General Category > Quadrajet Carb Talk and Tips
Float level and other Qs
Macadoo:
Thanks Cliff, that's all surprising info. But the older I get, the more I understand that reality and "sales pitches" are rarely the same.
But at the same time, there's no way I could lower a cast iron intake onto my motor by myself, especially with the motor in the car. Even so, I may keep an eye out for a pre-EGR iron intake on Facebook.
However, I'm stuck with, at the very least, a 1/2 inch spacer because of clearance issues. The bracket I have to use for the 200-4r TV cable interferes with the back runner and needs to be raised.
I haven't seen a semi-open spacer offered on Summit or Jegs so I may have to make my own from hardwood. I've done it before, it's not difficult.
I've already made the timing tape so I'll go ahead and use it (until it falls off). A fellow on the ClassicOldsmobile site made a printable template for the Olds balancer that is spot-on.
What's your take on moving the timing from the mechanical more to the initial, as I've done? A lot of talk on the internet claims that can be beneficial for large cams. I know it has increased my idle rpm, allowing me to back off the idle speed screw. I was too far into the transfer slots before the change. Right now I have a *park* idle of 1100 with no nozzle drip. In gear it drops down to 850.
Macadoo:
Update:
The timing tape was a big help. My dial-back light was jumping all over the place. My old style light and the tape was nice and steady. I've got 19* initial and 17* at the mechanical for a 36* total.
But I'm having trouble with the tip method for the APT. I set it at 2100 rpm and tipped in the choke. RPMs dropped so I lifted the power piston a half turn and tipped in again. RPMs still dropped. I kept turning the screw counter clockwise and kept dropping RPM. I got to about 6 turns out with no difference. So I tuned it all the way in and back out 2 turns. The tip in didn't drop RPMs at that setting but it didn't increase RPMs either.
It runs okay at this setting but wants to stall after a short WOT run. As in every time. Choke is set at 1/4 with 7 psi fuel pressure. Float needle is installed but not through a hole in the choke.
Cliff, what would it cost me for one of your custom Q-jet builds?
Cliff Ruggles:
1100 RPM is too fast for idle speed and you are seeing too much RPM drop when the trans is placed in gear. I suspect some of the mechanical curve is in and falling out when the additional load is placed on the engine.
I don't like to run that much initial timing either, and you shouldn't have to with your combination of parts. For most engines we build and/or tune here we set the initial timing around 10-14 degrees and they will idle great and not "buck" the starter on hot restarts.
We sell custom units outright, no core required, pretty long wait time for them at the moment. Price would depend on exactly what you wanted, and they are all fully restored with plated parts and colored castings.....Cliff
Macadoo:
I can verify the mechanical coming in at the 1100 *park* idle with a timing light, correct? So, Put it in Drive, the mechanical advance that's also increasing the idle speed in park, drops out and lowers the idle speed in gear even more. Kind of a viscous cycle.
But if I take the *park* idle down to, say, 800 or 850, putting it in gear, idle will drop to a point where it feels like it wants to die and the engine rocks in the bay like it wants to jump out of there.
If I wiped a lobe during break-in, it would act like a a sticking valve and show up on a vacuum gauge test, yes?
Cliff Ruggles:
Huge drops in RPM placing the trans in gear is usually distributor related with some timing falling out. This happens if/when aftermarket spring/weight kits are used, or if the stock springs are getting weak or stretched out. I've also seen worn pins and weight holes cause this.
Insufficient idle fuel to the mixture screws can aggravate the scenario, so when a load is placed on the engine timing falling out and not enough fuel as the vacuum signal is reduced causes the huge drop in RPM's and idle quality getting worse.......Cliff
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