Carb Needs

[bigvette1]

Really directed at Cliff.  You modified a Q-Jet that I have origionally coming  from a 1977 Chevy.  This is used on a 73 vette, 454, cam is a Crane 272 with 219/219 @.050 and .505 lift running 3;55 gears. 

You drilled out the idle air bleed tubes to compensate for fuel drip problem, along with other mods of jets, rods, and float inlet.  The tubes eneded up really drilled out to a large size.  Maybe your records will show this.  Anyway, I want to replace these tubes with a correct size as I later found a vacuum air leak at the hose connection  by the trans modulator which changed all characteristics of the engine vacuum. 

will you please tell me what size I can order from you to replace the drilled out ones or a common size that should be compatible. If further mods are needed I can work on that later, just get the carb working properly for now.  Thanks

Jim Parks
jamesparks17@yahoo.com
847-312-7530

[Cliff Ruggles]

Jim, there are no "idle airbleed tubes".  The carburetor does use idle tubes, which control the amount of of fuel available to the idle system.  There are idle bypass air holes in the baseplate, which help lower the throttle angle to keep the main system off line at idle speed (nozzle drip)......Cliff

[bigvette1]

Ok thanks.  I think I was referring to the brass holes in the primary that appeared to be drilled out.  anyway here are the specs on this carb.

Carb #:  17059507
Float:  set to 1/4"
Seat:  Windowed type with hole of .125

Primary:  Jets 75, rods 44 measuring .0625/.044/.025 on the 3 steps

Secondary:  Hanger "L", rods BG

What I called the air tubes or the air bleeds in the primary are at 3/64's or .046
If this is still confusing Cliff, give me an email address and I will send off some pics of that area that I am referring to.

I guess my question is does this setup seem correct for the car (73 vette 3400lbs) and engine (454 with cam specs listed)  parameters that I gave in the initial post?  Thanks again. Jim

[Cliff Ruggles]

cliffshp@embarqmail.com

[bigvette1]

Cliff, at this point I have the Q-Jet on the engine and running.  It has been on the shelf since summer so it needs some run time.  However, with the idle screws out 5 1/2 turns vacuum is at 17-18" and fairly stable.  Some hunting but nothing different than other carbs I have to play with.  The problem you worked on this carb a 2nd time was nozzle drip even when idled down to an acceptable level.

 Well... I see no nozzle drip at this time so the drilling on the air bleeds (believe that was what it was) seems to have corrected this issue.  The only problem I have to work on is there seems to be a "hitch" or almost like a notch in the throttle movement.  Can't tell yet if it is the acc. pump or throttle mechanism binding somewhere.  Overall all if we did not have a ton of snow in Chicago I would take the vette out and see how the carb runs under load.  At idle it is very positive.  I will still send off some pics of the area that I am referring to.  Thanks.

[Cliff Ruggles]

The accellerator pump may be sticking or have other issues.  Drive out the roll pin and remove the pump arm and see if it still "sticks".  We've upgraded the accl pump assemblies several times in the last couple of years, as the manufacturer wouldn't step up quick enough to get us a good product to hold up to this new fuel.  We've only had a couple of pumps fail, and will replace any of them at no cost no matter how long ago we did the work.

Good news is that the new pumps are fine, even in E-85, zero issues and zero failures to date.....Cliff

[bigvette1]

Will do and let you know.  If it is the pump mechacism sticking I will mail it back to you for replacement,.  Thanks for the service.
Jim

[bigvette1]

Cliff, exactly as you suspected.  I drove out the acc pump arm pin and there is zero drag on the throttle.  Manually push the accelerator pump and you can feel a bind about 3/4's of the way down.  I removed the pump and there does not seem anything wrong with it, but there is something about the bind on the sides of the pump chamber.  I will be shipping the pump to you tomorrow along with a ck for $9 to cover the cost of a new bowl gasket as the one on the carb is getting a little dog eared.  Again the carb is #17059507.

The area I referred to as "looked like it was drilled out" is shown in a picture that is attached.  Oops the pics are too large to send via the forum, so I will attached to your email.   The holes are directly adjecent to the cover screws inside the primary side.  Can you advise what these are.  Thanks again.  Jim

[bigvette1]

Cliff, still in a holding pattern due to wet weather.  Installed the new acc pump and gasket.  Will put on the car ASAP and let you know.  Thx.
Jim