Vacuum advance and Weber 45

[cliffsgt]

I recently installed a Weber 45 on my 2.3 Vega and was looking for any advice on hooking up the vacuum advance.
Should I try using a port off the manifold?
There is only one port on the 'runners' of the manifold going to the head.

[cjbiagi]

I would try full vacuum and see how it runs. The only reason ported vacuum advance exists is for emission purposes. It's easy to try both and see how your engine responds

[cliffsgt]

1972 Chevy Vega - 2.3 motor - Weber 45 DCOE sidedraft carb installed.
Thanks for getting back to me.
Well, unfortunately there is no vacuum hook-up coming off the carb - I think coming off the carb is called 'ported' vacuum.
I think the car originally came with the vacuum coming off the base of the carb - 'ported' vacuum.
I'll try using your suggestion and use the vacuum coming off the manifold and see how it acts.
If it behaves poorly I'll just un-hook it and let it be.

ALSO: Any suggestions on where I should hook-up the 'PCV' hose - nothing on the carb for the hook-up.
There are three spots/holes on the 'port' coming off the manifold I could hook-up a vacuum line too - so there is an option. Just not sure.
Considering just finding a Air filter type breather and stick that in the hole on the valve cover and just try to cover up the second hole.

[gt350fme]

Manifold vacuum should be good as Clyde mentioned but you MAY need to port to all 4 intakes or to a centered port to balance vacuum pulses
A DCOE Weber is a race carb not designed for emission issues.
I have this 40 year old pic of what I did and I’m trying to remember.
I ran a Mallory mechanical dual point distributor that got around the vacuum advance issue.
As for the PVC from looking at the pic I think I just ran a open road draft to below, shame on me, the smog police would not like that, for the PVC to work properly it would need to pull vacuum equally from all 4 int runners because porting to just 1 cylinder would cause a lean mixture at that cylinder, does your manifold have undrilled centered ports you could tap into?????
For what it’s worth my 140 did run good but the jetting and tuneing took a lot of trial and error.

[cliffsgt]

Vacuum advance: Hmm - don't really want to drill any holes in the manifold - But I'll try it out with just the one and see how she likes it.
PCV: Well, I suppose I'll have to do as you did and let 'em breath out below the car.
Not sure what a 'undrilled centered port' would look like - it's a Cannon intake I got from Pierce Manifolds if that tells you anything.
I've just got finished sleeving and re-building this motor and head - kinda pricey for gaskets and other incidentals but it's a tight motor. Ring gap is at a minimum.
YES, this Weber has been kicking my butt.
It runs out OK but hates trying to pull a hill from a dead stop - my driveway has about a 30 degree slant that I have to pull up, and I have to use the clutch a couple of times to get up it. It's like it's running out of gas or something, really 'boggs' down trying to pull it. On a flat road I can roast the tire - comes out of the hole strong.
I have a solid lift performance cam cut to run with stock pistons, headers, MSD box, Cannon intake and carb that's been mentioned, Traction bars, oh - and go faster headlights . . .

What modifications did you have on your Vega motor - any chance you could recall what you had in the carb?
Yeah right, 40 years ago - probably not. Thought I'd ask.

Thanks for the info!

[gt350fme]

Do you have the manifold part # couldn’t find it for DCOE 45 sidedraft carb?
A undrilled vacuum port would be a raised thickened area intended for installing your own vacuum nipple as needed, also could be a mounting point much like in my pic of the # 1 cyl manifold runner there is a round raised knob that would need to be drilled tapped for a nipple or bolt for hardware mounting, not sure what mine was meant for but it’s there probably a mounting point, for vacuum I would think somewhere just past the carb butterfly’s and centered to pull vacuum from all runners evenly, if it is not there perhaps pierce manifold tech line could help?
As far as carb tuneing make sure you have good fuel flow and pressure, and correct float level or it will never work well at all.
As for what jets, emulsion tubes and air bleeds you need has to be worked out by much trial and error, a real pain, OR take it to a performance tuner with a Dyno and be done with it, not cheep, perhaps $750? But done.
For what jets mine ended up with?, I actually still have the carb and manifold and will have a look soon but may not be exactly where yours is at, I had a similar build as yours with a next up performance cam

[cliffsgt]

Unfortunately, I could not locate any numbers on the Cannon manifold.
I got the manifold off Ebay a few years ago and it was shipped from Pierce Manifolds - that's where the carb came from also. I told 'em what I was putting it on but they were not familiar with the 2.3 Vega motor. Big surprise - but they set-it up the best they could I'm sure.
My manifold looks a lot like the one in your picture but it IS tapped (hole drilled in it) at the 'raised' area on #1 runner. I mean exact location.
My fuel flow and pressure is good - using fuel pump suggested by Pierce Manifold and a regulator. Pump is located very close to the tank.
The float level I'm not so sure about - I've tried setting it a couple of times.
Talked to Pierce Manifold, they said it should be set at 14 mm with a drop of 16 mm, measured at the middle of the float, now this is the newer 45 DCOE with the plastic floats. I've seen contradicting info regarding the proper float setting for this newer carb - go to the Pierce Manifold website and it says to set it at 12 mm. That info is listed under a 'Star' on their pdf info sheet on the 45 carb. So, not sure about it but will keep working with it.
Here is where I'm at for carb set-up:
Choke - 32
Main - 140
Air corrector - 160
Emulsion tube - F-16
Idle jet - 60F9
I'm considering swapping emulsion tubes and/or idle jets to try to get the 'bog' out of it when going up hill from a stop - but parts are pricey and I feel like I'm just guessing at this point. I even have a wide band Air/fuel ratio gauge on this motor to help me get it sorted out. Sure ain't like a Holley or Carter carb.
If I could find a shop that had a dyno near me (Birmingham, Ala) I would consider using them, $750 is probably a good guess but a bit pricey, but if you wanna GO you gotta pay. But would love to be done with it.
Very curious to know what you have in yours - if you could supply that info I'd be very appreciative. I feel like I'm in the ballpark with it but it's just not there yet. Very frustrating.
Thanks for your help on this - not many people willing to lend a hand or have the expertise.
Cliff

