7043202

[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.

[Cliff Ruggles]

You got lucky on the DCR's, they are usually out past .060", and the LIAB can be in the .080-.090" range.

Not sure what they were trying to accomplish with the reman's, but for sure those calibrations are chit.  Then they come along and drive .045" MAB's in them, to fatten them up there as well.

Every single one I've had come thru done in the last 20 years or so has been all hacked up, and calibrations all over the MAP.  Kills me as well how they drive the MAB's into the casting at the wrong angle and oblong the holes.

At least 50 percent will also have those "goofy" pressed in double "O" ring N/S assemblies, making the main casting useless!.......Cliff

[mcx]

I picked up another core 7043202, and everything is spot on except the primary jet/rod...it has  77 jets and a 48 K?   K rods aren't compatible in this core, correct?  I matched it with a B rod and it's not the same length by eye balling it.

[Cliff Ruggles]

Correct, assuming it has Quadrajet metering jets in it.

You could use "K" rods in it if the jets are from a 2bbl. 

I doubt if anyone reading this knows it, but there are 4 different jets available that will fit a Quadrajet, but only one style is correct. 

Quadrajet metering jets have a long tapered area leading to the actual orifice which is pretty deep in the jets.  They make and sell 3 other styles of jets and all of those with have the metering area much shallower, one type is even "flat" on top with the metering area just below the flat surface.

I see the WRONG jets used all the time in troubled carbs that show up here for repairs and custom tuning.

Now there I go, giving away secrets again.....

I'll add this while we're on the subject. I see a LOT of jets that are worn or drilled out far past the size marked on them.  For this reason we install new ones, and almost always new primary rods as well as few of them will check correctly for size........Cliff

[mcx]

No one pays it forward like Cliff Ruggles!!!   Thanks for sharing your expertise. I really wish you would come out with another qjet book...the sequel...MORE SECRETS!!!!!! .I'd buy it , HELL...I'd preorder.

[Cliff Ruggles]

It's been too long but when I wrote the first book my rough draft had something like 77 pages in the "high performance" section alone. 

The publisher wanted the chapters to be pretty much equal in length and photo count, and around 125 pages.....so I had to do some "trimming" to meet their needs. 

I still have a LOT of great information left over that didn't make it into print.

We talked about give the book a "facelift" several years ago.  I had a lot of things come up back in 2015-2016 so had to put things on the back-burner for a while.......Cliff

[77cruiser]

I'd buy it!

[blazer74]

^ ditto.