SAAC Forum

The Cars => 1967 Shelby GT350/500 => Topic started by: BryanT on September 11, 2023, 07:28:19 PM

Title: GT500 carbs
Post by: BryanT on September 11, 2023, 07:28:19 PM
I just rebuilt the BJ/BK carbs on my GT500. What are the opinions on the .125" check ball for the secondaries diaphragm of the BK carb. Use or not?
Title: Re: GT500 carbs
Post by: pbf777 on September 11, 2023, 08:28:44 PM
      YES!

      Scott.
Title: Re: GT500 carbs
Post by: Kent on September 12, 2023, 02:42:37 AM
The check ball is in both carbs, you also can take them out there is not really a difference.
Title: Re: GT500 carbs
Post by: Drew Pojedinec on September 12, 2023, 02:41:09 PM
I install them. Just make a bypass notch in the ball seat.
Not using them often makes the action a little too fast.
Title: Re: GT500 carbs
Post by: pbf777 on September 12, 2023, 03:21:47 PM
Quote from: Drew Pojedinec on September 12, 2023, 02:41:09 PM
Not using them often makes the action a little too fast.

     +1

      And too early an opening and/or rate of opening can cause a hesitation/slump in the vehicles' acceleration rate as there may not be an adequate air velocity presented at the venturi boosters in order to draw fuel into the air stream.   :)

      Scott.
Title: Re: GT500 carbs
Post by: BryanT on September 12, 2023, 06:32:58 PM
Thanks for all the input. I have been running the carbs without the check ball for many years and haven't noticed any problems. After the quotes from the members I will be putting them back in and check on the modifications to the ball seat.
Thanks
Bryan
Title: Re: GT500 carbs
Post by: Drew Pojedinec on September 12, 2023, 11:18:30 PM
Like anything, your mileage may vary.
Do what works.

If going without is fine for you, so be it
Title: Re: GT500 carbs
Post by: Kent on September 13, 2023, 02:32:30 AM
Just to add this it depend on the cam also and your setting, vacuum etc. on stock to the bone 428 PI´s I would keep the check balls. On modified engines the most times they run better without, its just testing it, try it without them and with the check balls installed there is definitely a difference.