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Edelbrock Thunder AVS Off-Road Carb

45acp

Sr. Member
Joined
Nov 11, 2003
Messages
488
Loc.
Texarkana AR
i honestly wouldnt waste my money, but thats just my opinion. all it is is a regular eddie/carter with a quick tune secondary air valve and springloaded needle and seat. you dont need the quicktune feature (has nothing to do with offroad) and the offroad needle and seat is around $12. if you have to have a new carb, go buy a $200 remanufactured unit and add the $12 offroad needle/seat.

alot of people say carter style carbs are crap offroad... this isnt true. there are many tricks to get one to run offangle. mine works just as good as if not better than a Qjet or motorcraft 2bbl at angle. if you get a carter style and want to make it work, just holler at me and ill be glad to help any way i can.
 

Yellow75

Bronco Guru
Joined
May 23, 2001
Messages
1,237
Loc.
Sioux Falls, SD
45 I need to chat with you then!! I have had the edelbrock 600 w/ manual choke since I got the bronco. I installed the off-road needles and seats which helped alot but It constantly dies on steeper inclines... Embarassing and dangerous!! :'(

Not sure what else I can try, i've gone through it with a rebuild kit and set the floats as best I can?

Another thing I notice, I can't blip the throttle from a stop at all. It will always die on me unless i'm up in rpm's.

Any tips or pointers you can give would be greatly appreciated!!
 
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Gummi Bear

Bronco Guru
Joined
Jul 8, 2003
Messages
3,647
Yellow75 said:
45 I need to chat with you then!! I have had the edelbrock 600 w/ manual choke since I got the bronco. I installed the off-road needles and seats which helped alot but It constantly dies on steeper inclines... Embarassing and dangerous!! :'(

Not sure what else I can try, i've gone through it with a rebuild kit and set the floats as best I can?

Another thing I notice, I can't blip the throttle from a stop at all. It will always die on me unless i'm up in rpm's.

Any tips or pointers you can give would be greatly appreciated!!
I don't know a whole lot about tuning carbs, I have taken mine apart and managed to get it back together without any major incident. I have run the Carter/Edelbrock for a few years now, and on the street, it is amazing, off road, it leaves some to be desired. With all that I have done it has worked pretty well overall, but first make sure that your brakes work really well, because you have to idle up quite a bit. Actuating the throttle and brake is the only way I can keep mine alive on a steep incline. I am quite sure that there are folks out there that can make them do miraculous things, I just want something that works, without having to fiddle with it.

That being said, I will likely put my stock 2 barrel back on for the moment. I will convert to EFI, but money is tight, and the other guys I went wheeling with this weekend all had 2 barrels, and they never missed a beat, even stood on end (literally).
 

Yellow75

Bronco Guru
Joined
May 23, 2001
Messages
1,237
Loc.
Sioux Falls, SD
I don't know if I want to get rid of the 4 barrel howl though!!! ;D Although it's not too cool when your truck dies.. I was seriously looking into propane injection for a while but there's not too much room in an EB to keep a tank of any real size and still keep some room to store stuff...
 

jerry

Contributor
Sr. Member
Joined
Jan 28, 2002
Messages
778
Loc.
Bakersfield, CA
Hey 45,

Any advice you'd provide would be appreciated! My Edelbrock 600cfm electric choke came with my Bronco, runs terrible when I take it off road and tilt it a little bit...
 

Rustytruck

Bronco Guru
Joined
Feb 24, 2002
Messages
10,872
While working on a friends edelbroc we got the best luck with installing a fuel pressure regulator and setting it so it just supplies enough fuel for climbing hills on the freeway. on his truck it was 4.5 psi. we then adjusted the float as low as we could stand and rechecked the fuel pressure again. also reset your Idle the carb doesnt like a really low idle. My friend also found some small tubing that fit in the fuel vents and he extended them as long as he could and still fit in the air cleaner he was using. he also installed the offroad kit. With this carb it seems to be necessary to put in a rebuild kit every 2 years even though the truck doesnt even see 5,000 miles in this time frame. This all works to some extent unless you play hard. He no longer had problems going up hill but then his problem moved to off camber pointing down hill. if you think stalling while going up hill is a problem try pointing steeply down hill off camber. After i put a Quadrajet on my truck he wanted one on his. we put one on his and he was so delighted within 2 hours of installing the quadrajet we went to his test area where hi truck always failed and stalled. the quadrajet was like night and day and 10 times better. we went back home and he tossed the edelbrock in the trash. I dont blame him as that damn thing almost cost him his truck several times. Run what you feel safe with. Knowing what I do I would run a quadrajet then an edelbroc then the ford 2 barrel then a holly in that order even knowing the the fuel injection runs best. They all have their own problems and even the best of them can be made better.
 

Gummi Bear

Bronco Guru
Joined
Jul 8, 2003
Messages
3,647
Rusty -

You'd take a 4 barrel Edelbrock over the stock 2 barrel on the trail? I went wheelin on Sunday, and the three of us that had the Edelbrock, were stuggling to keep them alive (I even had mine idled up to about 1300) Where the guys with the 2 barrel were having no problems at all. How much difference does it make to extend the vent lines? How about the off road kit? I've not heard too many positive reviews, it just doesn't make much difference.
 

45acp

Sr. Member
Joined
Nov 11, 2003
Messages
488
Loc.
Texarkana AR
ok, here are the things that you HAVE to do to get an edelbrock to run offroad. do this, and you will equal or beat a Qjet or motorcraft 2 barrel.

