Carb rule

[jimwheeler]

I just re-read the rule on carburetor's and have to admit the tech shed was right. "Other than as provided for in these rules, the carburetor shall not be modified in any way."
It does list the items that may be modified and the accelerator pump is not listed as an item that can be changed.
Jim Wheeler

I HAVE BOUGHT APROX 8 4776 CARBS NEW FROM HOLLEY OVER THE LAST 10 YEARS. I HAVE RECEIVED THEM FROM HOLLEY WITH BOTH 30CC AND 50 CC ACCELLERATOR PUMPS. WHEN I SAW THE DIFFERENCE I HAD CONTACTED THEM AND INQUIRED ABOUT THE DIFFERENCE. I WAS TOLD DIRECT FROM HOLLY TECH THE SOMETIMES THE RUN OUT OF PARTS AND INSTEAD OF SHELVING THE UNITS AND WAITING FOR THE 30 CC PUMPS THEY HAD INDEED PUT 50 CC PUMPS ON THESE MODELS. THEY HAVE INDEED MADE THESE CARBS BOTH WAYS. THERE IS NO SPEC PAGE I HAVE FOUND FOR THESE CARBS THE SPECIFYS JUST THE 30CC PUMP. WHERE DID THE TECH SHED GET THERE INFO?? I HAVE WORKED IN THE TECH TRAILER MANY YEARS.IN THAT TIME I SAW 50 CC PUMPS PASSED AND NEVER QUESTIONED.DONT UNDERSTAND WHERE THIS WAS DECIDEDAND AND HOW SO MANY THINGS CHANGE FROM YEAR TO YEAR. LEGAL LAST YEAR AND ILLEAGLE THIS YEAR WITH NO RULE CHANGES. MAYBE NEW PEOPLE THERE THAT NO VERY LITTLE ABOUT THE CLASS AND ITS RULES DOING THE TECH THIS YEAR. JUST MY FYI TO ALL.

[jimwheeler]

Kevin,
I have three holly carbs and they all have the 30 cc pumps. What you have said is very distressing. If the carb came from holly that way, then, hell, I don't know what to make of the whole thing.
Jim

I too have ordered a carb from summit and it came with the 50cc on it , we changed it to the 30cc for tuning issues anyways, and I was un aware you couldnt change that for tuning purposes, everything Ive ever seen says to tune the carb with jets power valves and acc pumps..... hopefully they overturn that DQ and he gets his win

[t4wallace]

Originally Posted by 23CRLmotorsports

I too have ordered a carb from summit and it came with the 50cc on it , we changed it to the 30cc for tuning issues anyways, and I was un aware you couldnt change that for tuning purposes, everything Ive ever seen says to tune the carb with jets power valves and acc pumps..... hopefully they overturn that DQ and he gets his win

While we could hope for this to happen (especially if in Mike's shoes), we all know that it's balmy and 110 in hell right now with no signs of a cool front any time soon.

A. Can we get Holley to officially support that both pumps were installed from the factory on 4776 carbs?
B. If that can happen, can it then be sent into SCCA so, at minimum, this is on record and no one else has to go through what Mike did? Assuming we have no prayer of that cold front coming.

This is making me ill.

Man I'm sick. They said they called Holley and ask if the carb was built that way and was told that it was not. I spent Sunday morning trying to find evidence (Time allowed) to talk to people but no one was open. I then called the same person that tech did and spoke with him,he assured me that they don't put 50cc pumps on 600. I ask him if he was sure he said that maybe if he look at archives on Monday that mayby there was that he didn't know about. He said he would talk to SCCA on the phone to tell them what he knew and there was probably no competition advantage but truly a tuning process. SCCA said they weren't concerned with the advantage but rather that it was not stock.END OF STORY JH WINS
MIKE
42AS

This is ridiculous. It makes me want to puke. I agree with Kevin in that of the 30 or so carbs that I have bought in the last few years (not just 4776's) it has been a crapshoot as to what pumps they show up with.

The pump shot is part of tuning the fuel curve to meet a particular engine's characteristics and use. Changing that is no different than changing a metering block or power valve. The rule does not state that the carb has to be "box stock," it states that it cannot be modified. Bolting on a direct Holley replacement part is not a modification. Per the GCR, page 146 -

"MODIFY - To change a component by reworking, but not by replacing."

The intent of the rule is to stop us from reworking the venturi area to make the carb flow more air, not to limit how we tune the engine with the air flow that is available.

This is what is wrong with this class, and the SCCA in general. The intent of rules and the bigger picture is thrown aside to satisfy other agendas.

I am really glad that I read this thread. I have yet to place my "carb order".



I was just gonna' go on-line with Summit, and take my chances. Is there a place to buy a "faster" 4776?

Bill

.

they gotta make Jh win something one way or another

We just checked our records and Tom has purchased approximately 22 Holly Carbs over the years for himself or his customers...

Not a single one had a 50 cc accelerator pump.

How do we get one that has it? Who makes the 50CC pump? REO?

We can put it on an engine on our engine dyno, and measure what kind of power difference it makes, if any...

Joe