kirkallen143
Famous Member
Howdy,
It has been so while now since I have posted any progress with the turbo vs. carb.
Just to let you know, I HAVE FIXED MY OFF-IDLE/PART THROTTLE leanness!
What it all came down to was legnthening the transitions slots (t-slots)under the throttle blades. Mine where about 0.025" too short and with the position of the blades at off-idle rpm I would not get enough fuel from the IFR'S (Idle Fuel Restrictors (they are in the metering block)) thru the t-slots. Because at light cruise and off-idle you are still working off the idle circuit and NOT YOUR MAIN JETS.
A good rule of thumb when checking your t-slot position, take the carb off and look under the throttle blade at each and you should only see about 0.020" of t-slot showing, nothing more. It should look like a little tiny square. NOTE: this should be done only after you have set you carb to run correctly on the engine. If your carb is set right/runs right, that is how much t-slot you should see under the blades, @ 0.020".
Another thing I did, well seeing if it would help first, was drill a 0.094" hole in the middle of each blade towards the idle and t-slot ports. This made any adjustment on the carb very responsive, whatever to did to the carb. Only downfall is that I cannot get the engine to idle under 750rpm w/ the above mentioned drilled holes (I can live with that). Also I drilled the hole because if I upped the size of the IFR'S in the metering block w/out the holes, it was so rich it would barely run (and burn your eyes).
So it only took me about a year to chase this gremlin of the lean situation at light cruise and part throttle. And all I can say is that I know this holley carb like the back of my hand now.
Kirk
It has been so while now since I have posted any progress with the turbo vs. carb.
Just to let you know, I HAVE FIXED MY OFF-IDLE/PART THROTTLE leanness!
What it all came down to was legnthening the transitions slots (t-slots)under the throttle blades. Mine where about 0.025" too short and with the position of the blades at off-idle rpm I would not get enough fuel from the IFR'S (Idle Fuel Restrictors (they are in the metering block)) thru the t-slots. Because at light cruise and off-idle you are still working off the idle circuit and NOT YOUR MAIN JETS.
A good rule of thumb when checking your t-slot position, take the carb off and look under the throttle blade at each and you should only see about 0.020" of t-slot showing, nothing more. It should look like a little tiny square. NOTE: this should be done only after you have set you carb to run correctly on the engine. If your carb is set right/runs right, that is how much t-slot you should see under the blades, @ 0.020".
Another thing I did, well seeing if it would help first, was drill a 0.094" hole in the middle of each blade towards the idle and t-slot ports. This made any adjustment on the carb very responsive, whatever to did to the carb. Only downfall is that I cannot get the engine to idle under 750rpm w/ the above mentioned drilled holes (I can live with that). Also I drilled the hole because if I upped the size of the IFR'S in the metering block w/out the holes, it was so rich it would barely run (and burn your eyes).
So it only took me about a year to chase this gremlin of the lean situation at light cruise and part throttle. And all I can say is that I know this holley carb like the back of my hand now.
Kirk
