I know I should trash it and go BBD, but I like to win my battles... So... If anyone has advice besides go carter, I’m all ears.

Long story short: I had a great 2300, i sold it Thinking I was going to be able to duplicate the one I had... (big mistake)

I tried many jetting options, using jets #50 to #55, power valvles (2.5 4.5 6.5 8.5 10.5 all the rates I can get down here) diffrent accel pump shooters (#20 to #30) and went crazy looking for diffrent cam colours before someone told me that they never got diffrent cams down here... that’s why the speed shops I visited looking for color cams gave me that look.

What’s the issue: light throttle: OK. WOT: OK. Everything in the middle: bog bog bog till the power valvle kicks in. Idle is OK the way I dialed it in now, but if I close one needle all the way in it doesn’t stall. In fact, if I close both needles abruptly (first one and then the other) it sputters bad for a minute then dies. So, I think, it’s awful rich? Or ain’t getting the correct amount of air, or fuel, or both.

Accel pump is working. Now I’m using 2 #55 jets, 8.5 power valvle, #22 shooter.

Work done: experimented with timing (even replaced the dist to a standars curved one, just to see if my curve was bad for this carb) jetting/shooter/power valvle combination. Never went up from 55 jets. Raised and lowered the bowl level. In desperation, I reamed the idle air bleed to 1.6 mm for an original of 1.47mm jus tto see what hapened, idle leaned out a li’l bit but the bog’s still there as soon as you want togo from say less than 10% throttle gradually into about 25 to 40% throttle. If you go from 5% to 75% she responds quickly and flawlessly with crisp power.

Symptom seems somewhat worse when cold. Should I try bigger fuel jets with all the same and see what happens? That’s the only thing I haven’t tried so far... bigger than 55 jets.

_________________
Juan Ignacio Caino

Please use e-mail button istead of PM'ing. I do log in sometimes but I'll be answering quicker thru e-mail.

_________________
Juan Ignacio Caino

Please use e-mail button istead of PM'ing. I do log in sometimes but I'll be answering quicker thru e-mail.

I'll try to help tomorrow if I get a chance, but I'm feeling qite ill write now and don't have the energy...and its midnite and I go to work in5.5 hours...

I don't have access to computer till tomorrow night again.

Gearhead

_________________
64 GTO...10.80's@122 on street radials
Destroked 455, Qjet, stock ign, 2400 stall

64 Valiant
Old 225, 4spd, 2.92-8.75, 2bbl, headers
dual 2.25"

Thanks Karl. I know what's like to go to bed after midnite and wake up at 6... It's kinda exhausting... At least (I got the idea from your juicy posts) you work doing something you like.... that's a big advantage. I thank god every morning when I know that I'll be in my shop, surronded by my tools and doing something I love to do and getting paid for it... It's like someone paying for you to play with your toys, huh?

I'm looking forward to hear your words about this.

Thanks again, hope you feeling better by the morning.

Juan.

_________________
Juan Ignacio Caino

Please use e-mail button istead of PM'ing. I do log in sometimes but I'll be answering quicker thru e-mail.

Well, after 3 days of banging my head against the wall... she's fine at last.

I completed this work:

-drilled then tapped the idle and high speed air bleeds
-lined an assortment of air bleed jets for this new tapped passages
-double cheched my venturis flow capability. Enlargened the venturis passage to 3.5 mm
-found a hole in the main body, under the passg side idle air bleed. Due to corrosion. Fixed it. It was leaking into or sucking from the diffusor.
-hammered down the checkball stop at the bottom of the accel pump diaphragm well.
-got a snap of various cam profiles and studied it, then I realized that the cam I had was right just needed to be set on #1
-fabbed a custom set of poliethylene gaskets. Soft enough to crush and seal, long lasting, fuel resistent enough to have the capability of being reused many times. I used 1/16" thickness.
-Double checked everuthing
-Reasembled using this setup:
main fuel jets #57
idle air bleed 1.3 mm
high speed air bleed 0.75 mm
accel pump shooter #20
needles opened 0.7 turns

Started the car, for the first time needed choke cold, then warmed up nice and purrs like a kitten, power is exceptional, no richness @idle, nice seat in the pants feel, lots of power (meaning, when I drive in town, and I go off a red light, my vac readng used to be 9. Now's 13-14 and my driving style hasn't changed, or if it changed it changed for worse due to this &#@% carb getting up my nerve. My idling vac reading is 21-22 in neutral, 18 in drive.

Still I'd like to know how to cosider the air bleed jetting matter when rejetting a carb, I'd love to understand it and not to be adlibbing (I'm accustomed to adlib a lot since I'm a jazz man, but I like to have backup on certain things)

Many thanks to everyone, Karl, I'm still waiting for one of your juicy clue-ins. I'll wait with my car running so if you're stacked with work I can wait a couple of days, but still I'd love to get the basic notion of the air jets.

