Box Stock

Carb No Go question

Competitive Karting

Competitive Karting

Member
I have a carburetor that the No go goes in but does not go thru. I had seen a video a while back that I thought the guy stated that the No Go was not to be able to stand up on its on. I was checking my No Go this weekend and when the temperature was cold it checked .615 at the tip and seam to be a little over .615 the closer you went towards the handle. I set a carb in front of a heater until it was in the 90s. Being that if I were at the track and it was cold and the carb was warm just to see what would happen. The way I look at it it is a No Go and if it does not go all the way thru it would be legal. Please let me know if I am wrong, the rules do not state that it can not start.
 
No you misunderstood. No-go means no-go it can not start. Hold the carb in you hand like it is on the engine, if the gauge will support it's self the carb is illegal.
 
Now I am really confused. The rule book just gives a max size of .615, it does not say that the entree of the Venturi can not be more. The carburetor has a Venturi that is over 1/8" long and I cannot find where it states what you are saying. I have tried to get No Go gauges that were correct I sent back 2 sets because the shape was incorrect and the No Gos were tapered. When I was checking the tip of the No Go it was .615 then I moved it towards the shaft and it was .615+ My no go would with the carb choke side up would hold the No Go but it would not go thru, not even half way. So your telling me that it is illegal but nowhere in the rules state that it can not start into the Venturi.
 

As Bennie correctly stated, the NO-GO may not start or enter ...

2016 AKRA RULE BOOK
Page 8

SECTION 2 - METROLOGY

"... If the gauge enters the feature in question, it shall be found out of tolerance. ..."

example: ... as in the checking of a restrictor plate .. if the gauge starts, enters, or supports the plate at any position the plate is illegal.

Same for the venturi check. The .615" maximum specification applies to the full length of the venturi. The NO-GO can not start or enter at any point.


Jim Stone
AKRA Steering Committee
AKRA Southeast Region Representative



 
stoney said:

As Bennie correctly stated, the NO-GO may not start or enter ...

2016 AKRA RULE BOOK
Page 8

SECTION 2 - METROLOGY

"... If the gauge enters the feature in question, it shall be found out of tolerance. ..."

example: ... as in the checking of a restrictor plate .. if the gauge starts, enters, or supports the plate at any position the plate is illegal.

Same for the venturi check. The .615" maximum specification applies to the full length of the venturi. The NO-GO can not start or enter at any point.


Jim Stone
AKRA Steering Committee
AKRA Southeast Region Representative



Click to expand...

Ok I purchased No gauges from Larry Jones I sent them back because they did not look like the ones on Dyno Dons page I was sent the same thing and had to to send them back. I then was sent the ones that look like the ones on Dyno Dons page. But guess what the new set is tapered too. So the tech tool will enter.
 
Competitive Karting said:
Ok I purchased No gauges from Larry Jones I sent them back because they did not look like the ones on Dyno Dons page I was sent the same thing and had to to send them back. I then was sent the ones that look like the ones on Dyno Dons page. But guess what the new set is tapered too. So the tech tool will enter.
Click to expand...

What does the tool measure at the point that touches the carb? If it's over 0.615 at it's smallest would it matter if it tapers larger toward the shaft?
 
Fast 34 said:
What does the tool measure at the point that touches the carb? If it's over 0.615 at it's smallest would it matter if it tapers larger toward the shaft?
Click to expand...

It matters when someone tells you that it is not supposed to enter and it does. My plate tools that I received are tapered too. I had a plate that was DQed because the guy was teching with the oval shaped ones that are tapered. You could see just maybe .010 thru the other side in 1 spot. He showed the guy that the tip was .499 and the plate was a .500. The guy said the it was not supposed to enter so he was DQed because of the wording not the tool being a .499. I know that common since was not used.
 
Gould Racing said:
Why cut it that close?
Click to expand...

I was experimenting with different temperatures to simulate what could happen at the track. Carb hot and tech tools cold. If the tool was warmed up it did not enter but a buddy showed me that if you entered it at an angle it would stick and if you entered it straight it would not stick.
 

