Paul, sounds like you are doing some pretty advance work....
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April 21 2008, 12:22 AM
I ususally don't reccomend that kind of work here on this forum.
Sounds like you have a complete 1.23 and then perhaps a 1.33 in pieces????
I know you are using your carb for racing, but be very careful about making so many changes that you cannot diagnoes what is going on with your carb.
A couple of things that you mentioned in your description I will offer advice for.
First many part can be switched out between the two carb since they both have the same design, HOWEVER, parts such as the boosters venturis, are unique for that carburetor, to switch say boosters from the 1.23 into the 1.33 will now cause the 1.33 to be forever messed up since the boosters are intended to run exclusively with the setting, idle bleeds, vacuum ports and the jetting for the particular carburetor. UNLESS YOU HAVE A VERY ADVANCE FLOW BENCH, ANYTIME YOU SWAP OUT BOOTERS IT IS PURELY LUCK OF THE DRAW. IT might work out fine and improve what you are looking to do, it might not work out and cause whatever you are looking to do to be worse, OR IN MOST CASES IT WILL SIMPLY MESS UP THE FINE EQUILIBRIUM FOR THE CARBURETOR, AND CAUSE YOU TO NEVER TO BE ABLE TO GET IT TO FUNCTION PROPERLY. Because there is absolutely zero data on boosters available, it is entirely a crap shoot. I played this game about 13-18 years ago and NEVER was ble to get any type of relaible gain that I could document and maintian. Too many variables when you do this. OH, and I had access to a flow bench then.
Tops should be compatible. no prob here.
But the fuel inlets are completley different, One is pipe thread and the other is flare, they will not interchange without a serious leak.
Why are you drilling into the throttle plates??? Usually people that do this, are doing it because they have overcarbed the engine and are trying to even out the idle. I NEVER DRILL INTO THE TROTTLE PLATES, there are better ways to deal with idle and that is to choose a preper carb (YES, EVEN FOR RACING).
Two booster gaskets? not sure of what one could gain here, but try it and see. I don't do this.
Same with jetting and bench setting. Stock, stock, stock, then small changes to get to optimal.
Yep those early carbs are all Holley jetting. (Holley designed the Autolite)
As you probably know I use the 1.23 2100 carburetors for my partners hobby stock. (would like to run the 1.33 but I have never been able to find a plentiful stock of them).
He is currently running a 79 cougar with a 351 Cleveland
I use a 68 ford truck carburetor for this application, (8T-A, 8T-B, 8T-C) they are plentiful, cheap and have what we are looking for for our application.
When I rebuild them, I DO A COMPLETELY STOCK REBUILD, USING STOCK BENCH SETTINGS.
The only thing I do differently is I completely remove the choke house and choke flapper plate and all the choke parts, I jet it ONE SIZE LARGER as we race a 5/8 track and the cleveland loves to breathe. We wouldn't need to but I like to run our race engine a tad on the rich side rather than on the lean side. We could make a few more ponies by running leaner but then risk detonation. In 5 years we have not blown an engine so we must be doing something right.
I spend lots of time making sure any internal casting flashing is smooth. We have a rule thats states we cannot do anything to the internals of the carb, so I have to be very careful here.
And then I put the outside of the carb (which is wide open to us)on a very strict weight loss diet, removing and smoothing anything that is not needed.
Doing just these things has made our carburetors much better than everyones elses and most are running the 350 CFM Holley.
Bottom line when racing, make sure you do not over-modify the carb to the point where you have no control over what it is doing and what changes are effective and what changes are hurting you.
I can tell you if you pick the right carb, a "stock" 2100 will supply you with all the power you will need. Don't make changes based on what some magazine says or what the holley boys are doing. You will end up WAYYYYY of base and not have a baseline to get back to. In fact if you do some of those changes you are talking about you will not have the parts available to get her back to stock baseline.
Thats also why I always reccomend if you are racing to have 3,4,5, or more carbs all the same and all with the same baseline, ready and available.Trust me thats how the big boys (NASCAR) do it and thats how the small successful boys are doing it as well.
Most people racing try to get the biggest toilet installed and then over-modify it with "All the tricks" and end up with something that they can't drive, is out of equilibrium, or is making power where they can't use it or its not needed.
Just look how many racers, backfire or have flame coming from the exhaust at the end of the straights. Thats raw fuel being dumped into the exhaust where it is continueing to burn, If its burning in the exhaust then its not burning in the cylinder and therfore not making them one iota of power. It tells me immediatley they do not have thier carbs set up for what they are running.
Hope that helps,
Bill White
White Automotive
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I did the Clean thing. brush & spray, Repeat, Repeat ect.
I Put in 68 jets. She runs cool but strong.
I must remove & weld on An AOD bracket. I guess they were not around back in '63
AOD's that is.
I added the double gaskets. but rest is stock. I even left the old style fuel shut off. The clip sucks!! I put in the power valve from the kit. Thinking of changing to the 4.5 I just purchased for it.
Turned the idle screws to 2 turns out! She run good no changes. She ran even better went I changed the arking plug wire. Damn GTP heads.
Paul
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HAVE A NICE DAY!!!!