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1971 Chevy C20

tthomasd614

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tthomasd614 New Member

tthomasd614

Posted
Posted

I am working on a 71 and would like to know the best carb to get for it. I like edelbrock but have heard mixed reviews. Also, when I install new carb, is there any priming or prepping I need to do?

 

 

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Daly Senior Enthusiast

Daly

Posted
Posted

What engine is in the truck? If it's a factory engine with a 4 brl, I'd say the best carb is the factory rochester. The Edelbrock is based off that carb, and I've never had problem with them… I've heard of people having problems with those carbs but, a lot of time the carbs are to big for the engine… If it's stock and staying that way, I'd get a factory rebuilt carb. I'd get the Edelbrock if you need more CFM then stock…

desrtrat Senior Enthusiast

desrtrat

Posted
Posted

there is nothing wrong with a properly built Q jet. factory rating for SBC was 780 cfm, BB was 860 cfm..i think a lot of the bad talk about the Q jet came from the after market carb manufacturers of the day, with their consent power valves leaking, and shade tree part changers who had no idea what they were doing..

ifixedit Enthusiast

ifixedit

Posted
Posted

I've rebuilt many Q-Jets over the years, they are a very good carb and aren't as difficult to rebuild as some think they are, however they have one issue. The well plugs on the bottom of the carb over time can tend to leak, causing basically what I refer to as a "leak-down" condition. So what happens is every time the vehicle sits the fuel bowl empties into the intake and the engine will either be flooded (if you just drove it 20 minutes ago) or it will require some cranking on the next cold start before the bowl fills enough to get fuel to the engine and the engine to start. If the carb is in this condition my opinion is it's time to find a new carb.

 

That being said, I had a Q-Jet displaying this leak-down condition on my 77 Camaro, after a few attempts to fix it I replaced it with an Edelbrock Performer (which by the way has no similarities with a Q-Jet and is also not based on the Q-Jet either). The performer is based on the old Carter AFB design. The Edelbrocks are excellent carburetors, very reasonably priced, very easy to tune, and are very well designed and made. They also provide both timed and straight engine vacuum ports, for yours you'd want to use the straight vacuum port unless your distributor is not equipped with vacuum advance which in that case you would simply plug both ports. In my application I noticed an immediate improvement in overall performance, especially in the lower RPM acceleration department where the Performer really trumped the Q-Jet and never any coughing back or sputtering either, they're calibrated very good from the factory. For daily driving and up to 400-450 HP the 600 CFM Edelbrock Performer is the one you want. Anything above that and I'd be looking into the Thunder series 650 CFM or larger.

Daly Senior Enthusiast

Daly

Posted
Posted

You're right, it's been so long since I've had to deal with a carb, I couldn't remember if it was Carter or Rochester…

ifixedit Enthusiast

ifixedit

Posted
Posted

Well, they are somewhat similar to a Rochester as well in their function at least and they're for sure nothing like a Holley. Speaking of which, I've never tried one but I hear the Street Avenger series by Holley is pretty good too. I've been very happy with the Edelbrock. A little tip here for all: Call Summit Racing as an example and ask them if they have any factory rebuilt Performers, they did at the time I bought mine. It showed up nice and shiny, looking like brand new, was completely gone through at Edelbrock with normal warranty and I picked it up for under $200. The salesperson tried to discourage me from buying it using the usual scare tactics, but I told him if it went back to Edelbrock and was completely gone through (which it was as it was verified by a tag in the box), I asked him if he really thought they would let an inferior product go out the door and take a chance of giving themselves a bad name? He didn't have much of an answer for that one. The carb has worked perfectly since day one, great carb!

Daly Senior Enthusiast

Daly

Posted
Posted

In a DD application I'd stay away from Holley (unless you are going with their EFI kit). It's been my experience with them that they require constant adjustment. They are good race carbs, but I've never had any luck with them on a DD…

barry G Senior Enthusiast

barry G

Posted
Posted

I loved my rochesters.. up until a 1984 monte carlo SS I was running in 1996.

I guess ethanol on high compression was all it took to make it not so good anymore.

pinging, unhappy. No tune was working. Ruled out EGR and other weirdness. My locale stops at 91 octane.

the compression had no excuses, although high, not like 1971 of course.

 

anyway, I'd remove the rochester sadly for a vacuum secondary equal barrel Holley for the 1971.

 

make it a fancy one, electric choke, etc.

 

A spacer also works.. in fact that almost saved the oe rochester, but it was not enough.

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