Carbs.

[Ronnie Russell]

After some discussion about AFBs vs. Holley, I wondered why you never see one of the magazines do a simple dyno test. They all have 450 hp small block "test mules". It would be simple to dyno 750 Edelbrock, remove and install 750 Holley. But what Holley do you use? The Edelbrock sells for $246. Do you compare with Holley 4160 ( $262) or 4150 ($632) or how about one of the Demons? I dont guess they can do that without offending advertisers. No doubt the Holley has reputation of being the best performance carb., but let us see it in black and white. Does anyone have a dyno test that I missed?

 

[models916]

Out of the box

On the E&R Superflow dyno, the Holley Avenger is always right on the money on street type engines. (10:1, Hyd cam, Vac dist, Newer style heads, Header exhaust) I am pretty sure they charge extra for AFB or spreadbore type carbs. Race engines always need carb tuning.

 

[Ronnie Russell]

Sorry models, I dont understand. The Avenger is right on the money-compared to what? That it will flow advertised cfm? Dont other Holleys, AFBs, Quadrojets flow advertised cfms? If they do, that would mean internal fuel delivery would be the difference. How much difference? Thouight there would have been a simple engine dyno comparison test to put questions to rest. I have always been curious about this, hope someone has evidence, other than " Everyone knows Holley is the best". If so, how much better? And which Holley? Oranges to oranges--Apples to apples

 

[Rockfish39]

Not so simple...

No doubt the Holley has reputation of being the best performance carb., but let us see it in black and white.

Hey Ronnie!!!!!!! How it goes???

A dyno wont tell you all that you really need to know. Carb manufacturers use sophisticated lab equipment and gas analysers to see what their development models are doing under a large spectrum of environmental and operating conditions, and using a variety of fuels. Not all gasoline is formulated the same way.

How much pulsing (cam overlap) can the carb take and still function properly?? How well does the carb transition, from idle to part throttle, to WOT?? Will it puddle the intake when its cold outside???? and so on, and so on....

Carbs are a real MIXED bag of engineering trade-offs. Always have been. That's why the aviation industry got away from them in the '40s

For nearly 50 years of brand loyalties and arguments Ive always consistently heard or read the following:

WOT/Racing: HOLLEY ! The HOLLEY CARB is OPTIMIZED for WOT operation but suffers badly under part throttle or when in transition conditions

Street Perfomance Driving in good weather: AFB !! Smooth easy transition, but pull manifold pressure up too fast , AFB mixtures become too lean to support combustion. Not permanently, of course, but just long enough to bogg or stall you out. Of course, the new AVS/AFB goes a long way towards solving that age old problem.

Daily Driver in ALL weather condtions?? Rochester !! Not the greatest WOT carb the world has ever seen, but in bumper to bumper traffic, hard to beat!

You want that perfect that 14.7:1 A/F ratio all of the time no matter what???
Electronic Fuel Injection is 100 times more accurate, and can respond to changes about 10,000 times faster than any carb can .

Rock

 

[Ronnie Russell]

Rock, All points you make are well taken. I guess what I am getting at is WOT dyno. runs on the same engine. Holley is better, ok, how much better. 4 hp, 9 hp, or 18 hp. Because of my tiny income , I have a bad habit of comparing horsepower per dollar. What hp is gained by using $650 Holley over $260 Edelbrock? I know it is irrelevant, because people will spend much dollars to gain few hp. But ofcourse if we just talk money, how about 2 $260 Edelbrocks to 1 $650 Holley? The new AVS/AFB was used on Chrysler products in the late 50s and early 60s. Why they quit on it , I dont know. The best of all worlds. Adjustable secondary air valve and 3 step metering rods. 40 years later they dust it off and realize that was a good carb. No doubt the Electronic Fuel Injection is the ultimate, however I am constantly evading computers. Besides I can barey afford a carb. kit much less EFI.. Thanks again for your input Rock, a very good explaination.....

 

[models916]

avenger

Avenger fuel curve is right on the money through the rpm range on a full pull up and down. Don't know about CFM. We never have to re-jet or change power valves on the avenger for street use. This is a bolt on street carb, no major changes needed. I you are racing you wouldn't use the avenger anyhow.

 

[Gus68]

carbs

Hey Ronnie!!! Iv'e been thinking the same thing you have for years!!! If they are afraid of one carb beeing tuned better than the other why not tell all the carb companys everything about there motor they are going to dyno and have the company fine tune the carb they are going to send. They would have to all flow the same cfm but other than that let them do what they want. They could dyno the motor 3 times with each carb to "dial" them in and take the best pull. I would also like to see the same test done on a car at the drag strip, to see the REAL world advantage, because you cant race a dyno!!! I have run a Eldebrock 750 on my car for years. Back then I used to run mid 14's and always tryied to go faster, every one said get a holley, I didn't, I changed some other things and got into the 13's, every one said run a holley, you'll go faster, I didn't. Got the car into the 12's , everyone said get a holley you'll go faster, I didn't. My best to date is an 11.99.