Fuel System: 500CFM or 600CFM on 289 V8

[Reo28]

Hi All. I am about to fit a 700R4 using a Fairborn adapter behind my 289 in a Silver Hawk. Currently use a WCFB carb and can't find any info on setting up the TV cable from the trans for this carb. I am thinking of fitting an Edlebrock carb and wonder if I should use the 1403 500CFM carb or the 1406 600CFM carb? I know that the 1403 is designed for small V8s up to 305 cu in, but wonder if the 1406 rejetted with leaner jets might be better as less throttle may be used hence as good if not better MPG. I do know that I will have to machine my inlet manifold to match the larger throttle bores of the Edlebrocks. The wise advice of you all is appreciated. Cheers Mal (from NZ).

[Mike Van Veghten]

This subject is huge if you just go into the "search" area. You'll find many hours of reading.

In short...will a 600cfm carb. work..yes. Will an 850cfm carb. work...yes...it actually will.
But if you plug into ANY of the carburetor vs. cubic inch size charts....just what you've already noted, the 500cfm carburetor will provide the best power/milage of most any out there. Actually, a 450 might work a little better, but there isn't many out in that size. The 500cfm carb. is actually just a tad too large...and that's with 100% volumetric effiniency...which "most" if not all but the top 1% Stude race engines deliver. You can figure maybe 80% efficiency for a good used Stude engine.

And no, "just" leaning a jet will not change the charactoristics of air flow...! Never has, never will. That's not how airflow in a carburetor works. You actually need to buy the correct ventury size to begin with.

Go with the 1403 (500cfm) carburetor, your engine AND you...will be happier for it.
The newer AVS, Thunder carburetor, while more expensive also has more adjustability if you like "playing" as some of us do.

Mike

[DEEPNHOCK]

Well said Mike...

[sals54]

Mike knows his business. Listen to him and you'll be much happier. Remember, the 600 cfm is usually cheaper but thats just cuz its the most popular. Don't be fooled. Get the 500.

[santa]

Agreed too.
I put one on two weeks ago and it is a completely different, and marketly better, car. Does not run like a worn out tractor any more. 500 cfm Edelbrock is just right.

[Reo28]

Thanks guys. You have confirmed my thoughts that 500CFM would be best. Mike your feedback and explanation is appreciated. This is such a great forum where you get very quick responses from people who have 'been there done that'. No point reinventing the wheel I say, when there are knowledgeable folk who can help.
If anyone reading this has done this swap with a 700R4 and still used the WCFB carb, I would love to correspond with you. Cheers Mal

[Mark57]

Just put a 1403 (500 cfm) on a 259 V8 equipped Champ pick-up last weekend and it runs like a top. As Mike mentioned, anything smaller is almost impossible to find.

[PackardV8]

Hi All. I am about to fit a 700R4 using a Fairborn adapter behind my 289 in a Silver Hawk. Currently use a WCFB carb and can't find any info on setting up the TV cable from the trans for this carb.

You can use the WCFB or either of the AFBs, IF you go to 'BowTieOverdrives at www.bowtieoverdrives.com/ and pay them what seems like too much money for their linkage and instructions.. Then, whichever carb you choose, it will be right.

FWIW, I'm an experienced shadetree and I couldn't get the 700R4 linkage right on my own. As a practicing CASO, I was determined to do it myself, but I wasted a lot of time and ended up paying their price anyway.

jack vines

[Reo28]

Thanks Jack, from yours and other replies, sounds like the 1403 is the way to go. I will still have to get a TV linkage kit from Bowtie ODs for the 1403, but are you saying the WCFB linkage kit is much more expensive than the 1403 kit?
Mal

[PACKERBACKER]

http://www.motorsforum.com/studebake...-net-6923-.htm This thread by John Poulos shows the R1 and R2 factory carb was rated at 625 cfm. I see that if you use a carburetor cfm calculator that it shows using a 1403 should work fine. Jim Pepper recommends and everyone else that I know that owns an Avanti that changes over to an Edelbrock carb uses a 1406 if they have an R1 or a 1407 for an R2. Now is this ok to use the larger carb because of the Avanti's higher performance output even though it does not agree with a cfm calculator. or does it mean that Studebaker did not know what they were doing and that some of the other experts that call out using the 600 cfm carburetor are wrong? I am not trying to be a smart ass, I am just trying to see who is right!

