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Quadrajet Carb Talk and Tips / Re: 17082224/SMAB /Fuel Economy
« Last post by Turbo26T on February 21, 2024, 06:42:46 AM »
Cliff: To be built 350 Chev , #2800 Model A Project ,2004R
 So Far I have:
 Early 2pc seal block
 Vortec 906 heads
 Edelbrock Performer Q/J intake
 Cam - TBD ( would appreciate suggestions)
 C/R -  at least 9.5/1
 Low speed mild street ,good manners , smooth idle ,good vacuum. Mainly interested in dialing in economy later
I'm 82 ,drive like an old man. 2000-2500 RPM tops ( occaasional blast to 3000/3500..Wow !) . I'm a data-driven tinkerer ,so looking forward to tuning this carb. Will be ordering everything I need from you eventually..
 Thanks for the reply & info
 Stan


 
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Quadrajet Carb Talk and Tips / Re: 17082224/SMAB /Fuel Economy
« Last post by Cliff Ruggles on February 21, 2024, 12:51:39 AM »
Those carbs have APT and "M" series tapered primary metering rods, so a nice carb all the way around. 

What are you trying to  use it on?
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Quadrajet Carb Talk and Tips / 17082224/SMAB /Fuel Economy
« Last post by Turbo26T on February 20, 2024, 05:14:17 PM »
 17082224 1672 FJP  Got it free and its  really clean & complete . Its an '82 SMAB ,no CC, single front pulloff. Should be OK for my near -stock 350 Chevy build.
 My questions are :
Being SMAB ,I assume its a truck carb
 Can it be tuned for decent mileage ?
 What was the original engine size that it came on ?
Thanks
Stan
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Lobby / Re: General Banter etc.
« Last post by quadrajam on February 15, 2024, 07:50:14 PM »
No link. I got mine from ebay. they are a copy of MSD 35051 for 1/3 the price.
The item # was LY-2048 and they shipped out of Odesa Texas.
Probably on amazon too, just make sure they look like the MSD crimpers.

QJ
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Diagnose a Quadrajet carburetor problem / Re: Quadrajet leanning out at WOT
« Last post by Cliff Ruggles on February 15, 2024, 01:58:51 AM »
"new needle and seat from Cliff's (I forgot the size and did not write it down but it is .130 or .135) "

It's probably .135" as I don't sell anything smaller than that.  Still not big enough for what you are doing.  I'd go to a .145" seat and make sure you have at least  7psi fuel pressure.....
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Lobby / Re: General Banter etc.
« Last post by Cliff Ruggles on February 15, 2024, 01:49:35 AM »
Do you have a link to them?
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Lobby / Re: 17057262
« Last post by Cliff Ruggles on February 15, 2024, 01:48:43 AM »
Difficult to recommend an exact "recipe" without knowing what heads and the compression ratio.

If it's only making 11" vacuum at idle speed and 214/214/112 cam the compression ratio isn't al that high or cam is retarded a bit.

If they are factory heads they will have casting numbers on them but you have to remove a valve cover to see them....
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Diagnose a Quadrajet carburetor problem / Re: Quadrajet leanning out at WOT
« Last post by 73ss on February 13, 2024, 03:33:22 PM »
I have a very similar set-up. 489 stroker with Brodix Race rite heads. Chet Herbert HR cam with almost identical specs except its on a 114 LSA. 200 4-R trans with 2500 ish lockup converter and 3.73's in the rear. I have one O2 sensor & AFR gauge.

Carb is 17080212. (Factory BB truck carb) Cliff set me up with a kit. 76 jets & the custom 50M rods.
.140 N&S
.040 idle tubes (originals were .039)
.054 idle downs.
.135 bypass.
.090 idle ports.
In tank holley pump with external regulator set to 6.5 PSI. It holds 5 PSI during a WOT run.

In 4th gear with the convertor locked, 2200 RPM, 72 MPH I'm seeing 15.0~15.3. I can lean/richen this with the APT. Car seems to run best at this range. No surging or audible detonation and actually some decent fuel economy.

At WOT I was getting 11.9 ~ 12.1  I leaned it out with a rod change, It's approx 12.4 now. It does not slowly climb as you described.
(If you want exact rod specs I'll get them, My notes are in garage and I'm in for the night.)

I have not had any nozzle drip with this setup. I opened up the bypass to .135 to get it off the transfer slot. It's still on the transfer slot more than I would like but am hesitant to go any bigger on the bypass.

I'm curious as to what your main air bleed sizes are and if the carb is the single MAB type? Also, .063 idle downs seem big to me and .038 idle tube a tad small? I'm not an expert though.

One thing I did notice on the AFR is it goes pig rich after letting off of WOT. It did the same thing with a holley that I was playing with. I assume this is because of the high vacuum created and it's really pulling lots of fuel from the idle circuit? Has anyone else seen this with a AFR?

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Lobby / General Banter etc.
« Last post by quadrajam on February 12, 2024, 05:31:48 PM »
If you dont already have one, do yourself a favor and get a pair of those
ratcheting spark plug wire terminal crimpers. Those metal blocks that come
with plug wire set are total dookie! Get an assortment of terminals and practice
with it ant make perfect factory style wire ends.

   QJ
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Diagnose a Quadrajet carburetor problem / Re: Quadrajet leanning out at WOT
« Last post by lightning boy on February 12, 2024, 12:39:34 PM »
Chris, I would install the fuel pressure regulator after (downstream) of the carb. Tee the fuel line coming from the pump into the carb, then put the FPR in, set it to 7 psi or whatever, then what the engine does not use goes back to the tank instead of trying to dead head it from the supply to the carb.
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