Opinions on a carb

[kyle67]

Hey guys!!

I want some opinions on the carb I should purchase for my setup. 5.0 w/gt40 iron heads, GT cam w/1.7 rockers,performer intake, C4,

I have a TCI converter and some 3.25s I'll be installing soon.

I was thinking a 500 cfm Edelbrock or the 525 road demon jr. in a manual choke.

What are your thoughts?????This is NOT a drag car but it is my Hot Rod for the street!

 

[D.Hearne]

OK, You asked. I'd prefer neither. I'm a Holley guy all the way. Something like a 600-650 cfm vacuum secondary carb with dual feed bowls, fitted with the lightest sec. spring there is. Or a 650 double pumper list 4777. I'm into cheaper parts by necessity, and can't see spending the extra $$ for a BG carb, for the little bit extra performance they may offer. I'd also never choose a performer intake when it's basically a carbon copy of the stock 4 bbl intake which can be had for less than $75 ( used)

 

[brianj5600]

I think the performer is a good choice for a stock gt cam. I will agree that 600 - 750 vacuum carb would be best. Double pumpers are harder to tune, and off idle don't respond as well as a vacuum carb.

 

[kyle67]

I got the performer used for 75 off Ehay.....

I talked to Superior performance and Edelbrock and both places said anything above 600 is too much, I had a 650 dbl and the car ran WAY TOO RICH...I do like Holleys I just don't want to always have to tune it. I have thought about going with a 600 vac sec right out of the box though.

BTW that demon is only 259....

 

['69Stang]

A 600 Holley vacuum secondary would be great with your set-up.

 

[Clark]

This is almost as bad as which oil you like, I vote for the road demon

 

[65fastback]

I really like the autolite 4100 series, I would use it, but get the one with the 1.12 venturi and not the 1.08 venturi. The 1.12 venturi is the carb they used for the 289 Hipo K-code motors. That is what I am using on my 65 Fastback 289 and I am in the neighborhood of 385 - 400 HP at the front end and the carb is right on the money.

 

[kyle67]

I hadn't thought much about the Autolite, I'll look into it...

Does everyone think I need a 600 cfm of some brand?

 

[67GTCOUPE]

I hadn't thought much about the Autolite, I'll look into it...

Does everyone think I need a 600 cfm of some brand?

If you already have an Edelbrock 500.......try it out. Make sure you rebuild it or have someone rebuild it if it has seen a lot of miles. With your combo it should rock! You will run out of intake and heads shortly after 5000rpm anyway.

 

[tchesney]

Well, I just spent the weekend in TX pondering this same question! First, took off a 650 dual line, double pumper that was on a 302, edelbrock performer rpm intake, in a 65 conv. WAAYY to rich, gas was dripping out the tailpipes, put on an out of the box 650 vacum secondaries, elec choke, stumbled, ran rich, etc, then put a 750 edelbrock that I had brought with me off my son's car, better, but still too rich, then went a purcahsed a 600 edelbrock, took it out of the box, installed it, and BAM!, up another notch! engine ran great, idled smooth, had good off-idle response, just all around another good experiance using edelbrock carbs.

Ok, you holley guys - open up!!!! I'm not saying either is better, I grew up with Holley's in the mid seventies, and I could write a book about changing jets on the side of the road, blown power valves and such, but anyone would have to admit, you can just about put an edelbrock carb on and it will run within 10 to 20 % of it's max potential, Holley will have to tweaked and rejetted and tuned before you get much over 50% of it's potential out of the box.

And for bracket racing and such, I would ALWAYS go with a holley, because you can really dial them in to your particular combo, and once you've got them set, they are really predictable, but for street cruisers, Edelbrock gets my vote!

FLAME AWAY NOW!!!!!!!

 

[12sec67]

i with tchesney if you want reliablility you should go with an edelbrock 600.the one i had before right out of the box did better than my holley vacuum sec did tuned in performance and drivability and gas milage!

 

[D.Hearne]

You cannot expect any carb to be "dead on" right out of the box on every motor. Ani't gonna happen. Tchesney just happened to have the motor combo that the Edelbrock carb liked. I rarely have to change jets on a Holley, and never had a blown power valve. Only Edelbrock carb I've had any experience with was on a 351C 4bll head motor with a wild cam, stock exhaust manifolds. Fiddled with it for 20-30 minutes and it never would run right.As far as reliability,the 650 DP on my Ranger's 302, runs fine all day, everyday, never have to adjust it, it's been on three different engine combos in the last 2 years and never let me down. Sure it runs a little rich at WOT, but that's the way I like em. RAther have too much power than not enough.

 

[kyle67]

marcus at Edelbrock recommended the 500cfm for my setup, I think thats what I'll get. The 600 would be too rich for a stock cam, he said.

 

[RGS0907]

marcus at Edelbrock recommended the 500cfm for my setup, I think thats what I'll get. The 600 would be too rich for a stock cam, he said.

The old rule is that you can't go wrong with too small of a CFM for the street. With a 3.25 rear axle ratio I would consider the 500 too. You may lose at the top end, but gain off the line and at 0-60 which is what you want. But if possible, get a carb with a vacuum advance, it will help your idle & fuel economy.

Bob

 

[The Dan]

Take a look at the Holley Street Avenger as well. It's a 570 cfm w/ vac. secondaries. I just put one on and it's pretty close right out of the box. The tuning I did do was very easy, and it comes with the quick change secondary spring set-up as well. I think it does well with my relativly stock 289.

 

[12sec67]

i didn't say it was dead on...i said it was better than....

 

[kyle67]

If I took the 600 Edelbrock over the 500, What would be the downside?

I don't want a car that is too rich....

I like the street avenger and am considering that one too but the Demon Jr, I've heard is similar.

 

[12sec67]

If I took the 600 Edelbrock over the 500, What would be the downside?

I don't want a car that is too rich....

I like the street avenger and am considering that one too but the Demon Jr, I've heard is similar.

just like any other carb you can adjust it, and with your heads you might need a little more fuel.

if you have the cash go with demon jr, those are pretty nice.

 

[65fastback]

If you run to much carb and run rich all the time, you will wash the walls and really shorten the life of your motor as well as increase the possibility of heat scoring your walls and going Bang.

 

[PoliceInterceptor]

Of your two choices I'd go with the Road Demon. The 570 SA that was suggested is also a really nice carb.