I’m unsure as Rochester doesn’t stamp the sizes on the outside of the jets like Holley does, but a .067 numbered drill bit fits loosely through it. And the next size .070 bit is too big.
Does that help?
At my wits end with this QuadraJet
- Thread starter Rktpwrd
- Start date
- Status
I’m unsure as Rochester doesn’t stamp the sizes on the outside of the jets like Holley does, but a .067 numbered drill bit fits loosely through it. And the next size .070 bit is too big.
Does that help?
Yep, and I’ve just blown air through them as a double check. They’re clear and flowing freely.
I added 44k primary rods, 71 jets in the Holley reman and 73 in the factory 403 carb. Both ran awful on my 350. I was going to suggest drilling holes in the primary plates but you don't half as anything. Man, 69 rods are huge, the jets must be around a 90.
Sorry, my apologies. The SECONDARY rods are 69’s. The primary’s are hard to read, but they appear to be either 37 or 87k’s.
Secondary rods should be letters. I am betting 37K primary rods and that jet size sounds right. I added a thread I plug and notched the APT adjuster, it made a difference at the track, turns out and mileage as well, turns in.
Well then I’m totally ****ed up. Don’t know where in the hell I got “69’s” from, it’s just what I had written down on my rebuild sheet.
Examining the secondary rods tonight, it appears that they’re “DP’s”???
Any idea what the primary and secondary jet sizes would correspond to with those rod sizes?
Secondary jets are fixed and only one size. Usually the rule is the jet should be .030" larger than the primary metering rods. The DP secondary rod is very lean, most are CV rods with various hangers, H through M for hangers, lower letter raises the rod more. Here is the Qjet secondary chart.
http://tech.oldsgmail.com/carb_sec_rods.php
http://tech.oldsgmail.com/carb_sec_rods.php
Thanks for the info. I feel so woefully inadequately informed on these things. I’m trying to learn and soak up all this stuff as quickly as I can.
So my secondary hanger looks like this...
...does that mean it’s an “I” hanger?
OK, sorry if this was covered and I missed it D. And, if the following seems "overly" rudimentary, this is the way I talk to my brain, not yours, OK?
Once hard to the floor and the choke should set. Is this happening? Does it cold "fast" idle and idle smoothly under choke? No, your problem actually starts here.
If yes, once warm and the choke relaxes [does the choke relax?], you should be able to lightly tap it off the fast idle cam to the 2nd position [my 87 it is like 1400rpm down to like 1050]. Does it idle "smoothly" in this position? No, the problem starts here.
Once it idles in position 2, a light tap should knock it off the fast idle cam to the idle screws down to where ever they are set. Is this where the problem is? If so, screw them in until it will idle. Then see if you have gone so far as to actually crack open the primaries. That is what my big block initially required.
So, on my big block, I had to take the idle bleeds to .056 and I chose adding the small air holes [I think .075 but it's been a while] to the primary butterflies on my CCC. Yours being just a small block, with a relatively mild cam, yours should be fine as is. Also, if you have ANY kind of vacuum problem, the engine will not get enough fuel and lean out badly enough to die where it maybe doesn't on choke or fast idle or by feathering the throttle.
And I've had thermal vacuum leaks before that cured themselves when the engine heats up. A real PITA those can be. But, not enough fuel even when the choke is no longer involved because of the leak, then the gasket or seal seals the hotter the engine gets.
Once hard to the floor and the choke should set. Is this happening? Does it cold "fast" idle and idle smoothly under choke? No, your problem actually starts here.
If yes, once warm and the choke relaxes [does the choke relax?], you should be able to lightly tap it off the fast idle cam to the 2nd position [my 87 it is like 1400rpm down to like 1050]. Does it idle "smoothly" in this position? No, the problem starts here.
Once it idles in position 2, a light tap should knock it off the fast idle cam to the idle screws down to where ever they are set. Is this where the problem is? If so, screw them in until it will idle. Then see if you have gone so far as to actually crack open the primaries. That is what my big block initially required.
So, on my big block, I had to take the idle bleeds to .056 and I chose adding the small air holes [I think .075 but it's been a while] to the primary butterflies on my CCC. Yours being just a small block, with a relatively mild cam, yours should be fine as is. Also, if you have ANY kind of vacuum problem, the engine will not get enough fuel and lean out badly enough to die where it maybe doesn't on choke or fast idle or by feathering the throttle.
And I've had thermal vacuum leaks before that cured themselves when the engine heats up. A real PITA those can be. But, not enough fuel even when the choke is no longer involved because of the leak, then the gasket or seal seals the hotter the engine gets.
I have the Cliff Ruggles book Donovan. I’d be happy to let you have it. I’m not gonna mess with a carb ever again. Lol
I wouldn't worry about the secondaries until you have the primary running right. If you have the rods and jets that the carburetor came with the engine will run with that carburetor. It may be lean but it will still run
- Status
Similar threads
