17057231 specs?

[Cadman-iac]

Does anyone have the specs on this  carb, specifically the idle bypass size and the mixture screw hole size?
 If you have the idle tube size and the secondary bleed tube sizes, I would really appreciate those too.
 Many thanks in advance, Rick

[GSP7]

I have a 1980 , 17080213 that I had measured the Idle Bypass Air holes in base plate , .108".

If that helps.

[Cadman-iac]

  I appreciate your input but this is a 1977 Cadillac 425 carb and I think the calibration might be a bit different than yours. Hopefully someone will have the information I need. Thanks for your effort though.

[Cliff Ruggles]

What are you trying to do with it?  Stock application or something else?

All of the later Caddy units are pretty close for calibration and used small MAB's and large CFM castings. 

They make excellent HP carburetors, just need a little help in a few areas. 

I have every single part available for them including the most complete/correct rebuild kits in this industry.......

[Kenth]

Here are the specs for 1977-8-9 Cad M4 230 units. Like Cliff says, similar all years.

[Cadman-iac]

What are you trying to do with it?  Stock application or something else?

All of the later Caddy units are pretty close for calibration and used small MAB's and large CFM castings. 

They make excellent HP carburetors, just need a little help in a few areas. 

I have every single part available for them including the most complete/correct rebuild kits in this industry.......

 Hi Cliff,
 Thanks for getting back to me.  I'd like to use this on a SBC 350, but I don't know what parameters to use to make it work.

 Another issue is that it has the wrong base plate on it, it's the later version using the 3 mounting screws and has a cracked mounting ear on the back.

 I have the correct style base with  .050" bypass passages and  .055" mixture screw holes, but I don't know if this is enough or too big for what I want. I suspect it's not big enough, but can be modified.

 Something else that I'm not sure would affect this is this carburetor has the primary pull-over enrichment system on it. Will this be a problem, and if so, can you remove the tubes to disable that part of it?

 And lastly, since the base needs replaced, which secondary actuation lever length should I use, the more common short one,  the medium one, or the longer one?
 I noticed these different sizes recently and I don't know what the purpose is. The longest one allows the primaries to open farther before the secondaries begin to operate,  and the only thing I can think of as to why is to allow you to stay out of the secondaries for better mileage.

 Would you recommend having your secondaries open sooner or later if you are going to use the carb on a vehicle for towing?

 I will need a kit for this too if you think it will work for what I want to use it for.  Do you need any other information or was this enough?

 Thanks for your help,  Rick

[Cliff Ruggles]

For towing, use the LONG arm for the latest secondary application.  This provides more range on the primary side for climbing steep grades, towing, etc w/o getting into the secondaries.

I am NOT a fan of swapping baseplates around on any Q-jet unless the donor part comes from one with the same part number.  More things get changed than just the size of the holes under the idle mixture screws and idle bypass air.

I specialize in providing complete rebuild kits with high performance and tuning parts in them exactly for the application.  I require all of the engine/drivetrain vehicle specs and carburetor part number. 

Shop number is 740-397-2921, hours 7am-4pm, M-F EST.......tks......Cliff

[GSP7]

Here are the specs for 1977-8-9 Cad M4 230 units. Like Cliff says, similar all years.

Where do you get those info charts from?

Id like to see that info for the Qjet that I own

Thanks

[Cadman-iac]

  Thanks for the quick reply, much appreciated.

 I'll look for another carburetor with the same number. I think the Cadillac my father-in-law has may be the same, it's also a '77, and it's been needing a tune-up anyway. I can take a peek at it then.

 What about this pull-over enrichment system?  Does it matter if I use it with a smaller engine?

 And thank you for explaining the lever length, I thought that's what the reasoning was for the various lengths. I posted a question about this earlier but I don't know if you saw it. I  might have put it in the wrong forum.

 Thanks again, 
  Rick

[GSP7]

That 1977 Cadillac Idle Air bypass of .039 seems real small...? (?)

At least compared to my .108 on my 17080213. I also I have a 7041211 IAB is .95 at least

Why does a Cadillac carb have much smaller IAB holes?

[quadrajam]

Rick,
I have a 77 caddy parts carb with a nice clean complete rebushed baseplate.
Carb is 17057235 I replaced the primary shaft with a Chevy style and was using
it on a 406 and a 350 long ago.
Idle screw holes are .086, Idle bypass is .082 both sides, Has the long actuator on it.

Just talking about the baseplate, not the whole carb. If interested get back wit me.

QJ

[Cadman-iac]

That 1977 Cadillac Idle Air bypass of .039 seems real small...? (?)

At least compared to my .108 on my 17080213. I also I have a 7041211 IAB is .95 at least

Why does a Cadillac carb have much smaller IAB holes?

I don't know why those are so small on the 425, unless it has to do with the design of the intake manifold. The 425 intake is a single plane instead of the normal dual plane manifold used on the 472/500 engines. 

[Cadman-iac]

  I lucked out and found a 17057230 carb in a friend's collection with a good base on it.

 I have a question though.  The 17057231 that I already had has the pullover enrichment system on it, this 17057230 I just got does not have that.
  Is this common?  I have a 17059232 I'm using on a 472 and it also has the pullover enrichment system on it. I think it came off of a 79 425 if memory serves.

 What did a vehicle have to have in order to get a carburetor with this system in it? Is it an altitude option, or a California versus federal emissions thing?
  How does it effect the tuning?

 Sorry for all the questions, just trying to understand these variations and what I need to do to make it work.

[Kenth]

From the Delco/Rochester Manual:

[Cadman-iac]

 Thanks Kenth,

 That's a little more than what Cliff explained in his book.
 Does that Rochester book give any information on altitude calibration differences, or what might be different between federal and California carbs, or why one would have a pullover system and not the other?
  Is the 17057230 a good carburetor to use on a 350 SBC?