Thread: Project Special K

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IMHO, there is nothing wrong with Edelbrock (aka Carter/Weber) carbs. They perform fine, they do the job just as well as any carb does. They tune differently than Hollies and this is where the bad press comes from. Holley uses a power valve for fuel enrichment under load, Edelbrock uses meter rods. Both methods serve their purpose and provide fuel enrichment under load conditions. However they tune differently, and this is where the confusion and trouble comes from.

Most of us do not take the time to fully understand the functions and operations of a carb, let alone two different designs. Hollies are more forgiving in some areas, while Edelbrock are in other areas (function & tuning). I've used both designs on numerous vehicles and like them both. The caveat with either design is tuning. A carb is a mechanical device the meters fuel into the engine via linkages and vacuum (manifold and venturi), for it to function and give the best performance it must be tuned to operate within its perimeter to the engine it is installed on. Remember the guy you went to school with that always had the faster car? Even when someone else had the same make and model his was faster. SECRET, he knew how to tune.

"Stovens" back to your question about accelerator pump fitting.

Edelbrock uses two different pumps, the only difference is the spring, a weaker spring is used on the smaller carbs, a stonger spring on the larger carbs. Length and diameter are the same, adjustments are made to the linkage arm to tune the pumps operation (three holes), but also the linkage rod can be bent at the knee to further adjust the pumps action. And, keep in mind the two spring tensions can be used to aid in tune as well. The weaker spring will produce a lazier but longer duration of fuel (slower/longer squirt), the stronger spring will be quicker with less duration (sooner/shorter squirt).

BUT, before we get into pump tuning, let's make sure there isn't another tuning issue first. Believe it or not, a lot of carb issue are caused by the ignition. Low initial timing can cause the carb's throttle stop to be adjusted too high (idle speed adjustment) to raise idle RPM, when this happens the carb is operating partially through the transition circuit and when you accelerate there is insufficient fuel enrichment to prevent a lean stumble. The solution is to raise initial timing and lower the throttle stop adjustment. More initial time will raise the idle speed allowing the carb’s throttle stop to be lowered and operate on the idle circuit (mixture screws), then as the throttle picks up the transition circuit adds fuel along with the accelerator pump, enriching the fuel mixture and preventing a lean stumble.

The caveat with ignition timing is, when you adjust initial timing (up or down) TOTAL timing must be checked and adjusted if needed.

Sorry for the book……….

We'll agree to disagree. AFB"s, IMHO, are fine as long as you don't have to open it up.
In 64 while I was in the Marine Corps a good buddy stuffed a Caddy 331 in a 57 Del Ray and he was having a devil of a time trying to get it to run right. It had a Carter AFB that was all messed up. another good buddy who was somewhat of a carb guru at the time spent an hour or so trying to get the floats adjusted. It was a lot of trail and error but he finally had it running fairly well. later I ran him with my coupe, 36 5 window running a 301 with 2-4's and smoked him pretty bad.
Moral of the story: with a Holley all that would have need to be done was open the sight glass on the front fuel bowl and adjust from the screw on top, 5 to 10 minutes tops.

Ken, I agree and I’m not trying to argue, but as I said, some areas of each carb’s design are easier on one than the other, and visa versa.

IMHO, Carter/Weber/ Edelbrock has a very specific adjustment for float height and drop, get it off and your troubles begin. Set the floats too high and the gas spills through the bowl vents flooding (bowl vent are low in the horn on this design), set the floats too low the jets are starved (I forgot to mention pressure differences in the operating aspects). Set the float drop too low and the gas doesn’t cover the jets fast enough to prevent them from pulling air, set the drop too high and the needle doesn’t open enough to fill the bowls fast enough to keep up. It’s a quirk to the design.

However, small jet changes and power enrichment is a breeze on the Edelbrock design. Simply change the rods to lean or richen the mixtures, yes mixtures, both main jetting and enrichment can be adjusted by the rods. And, simply change the rod springs to bring power enrichment in sooner or later. Two screws and a few minutes is all it takes, no gas spills, no gaskets. Holley’s, not so easy, you have to drain and pull the bowls to change jets and remove the metering block to change a power valve.

Agree there’s more aftermarket tuning support for the Holley design, and in most cases it is better suited to racing. I guess what I failed mention in my earlier post is both designs have there pros and cons, so it’s usually boils down to an individuals preference and knowledge.

