Author Topic: BJ-BK float settings.  (Read 312 times)

1967 eight barrel

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BJ-BK float settings.
« on: January 12, 2019, 05:24:03 PM »
Does anyone have the primary and secondary float settings for primary and secondary bowls?
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67_1183

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Re: BJ-BK float settings.
« Reply #1 on: January 12, 2019, 08:45:19 PM »
The last page of this TSB lists the recommended levels (both dry and wet).  The forum has previously suggested that the float levels be lower however due to current gasoline volatility.

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shelbydoug

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Re: BJ-BK float settings.
« Reply #2 on: January 12, 2019, 09:06:20 PM »
The last page of this TSB lists the recommended levels (both dry and wet).  The forum has previously suggested that the float levels be lower however due to current gasoline volatility.

Absolutely. The dry setting will flood you out. Top of float to bottom of sight plug hole is about right.

If you are going to do hill climbs though, everything goes out the window and in a hard panic stop, the car will stall. It's very hard to get them just right.

1967 eight barrel

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Re: BJ-BK float settings.
« Reply #3 on: January 13, 2019, 09:12:04 PM »
Dry settings call for 1/2" Primary, 3/4" secondary.  on the 2804-2805. Recommendation was also to turn the needle and seat back a couple flats off that setting. Then keep them below the window being they are mounted backwards.
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Kent

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Re: BJ-BK float settings.
« Reply #4 on: January 14, 2019, 03:37:48 AM »
keep in mind that the the carbs are not sitting horizontal on the intake they have a 10-15° angle depend also on the suspension etc. so every Car with Bj-Bk need a little bit different setup.
SAAC Member from Germany and Owner of a unrestored 1967 Shelby GT500, 1968 1/2 Cobra Jetīs and some nice Mustang Fastbackīs 67/68

shelbydoug

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Re: BJ-BK float settings.
« Reply #5 on: January 14, 2019, 08:20:02 AM »
Dry settings call for 1/2" Primary, 3/4" secondary.  on the 2804-2805. Recommendation was also to turn the needle and seat back a couple flats off that setting. Then keep them below the window being they are mounted backwards.

You need to balance these settings. If they are too high they will flood at idle on level ground and at any incline. If they are too low, you run the risk of running dry under running conditions.

If that happens, the engine will violently back fire through the carbs. Often that will be so violent that the choke plate retaining rod will be bent or the choke will completely will get blown out of the carb.

It's like a hand grenade going off right in the intake manifold.

I find that the top of the floats being set just at the bottom of the sight port is about right.

At one time I had gone back and set the carbs dry, off of the engine, exactly according to the Holley instructions. Upon reinstalling the carbs, they completely flooded the engine. Flooded in the sense that I heard 'God's instructions,"Noah, build an arc."

Pity me. I have two engines running 2x4 set ups. They are not easy to get just right. Webers are child's play by comparison.

Oh. I'd also STRONGLY recommend that you change the floats to the solid Nytrofil plastic ones. DON'T ask me why. You don't want to know why.  ;)

JWH

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Re: BJ-BK float settings.
« Reply #6 on: January 14, 2019, 05:45:51 PM »
      (Wet Setting) -- After much trial and error, I have my carbs set so that with the engine idling and car sitting on a flat surface, when the site plug is removed from the bowl no gas spills out. But with a very slight rocking of the car side-to-side a little gas dribbles from the site plug hole. All four bowls are set at this level and the engine is very happy. I hope this helps. If you have the rock the car fairly hard to get gas to dribble out of the bowl, the float is too low.
Regards,
Jeff
             
« Last Edit: January 14, 2019, 05:49:25 PM by JWH »