In the tech article in the tech area on TGO, there is an article on how to chose a carb. It says that holley is #1 for making HP and edelbrock is dead last, what exactly is the difference, and what kind of spread are we talking about, also, what applications?

I'm running an edelbrock on my 310, what would the diff be on the dyno if I went to a holley? Does the spread increase as the cubes increase?

Just curious on exactly HOW different they are.

 

bump. interested. would a 650dp holley make more power throughout the curve than a 600edel

 

Both carbs perfectly tuned you will see very little if any difference. I have a feeling the 600 edelbrock would do better on the bottem end due to the velocity valve on the secondaries and the slightly smaller primaries for better velocity. The Holley would probably make a little more top-end HP at the expense of a soggy bottem end.

 

Jester is a Holley true believer and genuinely dislikes all things Edelbrock. So true objectivity is not likely to be found in any of his musings on the subject.

 

Yes, but Edelbrock sucks.

 

FWIW....i ran my car at the drag strip this summer with a 600 edelbrock and a 670 holley street avenger....with the edelbrock i ran a best of 13.67 and with the street avenger i ran a best of 13.56......i know there are still a lot of factors that could have changed from the two different runs......but i must say it sure feels like the holley has a lot more part throttle acceleration than the edelbrock...seemed like the edelbrock just didnt have anything when i was at half throttle...with the holley you can REALLY feel it!! + HOLLEY+ =

 

That sounds to me more like the part-throttle circuits on the Edelbrock weren't tuned as well as they could have been.

 

Reality tends to produce the opposite results. The capability of full flow immediately upon WOT produces more low RPM torque. At the peaks, the Edelbrock & the other demand type secondary carbs tend to produce the same torque & HP as the double pumper type carbs.

 

A vacuum secondary Holley would be another "demand based" carb, although they're quite different from the Edelbrocks, AFBs, AVSs, Thermoquads, Quadrajets and the rest of that "air valve secondary" ilk.

One disadvantage of the Edelbrock Performer carbs is that the opening of the secondary air valve isn't readily tunable without modifying the counterweights.

 

I guess I read "DP" in the first response, then didn't make it clear in my response that was what I meant.

My scenario assumes a mechanical secondary carb vs. any demand-based secondary carbs.

 

Well it was clear to me, just wanted to make sure it was clear to everyone else.

 

is a tenth of a second,
really worth the loss of the capabilities
of carbs with air-valve-controlled secondaries?

am I the only one who uses a Carter AFB most of
the time, but keeps a Holley DP available for
emergencies?

contactpatch

 

What exactly would those "capabilities" be?

About the only one I know of is the ability to compensate for overcarburation. Why would you need that capability? Because you have two cars, one with a 305 and one with a 454, and only one carburetor?

 

five7 writes,
> What exactly would those "capabilities" be?<

streetability,

air-valve-secndary carbs, tend to have
primary-secondary differential bores, {not that
it necessrily needs to be that way}

as compared to, my understanding is that the
vast majority of Holley designs -
pri-sec same diameter, off idle will always
be better, or at least easier to get right,
with a smaller primary.
Note that, for some reason, some people seem
to like the idea of -->
open the primary a tiny amount, and get big power,
I don't.

a-v-s carbs are resistant to, overcaburation bog,
although that might not be important to someone
who has a disiplined right foot.
Even when creeping along , in top gear,
I can floor it, and know that the secondaroes will
not open until there is enough airflow-demand
to suction fuel into the venturi.
This might be a gas savings only, as
I assume Holley gets around that problem
by throwing fuel at the problem,

I realize that it takes some vacuum to open
the valve,{how much that is, I don't know,
when I posted here, no one answered.}
but when the valve is open I assume it is
kept open by airflow. Therefore the only
'loss' to a avs v. a mechanical,
would be at the air-demand just below where
the secondaries will open.

Note that, IMO, special rules seem to apply
to the Rochester Q-jet, because of the Big differntial
in bores, they apparently need to slow down the
opening of the air valve with a vacuum-brake.

 

you might think about a demon if you were thinking about going the holley route. They are a little pricier but, they can be tuned a little better and they are shinier looking (shiny is good).

 

Not looking to switch at all. Was wondering how much of a diff the HP made between the carbs was on a dyno.