Mild 17059247 Build

[Rhett]

I built a 17059247 from a 79 Buick for use on any of my cars - a 65 Buick GS401, a 73 Century Stage 1 or a 71 GS455.

Initially it will be going on the 65 (stock cam and manifolds), so I left the primary side mostly alone. My question to the group is: with the APT adjusted, will I have enough idle and off-idle fuel at basically stock specs? Will that change drastically if I swap over to the Stage1 car (headers and intake, otherwise stock)? Both cars see occasional strip duty.

I went conservative on the idle specs, because even though I stuck to Cliff's "recipe 1"s my last few builds I went too far - they run like hell, but wont idle below 1000 rpm and kinda stink at idle.

Here are my build specs, Sorry the columns don't line up well -
            Stock 79 247   Modded 247
Fuel Inlet     0.125   0.135
Float Level   0.437   0.425
Accel Discharge   0.032   0.032
Idle Tube   0.033   0.033
Idle Channel Restriction   0.046   0.046
Upper Idle Air Bleed   0.059   0.059
Lower Idle Air Bleed   0.079   0.079
Main Air Bleed (upper)   0.047   0.047
Main Air Bleed (lower)   0.047   0.047
Mixture Hole   0.070   0.070
Primary Jets   0.073   0.073
Primary Rods   .056P    inf.
PrimaryPOE restriction    0.025   0.025
Secondary Well restriction   0.040   0.040
Secondary POE Restriction   0.052   0.055
Secondary Tube Restriction   0.026   0.035
Secondary Rods   CZ .0950   CK .0567 L
Secondary Valve Opening   1.188   1.130
Secondary Hanger   L   L

[carmantx]

Does the stage 1 car have the stage 1 cam?  I would think you need to open your idle tube to .035 or so and may want to go larger in jets.  Earlier stage 1 carbs had 75 jets

[Rhett]

It has a KB "cheater" cam in it.  I do have a 76 240 carb on there now that runs pretty good with .039 in the Idle tube (don't ask me where I came up with that spec....but there it is.) and 75 jets, so your point is proven....

I'm really thinking this will be the primary carb for the nailhead for the immediate future.

[Rhett]

I forgot - the .033 spec was the stock tubes. I put in a new set from Cliff that measured .036 right out of the package.

[Cliff Ruggles]

Pretty low float setting for those units, and that will effect the tune some.....Cliff

[Rhett]

I thought so too, but I wanted to start out as stock as I could on the primary side....what would you suggest for float level? Any other changes you'd suggest for this carb in a nailhead application?

I'm just gun-shy these days because I've been going too heavy on idle and main air bleeds and now I have great running carbs that are hard to calibrate at idle...from here out out I start slow and make one change at a time on the primary side...

Thanks for your response - I'll be in touch, I just picked up a 17059249 to play with too and need parts....

[carmantx]

Set the float at 5/16". Or .3125

[Cliff Ruggles]

Did you install one of our kits in it with the correct high flow needle/seat assembly and small float?

I would also use a much better primary jet/rod set-up, the 56P rods are too big on the upper section and not full taper........Cliff

[Rhett]

Brought the float level up to 5/16ths

I did get the parts from you, Cliff - New .135 needle and seat and your tapered rods  -

Are those rods matched specific to the 73 jets, or can they also be used if I bump the jets to 75's and use this carb on the Stage1?

[Cliff Ruggles]

The later style metering rods can be used in any later style carburetor that originally used metering rods with .026" tips.  They will replace "K", L, and "P" rods in all later carburetors.....Cliff