Don Terrill’s Speed-Talk

Geoff2 wrote: ↑Fri Feb 16, 2018 4:03 am What MT said that was correct was that a smaller air bleed starts the the circuit sooner & a larger AB starts the circuit later....& that goes for all carbs, not just Holleys.
And it is drawing a very loooong bow to say that the A/F mixture, once it starts to flow, will always be richer with larger air bleeds; much will depend on the emulsion tube hole positions & their size.

Geoff2 wrote: ↑Sat Feb 17, 2018 12:23 am treyrags,
Tuner said: "Smaller ABs make that cct respond richer/sooner...."

Blanket statement, no mention of the words could do, might do, probably etc.

Tuner wrote:"This just isn't so with Holley type metering. In fact, it is exactly backwards, the opposite is true. I wish you guys would quit repeating this misinformation. You need to read this https://www.tapatalk.com/groups/racingf ... .html#p118

More bleed air from a larger main air bleed (or high speed bleed, whatever you want to call it) pushes more fuel up the main well through the circuit and out the discharge nozzle. A bigger high speed bleed or larger or more E-bleeds makes it richer at the beginning of flow. Depending on other factors, such as size of main well and nozzle relative to venturi and jet size, a larger high speed bleed may or may not lean the WOT high RPM range.

Tuner wrote: ↑Tue Feb 13, 2018 4:59 am

MTENGINES wrote: ↑Tue Feb 13, 2018 1:03 am

tresi wrote: ↑Mon Feb 12, 2018 12:37 am I have many book on Holley carbs but none speak of the air bleeds other than the fact that they are there. What would be some good books that will make me at least somewhat functional at tuning air bleeds?

Probably because as society gets dumber, lawsuits go up. So to cover the publisher's butts, they redact any useful information. Because tuning airbleeds and emulsion circuits can ruin an engine. Not saying power valve, main jet timing can't. But it really is best to have someone with a good understanding make those changes.

If you have a basic underswnding of carbs and know how to rebuild one. Just do yourself a favor and trace each circuit, learn how they work and you can come up with the correct assumptions to fine tune them. Otherwise do a search here or on Google. Ask questions. We can help you.

Here is a quickie.
Smaller air bleed makes that circuit respond sooner/richer , larger later/less. S-S, L-L.. you are adjusting how hard the siphon is working by bleeding some off. Or having less bleed off.

Ask any questions you may have and write down in a notebook our responses. Just make sure you make 1 change at a time and log it. Other wise I may suggest pissing in the wind as a hobby.

Tuner wrote:

MTENGINES wrote:
Smaller air bleed makes that circuit respond sooner/richer , larger later/less. S-S, L-L.. you are adjusting how hard the siphon is working by bleeding some off. Or having less bleed off.

This just isn't so with Holley type metering. In fact, it is exactly backwards, the opposite is true. I wish you guys would quit repeating this misinformation. You need to read this https://www.tapatalk.com/groups/racingf ... .html#p118

More bleed air from a larger main air bleed (or high speed bleed, whatever you want to call it) pushes more fuel up the main well through the circuit and out the discharge nozzle. A bigger high speed bleed or larger or more E-bleeds makes it richer at the beginning of flow. Depending on other factors, such as size of main well and nozzle relative to venturi and jet size, a larger high speed bleed may or may not lean the WOT high RPM range.

tresi wrote: ↑Tue Feb 13, 2018 2:15 am

MTENGINES wrote: ↑Tue Feb 13, 2018 1:03 am

tresi wrote: ↑Mon Feb 12, 2018 12:37 am I have many book on Holley carbs but none speak of the air bleeds other than the fact that they are there. What would be some good books that will make me at least somewhat functional at tuning air bleeds?

Probably because as society gets dumber, lawsuits go up. So to cover the publisher's butts, they redact any useful information. Because tuning airbleeds and emulsion circuits can ruin an engine. Not saying power valve, main jet timing can't. But it really is best to have someone with a good understanding make those changes.

If you have a basic underswnding of carbs and know how to rebuild one. Just do yourself a favor and trace each circuit, learn how they work and you can come up with the correct assumptions to fine tune them. Otherwise do a search here or on Google. Ask questions. We can help you.

Here is a quickie.
Smaller air bleed makes that circuit respond sooner/richer , larger later/less. S-S, L-L.. you are adjusting how hard the siphon is working by bleeding some off. Or having less bleed off.

Ask any questions you may have and write down in a notebook our responses. Just make sure you make 1 change at a time and log it. Other wise I may suggest pissing in the wind as a hobby.

Is .001 one step? Is .005 a lot or a little? I don't have a question about a certain situation. It's just some that I should have an understanding of and I know a little knlowedge can be worse than none.

tresi wrote: ↑Sat Feb 17, 2018 2:47 pm I'm not currently trying to fix anything except my knee so I can walk and get back working on stuff. I just want to learn before I need to know.

Tuner wrote: ↑Mon Feb 12, 2018 12:48 am https://www.tapatalk.com/groups/racingf ... .html#p118