[gt350fme]

So my jet #s are as follows but do consider I did this by seat of the pants, and messed with it for many months.
Was I happy with it, sometimes, a o2 sensor would have been very helpful, I use one now days.
One other difference was my head was fully ported.
Main-160
Air correction-210
Emulsion tube- f8
Idle 55 f8

One good thing about DCOEs is jetting is very easy to change.

I just noted that my manifold has a passage just passed the carb linking the 2 sides together, I would try tapping into that for a vacuum port.

Would also recheck valve clearance.

Also bump up the base timing from 12 - 14 BTDC but no pinging on hard acceleration

Good luck let us know how it goes.

[cliffsgt]

Quite a difference from what I have in mine.
Gives me more incentive to swap out my emulsion tube after seeing what you used - maybe the idle jet also. I'll try one at a time and see the what the effect is.
Yeah, I wish I had my head ported but . . . oh well.
What main 'chokes' were you running?

My Ignition timing is at 9 BTDC so I'll see about bumping it - just afraid of that dreaded 'ping'. I killed a motor that way so I'm a bit gun shy.
I'll try bumping the timing, that should make a big difference.
Still not crazy about putting a drill on the manifold - we'll see.
OK - I can go over the valves again.
I'm swapping out my distributor for a re-condition one in hopes of getting a bit more consistency out of the motor. Due to a funcky acting centrifugal advance. I should get it late this week.
After I research a bit more on the emulsion tubes/idle jets, I'll need to order them - but I'll post an update when I get the stuff done.
If it works I'll owe you.
Many thanks for the info - you are literally one in a million.
Cliff

[cliffsgt]

I just ordered the Etube F8 from Pierce Manifold, and now I wait.
After much research, I feel good about swapping the F16 for the F8.
Hopefully, it'll be a 'Euerka' moment with much celebration!
When I get these parts in and installed I'll give ya'll an update on how things are going.

Any chance you could get me the main 'choke' size on your Weber 45 carb you were running on your Vega motor?

Cliff

[dindin]

looks pretty close have fun..https://www.carbparts.eu/calc

Al

[gt350fme]

I never messed with the choke jets but if I have the correct jet it would be 60 f5, # 6 and 10 in pic.
Also never messed with the Pump jet # 12 size 40

Hope my jet choices get you close, but I suspect it will be a starting point, at least you have a o2 sensor to help.

Good luck

[cliffsgt]

-45 weber.jpg

I like the Weber calculator - I realize one should go here before selecting a carb but I really wish you could actually choose which carb you have. On the results page there is a box next to ‘choke’ with a ‘?’ in it and if you click on it, it does reference a 45 DCOE, so that’s nice.
However, I was asking about the part high lighted with a box around it and referenced here as part number #14.
What size choke are you using?

[gt350fme]

Ok, we’re on the same page now, it is a “36”, I also never messed with that, also did not know they called that a choke, learned something.
The DCOE 45 I purchased from IECO a lifetime ago may have had some ballpark jetting and other part choices specifically set for the Vega ???

Hope this helps we’re pulling for you.

I do still have the Mallory mechanical distributor.

[cliffsgt]

Ahh - a 36 choke.
Wow, much larger then what I'm currently running - a 32 choke. I've got a 34 choke, so I'll try to see if I can get by with that.
It's interesting you would suggest that distributor 'cause I've got one. I must've bought it 35+ years ago, a Mallory Dual point. I thought about going with it before I order the re-condition electronic one off Ebay. I'll use the new one for now and see how it performs. I have to say I like getting away from the 'points' - but I'll re-access my ignition later. It would be kind of novel to use it - Sort of nostalgic if nothin' else, but also, it could make it run better! We'll see . . .
I just purchased a Gunson Colortune to help me with the tuning of the carb. I'd never seen or heard of one of these before and looked like it'd be handy. Another 'Toy' is all I need!
I should get the emulsion tubes later this week and I'll install 'em and see where everything is at on the 02 sensor. It's been running rich through out so far, but I'm sure I'll make other changes that you have outlined.
I haven't heard anyone reference IECO in decades but they were the 'Vega Experts' so I'm sure they set the carb up with your Vega in mind.
I'm feeling better and better about getting that car on the road and running strong - I'm anxiously awaiting the parts!
Just for kicks - do you, by any chance, still have that head with the cam in it?
I'll give an update when I get 'er done.
Thanks again - you've been of great help.
Cliff