sucked into the manifold."

 

I agree with GD's statement, but the way you have this one hooked up in the picture will still suck oil from the heads. The left and the right breathers need to be independent from each other to create cross-flow. The diagram in the FSM is very accurate and is what I based my design on. I outlined it in my engine build, including a weber setup: http://www.ultimatesubaru.org/forum/showthread.php?t=114817&page=4

[GeneralDisorder]

The left and the right breathers need to be independent from each other to create cross-flow.

 

The smaller ID line is an "orifice" - otherwise they effectively ARE independant. More will flow through the larger diameter side and you will get positive flow.

 

GD