I have some pictures of almost the entire process (except for the part where I banged my head against everything and the other part where me and the wife argues about the high amount of time that I dedicate to "my mistress" as she calls her. I'll post soon

_________________
Juan Ignacio Caino

Please use e-mail button istead of PM'ing. I do log in sometimes but I'll be answering quicker thru e-mail.

An air bleed works with a fuel jet to control the slope of the fuel mixture curve..........

With no air bleed, the fuel mixture would get richer and richer as more air flows thru the carb. You use air bleeds to compensate for this..........

Lets say you have the mixture correct at WOT and at 5000 rpm. But at 3000 rpm, you're very rich. You need a steeper slope or a smaller air bleed and then less main jet.

Or the other way around, you're correct at 3000 rpm, but very rich at 5000 rpm. You need a flatter slope or a large air bleed............. you may or may not need to change the main jet here...........


Also, by changing the air bleed, you may need to change the main jet too (as in above examples)

_________________
Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

I missed something in the translation. What's a slope?

_________________
Juan Ignacio Caino

Please use e-mail button istead of PM'ing. I do log in sometimes but I'll be answering quicker thru e-mail.

x axis volume of air going thru carb
y axis % of fuel

with no air bleed, the % of fuel would go up with the volume of air, constantly making mixture richer........

cant plot it here, but plot this (not actual % and volume)

NO AIR BLEED
X , Y
100, 10%
150, 15%
200, 20%
250, 25%
(increasing richness with volume slope is would look like 45degree angle)

when actually you want something closer to this
X, Y
100, 10%
150, 10%
200, 10%
250, 10%
(flat slope, 0 degrees)

If you get
X,Y
100, 10%
150, 12%
200, 14%
250, 16%

you're better than no air bleed, but still going too rich with increasing air volume so you need a bigger one to flatten the slope (less than 45 degrees)

If you get
X,Y
100, 10%
150, 9%
200, 8%
250,7%
(negative slope)

you're going lean and need a smaller air bleed (increase the slope)

_________________
Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

great info... now...
there's 2 air bleeds per barrel. The "idle air bleed" (large) and the "high speed air bleed" (small, and this is a stupid remark cuz I'm sure there's some carbs that not necessarily have the idle bleed larger than the high speed one)

So if I get it right, the high speed air bleed is smaller (in this particular engine) cuz we're trying to revert a negative slope.
Now, where exactly the transition happens and how can I tell? I mean, when does the idle air bleed stops and the high speed bleed kicks in? I know that idle air bleed may provide the mixture air up to xx mph (or revs, or "Hg...)

I can figure that I leaned out the high speed circuit by going larger in diameter than OEM specs... and I did the reverse work on the idle circuit. Now that I understand this I think I might try to lean the idle circuit a bit.

I gotta tell you, Ed, felt a lot better when after a week of fruitless dialing in attempts (robbing time and money here and there...) she finaly got running I'd say @ 90% perfect. And of course, the air bleeds modification I did is great news for dialing it in.

take a look:



then I lined jets in pairs, .7mm .8mm .9mm 1mm 1.1mm 1.25mm 1.35mm 1.45mm

This is the problem I found and cured:

(see the passage in the front hitting the diffusor right near the venturi?

solved!

and topped my tendency to overfabbing with this set of reusable gaskets



I greatly appreciate your help. Thanks a zillion.

_________________
Juan Ignacio Caino

Please use e-mail button istead of PM'ing. I do log in sometimes but I'll be answering quicker thru e-mail.

Smaller air bleed............richer high and mid rpm mixture.
Larger air bleed.............leaner high and mid rpm mixture.
Smaller fuel jet...............leaner low and mid rpm mixture.
Larger fuel jet................richer low and mid rpm mixture.


got it from

http://personal.riverusers.com/~yawpower/carbtun.html

Not sure specifically about your carb, but from my motorcycle carb experience (CV40 (constant velocity 40mm)). the low speed circuit (or idle) is in play to about 1/4 throttle (diminishing in effectiveness with more throttle). So the idle air bleed would only be effective and in use for the same amount of throttle.........

_________________
Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

Sorry it took so long...I got sicker and sicker and woke up at 2am with some of the worst cramps I've ever felt. I think the cough I got from the kids here must've grabbed hold in my overworked, underslept body. Never made it to work, and spent yesterday alternately sleeping, puking, or cramping...oh yeah...

Anyway, I'm glad you got it running well, my suggestion would've been that your on the right track in venturi obstruction/leaking-signal. Ed has given you some great info to go on.

Another thing I didn't see mentioned but I still have a headache so who knows...

