Carb Adjusting?

[68 Valiant]

Hey guys this may seem simple to alot of you but I don't have any experience tuning carbs. Its time I learned and since there is no time like the present... does anybody have any tips. Even the most basic ideas will help me out. Maybe there is a good How-to-Book that I should pick up. By the way I'm working with a 750 Demon, Vaccum Secondaries, its sitting on a 360 Dodge small block.
Thanks in Advance!

[Bamfster]

Re: Carb Adjusting?

HP Books has alot of good Holley books to cover rebuilding, modifying and tuning. Its how I learned....

[milner351]

Re: Carb Adjusting?

Yup -
I think the first one I read was called "holley carburetors and manifolds"

There's another titled "tuning for performance and economy"

there's lots of them out there. HP books rules.

check out amazon, ebay, etc, you can likely find some cheap used.

[Ron Ward]

Re: Carb Adjusting?

I was fortunate to have a helluva good mentor when I learned how to work on carbs. Find somebody who knows what the hell they are doing and ask him/her for help in learning how it all works. Nothing beats experience.


Ron

[malc]

Re: Carb Adjusting?

If you don?t have the manual,
http://www.barrygrant.com/fromBarryG...n%20Manual.pdf

There is more to read at,
http://www.barrygrant.com/pages/manuals.aspx

It helps if you turn the carb over and make sure all the butterflies are syncronised,
all the transfer slots are equal, before messing with the mixture.

[milner351]

Re: Carb Adjusting?

do you know if it has the "idle-eze" feature?

Look into it on the barry grant site.

I have one carb with it, and one without - the one with it is a TON easier to set up for a good idle.

[68 Valiant]

Re: Carb Adjusting?

I picked up "Demon Carburation" by Ray Bohacz, so I'll read through it.

Not sure about the idle-eze. I have to look into that.

Probably won't be able to get to look at the car for a couple weeks

[antmnte]

Re: Carb Adjusting?

Ray Bohacz is a sharp guy,he seems to really know his stuff.Im gonna buy that book.

[malc]

Re: Carb Adjusting?

These are the books I have used.

[Scott Liggett]

Re: Carb Adjusting?

I have the last one around here somewhere.

[68 Valiant]

Re: Carb Adjusting?

Got some time to play around with the car this week. I do have the idle-Eze on this carb. We set the timing to 34-35 degrees. Turned the idle-mixture screws in all the way, then backed them out 3/4 of a turn. The car stillstalls out when you go to take off. The idle speed is only 650 RPM so I'm going to pump that up to 750ish.

[Mr4Speed]

Re: Carb Adjusting?

Invest in a vacuum gauge-it's really helpful and pretty much required. If you get an Auometer or similar you can use it hand held under the hood and also mount it in the car. Adjust you idle mixture screws for highest vacuum, and check it in neutral and in gear. you may have to split the difference a little to make it happy. If it's got a bit of cam in it 650rpm may be a bit too low.

[68 Valiant]

Re: Carb Adjusting?

The cam is 230/[email protected]" with .501"/.513'lift. I pumped the idle up to 750 RPM. Unfortunately I can't get a vaccum gauge tonight. Thanks for the advice.

[DanStokes]

Re: Carb Adjusting?

Wayne's Dyno in Jacksonville, NC. Wayne knows what he's doing and can do it under load. I do not and cannot. Easy decision for me!

Dan

[TC]

Re: Carb Adjusting?

Just a couple of tips off the top of my head. One your idle mixture screws should be out 1 1/2 turns, no more than .060 of the idle transfer slots should be exposed with the primary throttle blades closed, that is looking at it from the bottom of the carb. If more than .060 is showing you'll need to open the rear throttle blades a little so that you can close the primaries to get the less than .060 that you need showing on the idle transfer slots. If adjusting the springs in the vacuum diaphragm keep switching the springs until it bogs a little when you floor it, then go back to the the previous spring that didn't bog. When adjusting the float bowls you want the fuel to just barely seep out the sight plug holes.