Re: My 304 - fixed?

[Darrel Kline <darrelk@domain.elided>]

Tommy wrote:

>Anyhow.. 
>
>Accelerator pump is back to non-functioning essentially.. I have an 
>Orange cam on it (what the carb came with).. it looks to me like the acc. 
>pump is puking it's guts out before the motor actually needs the fuel.. 
>it's quirting out (30cc) awfully quickly.. almost before the motor starts 
>the VR of the ..... OOOOM cycle.  I'm assuming I need the fuel to squirt 
>in there somewhere between the moment I hit the throttle to the floor, 
>and when the motor's vacuum causes the main metering system to catch up.  
>In other words, I'm thinking I'm getting premature pump activation. :)  I 
>had it adjusted somewhat better before, but it still wasn't ideal.  
>
>Anyone know their Holley acc. pump cam colors and characteristics?  
>Darrel Kline's running the same setup I think..

I'm running the brown cam. This is a bigger cam then the orange cam.  More
volume and longer duration. :-)

BTW: These pumps don't put out anything near 30 cc (for 10 strokes). 30cc's
is the maximum possible volume, but in reality they deliever maybe 10-20cc
depending on the pump cam and adjustment. 

You can try the brown cam and see if makes any difference...I would use
position #2. I have found that the pump cam is not that critical unless
your running a very long duration camshaft...which, of course, you're not.
Big cams have slow airflow at low engine speeds, so they need more pump
shot (i.e. fuel) until the air speed comes up and the main circuit starts
following. You have decent vacuum (for your elevation) which is a good sign. 

The brown cam may help hide the problem. Make sure that you have zero
clearance at idle and .015 extra at WOT. Also check where the lever is
located on the cam at idle. Sometimes the lever can be on the wrong part of
the ramp for whatever reason. 

I think in the end you will find some other problem. Like a piece of gasket
material in a main jet, or in the needle and seat, or ???? 

>I think I'm going to the rifle range tomorrow, which is located on 
>MacDonald pass.. that'll be the real test.. can I climb the pass w/o fouling.
>
>Deer & Elk open tomorrow.. but you won't find me out there (yet).. 

I got a Elk on Tuesday in the Flat Tops Wilderness (no road hunters, thank
goodness)...I'll be trying for my second Elk next month. 
You get your Elk and we'll have another cookout at the RMIHR in '99. 

>Hopefully this is it.  :)
>
>Thanks, all.
>
>-Tom Mandera, Helena MT
>http://www.tmcom.com/~tsm1/scout
>'77 Scout II - 304V8 that'll pull a load now?
>'72 rebuild, '77&78 combining into a racer

Darrel Kline
Colorado Springs, CO 
1980 Scout, 304, T19 Close, 4-1 Dana 300
Springover with custom steering, Fullfloating disk-brake Dana 60 rear