Fuel Mixture Control

[dr gary turner]

How do you guys hook up your fuel lines to mixture controls such as the Bob Violet, Al Hobbs mixture control Nova Rossi etc

A. Fuel from tank the the bottom nipple and side nipple to the carb

B. Fuel from tank to the side nipple and the bottom nipple line to the carb

C. Makes no difference

I just read the directions on a new BV MIXTURE control and what was recommended was not the way I have done for years

 

[JimZaremski]

I was told it makes little to no difference once you get your flow dialed in. mine are set up whichever way lets me get the absolute shortest length of fuel line from the needle outlet to the carb inlet nipple.

 

[Danny King]

It will work fine either way for most engine sizes.
follow the taper is the general rule of thumb for best flow.

 

[brad nichols]

Al will tell you the bottom goes to carb

Brad

 

[dr gary turner]

I have always ran the fuel into the top nipple from the tank and from the bottom to the carb, following the taper of the needle

The new BV INSTRUCTIONS which I read for the first time stated to run from the bottom and out the top flowing against the taper ??

 

[dave roach]

It makes a difference the way the fuel lines go on. Do a test with your flow meter and you will see.Fuel flow down the tapper of the needle.So the fuel outlet would be on the bottom.

Dave
K&D flow Meters

 

[Don Ferrette]

I always follow the taper of the needle, in the top out the bottom.

 

[Bill Gibson]

Such great information.........I forgot how to run the lines for a mixture control, just like I forgot how to run lines for a hopper tank..........there is always someone who will chime in with the answer!

 

[John Beardslee]

Such great information.........I forgot how to run the lines for a mixture control, just like I forgot how to run lines for a hopper tank..........there is always someone who will chime in with the answer!

Yup, IW is great! All you have to decide is if those chiming in are correct!

 

[Terry Keeley]

I always follow the taper of the needle, in the top out the bottom.

Me too. But in the end isn't an orifice just an orifice?

 

[dr gary turner]

Next time I won’t read the DIRECTIONS.

 

[Stuart Barr]

The (BV) Stu Barr Needle Valve will flow both directions. I found the flow rate is different if you plumb with the taper of the needle. The flow is more consistent if you plumb by the instructions (against the taper). I know reading instructions is not a guy thing.
Stu

 

[Mario Johnston]

^ I have noticed a difference in my flow meter numbers since I stopped by and we discussed flow against the needle, Stu.

 

[timothy johnson]

Thanks Stu for the input! Follow the flow or follow the manufactures instructions, your choice.

 

[Jeff Lutz]

I checked this a year ago after buying some new Violet valves. Interestingly when going against the needle it leaned it and had to be opened more to get the same flow.

 

[Brad Christy]

The (BV) Stu Barr Needle Valve will flow both directions. I found the flow rate is different if you plumb with the taper of the needle. The flow is more consistent if you plumb by the instructions (against the taper). I know reading instructions is not a guy thing.
Stu

Doc,

My takeaway from this is the "consistent" part.

It's pretty evident that the flow readings are different going with the taper vs going against. This is not a big deal, as we find a setting we like and go with it, seeking only to be able to repeat it on race day. But, anything that improves repeatability is always a favorable addition to any race program. Read anything you like into this....

Thanks. Brad.
Titan Racing Components
BlackJack Hydros
Model Machine and Precision LLC

 

[Julio Almazan]

Hi:
This discussion is very interesting!! ... it would be very appropriate if you could put some pictures of the different systems ... new BV MIXTURE control,
the previous Bob Violet, Al Hobbs mixture control, NovaRossi, etc
Just for informations...
thanks for all your support
Julio.-

 

[Samuel Hagan JR]

I’ve always gone against the taper. Seems like the needle is more consistent and with the harder flow it keeps more pressure in the tanks, helps with 2 tank, 3 tank setups.

 

[gilbert galli]

when the fuel mixture control is integrated into the carburetor, the fuel enters on the side nipple and exits from the bottom

 

[Daniel's Racing]

Exactly. If it where in the carb you wouldn't have a choice and it would be flowing with the taper not into it.
If there is a better way you would hope it was the way they were when in the carb and there was no choice.