Norm Peterson

That's when you start playing around with the shape of the rods that you do have. Reducing the diameter fattens the mixture. Moving the step or changing it from an abrupt thickness change to a taper will change the fuel timing and/or make the transition from cruise to part throttle acceleration F/A more gradual.


Norm

kalli

yah .. i liked that fact that you can change them from top, without disassembling the carb. i just changed rods so I had the correct size for cruise and then looked for a rod with same bigger diameter but different smaller diameter to get the powermode right.
obviously you need an arsenal of rods and jets, but without a full jet/spring/cam/pv kit there's no point fiddling with a holley either
Further I like the way they have diagrams that tell you whats' in there and what to change to in what situation. that helps a bit with the guesswork.

Still in the long run I preferred the holley, simply as for my car it seems to make more power. but that can be down to missing experience with the edelbrocks as well. (i know nothing about holleys and less than that on edelbrocks ...)

Starfury

CPR, I've never had a problem getting my Edelbrock in good street tune. Is it as precisely tuned as a Holley would be? No, of course not. But it works, and it took me a fraction of the time and know-how to get it there than it would have with a Holley, Demon, etc. And it'll stay in tune once I set it there.

If you don't have the proper rods, you can't have any hope of getting one tuned. I actually had to buy my last set of rods separate from a kit. Not a big deal, and not really any different from a Holley. If you don't have the right jet or pump cam, you have to buy it, right?

Point being, Edelbrocks are perfectly acceptable street carbs for small blocks, especially on mild motors. Where I find they have fault is in very high performance engines (especially those with low idle vacuum) and in high speed turning/stopping situations. I wouldn't put one on a mean big block or a car that sees open track use, but it'll work fine on a car that gets driven on the street often. As an added bonus, the owner won't be tearing his hair out while trying to get it tuned.

I'm not saying Holleys are crap, just that they take a lot more effort to tune properly.

THUMPIN455

So what you guys are saying is if you are a noob who doesnt want to learn how to properly tune a carb, you should go with an Edelbrock. Pretty much how I see it too. They are very basic carbs that will run on a relatively stock engine. If you need to change things because of a larger cam, lower vacuum, etc, then you will be hard pressed to do so with an E carb.

I have yet to get one running decently on any of my 400-455 Pontiacs, they either pull too much vacuum or not enough, and there is no way to change the secondary flap opening. Consider me spoiled though since I love Qjets on my Pontiacs. Sure they run, but they idle rich, go lean on top, and are quite a bit slower in the 1/4 than either the Holley style carbs or the Qjet.

I have something like ten Holley carbs from 600 economy carbs to a 1050 Dominator. I have yet to have a problem with one for reliability. They dont always get as good of mileage as my Qjets, but they always work or I can throw some gaskets at them and make them work. Its a bit more involved than turning the idle mix screws or swapping jets, but not much more with a Holley. It will do the things you cant with an E carb.

If you have no clue what you are doing and dont mind burning more fuel, the E carb is perfect for you.

Starfury

Considering most people don't know the first thing about carb tuning, Edelbrocks are a good choice for most people. I got mine because I didn't want to have to nitpick at it to get it to run properly. And it does, even on my 331 with an aggressive cam, heads, headers, etc. Is it perfect? No. Does it make that extra 5-10hp at the top end that a Holley design would? Probably not. Does it matter for a daily driver? Doubtful.

Like I said, I'm looking at a Demon (or maybe a QuickFuel) in the future to gain that extra tuneability, but the Edelbrock works fine for now and I have no qualms recommending it to anyone looking for an entry-level street carb that's reliable and easy to tune.

kalli

seems like we all agree :-)

cprstreetmachines

Maybe not, but there are many cars that are different from yours, and you happened to get it to work on yours.
Explain to me what on a holley changes the tune ? A tune change comes from a fuel requirement from the engine. So if an engine ACTUALLY needed more fuel after it was initially tuned, that's a problem of the engine, not the carb.

I just see it all the time. Guys come in a wnat an E carb because their holley is too rich. IT ends up being a 650 DP on a mild motor, or they were messing with idle mixture screws without knowing what they were doing. Or their tank is full of crap block circuits in the carb. Change to a different carb, and suddenly it the "Stupid Holley" 's fault. lol

There really isn't any nitpicking about tuning a carb. If you understand it, you make intelligent choices on which way to take the carb. Too often guys want to change their jetting because their cruise is too rich. Then blame the carb because it just wasn't put on right. Just took a 600 of a stock El Camino with a bone stock 327, and the secondaries opened toofast even for a stock motor. I know you have a hot motor, does you engine not bog AT ALL when it's floored ?

2+2GT

I spent a lotta time on a car exactly like that this week. Crud in tank, crud in lines, crud in carb. Tuning way off. Distributor curve way off. Carb adjustments way off. It still has a bit of a bog despite my best efforts, because it's a bone stock 289 4V with a Cobra Le Mans Holley 715 carb on it. The guy refuses to consider a smaller carb. Yeesh.

cprstreetmachines

Yeah, been there done that. Have to waaay over do the pump shot because of the lack of vacuum signal. Doh !!

Starfury

I'm sure it helps that I have a 600 CFM carb on a 331 (undercarbed), but I didn't have a bog before I did heads. There's a very slight bog now, but I think the cruise circuit is a bit rich, and the pump rod is in the middle hole. I've got room for adjustment.

I've found that the 7" stepup springs Edelbrock likes to put in their carbs at the factory don't work well with an aggressive cam. Not only does it run rich at idle as the rods pop up (and further kills vacuum, making it even more rich), but it provides a nasty hesitation when switching from cruise to power mode. I think I'm running a 4" spring right now. If richening the cruise mode and altering the pump rod location don't help, I might play with the springs again.