Edelbrock Thunder AVS 650 Carburetor

i have it on my cat "as bought", needed some play with jets and rods.( easy charts to choose ) Can't compare it to another , on my vette there was a Holley also working perfect....find the rods more confidend than the power valves in Holleys ( backfire ) and all jetting can be done from above , without fuel over your engine....so , yes, i prefer the Edelbrock.
"my" throttle respons is amazing , any rev,any gear

and.. Panteras are a pain in the &ss to play with the carb... ( see my avatar ) ... for that i loved my vette

Belgiumbarry,

could you let me know your actual rod / jet combination which works best on your engine. I have a 650 thunder and throttle response is very poor. what kind of ignition do you use and what settings? do you have a stock engine? what is the fuel consumption with this combination?

thks for letting me part your experiences.

Wolfgang

i will see what i can find...i bought a box with jets/rods to play.I'm not sure i know with what i ended...
Can compare out of the box setting and what i have left in my box...
sure remember me i have richer secondary jets installed and loosen the spring on the butterfly above the secondaries as almost no tension...just enough to return itself !

don't even know what ignition system i have , should check it... but sure it's around 20° static advance and 36° all in by 3000 rev.

MPG... i don't know...do i want to know ?
i fill up , enjoy a sunday and put it back empty in the garage.... think with spirit driving it's around 30L/100km...
Ever measured it on my vette with a Holley , it was 28 l ...

HI Wolfgang
Let me first start with recommending buying my book, link below, it
s exactly what you need right now . It does deal primarily with Holleys, but the general idea is the same, and you can easily follow the process.

That said, can I help? My first input would be that a throttle response issue on an otherwise pretty OK functioning carb is usually not a rod/jet issue, more likely an accelerator pump issue. You need to get that fixed first before you start playing with rod/jets, or you risk going way too rich on rod/jets in an attempt to compensate for a incorrectly set acc pump.

Let me know if you have any questions.

Belgiumbarry,

thks for checking out your jet/rod box.... I am curious what you´ll find out!

In the moment I have mounted a 600 performer carb (1406) and the car runs best with the original jets/rods but with the very hard pink springs. Throttle response is so so, not better than with the 650 thunder....

But of course I know; I have to check out ignition and some other points first....

Wolfgang

Mikael,

ok, you have sold another one....

I have asked an experienced guy to help me concerning this matter and I´ll report what we´ll find out. In general he told me that has made better experiences with holley carbs with mechanical secondaries as the vacuum secondaries of the edelbrocks often lead to a slower throttle response. But as you can see clearly I am an absolute newbie concerning engine tuning and I still have a long way to go untinl I understand everything properly.... I am sure your book will help....

I am happy to hear your further comments!

And of course I am watching your paint adventure!!! Great!!!!

Wolfgang

Are the Edelbrock carbs made by Weber? Just noticed the base of the carb has the Weber name & logo cast into it in Belgiumbarry's photo. Interesting! I've always liked the old Autolite design with no gasket surfaces below the fuel level and thought the Edelbrock carbs looked interesting in that they share that design element.

Cheers!
Garth

quote:

no gasket surfaces below the fuel level

Get a Summit carb, it combines the best of Holleys' and Edelbrocks. I've had two, best I've ever had.

Wolfgang,
Holley mechanical secondary carb has awesome throttle response especially at mid to high rpms but it is designed to run rich. Fuel consumption is about same as any other carb, not that it matters too much in a Pantera.
Shah

+1 on the Summit carb. No leaks, no hesitation, and completely tunable with Holley parts. I have a vacuum secondary version, but I am sure the double pumper works well also. It is a little taller than an Holley, so keep an eye that if you end up going that way.

quote:

no hesitation

Yes, best throttle response I've ever experienced. It's the carb Holley should have made, but they would rather milk the profit from the old design.

FYI

The Summit carb is actually an "old design" in its own right.

Summit purchased the rights to the "Summit carburetor" from Holley, it was originally a Holley model 4010 carb, but the carb, as manufactured by Holley had issues, and it never was a big seller for them.

The person who designed the 4010 for Holley supposedly assisted Summit in redesigning the carb, fixing the shortcomings of the 4010 design, and the carbs are supposedly still manufactured by Holley for Summit.

Going further back in time, the Holley 4010 carburetor was actually a copy of the Autolite 4100 carburetor, Ford's four barrel carburetor from the late 1950s to the late 1960s.

The Autolite 4100 four barrel carb is basically identicle to the Autolite 2100 two barrel carb, but with 4 venturis and two fuel bowls. The 4100 carburetor was very simple, very reliable and operated for many miles without needing servicing. It was equipped with annular boosters, which made the carb a good performer too. The carb guy I used to take my business to decades ago was a big fan of the 4100 carb, and his enthusiasm for the carb rubbed off on me. The 4100 carb is well liked by a lot of old school Ford devotees. Unfortunately Autolite never manufactured the carb in models having large air flow capacity.

I'm not sure if the Holley version had annular boosters, but the Summit versions I've seen pictures of do have annular boosters.

I think its cool in a "feel good nostalgic kind of way" to read that you guys are happy with the performance of the Summit carb. The Autolite 4100 keeps on truckin'.

-G

Hello Mikael,
May I ask which Summit carb are you referring to. Is is vacuum or mechanical secondary? What is the cfm and the part number?
Shah

Wasatch Cat,
Which Summit carb are you running and how is the throttle response with vacuum secondaries?
Shah

Shah, I've used the Summit carb on my previous Pantera and my current Longchamp, both around 300HP. I used the 600 Vac with excellent throttle response right out of the box. Vac sec carbs can give just as good throttle response as a double pumper if set up properly. Part# is SUM-M08600VS, remember to buy SUM-220104, that is leak free as opposed to the standard hardline. And of course the tuning parts that are unique to this carb:
SUM-M08060
SUM-M08040 optional
SUM-M08041 optional

I don't have the Summit carb on my current Pantera, I use the carb the engine builder MME put on and with 600HP a 750 carb would be too small.

quote:

it was originally a Holley model 4010 carb, but the carb, as manufactured by Holley had issues, and it never was a big seller for them.

I had one of those on a 82 Z28, never got it to work perfectly and it seemed to change its own adjustments.

Shah, I am running the 600 cfm vac secondary. My motor is near stock and I am at 5000' so the 600 cfm works well for me. The 750 cfm maybe a better choice for a built motor that runs at sea level. The secondary response is great once you put a lighter spring in it. I think the annular boosters also contribute the improved secondary response. The Pantera being a manual and such a light car, you can run the "yellow" or in my case a "light yellow" spring and it will pull hard with no bog. I have no experience with the double pumper version, but it should run at least as well as the Holley given the secondary annular boosters.

The carb is a very light, the throttle linkage works out of the box, and the mixture screws are in a convenient spot when installed on a Pantera. I did use the thermal insulating gasket that came with the carb, but it is a standard holley bolt pattern that would work with almost any spacer you decide to run. I have had no problem with it staying tuned.

Thanks guys for all the valuable info. I have a slightly modified motor and my car is only driven on the street. It seems that Summit 600 cfm carb should be fine for my application.
Shah

quote:

Thanks guys for all the valuable info

Any time. Let me know your view on my book when you've read it, it's such an exciting page turner, you'll read it in one evening/night!