Carb question

I’m working on building a mild street engine and I’m thinking it will need around an 850cfm carb. I have an 1190 King Demon and I was curious if it could be jetted down and used effectively? I will probably just sell it or trade for a smaller carb but figured I’d ask first.

850 carb is too small for a bbf. been there done that. weld some bungs in your headers for a wide band set up. then go tune the bigger carb you have....

Have a look towards a 950... I had some years ago a 1090 Demon, it was a P.O.S . No matter what we did spending a whole afternoon on a chassis dyno could not get enough fuel out of it ..
Had a 2 circuit 1050 custom built by Performance Carbs in California . Still there to this day

It seems there’s no in between with a demon. They either work great or they don’t. I’ve never had an issue with this one and I ran it for 8-9 years. I have a guy wanting to trade me a 950 xp but now I’m on the fence about it.

curiousgeorge wrote:It seems there’s no in between with a demon. They either work great or they don’t. I’ve never had an issue with this one and I ran it for 8-9 years. I have a guy wanting to trade me a 950 xp but now I’m on the fence about it.

Trade him! Barry Grant stuff is junk!

Where does this idea of "jetting down" or "jetting up" originate ...?

This is nothing but a bunch of hogwash ... the carb is still the same CFM size.

BBFTorino wrote:

curiousgeorge wrote:It seems there’s no in between with a demon. They either work great or they don’t. I’ve never had an issue with this one and I ran it for 8-9 years. I have a guy wanting to trade me a 950 xp but now I’m on the fence about it.

Trade him! Barry Grant stuff is junk!

I’ve heard that but my experience with this carb has not been that they are junk. Required no more tuning than the 4150 on my brothers truck.

rmcomprandy wrote:Where does this idea of "jetting down" or "jetting up" originate ...?

This is nothing but a bunch of hogwash ... the carb is still the same CFM size.

Sorry for using the generalized term “jetting down”. Maybe I should have said: Is installing the proper air bleeds, power valves, jets and tuning to achieve proper air/ fuel ratio was possible with a mild street motor.

curiousgeorge wrote:

rmcomprandy wrote:Where does this idea of "jetting down" or "jetting up" originate ...?

This is nothing but a bunch of hogwash ... the carb is still the same CFM size.

Sorry for using the generalized term “jetting down”. Maybe I should have said: Is installing the proper air bleeds, power valves, jets and tuning to achieve proper air/ fuel ratio was possible with a mild street motor.

In a word, yes. The CFM size only comes into play at wide open, or near wide open. At part throttle, the CFM is much less, and well within the usable parameters of the engine.
Tune it to run good at part throttle / cruise...and the WOT will be pretty close to optimal (But will still need some fine tuning to get it spot on,)

curiousgeorge wrote:

rmcomprandy wrote:Where does this idea of "jetting down" or "jetting up" originate ...?

This is nothing but a bunch of hogwash ... the carb is still the same CFM size.

Sorry for using the generalized term “jetting down”. Maybe I should have said: Is installing the proper air bleeds, power valves, jets and tuning to achieve proper air/ fuel ratio was possible with a mild street motor.

The carb is still the same CFM size no matter what else you change, unless the actual ventui's are changeable.

Getting the correct air/fuel ratio will require certain jets and other stuff ... anything else won't work correctly with that carb.

rmcomprandy wrote:Where does this idea of "jetting down" or "jetting up" originate ...?

This is nothing but a bunch of hogwash ... the carb is still the same CFM size.

I always get a laugh when people say wow that 1050 Dominator is going to be to much fuel for your engine,until i say you know that 1050 Cfm is an airflow rating not fuel!!

If this is a mild 460 for street use a 750 cfm carb would be plenty. One with annular boosters for crisp throttle response and great street manners is what I used.

rmk57 wrote:If this is a mild 460 for street use a 750 cfm carb would be plenty. One with annular boosters for crisp throttle response and great street manners is what I used.

Did you used to post on Yellowbullet.com?

Mark Miller wrote:

rmk57 wrote:If this is a mild 460 for street use a 750 cfm carb would be plenty. One with annular boosters for crisp throttle response and great street manners is what I used.

Did you used to post on Yellowbullet.com?

Every 1-2 years I'll check in for a bit, why?

rmk57 wrote:

Mark Miller wrote:

rmk57 wrote:If this is a mild 460 for street use a 750 cfm carb would be plenty. One with annular boosters for crisp throttle response and great street manners is what I used.

Did you used to post on Yellowbullet.com?

Every 1-2 years I'll check in for a bit, why?

Do you have an old Ford with a 460 in it?And did you used to post in the Do you want to know about 351 Clevelands Thread?

Mark Miller wrote:

rmk57 wrote:

Mark Miller wrote:

rmk57 wrote:If this is a mild 460 for street use a 750 cfm carb would be plenty. One with annular boosters for crisp throttle response and great street manners is what I used.

Did you used to post on Yellowbullet.com?

Every 1-2 years I'll check in for a bit, why?

Do you have an old Ford with a 460 in it?And did you used to post in the Do you want to know about 351 Clevelands Thread?

Ah yes, the Cleveland thread that wouldn't die. Gave up on it and doubtful I'll go back to it.

rmk57 wrote:

Mark Miller wrote:

rmk57 wrote:

Mark Miller wrote:

rmk57 wrote:If this is a mild 460 for street use a 750 cfm carb would be plenty. One with annular boosters for crisp throttle response and great street manners is what I used.

Did you used to post on Yellowbullet.com?

Every 1-2 years I'll check in for a bit, why?

Do you have an old Ford with a 460 in it?And did you used to post in the Do you want to know about 351 Clevelands Thread?

Ah yes, the Cleveland thread that wouldn't die. Gave up on it and doubtful I'll go back to it.

FWIW maybe just go to that thread and let everyone know you are ok,some of the guys were worried since you didn't post in the thread in some time!!

Mark Miller wrote:

rmk57 wrote:

Mark Miller wrote:

rmk57 wrote:

Mark Miller wrote:

rmk57 wrote:If this is a mild 460 for street use a 750 cfm carb would be plenty. One with annular boosters for crisp throttle response and great street manners is what I used.

Did you used to post on Yellowbullet.com?

Every 1-2 years I'll check in for a bit, why?

Do you have an old Ford with a 460 in it?And did you used to post in the Do you want to know about 351 Clevelands Thread?

Ah yes, the Cleveland thread that wouldn't die. Gave up on it and doubtful I'll go back to it.

FWIW maybe just go to that thread and let everyone know you are ok,some of the guys were worried since you didn't post in the thread in some time!!

Touched bases. It's almost like time stands still in that thread.