Welcome to the Corvette Forums at the Corvette Action Center!

Holley or Edelbrock

C

cmegga

Guest
I have a Edlebrock 750cfm carb, with electric choke. I has been being a bit difficult to get the choke set right. i takes a good 10 - 15 min. of running to keck it off.

My mechanic thinks I should just switch to Holley double pumper. He thinks it will make a big performance diffrence for me. He said about 30-40 hp.

Any one ever compared the two. I have a rebuilt 350 boarded 20 over, with a 3000 rpm crane cam and edelbrock rpm aluminum heads.

What do you think?? Is it worth the investment to give it a try.
 
Joined
Apr 18, 2002
Messages
1,441
Location
Staten Island, NY
Corvette
1999 Torch Red Coupe
No way will it give you 30 to 40 HP differance. Chokes have always been problematical, and I do like Holly carbs the best, they have easy adjustments and a very large amout of available parts like jets and such, Edelbrock carbs seem like rebuilt Q-jets, or they did when they first came out.

I have had better results on my old Pontiacs (2 GTOs and a few 400 powered 74 Grand Ams) with Holly carbs, did try an Edelbrok carb a few times, liked the Holly better, but no major gain in power if the application was correct in the first place and the unit was in good shape.

A doulbe pumper may be a bit much- Is your car an auto or 4 speed?
 
C

cmegga

Guest
Its a 4 speed automatic. However I do have a good stall speed around 2000 rpm.
 
B

Bullitt

Guest
Avoid the double-pumper. It's just overkill really for a street car. I've tried both Edelbrocks and Holleys and like them well enough. Back in '97 when Holley had a strike or something, I couldn't get a rebuild kit for mine, so I had to go with a Edelbrock since the price was so good. My uncle tuned it and liked the Eddy too. That Camaro was flying sweet!

What I really want to try is a Speed Demon. Once I can justify the need to buy another carb. (forgetting about my almost-new Holley) then I'll splurge. :)

--Bullitt
 
S

Scott81

Guest
I have an AED Holley 750HO(4150 no choke) and man does that thing pump the gas! But on the other hand my motor is just barely streetable (according to my tuner anyway) and was originally set up for running mostly at the strip. Can't tell if it's better or not but it works and that's all that matters. I am going to have to learn more about it so I can work on it myself. My gas milage really sucks, but the car goes like it's on fire :D

My uneducated opinion is that as long as you have good fuel/air flow stick with what you have.

Bullitt- if you're looking for a Demon I found them on RaceSearch.com for $399. I looked all over for about a week and that was the lowest price I found. I was thinking about getting one but decided to spend the money on other more necessary mods for now.
 
Joined
Apr 18, 2002
Messages
1,441
Location
Staten Island, NY
Corvette
1999 Torch Red Coupe
The double pumper is not good with an automatic, you dont want to power brake every time. I used the 4150 and the 4165s and a 4 speed is a must (Or 6 speed).

But at any rate, dont count on seeing that much extra power from either even over a stock Q-jet
 
P

page62

Guest
There's two flavors of Edelbrock carbs: Performers (aka Carter AFB) and Q-Jets (aka Q-Jets). Which do you have?
 

maxrevs85

Well-known member
Joined
Dec 17, 2001
Messages
709
Location
Eaton Rapids, Mich
Corvette
!985 ,blue coupe, 4+3 Z51
Definitly go with the 4150 Holly . The extra HP is there and can yield 30 Hp . the Eddy just doesnt breath as well and the Holly is much easier to tune . The choke deal on a modified engine is never going to work right . The bigger cams just dont like a cold engine and it will be hard to get the choke set to work well.
 
C

cmegga

Guest
I have the performer series carb, with the rpm manifold. If I do switch to a Holley, can I run the same manofild or will I have to switch that as well. The carb I have now has the 2 small barrels and two oversized secondaries, is this the same on Holleys or are they all the same size ??
 

Tom73

Well-known member
Joined
Aug 21, 2001
Messages
1,427
Location
Round Rock, TX
Corvette
73 LS4 Coupe - 04 CE Conv
The Holley vs Q-jet is a battle that has been going on forever and will never be settled. Both are good carbs. The Q-jet (or Edelbrock) is a great street carb. Once you get it set right just forget it. The Holley is great because of its adjustability. Easy to change jets and make adjustment to. That is great for the strip, you can make changes between runs. Very hard to do that with a Q-jet. But for the street the adjustability is almost meaningless. Once you get a street carb set you leave it alone. You don't change jets between stop lights. So the Holley's adjustability is almost wasted on a street car. Me? I would stay with the Edelbrock.

tom...
 
P

page62

Guest
You have a spread-bore carb, but the Holleys are square-bore. So you would indeed have to change manifolds.

You can fix the choke a lot cheaper than getting a new carb. They're not THAT difficult to fix. (It sounds to me like the electronic sensor is malfunctioning, so the bimetal spring is not releasing the choke until the carb itself warms up!)
 
