If the power valve is blown it will idle with the mixture screws all the way in.
How?
If the power valve is blown it will idle with the mixture screws all the way in.
The secondaries are almost closed. I cracked them open about 1/3 of a turn on the screw.What about the secondaries?
The secondaries are almost closed. I cracked them open about 1/3 of a turn on the screw.
Dart_68,
A lot of things are not adding up.....
Only 5" of idle vacuum, & you want it to idle at 700 rpm? I doubt that will happen.
If the low vacuum is from a long duration cam, hard to believe that both pri & sec t/blades are almost closed, because the engine should need a lot of bypass air for it to idle. The engine gets this air from opening the t/blades further, drilling t/blades, etc.
Do you know the cam specs & comp ratio?
I wonder if the PCV [ if used] is part of the problem. Probably open at idle, admitting a lot of air, hence t/blades not reqd to be cranked open further.
Don't know yet, was 4. I'll have time to run it either late tomorrow or sometime Saturday.
Here are the cam specs as provided by Oregon Cam Grinding.Crap, what's the duration @.050"?
Here are the cam specs as provided by Oregon Cam Grinding.
Cam lobe lift .359 intake .372 exhaust
Duration @ .050 - 235/247
Lobe separation 110
Intake center line - 106
PVC is connected to the throttle plate port on the back of the carb and gets full manifold vacuum.You got somethin WRONG. There's no way in HELL that cam is not pullin more vacuum than it is. Maybe a wrong gasket in the carburetor....internal vacuum leak or somethin.....Hell, my slant 6 pulls more idle vacuum and it has [email protected] on a 108. Let's go the direction Bewy was.....are you running a PCV valve? If so, yank it off and plug the port where it's plugged in....and that IS in the carburetor, right?
As an FYI, I've looked for vacuum leaks elsewhere and can find none. No uncapped or unused ports, no leaks around the base of the carb or intake. Only place I can't look is the underside of the manifold.You got somethin WRONG. There's no way in HELL that cam is not pullin more vacuum than it is. Maybe a wrong gasket in the carburetor....internal vacuum leak or somethin.....Hell, my slant 6 pulls more idle vacuum and it has [email protected] on a 108. Let's go the direction Bewy was.....are you running a PCV valve? If so, yank it off and plug the port where it's plugged in....and that IS in the carburetor, right?
It CAN idle at 700...it just doesn't like it. 850 is far more stable.Dart_68,
A lot of things are not adding up.....
Only 5" of idle vacuum, & you want it to idle at 700 rpm? I doubt that will happen.
If the low vacuum is from a long duration cam, hard to believe that both pri & sec t/blades are almost closed, because the engine should need a lot of bypass air for it to idle. The engine gets this air from opening the t/blades further, drilling t/blades, etc.
Do you know the cam specs & comp ratio?
Lol, can't or don't want to. (Just kidding) Could you possibly be pulling air from an internal heat crossover leak?...Only place I can't look is the underside of the manifold.
Well, the intake is a Holley Street Dominator so there is no heat crossover passage. However, it does have an EGR mounting pad but I've checked that for leaks.Find someone with a known good carb you can test your Holley against?
Lol, can't or don't want to. (Just kidding) Could you possibly be pulling air from an internal heat crossover leak?
Well, the intake is a Holley Street Dominator so there is no heat crossover passage. However, it does have an EGR mounting pad but I've checked that for leaks.
Perhaps you're correct but the heads are Speedmasters and they don't have a heat crossover.If it’s a STREET Dominator it has a heat crossover. If it’s a STRIP Dominator it doesn’t have the crossover.
Its a 3310-2 VS 750 CFM. Air bleeds are not adjustable. Only things you can readily adjust are idle fuel mixture via the screws, main fuel mixture via standard jets and PV, secondary main metering via a plate, primary and secondary throttle blade positions, float level, and VS opening rate via a diaphragm spring.Can we get a list or model number? How much adjustability does the carburetor have? Air bleeds? Fuel restrictors? What exactly are we talking about in a carburetor here?
Its a 3310-2 VS 750 CFM. Air bleeds are not adjustable. Only things you can readily adjust are idle fuel mixture via the screws, main fuel mixture via standard jets and PV, secondary main metering via a plate, primary and secondary throttle blade positions, float level, and VS opening rate via a diaphragm spring.