71valiant
Make fast, break, repeat.
Gotcha.
Brass set screws I assume is meant?the stock emulsion bleeds in the metering block were .031 drilled. You can drill and tap for 6/32 brass.
That is good.... So in the metering block, are those 2 sets of 3 vertical holes wide open and tapped with threads? Or are there some inserts in the holes that have very small holes in them? If these holes are wide open, then they should be closed up with emulsion tube air bleeds like 340mderoy describes (or the homemade ones made from set screws as he suggests).
Does the front metering block's same 2 sets of 3 holes have small brass inserts in them with small or no holes?
340mderoy, where are you getting the bleed and jet info for this? Just curious....
OK, just don't want them to be missing. Hard to see down in those holes via the internet!I dont recall them having any. I will pull it apart again tonight and be totally sure. I'll snap some pics as well.
OK, tnx, good info. My son and I are going to be working on his 670 Avenger for fuel mileage and the data points are good. That is, after we try my old 6619 to see how it fares on his engine for mileage.Demons I have run rich on the idle circuit (idle - approx 2500 rpm) After 2500 the Primary Jet comes in. I always go smaller on the IFR to lean the idle circuit, smaller PMJ to lean highway cruise, and bigger on the PVCR to richen WOT when the PV is open up front.
Yes, the inners looked abnormally big. Sounds like you are pretty close to a good baseline now. When I saw the inners drilled out, and the rather largish air holes in the primary throttle blades, my reaction was 'uh-oh, what else has been changed'.....And the outer air bleeds are #50 drill bits. The inners are #51 drill bits.
****. Can I send you mine. You seem to know what the hell youre doing. LolI have a 650 and 750 demon I run on my car.
All the info used to be on the demon website but since holley took them over it is gone.
I have drilled and tapped the emulsion, IFR, PVCR for 6/32 x 1/8 brass set screws and tuned both of my carbs.
The 650 and 750 metering blocks are the same and have 3 .031 drilled holes for each tube.
IFR is .031
PVCR .059
Demons I have run rich on the idle circuit (idle - approx 2500 rpm) After 2500 the Primary Jet comes in. I always go smaller on the IFR to lean the idle circuit, smaller PMJ to lean highway cruise, and bigger on the PVCR to richen WOT when the PV is open up front.
And the outer air bleeds are #50 drill bits. The inners are #51 drill bits.
The #51 .067" is way to large for a MAB and explains why the PMJ and SMJ are so small. The previous owner made the mistake of trying to lean a 750 to work on a mild engine.
This is what I would do:
- Get your ignition curve set. Your combo needs more initial timing to clean up idle and throttle response. Get initial around 26* and total mech 34*.
- Move the #51 .067" air bleeds to the outer holes (IAB)
- Put the new .039 air bleeds you bought in the inner holes (MAB)
- Use a 65 PV up front, leave rear plugged.
- Change primary main jet (PMJ) to 75, change secondary main jet (SMJ) to 83
- Set the throttle blades up front to .020, set rear blades to the point you just see the transfer slot appear.
- 31 accelerator squirters front and rear. You may need a 33 up front.
- If you have an AFR gauge get the motor to idle around 12.9 AFR in neutral 1000 rpm engine fully warmed up.
- Disconnect the secondary linkage and drive the car as a 2 barrel. Tune the front of the carb to get crisp throttle response (you may have to change the ignition curve to really dial in)
- Hook up secondary rod and dial in WOT.
Yeeeeah! He brought it back and said.... "May need to turn that timing down, I got some pings"
NOOOO ****?!?!