Emulsion tubes...these are included in many carb designs including Holleys, and are part of the metering block in a Holley. The float level is designed to drop at a certain rate during high speed accel so that the emulsion tubes(which have vertical holes drilled in them) are less and less covered by fuel as you increase rpm. As the fuel level drops, more and more of the holes become uncovered to air which leans the mixture by reducing the signal(hole in a straw theory).

In other carbs, the air corrector jets(air bleeds) do the same thing, but like in a Qjet, the holes are placed in a location that has been measured by the design engineers, so that the signal changes over time as the velocity of the air flowing thru the carb increases. Much as on an airplane wing, the center of pressure(point of pressure producing lift) changes with velocity over the wing. The amount of pressure at the air bleed will change with air flow thru carb. Thereby changing fuel flow demands. Otherwise, the mixture would go over-rich, and continue to go richer as velocity increases, because there is a geometric relationship of the signal at the venturi vs airflow(shape of slope of fuel curve is not flat, but increasing more and more)

In other words, the signal seen at the venturi is not linear, but gets stronger and stronger with air flow, but at a rate greater than required to maintain a specific air/fuel ratio. It is similar to stress on connecting rods vs rpm. It goes up as a cube function, so that each increase in rpm brings a cubed increase in stress.

Did any of that make sense?...typing and staring at the keyboard is hurting my head...and todays my Birthday...I did have big plans...

Gearhead

_________________
64 GTO...10.80's@122 on street radials
Destroked 455, Qjet, stock ign, 2400 stall

64 Valiant
Old 225, 4spd, 2.92-8.75, 2bbl, headers
dual 2.25"

Hey There.

Happy birthday Karl! hopefully you'll start to feel better as you warmup. Some of us are like starting a car during the winter without choke and for making things even worse without heat riser... I belong to that group. My saying is "being alive hurts in the morning"

Ed and Karl, thanks for your help.

As far as emulsion tubes are, I though they were clogged or out of size, so I changed my metering block and the issue still remained so I figured that the issue was with the body of the carb.

One modification that the penin 2300 I sold has where an extra hole in those emulsion tubes, making the leaning-riching proces more even. My present mtering block has 3 holes, the 2 on the top are closer, then there's a space for another one wich is undrilled and then the 3rd is on the bottom. In that spce, Nestor penin placed another hole (smaller in diameter). I may try to duplicate that in my spare metering block.

I think that my carb didn't run over 2 things: the big rust hole in the idle air bleed, leaning it out awfully, and furthermore disbalancing all the circuits (cuz it was perforated on one side, on one barrel) and a stupidly bad cut gasket reducing the venturis fuel flow capability.

Now that I got it running, I may try diffrent bleeds-fuel jet combinations to squeeze out the best performance out of the carb, but so far I'm back in the ballpark and with great success.

I gotta tell you, I'm pretty familiar with 2300's and I never had such an issue before... I got scared the hell out of it. I thought I was under the D/W-SSD spell

One nice thing about holley's 2300 and 4150 metering blocks is that the passages are super clearly visible in the casting, so you can figure out very quick what's happening and wich hole connects with wich other...

Guys, I really appreciate the support.

Karl: have a nice birthday. Hope you have a good time!!!

Have a nice weekend you all.

_________________
Juan Ignacio Caino

Please use e-mail button istead of PM'ing. I do log in sometimes but I'll be answering quicker thru e-mail.

Get better...fast!

First: Gearhead: get better soon & do your birthday thing when you get better! You're very informative and helped me so much to understand the carb stuff and your other stuff.

argentina-slantsixer:

I'm still confused where is the gaping hole (corroded) that gave you hard time on that carb? The two pictures seems not to show this?

To all others:

What about the jets and emulsion tubes as a set? This is found on Holley/Weber 5220-6520 carbs. I rebuilt and repaired 5220 in my 2.2 1987 caravan. Seems to work and no bog at all throttles and at idle but I'm not sure if this carb is tuned properly for mid rpms. Have to be sure to pass emissions check. Only time I have bit too much fuel out the exhaust is when started cold for first 5 minutes, oh yes, had to do some convicing to get it started when cold, even choke is shut correctly. I thought carb is good at cold starts with one turn of key? Mine needs 2 to 5 turns and one or two pumps on gas then engine finally caught.

Cheers, Wizard

hey wizard.

this is the gaping hole



that was from previous intends to cleand this passage with too agressive means


as far as for emulsion tubes, main jets and the whole thing being part of the same "duct", I have seen 2300 modified metering blocs that had this feature. You have to plug the original air bleed passages on the main body and cut the front of your carb's main body air filter support, just below the choke tower (so you can give the air bleeds and emulsion tubes their space, they end up popping out the metering block) that's fine if the metering block is otherwise unusable, but with a good metering block I prefer the holley system... I don't like webbers.

_________________
Juan Ignacio Caino

Please use e-mail button istead of PM'ing. I do log in sometimes but I'll be answering quicker thru e-mail.