Billy - I found the part number you referenced before - its a CARDONE # 30-2808  ($40.99 + $10.00 core chg.)

The photos show an "Autolite" style distributor of the '57 and later variety - so it should be workable. It is shown with a vacuum pot that adjusts as shown below.....

It uses a 3/32 or 1/8 hex key wrench inserted into the vacuum nipple opening to adjust the preload on the spring. Turning the wrench CLOCKWISE (CW) backs off the preload on the spring and thus increases the advance for any given amount of applied vacuum. You may find its already all the way in this direction.

Turning the wrench COUNTERCLOCKWISE (CCW) moves the internal adjustment nut toward the spring loads it up and decreases the amount of advance at any given vacuum level.

Might help to squirt some lube in there - WD40 - becauses sometimes the nuts are tight -and you don't want to strip the threads! A little care goes a long way here..... Just don't force it, you'll be fine.

When the Holley 4160 type carb is running at idle - the upper, "ported vacuum" outlet (on the passenger side of the primary metering block) should not have any vacuum signal. Do you have one as it sits now? 

 

 
 Steve Metzger       Tucson, Arizona

Which distributor do you have?

Does it look like this with the cap and rotor off? (Load-o-Matic) has "straight" points/ two visible springs

Or does it look like this later model Motorcraft shown below? - has "curved" points - no springs showing

If it is the "Load-o-Matic" - the modern "4160" style Holley has no ports that will provide the equivalent vacuum signal to the early distributor. 

 
 Steve Metzger       Tucson, Arizona

Take some time to see just what you're mechanical advance is doing. Some of them will provide as much as 36 degrees of mechanical at the crank. Combined with springs that allow it to come in too fast, it could be contributing to you're problem if it's not the cause. With some help, you can make a graph in several hundred rpm increments to see just how much advance you have, how fast it comes in, and when it is all in. Don't trust that they remaned the distributor to the correct specs.


Lawrenceville, GA

Thanks for the reply. I am using the vacuum port that increases the vacuum when accelerating.

the carquest carb is for 56"and up "y" blocks

Hi Steve,the trans is auto. I have been using the vacuum port that increases above idle. I tried changing ports, and the idle increased. What would correct the vacuum advance being wide open? Thanks again...Billy

Hi Billy - Thanks for the aditional info, clears things up a bit. It sounds to me like the vacuum advance pot on the distributor is set "wide open". In that situation - at idle where vacuum is maximum - its going to kick things up quite a bit when operating on live manifold vacuum - more than you would want it to be. Is this a stick shift car - or an auto? The 6° initial is typically factory recommended for an auto I believe.

These graphs are in the mid-seventies Ford training information for distributor service techs....they are typical values for Ford distributors - not exactly what every last one is set up at. As you can see on the upper chart, at vacuum reading of 10 to 15 In.Hg. (inches of mercury) - the added advance in distributor degrees could be as high as 10°. That would equate to 20° at the crank. So when you add the vacuum advance to your initial - you could get (for instance) 6° plus the 20° - making the advance go to 26° - if the engine did not increase in idle speed (which I'm reasonably sure it does).

On the second (lower) graph - at 500 distributor rpm (1000 engine rpm) the mechanical advance of the distributor is shown as 3-1/4° to 4-1/2° - which is doubled at the crank, so now its up to a range of 6-1/2° to 9°. This - added to the inital and vacuum numbers seen above - gets you up to 32-1/2°/35°. So its very possible to be creeping near to the 40° you are speaking of.

The Holley carb most likely has two small vacuum control ports - one of them should only provide a vacuum source when the engine is revved up off idle - ported vacuum - have you tried using that one? It might help this situation out without having to get too deep into retuning the car. 

 
 Steve Metzger       Tucson, Arizona

Billy, are you sure you are using the timed vacuum port. If you are using the full vacuum port full vacuum advance would be applied as soon as you hooked up the vacuum line. 34 degrees is still a lot of vacuum advance though. Mike

1956 Fairlane Victoria (ORREO)

 

Overlooking Beautiful Rimrock AZ

I can't figure out how to use the Carquest website. Is that distributor, REB 30-2808, the correct one for your '55 or is it for '57 and up?


Lawrenceville, GA

Hi Steve, thanks for your assistance. Here is the info you need. The correct timing is 6 degrees BTDC, This is with the vacuum disconnected, With the vacuum connected, the reading is 40 degrees at idle. The idle is set 700 rpms, there are no vacuum leaks, and the holley carb is 600 cfm. Again thanks for your assistance. If you need to talk too me call me collect at 352-854-8142..Billy