Drill kill bleeds or not? 750 Holley track warrior.

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Pablo
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Drill kill bleeds or not? 750 Holley track warrior.

Post by Pablo » Thu Oct 11, 2018 12:45 pm

I have this 4150 750 track warrior carb. The metering blocks appear to be the same as the ultra hp carbs. They have 5 emulsion bleeds.
I'm correcting this to have less emulsion and have already gone to two .028 bleeds to try and correct the ultra rich problem these carbs have when the mains first start.

The thing is these blocks have no kill bleeds, just a dimple. Given the down leg booster it seems like I should have kill bleeds. Should I go ahead and drill them? Is .028 ok?
I'm hesitant because it's hard to un-drill a hole :)

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Re: Drill kill bleeds or not? 750 Holley track warrior.

Post by prairiehotrodder » Thu Oct 11, 2018 2:24 pm

i have 2 of these carbs on a tunnel ram. They work great for me. I tried changing the emulsion setup but that was a bad idea. I put them back to stock configuration except for a smaller IJ which was necessary because of the 2 x 4 setup.

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Re: Drill kill bleeds or not? 750 Holley track warrior.

Post by Walter R. Malik » Thu Oct 11, 2018 3:59 pm

Carburetors with down-leg type boosters usually do have anti-siphon "Kill" bleeds and straight leg or most annular boosters don't.

If your carb boosters siphon after shutting the engine off, then drill them ... if not any siphoning then I would leave it alone.
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Re: Drill kill bleeds or not? 750 Holley track warrior.

Post by Pablo » Thu Oct 11, 2018 6:02 pm

Thanks for the replies.
Yes the carb runs awesome at wot with the box stock calibration. Nice fuel curve. It just goes rich as hell at part throttle when the mains just start flowing.
I went to the 2 bleed emulsion and a smaller MAB and it still looks like it goes pretty rich although I haven't jetted down to compensate.
It just seemed like a given that downleg carbs should have a kill bleed from what I was reading online.

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Re: Drill kill bleeds or not? 750 Holley track warrior.

Post by jmarkaudio » Thu Oct 11, 2018 6:47 pm

Because the bottom of the booster is so low on a down leg it does need a kill bleed to be safe, prevents it from siphoning. I usually drill them .024. And it doesn't need 5 emulsions...
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Re: Drill kill bleeds or not? 750 Holley track warrior.

Post by Pablo » Thu Oct 11, 2018 8:01 pm

Thanks, for the reply Jmark. I've actually learned a lot about emulsion tuning from searching your posts. I appreciate you sharing your knowledge.
Should I expect a noticeable delay in main flow at .024 on the kill bleed? My primary goal was to correct the overly rich condition which is partly why I have been considering opening it.

And while I have your attention, would you consider two .028 e bleeds in addition to the kill a good starting point? MAB is at .028 aswell now.

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