Barfly

was scheduled as the last race of the year at the near by Dragway. It was also the day our new Holley 650 double pumper came in the mail. As you might guess we did not get the carb installed for the race..... However! the race was canceled do to rain and re-scheduled for this Saturday!!!!!

The carb has really made the truck SCREAM!! but we still have that darn flat spot (sometimes backfire) when going from a dead stop to wide open throttle.
I thought for sure the Holley would cure this, nope.

Tonight I took the truck to the local repair shop (eeeeeK, I know) to have the exhaust fixed (leaks at the drivers side manifold where the Y pipe is attached) and asked the mechanic if he would take a look at the "fall on it's face" trouble to.

I'm crossing my fingers we are in good shape for Saturday.

67 GTX

good luck at the race
post the results

Archer

Joe -

Thought you'd like it.

Guess you've ruled out the carb as the source of the stumble (OK, technically you haven't, because you didn't say you tweaked it yet), but with the new carb, have you rechecked for vacuum leaks around the manifold or vac lines (brake booster)?

Also, if you're backfiring THRU the carb, you might start having power valve issues. First sign is the engine running rich. The flat spot can be annoying, the backfires can be more serious.

Please keep us posted.

Archer

Barfly

I have heard about the power valve issues with the Holley Carbs, makes me kringe each time it does it. I have a vacuum gauge and at idle 6-700 rpm I have a very steady 18 hg. Of course when I punch it it goes straight to 0.

I am really glad to have the carb regardless of this issue still remaining tho. Man there is nothing like getting rubber at 45 mph coming out of 1st into 2nd . The truck is really running like I knew she should, except......

Here is a link to a video I found on youtube just to give you an idea of what the track looks like.

Wouldn't it be something if fixing that exhaust leak cured the problem (hey what's the smiley for crossing your fingers)

78D200

We can all hope that is the case Joe.

Have you looked at the dizzy? I don't remember if your running a pickup or points. I'm just wondering if the timing is off just that little bit to cause this but is good enough to not be noticed (know what I mean?).

Barfly

When I bought the truck the vac advance unit was shot so I ended up replacing the Dizzy. I have experimented with anywhere from 4* to 12* Before with no mentionable change. It's has a magnetic pickup and came factory calibrated. Recently I tried disconnecting the vac advance altogether, just made it run rough at highway speeds.

Joe.

1966sportfury

sorry