Inliners International Forums General Discussion Engines 292 triple single offy or 4bbl clifford

I was wondering which would give me better fuel delivery... would it be the offy with the triple singles? Or clifford with a holly 600cfm?

98% or 99% of the time, you are going to use either one single-barrel on the tri-power if progressive linkage, or the equivalent of a 2-barrel on the Clifford. Either way, the delivery is from the center of the manifold, and neither is really any better than the other. Each has plusses and minuses.

At WOT, the tri-power is better for fuel distribution.

An alternative is to connect the tri-power to use all 3 carbs all the time instead of progressive linkage. This setup has drawbacks, though, just like any combination.

The most important question that you need to ask is "what conditions is the engine going to operate within MOST of the time?" The answer to it should help guide your choice of manifold and carbs. And don't forget that your choice of internal components (cam, head flow and compression ratio) has a big impact on how a given induction system works. It's very easy to over-carb an engine. That's one reason to approach the tri-power with caution, especially with non-progressive linkage.

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David
newbie #4153

As usual, David's advice is right on...but there's an undeniable goose-bump kind of thrill in that instant with a well-tuned inline when you plant your right foot, it goes on the cam, three big throttle bores open up and you're thrown back into the seat! A four-barrel is better MOST of the time, and more practical ALL of the time...but for the pure excitement of lightning-quick response and torque, the straight shot of multiple carbs can't be matched. If you've never tried it, you don't know what you're missing.

Ok fellas... off comes the 4bbl, and on goes the triples

Sorry guys but can I hi-jack this thread for one very quick very brief question to Jack or David?

I have a new 500 cfm Edelbrock with electric choke on my 292. We will get around to installing the engine either tomorrow or Saturday. This 292, if you'll recall, has a .060 overbore, 36" long tube headers and a relatively mild (194/204 @ .050 and .464I/.490E) cam. Head is fully rebuilt, but rebuilt back to stock. The bottom end has the stock type dish pistons. Thus compression is probably the same as a stock engine. Will this carb still work on the engine or am I likely to be "overcarbed"? Thanks!

-magic mike-

[This message has been edited by magic mike (edited 09-10-2003).]

The last time I had a Holley on a stock compression, stock head motor, it was a 600 cfm vacuum secondary with electric choke. I was never dis-satisfied with that combination, as I don't think the secondaries ever opened up! The 500 should work fine also.

The only recommendation that I can give you is to make sure and get the tailpipe emissions checked as soon as you can. If the carbon monoxide (CO) is higher than about 4% to 6%, then seriously consider rejetting the carb. Usually you would want between 2% and 4%. If it's higher than about 8%, then the motor will wear out prematurely due to a phenomenon called "cylinder wash-down". The too-rich mixture causes the engine oil to dilute and then it cannot protect the walls and rings properly. The higher the CO, the faster it wears.

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David
newbie #4153

My experience with the 1405/1406 Edelbrocks is that they are jetted pretty close right out of the box, but because 99% are sold with 350 V8s in mind, you may have to make some adjustments with the metering rods and/or step-up springs. Edelbrock's owners manual is very detailed about how to correct various lean or rich conditions. And their 800 tech line is very good to help in sorting out drivebility issues. Just make sure all possible sources of vacuum leaks are closed before you hit that starter for the first time - there's nothing scarier than a new motor that won't run below 3000 RPM!

I can only talk from experiance,a 3x1 or 3x2 set up is definately a great feeling when your cruizin'. The "Wow" factor when you open the hood is worth it alone. If you're worried about gas milage, stay with the single 2bbl.
If you want to be cool and stay up with the bent 8 crowd, get a 6-pack!

RapRap
1940 Chevy Coupe

[This message has been edited by raprap (edited 09-11-2003).]

Hey, what about 3 HOLLY-WEBBERS on a 3X1 manifold,with linkage set up to leave the engine on the center carb until it starts to tip in the secondary,then speed up the end carbs so they all hit WOT together, like the old pontiac set up? I'm building a 292/301, mild portwork, (gasket matching and smoothed intakes) and a WOLVERINE cam and shorty zoomies W/ baffels for a track tee shop project, I'm looking for eye candy, but will will shurly nostailgia race and bracket it some before I send it to it's new home.
It's set up with a vintage IFS and a 4 link ford 9! looks like the finished weight will be well under 2000 Lbs.with a POWERGLIDE this girl outta rock... any thoughts?

A little question here for future knowledge...which setup would give the best gas mileage now that raprap brings it up? Would it be the 3x1, single 2 barrel or a single 4 barrel carb? How big of a difference is there in gas mileage between these setups?
From what I've heard the primaries on a 4bbl carb are smaller than the ones on the 2bbl so if you have a 4bbl but stay out of the secondaries then you would get better gas mileage than a 2bbl. But what is the difference between the three?

I vote for 6pack, 3 side drafts. Thats what I have for my 301. (see pics here) http://jetson63.tripod.com/hotohc67firebirdsprint/id8.html

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-HOT OHC

Olsixrod,
If I was going to use 3 Holley-Webbers, I'd run all 3 straight up. Those primarys are small. The mixture distribution would be better running all 3 together too.
Jim R

That's a sweet engine you got there hotohc. What gas mileage are you getting with your setup? Im pretty sure you get a whole lot of power.

What gas mileage are you getting with your setup?

Gas milage? What's that?

HOT OHC.....MY little brother had one of those Firebirds some years ago. I'm gonna print your engine photos and show him what might have been had he not been such a weenie about having a V8. Thass a FINE looking piece of machinery....almost be a shame to git it dirty. Later, Don (aka TwoBit)