Edelbrock Performer Carburetor Review - The Ultimate Carb Test Follow-UpPosted in How To: Engine on March 1, 2002 Comment (0)
Back in the May, 2001 issue of Four Wheeler I had the chance to compare three popular carburetors: an Edelbrock Performer-a new and slightly modified version of the reliable Carter AFB; the ubiquitous blue-printed Holley 1850 square bore; and a Rochester Quadrajet rebuilt and modified by Jet Performance.
While all three showed their strengths and weaknesses, I was disappointed by the performance delivered by the Jet Quadrajet. Judging from what campfire b.s. sessions, trailside reports, and personal experiences tell me, this carb should have produced better results than it did. The thing's chief problem was this: Hitting a bump under hard acceleration on a steep incline resulted in complete engine stoppage. I made several changes after a phone conversation with the builder, and even sent the Quadrajet back to Jet for a bit of the company's magical touch. While it was somewhat better after this work, it never was right.
As a result, we gave the nod to the 600-cfm Holley and 600-cfm Performer as the superior carbs for off-road use. But still we wondered about the Quadrajet. We'd expected great performance from this unit. Though it's rated at a considerably higher 850 cfm-that's enough for a big-block engine-its low-speed performance is not compromised by its size when it's mounted on a small-block. That's because small primary bores ensure good fuel vaporization at low engine rpm. Its very large secondary system provides the necessary airflow for maximum horsepower as rpm rises. In fact, we noted a bit more overall power with the Quadrajet during our sand-running portion of the original testing without any loss of low-end. So we were especially disappointed when we couldn't make the thing work.
All of which brings us to the here-and-now. I still had hopes for the Quadrajet to be the best off-road carb, so when I found out that a completely new and significantly upgraded version of the Q-Jet now is available from Edelbrock, I ordered one, and asked the technicians there to include a calibration kit just so I could do some fine tuning, if needed. What came to me was a brand-new 1910 series Edelbrock Performer RPM Quadrajet.
While this particular model was not smog-legal, Edelbrock does offer four other versions of the Quadrajet that meet emission requirements. Keep in mind that these are brand-new carburetors, not rebuilds or units remanu-factured from old cores. When the new carb came, it was bolted onto the same 383ci Chevy, in the same Jeep CJ-5 used in the previous carb testing.
We put this carb through every conceivable test we could think of, other than trying to run it upside down (and even came close to that a couple of times). We literally stood the Jeep on its tail and on its nose on more than one occasion and on its side even more so. This new carb took all of this abuse without a trace of hesitation. Without any changes whatsoever, right out of the box, it performed more than admirably even at altitudes in excess of 10,000 feet. Admittedly it ran slightly rich at this higher altitude, but not that much differently than at the 4,000-foot elevation where we live. The fuel mixture leaned out a bit at sea level but not to the point of running lean. In fact, it still was a tad on the rich side for maximum fuel mileage, which is something we need to address with a jet and metering rod change (this is where the calibration kit becomes important). Edelbrock has conveniently made access to the throttle adjustment through the top of the carb and we were able to improve the cruising-speed mixture to a more acceptable figure.
Here's my conclusion: This carb is the next best thing to fuel injection, and without the drawback of things like sensors, computers, electric fuel pumps, and fuel return lines. It's relatively easy to tune, and pretty much fail-safe. I am so impressed that I am really considering using this carb on my new Jeep presently under construction instead of the planned fuel injection.