W

wolf_walker

Guest
Your fuel millege will likely also drop with a Holley, don't know if that's a concern or not. How high does it idle? I see a lot of q-jet and similer carbs on big cam high idle motors have trouble because there not idleing in the idle circuit, past it's limited RPM range. One quick fix is to drill holes in the primary throttle valves to increase air flow at idle throttle settings. Then you can tune things. There a good carb, Mopar used the Carter AFB, which is about what that Edelbock performer is, on many healthy motors.
Not that holley's are bad, just different.
 
Joined
Apr 18, 2002
Messages
1,441
Location
Staten Island, NY
Corvette
1999 Torch Red Coupe
Holly carbs come in spread boar or square boar, I had them both.
The 4165 is a replacement for a stock Q-jet with small primarys and large secondary boars, fuel economy should not suffer if you get the right size. There are many adapters to put either on a square boar manifold but performance will suffer.

I dont care what anyone says, you will not get 30 to 40 HP from just a carb change alone. (unless the previous carb was just wrong for your application, or worn out and needing a rebuild).

Holly has a very good tech line, give them a call.
 

JHL

Senior Member
Joined
Oct 24, 2000
Messages
403
Location
Everywhere
Corvette
81 4 speed
I will go with the Edelbrock, I changed from a Holley which never seemed to run right. Straight out of the box the Edelbrock ran as smooth as you like. When I rebuilt the engine I rejetted a little richer in half an hour without any problems and once again it ran perfectly and is more than enough for a street car.

I have had double pumpers before and all I got was lousey gas mileage and not much else, might be ok at the track but for the road I would stick with the standard carb.

J.
 
B

Bullitt

Guest
I'm with Warren on this. All things being in tune, there's no way a carburetor from any manufacturer is going to shoot you 30hp from just a swap on a streetable engine. If that was the case, everyone would be running that particular carburetor.

Running an adapter plate will steal cfm, like Warren points out. According to the Holley Carburetor Handbook, "a 3310 Holley drops from 780cfm to 640cfm when an adapter is used between it and a manifold with the spreadbore pattern."

Besides start-up, how else does the engine perform? What are the characteristics at idle, etc.? Like pages62 said, it's probably cheaper and easier to find out if the choke is just malfunctioning.

--Bullitt
 

JHL

Senior Member
Joined
Oct 24, 2000
Messages
403
Location
Everywhere
Corvette
81 4 speed
Mine is a manual choke and with the right parts it can be converted to electric. Is it possible to go from electric back to manual ???? this might be an easy way to solve your problem.

Who said Edelbrocks don`t breath !!!
Mvc-812f.jpg
 
B

Bullitt

Guest
Yeah, it should be fairly easy to convert over to a manual choke, whether temporarily or permanently. Shouldn't cost more than $10-20.

--Bullitt
 
C

cmegga

Guest
Thanks for all the feed back guys. I stoped in to the mechanic this morning he made some on the spot adjustments. He dialed down the choke and turn up the warm up idle. It seemed fine all afternoon, but when I got to the ride home tonight the high speed idle would not come down from 1200 rpm. How ever I had no more choke problems.

Ill stop back tommaorw and see what he can do. If we can get this adjusted right I think Im going to stick with the Edelbrock.

It dosent sound like it going to be a much of a gain for the investment to switch.
 
S

Stingray72

Guest
First, I agree with most of the above in that you will not see anything like a 30-40 hp gain just swapping to a Holley. If your car is running well, a choke problem isn't worth the expense of swapping carbs. Also, I would recommend keeping the electric choke. They are much more reliable than any of the older manual choke designs.

The thing I would check first is the voltage at the wire going to the choke. It should be about 12 volts. If it's an old, worn wire, the voltage could be lower causing the choke to move slower.

A couple other thoughts:

When you start the car, does it start right up? If there's any smoke or if it's running rough for that first 10-15 minutes, then your choke pull-off might not be working. If it's running fine for that first 10-15 minutes, then all you probably need to worry about is adjusting the fast-idle cam. I'm not familiar with the Performer carbs. Try to see if there is a way to adjust the fast idle cam independently of the rest of the choke.

I have a pretty big cam and a Performer intake manifold with a 1985 Rochester Q-jet with no electronics except the choke (it has an electric choke) on my '72. I have the choke adjusted extremely lean. It takes about 3-4 pedal pumps to get the car to start right up after it's been setting for a few days. Afterwards, it idles at about 1000 for 2 minutes and then settles to a decently smooth 850. Of course, I still have the stock heads. When I go to aftermarket heads, I'll not be surprised if I have more choke/carb problems.

Good luck.
 

Corvette Forums

Not a member of the Corvette Action Center?  Join now!  It's free!

Help support the Corvette Action Center!

Supporting Vendors

Dealers:

MacMulkin Chevrolet - The Second Largest Corvette Dealer in the Country!

Parts/Accessories:

Vetteskins

Advertise with the Corvette Action Center!

Double Your Chances!

Partners

Top Bottom