2016 AKRA RULE BOOK
Page 8

SECTION 2 - METROLOGY

"... Whenever possible, all inspections should be performed with components and gauges at ambient temperature. ..."


Jim Stone
AKRA Steering Committee
AKRA Southeast Region Representative



 
Would it be out of the question to ask the tech man to mic the gauge with a caliper if its size was in question?
 
Fast 34 said:
Would it be out of the question to ask the tech man to mic the gauge with a caliper if its size was in question?
Click to expand...

The tech man did not have his Micrometer with him. He had a slide mic and used it right in front of the guy. The guy told me it read .499 and he is a Machinist. Needless to say we lost (4) racers and some good people after this deal. They quit kart racing and moved to car racing.
 

Competitive Karting said:
The tech man did not have his Micrometer with him. He had a slide mic and used it right in front of the guy. The guy told me it read .499 and he is a Machinist. .........
Click to expand...

By "slide mic" I assume you mean dial caliper ? Most dial calipers, with the exception of the more expensive ones, have an accuracy of +/- .001" ... usually stamped on the face of the dial. So assuming the dial caliper reading (.499") was on the -.001 side of the tolerance the actual size of the NO-GO gauge would have been .500" .......

You can't use an instrument (dial caliper) with less inherent accuracy to verify the accuracy of a gauge with higher inherent accuracy (NO-GO gauge)


Jim Stone
AKRA Steering Committee
AKRA Southeast Region Representative

 
stoney said:



By "slide mic" I assume you mean dial caliper ? Most dial calipers, with the exception of the more expensive ones, have an accuracy of +/- .001" ... usually stamped on the face of the dial. So assuming the dial caliper reading (.499") was on the -.001 side of the tolerance the actual size of the NO-GO gauge would have been .500" .......

You can't use an instrument (dial caliper) with less inherent accuracy to verify the accuracy of a gauge with higher inherent accuracy (NO-GO gauge)


Jim Stone
AKRA Steering Committee
AKRA Southeast Region Representative

Click to expand...

I understand you can not use a dial caliper but I see techs use them all the time down here. I have gauge blocks to check my stuff and I use No Go's when building motors. I just broke down and purchased a dead weight checker and compared it to my intercomp spring checker and it was dead on. I have a Starrett brand outside 1" micrometer that has been checked out along with a Brown & Sharp, Mitutoyo, Starrett dial calipers and all read the same. When they check the No Go to read .499 at the tip I have to believe it is .499. All of my plate No Go's and my .615 read tapered. When I talked to Larry Jones they told me that is how they make them. I told them that the .500 was supposed to be .5002 I think.
 
If the tech guy has tooling that is certified to calibrate his tools, he is able to use any tool necessary. There is nothing in print that states a tech must have a special tool for this or that other than the spring tooling and the no go's for the carb.
 
DynoDon said:
If the tech guy has tooling that is certified to calibrate his tools, he is able to use any tool necessary. There is nothing in print that states .................
Click to expand...
Careful Don. How many times has it been said by you and countless others, "if it doesn't say you can, then you cant"? While I don't subscribe to this point of view and have been berated on here for my views many times, MANY folks have been DQed with the statement, "the rules don't say you can". If that statement is going to be held as a "truth" (as silly as I think that is) then what's good for the goose is good for the gander. The rules must hold true for ALL of us. Tech and competitors alike. JMO
 

Competitive Karting said:
I understand you can not use a dial caliper but I see techs use them all the time down here. .......
Click to expand...

I didn't state that a dial caliper was not appropriate for use in tech .... that is my instrument of choice for cursory measurement in tech. However if a situation arises where a measurement must be verified to determine legality, I revert to a micrometer and gauge block for final determination.


Competitive Karting said:
... I told them that the .500 was supposed to be .5002 I think. ...
Click to expand...

NO-GOs are generally +.00015 to +.00025 of the specified size.


Jim Stone
AKRA Steering Committee
AKRA Southeast Region Representative

 
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