IMHO both designs have their merits, and the bottom line to either is tuning, tuning will give you more horse power and reliability than you ever expected.

true enough. both designs have good and bad built in. Myself, I'm a holley guy. Just found them easier and less fussy.

Like Ken I grew up with WCFB's, but I didn't find setting the floats to be difficult as long as you had the gauges in the rebuild kit and followed directions, or at least followed directions. Now if you pulled the top and decided to adjust by the seat of your pants? I can see that being a bit frustrating, but why would you do that?

I agree with Bob, it's a matter of personal preference, but I'd say more important is the individuals knowledge and understanding. For me? If I have a problem I'm going to go visit Bob/36 sedan

Originally Posted by rspears

For me? If I have a problem I'm going to go visit Bob/36 sedan

I hear you on that.
I've been reading his comments; that bloke has forgotten more than I have ever known about carburetion.
And I know even less about computerised fuel injection. Just spent NZ$4000 on getting the bus running sweetly.
The man spent sixteen hour on it.

What do you know about fuel injected computerised systems Bob/36 sedan? I'll pay your airfare out here!


(Well... maybe not...)

Update. I'm pretty sure the fuel pump is the root of all the starting problems. No gas getting to carb or even before the fuel filter. Considering this is 10-12 years old now, and it's a cheap 20 dollar Carter stock pump. So I ordered a Edelbrock fuel pump designed for my Edelbrock performer set up between manifold, carb and this they should all work better together. Don't remember seeing these the first time round.
DETAILS
Edelbrock part #1726 Performer RPM Series fuel pump is for 429/460 Ford designed for use with all Edelbrock carburetors used in Performer or Performer RPM applications. These high-performance's street Fuel Pumps feature a high quality three stage polished finish. The unique valve design improves flow quantity and quality, and will support engines up to 600 hp. High-volume, 3/8" NPT inlet and outlet surpasses the capacity of conventional models. Produces 6 psi and does not require a regulator. Use with gasoline only. Clockable lower housing can be rotated in 60 Deg Increments for best inlet/outlet alignment.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

It comes today so on next day off I'll install it and one fix the problem or 2 rule out problem. I did fill gas tank before trying to test fuel pump!

That's a really nice pump, but IMHO, it should be gold plated at that price. Since you can reclock the bottom that means it's also rebuildable, that is if you can find the parts.
But for the peace of mind I guess it's worth what you paid.

I'm guessing it will hold up better to ethanol as it is a new and probably better design. At least that's my hope I can't imagine it being worse!
Also investing in this product from Mikes Carburetors
https://www.carburetor-parts.com/Eth...e-_p_5986.html
he has some good youtube help videos too

They also sell on amazon for same price , and in 32 oz size which I went for at $27.99.

Sta-Bil has an Ethanol treatment stabilizer, too..
https://www.amazon.com/dp/B0081ZVBDQ...ing=UTF8&psc=1

Roger I haven't had much luck on the seldom used vehicles with stable, as I think it only adds 6 months of stability if I remember the packaging details. California adds a bunch of products to gas here that make our gas difficult to store long term, and also cause trouble in the 89 Softail Harley if tank isn't full with eating tank liner out of tank. Must be oxidative process due to too much air in half filled tank? Anyway after a winter project of going after the Harley carb issues with Stable in the gas tank, I switched to adding SeaFoam as additive instead. Seaform can protect up to a year or more, is completely combustible and does an amazing job dissolving particulate gunk from jets, and carb floats. What caught my attention with this product was the carb specialist from Mikes carburetors online and his accolades for the the specific ethanol protection from this product. It seems from this add it is much more cost effective as well as has the most benefits of all the products it was compared with. I figure it's worth a try! I will give feed back as the year progresses on it

Looks like it should be good!

I've basically stopped buying ethanol blend fuels, opting instead for ethanol free. People say it costs too much more, but they don't consider the increased energy improving efficiency/MPG. Especially this past year, my truck has a 36 gallon tank, and I've only put about 3000 miles on it in 12 months!

Thats our main problem here, very hard to find anywhere but airports in the whole county for ethanol free gas. classic california move, we already on average spend 1.00 more per gallon of gas compared to rest of country, even states who have to truck gas from oursame refineries, over 500 miles more , pay a buck less!