I'm curious, when installing Holley acc. pump cams do the numbers on the cam face out towards the sides of the car, or in towards the carb? I've fiddled with them so much I have no idea anymore...seems like the different ways would give two completly different curves and shots. Just trying to track down a bog I'm getting off the line and need a starting point.

Also, if I want to install the pump cam in the #2 position, do I install the screw both in the #2 position in the actual lever hole that is physically attached to the carb and the pump cam, or do I keep it at #1 and just put the cam in the #2 position?

Thanks for the info- I already checked Holleys website but it wasn't very helpful.

If I remember correctly, the numbers on the cam will be towards the carb. They will want to be in the same order as the numbers on the throttle lever. #1 on top and #2 on the bottom. The ends of the cams have a tab/notch, the long side of the tab goes towards the throttle arm....

Put the screw in the #1 throttle hole, and the #1 cam hole for #1 position. Put the screw in the #2 throttle hole and the #2 cam hole for the #2 position. It doesn't look like it moves it much, but it does move the position of the cam just a little bit. And it can make a big difference sometimes.... Good luck!

chris

Thanks for the reponse, very helpful!

While you are working on this, make sure to check the obvious. Eliminate all vacuum leaks and check the pump adjustment. Just last week I fixed a bog that was the result of an accelerator pump that had way too much clearance.

What is the correct asjustment for the accelerator pumps? Is it the same for primary and secondary?

Holley pump adjustment (http://www.holley.com/HiOctn/TechServ/TechInfo/TI-221.html)

Holley can explain it much better than I can.... smile.gif

Chris

just to clearify which way the cam goes in......the numbers on the cam itself goes to the outside of the car facing the fenderwell........if you point them inward (flipping the cam over) then you would have #1 down and #2 on top which is back wards.....

face the numbers to the outside fender and place #1 in the one position or place #2 in the #2 screw hole........

the #1 slot makes the pump cam start sooner and the #2 hole makes the pump cam start later...........

the smallest to the largest cams are in this order.......
white #218
blue #427
red #240
orange #466
black #234
green #290
pink #330
brown #336

the last three pump cams are the really big shots this give way higher lifts then the others.....

white cams are economy stockers.....

hope this helps