1- offroad needle and seat. doesnt do much on its own, but it is necessary.

2- set the floats as low as you can bear to run them. this will take some trial and error. plan on reseting them several times to get a "livable" level. you want them as low as you can get them, but still be able to accelerate down the road without starving out the motor.

3- ADJUSTABLE FUEL PRESSURE REGULATOR. this is the be all/end all trick to running an eddie off angle. when i get on the trails, i run mine on 2psi. yes, i will say it again, I RUN IT ON 2PSI. with a 300hp 351W it will run @ 2spi up until about 3800rpms before it starts to cut out. with low gears and rock crawling, i have never found a need for more than 3800rpms anyway. if needed, i could turn it up to 3-4psi and get more revs. YOU MUST USE THE REGULATOR. there is no way around it. basically you run low pressure to feed the carb just enough fuel...... but not so much that the bowls spill over in the motor off angle. mine is a purolator brand, and i cant remember were i got it. it is adjustable from 1-7psi (i think). if you wheel were there is mud, no worries. just get out before you get in the pit and turn it back up to 6 psi. this is only if you need to run close to redline.

do what i have mentioned, and your Edelbrock WILL run off angle better than you could ever imagine. i have still had mine sputter, but it wont die. the only time i had mine sputter was on an incline great enough that i almost went over backwards and was carrying the front tires in the air. it never stalled.
 

HotWheels

Bronco Guru
Joined
Jul 8, 2003
Messages
9,179
Loc.
Twilight Zone
Yellow75 said:
I wouldn't jump in so soon hot wheels.. I'd still get a BCBroncos Quadrajet before the holley.

y not. I thought the HTA was a killer? I've hearn nothing but positives from everyone that has actually tried them. Buck even took one to Moab and ran it almost vertical. Please explain.

?:?
 
OP
OP
A

adambronco74

Full Member
Joined
Mar 1, 2003
Messages
202
Loc.
Northern Colorado
Hey guys, thanks for all your input! I guess I forgot to mention that I have a Truck Avenger now, but was wondering if the Edelbrock was any better. The Avenger made a big difference, but I've just never been able to adjust holley's that well. Anyone have any tips? Anyway, after reading all the posts, I think I'm going to stick with my Avenger and attempt to tune it better.
 

BoltBuster

Bronco Guru
Joined
Jun 5, 2002
Messages
2,051
With a little patience and tenasity Holley carbs are easy to modify and tune. I started out with 2 books. Holley Carburetors and Manifolds by Mike Urich and Bill Fisher and *Holley Carburetors Super Tuning and Modifying by Dave Emanuel.

There is so much to tuning and being satisfied with the right application and there is no way I could list each step without knowing each result and listing them. Your going to need a vacuum Gage for sure though, tuning by ear is going to disappoint you possibly later either in fuel, performance or power.

The best advice I can give you is to understand and to know exactly how a Holley works and what parts make effective changes, what you have inside the carb, Jet size, spring color, power valve etc. and the application its going on requires.
 

HotWheels

Bronco Guru
Joined
Jul 8, 2003
Messages
9,179
Loc.
Twilight Zone
gonna order my edelbrock performer, cam, lifters and Holley truck avenger tomorrow! Yea!! got the ok from the financial manager (read: wife).

;D
 

thumper

Full Member
Joined
Oct 16, 2001
Messages
289
Loc.
Bountiful, Utah
Give me my BC Q jet any day! No hassle, no stumble, no maintenance!! Next to disc brakes, the best mod ever. Of course, going up a rock face it is the best mod. Coming down a rock face, I have to go with brakes as best!!! hehe
 

Rustytruck

Bronco Guru
Joined
Feb 24, 2002
Messages
10,872
The problem with me and the 2 barrel is its tendancy to vapor locking. My 74 I ran with the 2 barrel for over 24 years but as i played harder it was much harder for the carb to keep up. Primary problem is high under hood heat and the fact that the bowl hangs out in the hot air and boils the gas at 200 degrees. It doesnt help that I have fuctional EGR. I spent have of my life making that carb do as best as it can. The other problem is I live at near sea level and go play up in the moutains at close to 8,000 feet and when the temp around here gets 90 and above you either change the jets or toss the hood or both. When the information about the quadrajet became available I did a little research and bought a wrecking yard reject and rebuilt it. For about 85 dollars total I dropped the 2 barrel and went to the quadrajet. It was instant sucess all of my problems went away and the offroad milage over what i was getting with my 2 barrel was doubled. I have had this carb on now for over 3 years and wont change it. On my friends Bronco he started with a Holly and we spent time and money getting it balenced and a year later it was crap. he decided to go edelbroc so we spent time and money and got it running as best as it can which was better than the holley by at least 50 % and after i had made the change to my quadrajet he got very unhappy with it since he could no longer outshine me. My 2 barrel was a big hold-up to the club but he no longer could keep up with me. So i picked up a quadrajet for him set him up and he sent his edelbrock to the dumpster. Now I cant vouch for the sucess or failures of others and of brands but us SO-Cal boys have a wider elevation and temprature extreme than most except we dont get nearly as cold. It is common for us to have to drive 300 miles to play in a different spot and run from 30 degrees to 110 degrees and at elevations of 0 to 8,000 feet all in the same day. To top it all off we are stuck with special environmental fuel the vaporizes at a lower temperture in the summer time. In these situations with a hot running Bronco fuel injection is king but after that start looking at a quadrajet. Especially if you dont have really low gearing.
 
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