[Mike Van Veghten]

Packer -

As the clock moves on...so does experience and knowlege (hopefully).
Not that the 1955 Stude engineers didn't know what they were doing...they just didn't know more thAn people know today..!

Are you old enough to have been around in 1955 ? What doctor would you like cutting into your body....someone from back in 1955 (via time machine)...or someone from 2011. Not saying all doctors, just as designers are equal...but time, experience, experimentation, knowlege...rolls on.

What was the maximum speed a piston driven car could obtain in 1965 in the quarter mile ? I guarantee you it wasn't over 320mph..! They weren't to 200mph yet..! Again, experimentation, experience, knowlege.

So yea...to answer your question, for a stock 259, 289, R1, R2 Studebaker...the 500cfm carburetor is more thAn enough. Even a mildly worked over Stude engine.
Go back and reread my first post. I'd bet that if I played enough, I may even be able to get a Holley 1050 Dominator to work on a 289 Stude engine.
That does NOT mean that the engine will run as good as it could run.

And yes, I have tried several different sized carburetors on my 259 Lark...an old worn out 500cfm Edelbrock is back under the air cleaner..!

Hey...it's your car, it's your gas money, it's your driveability...do as you see fit. I'm not telling you what to do, I just relaying the current, and well thought out by many people....and the "math" what works.

Mike

[DEEPNHOCK]

All that, and the fuel is way different today, as compared to way back then.
And technology does not stand still, so you can't really say that what was engineered way back then should be locked in stone as gospel.
Those numbers were selected to get the Studebaker through, and out of, the warranty period with the least cost to Studebaker.

What has been posted here is current experience, using currently available Edelbrock carbs, on currently running Studebaker engines, running on current gas.
If somebody can bring more current info...Bring it on!
Jeff

[PackardV8]

Jim Pepper recommends and everyone else that I know that owns an Avanti that changes over to an Edelbrock carb uses a 1406 if they have an R1 or a 1407 for an R2.

It could also be most CASOs can't bring themselves to special order a #1403 500 CFM and pay $319.95 plus shipping when their local FLAPS has the #1405 600 CFM manual choke remanufactured version as a advertising loss leader for $229.99 plus tax.

jack vines

[PACKERBACKER]

Now I'm even more confused. Looking at http://www.carburetion.com/calc.asp using a 289 engine that max's out at 6000 rpm in stock form you get 426 cfm required, for a mildly built engine 476 cfm. Now if you look at http://www.edelbrock.com/automotive_...fm_rules.shtml Edelbrock tells you that you should usr a carb that is rated 110 to 130% of the required cfm of the engine requirement for maximum performance. If you take the 426 cfm and figure out 110% a 500cfm carb would work fine, using 130% or even 120% it is slightly higher than a 500cfm carb puts out. For a slightly modified engine, like an Avanti, the numbers look like the 600cfm carb is closer to being correct. Am I missing something, or is this not true?

[Mike Van Veghten]

We could drag this on for years.

And to see any Stude engine in most Stude cars today running to 6000rpm...can you spell "figment of someones imagination". Maybe...a fresh, high dollar, very carefully assembled Stude engine. Most will stop at about 5000.

Plus you gotta note reality...just how long (in seconds) do you plan to spend at this imaginary 6000rpm ?

As noted, do as you see fit, it's your engine. Like I said above, an 850 Holley will bolt on and work also.

Now...just to throw in some more confusion...after all my professing above...I've got a brand new 700CFM Quick Fuel carburetor waiting for my Conestoga's 299 engine to be completed.
BUT, I've also got a lot of rear end gear, a 2.9 first gear trans. being built, a LOT of cylinder head work, a one off (well maybe three) intake manifold (that nearly matches the heads flow wise), over 10 to 1 compression...AND...hoping to come up with a cam shaft with over .400" lift...
EVERYTHING...is a combination. If you don't have everything working well together...well, there goes the driveability, power, milage AND money fer nuthin.

Unless you are racing at Maxton or Bonneville...well you know.

Mike