General Category > Quadrajet Carb Talk and Tips

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mcx:
Cliff....Picked up this clean  core and on closer examination it appears I have finally come across a dreaded remanufactured!  LOL....the main body  section of the carb has the Idle air passage holes plugged with slugs on both sides.....and the main air bleed in the airhorn is bushed to .0465" but I'm pretty sure it should be the unbushed type  .120",  or abouts on a 1973 Chevy truck...also the primary jetting is downsized to 66 prim jet/40b prim rod, the book says it should be 73/44.... do all remans make these three drastic changes?

Cliff Ruggles:
They make other changes that you haven't seen yet. 

9 times out of ten they will open up the LIAB's, then install HUGE idle tubes to compensate.

They also have a bad habit of drilling out the threads for the N/S assembly and pressing in this POS double "O" ring deal making it so you can't rebuild it.  They ALWAYS leak at the "O" rings.

The process they put them thru (acid bath) also "softens" the material and 99 out of a 100 will leak at just about every bottom plug in them, and the threads strip out easily if you put too much torque on them during the assembly.

I quit taking them in here quite a while ago, and do everything I can to avoid them.

I ALWAYS get a perfect end result if I'm working with a "virgin" unit, about half the time I'll have trouble on the test engine with a "reman" despite my best efforts to rebuild and set it up for the application.

My advice is to move on and spend your time/funds on a nice unmolested core, there are still PLENTY of those out there as they aren't overly popular like the 67-71 Chevy carbs........Cliff

mcx:
Unreal....who do think was the " think -tank" back in the day  to come up with these one size fits all calibrations?    I just took another look at it and sure enough the lower Main bleeds(throat) were bushed , but it was done very sloppy...one side was barely flush and the other was protruding heavily into the airway bore?   I decided to pull out the Main and lower Main and it's back to .120"...I swapped in 74/43 in place of the 66/40....I'll pull a idle tube just to verify....I measured the lower idle air bleed and its.0765", seems it has been enlarged? Other early 70 Chevy were around .0675",  I guess I can try shrinking it or drill/tap a brass set screw.

Cliff Ruggles:
Yep, they do a half-ars job of driving in the restrictions and usually deform the bleed sizes.

I haven't ever seen one that didn't have bent power piston hanger arms, and not just a little bit.  They are usually bent all over the place with the metering rods hanging at different depths in the jets.

It wouldn't matter anyhow, the calibrations are chit and they never perform anywhere near as well as a correctly rebuild original unit.

I tell all my customers not to send any here, they are too labor intensive and I don't like how the acid bath "softens" the material.......Cliff

mcx:
LOL....I pulled out the Idle tubes last night and sure enough they were opened up past.039, as large as I can measure with my micro set...i installed a used pair which were .035"ish.....I checked the down channel restriction and those were at .054"...I'll install some set screws and drill it at .045".
..and I agree I should of just use this for spare parts but I was able to get the base plate APT screw free and was feeling pumped up!!! Its a battle freeing those up.

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