17057231 specs?

[Cadman-iac]

 Just realized I asked about the wrong carb number. I meant to ask if the 17057231 a good one to use on a 350 SBC?
 Thanks for your help.

[Cliff Ruggles]

Primary POE is just that.  It ADDS fuel with quick throttle movements and when pressure differential is greater above and below the primary throttle plates. 

It wasn't used on 99 percent of the Q-jets produced and they work fine without it.  I see no need to use it for anything more than it was meant for, really lean set-ups trying to squeak thru the EPA's ever tightening emission standards.

Since most of or all of the emission devices on these engines have been removed or disabled, and most also have engine changes, there is really no reason to use it or any advantages doing so.

Your Caddy carb is a nice unit, but as with any other carb selected it must be set up exactly for the application.  Out of the box it may show a slight advantage to other carbs from that period as the big Caddy engines weren't as efficient as other designs and it delivers more fuel just about everywhere in stock form.........

[Cadman-iac]

  Thanks Cliff,

 I guess I am in need of a kit for it then. Can I order it directly from your website or should I call and speak with you about this?

 Rick

[Cadman-iac]

  Ok, from the factory service manual I found out what the difference is between the 17057230 and the 17057231.
  The 17057230 fits all federal emission rear wheel drive Cadillacs for 1977, and the 17057231 fits the 1977 Eldorado with federal emissions. I guess the Eldorado warranted the POE system for whatever reason.

 Cliff, I need a kit for one of these, I guess it would be the same for either one, but can I order it through the website or should I contact you directly? Please advise.

 Rick

[Cadman-iac]

 Spoke with Cliff today and ordered a kit and a set of rods for the 17057230 carb. Looking forward to getting the parts and setting up this one.
  Thanks Cliff for your help, I appreciate it.

[Cadman-iac]

 So just updating this thread.  Here's what I've got on this 17057230 carb.

                    Stock:              Now:
Idle tubes:    .035"            .040"
DCR'S:          .046"             .057"
UIAB:            .048"             .061"
LIAB:            .078"             .078"
Bypass air:  .039"             .095"
Idle holes:   .052"             .078"
Float:           13/32"          12/32"
PAB-body:   .040"             .040"
PAB-horn:   .070"             .070"
Main noz:   .055"             .055"
Main jets:   #72.              #72
Prim. Rod:  52P.              44J- Cliff's
P/V spring: 3-10"           4-12", red
APT set:      2 1/4.          5
Acc noz:      .025"           .025"
Lvr hole:       Outer.          Inner
Sec. Rods:   DS.              CV
Hanger:        T.                 K
Sec bleeds:  .028"          .028"
Well holes:   .039"          .039"
A/V spring:   1/2.            3/4

Cr jet area:      1.95.         2.56
WOT jet area: 3.31.         3.54

 Doing the WOT tests with the secondaries locked out, I started out with the #72 jets and Cliff's 44J rods.
 I used a stopwatch to time my 0-45 mph runs and kept trying different smaller combinations in search of improvement.  Using what I have on hand and doing the math, my next set were #71/44J, then #70/44J, then #69/37J, but didn't really see any improvement. On the last combo It felt like it was running around bit lean, although the gage didn't show that it was too lean, the performance just wasn't there.
 So i went back to the #72/44J 's and cranked up the APT to 5 turns. I then filled the tank and hit the road to test drive it. I ended up driving 275 miles and one state over and very worn out. From what I saw on the AFR gage I think it's pretty close, I still have to fill the tank again and check the mileage. I'm thinking about trying one jet size bigger and see what that does.
  I had tried to figure out the best combo by doing the calculations, I took 7 different carburetor specs and figured out the WOT metering areas and the cruise areas then averaged them to see where my combo fell.

 Here's what I used for comparison:
Carb #       WOT area     cruise area
Jet/rod
17058204.       4.12.             2.53. 
77/52K
17058504.       3.42.             2.63.
71/41K
  7029202.        2.99.            2.14.
67/42
  7029207.        2.88.             2.40.
66/36
  7040511.         4.00.            3.02. 
76/44
  7045213.         3.10.             2.83.
68/32
17059207.         3.54.             2.75.
72/41

 The average for these was:
WOT- 3.43.       Cruise-2.61.

My setup:
WOT-3.54.        Cruise-2.56

 I realize that there's a lot of factors that affect the correct metering, but I thought that this method would get me in the ballpark and I can adjust from there.
 Plus this is where Cliff suggested i start as well. I'm just trying to figure out how to come up with the same conclusion.

  I'll post the engine specs in the next post, I don't have those handy right now.