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Everyone,
I recently finished installing my S&S motor. I had the Holley Truck Avenger on the old motor and it ran fine. The new motor has a little higher compression and a different cam, and the carb need tuning. Bear in mind that I live in the Phoenix Valley, and the air is hot and thin.
Anyway, I had a steady stream of black smoke coming from the tail pipe when cruising down the road. I reduced the size of the primary jet from the factory 68, to a 65. The smoke is now gone and the car feels better. However, when I hit the gas fairly hard from a stop, the truck hesitates really bad, sometimes throws a small backfire through the carb, and then takes off. This I assume is the accelorator pump. My question is, for those of you with a Truck Avenger, which position do you have the acc. pump on, 1 or 2? Secondly, did you change to a different accelorator pump cam? When the truck heisitates, there isn't a black puff that comes out the tailpipe, so I know it isn't too rich of a shot. Do I need to try a different accelorator pump all together?
Finally this weekend I put enough miles on the jeep to feel comfotable taking the truck into higher rpm ranges. My base initial timing is 12-13 degerees BTDC, and the Z&M HEI dizzy puts approximately 16-17 degrees of mechanical advance for a total of about 29 degrees. What I noticed, is that the truck pulls nice and smooth through second gear until I hit about 65 mph (Second will go just past 70). At that speed, the truck surges and can not accelerate any faster until I shift into third. It feels like it hits a speed limiter and just kind of bucks and surges until the rpms drop down in third. I was always told that surging is a sign of a lean mixture, however, I have also read that the 89 secondaries are too large. For the record, I have never hear this engine ping yet, and it runs nice and cool out here in AZ 100 degree nights. What should I be looking at to solve the surging problem?
Thanks for any insite.
Kevin.
I recently finished installing my S&S motor. I had the Holley Truck Avenger on the old motor and it ran fine. The new motor has a little higher compression and a different cam, and the carb need tuning. Bear in mind that I live in the Phoenix Valley, and the air is hot and thin.
Anyway, I had a steady stream of black smoke coming from the tail pipe when cruising down the road. I reduced the size of the primary jet from the factory 68, to a 65. The smoke is now gone and the car feels better. However, when I hit the gas fairly hard from a stop, the truck hesitates really bad, sometimes throws a small backfire through the carb, and then takes off. This I assume is the accelorator pump. My question is, for those of you with a Truck Avenger, which position do you have the acc. pump on, 1 or 2? Secondly, did you change to a different accelorator pump cam? When the truck heisitates, there isn't a black puff that comes out the tailpipe, so I know it isn't too rich of a shot. Do I need to try a different accelorator pump all together?
Finally this weekend I put enough miles on the jeep to feel comfotable taking the truck into higher rpm ranges. My base initial timing is 12-13 degerees BTDC, and the Z&M HEI dizzy puts approximately 16-17 degrees of mechanical advance for a total of about 29 degrees. What I noticed, is that the truck pulls nice and smooth through second gear until I hit about 65 mph (Second will go just past 70). At that speed, the truck surges and can not accelerate any faster until I shift into third. It feels like it hits a speed limiter and just kind of bucks and surges until the rpms drop down in third. I was always told that surging is a sign of a lean mixture, however, I have also read that the 89 secondaries are too large. For the record, I have never hear this engine ping yet, and it runs nice and cool out here in AZ 100 degree nights. What should I be looking at to solve the surging problem?
Thanks for any insite.
Kevin.
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