84 z28

I have been reading some conflicting info on the web and want to know what my fellow demon owners are doing with the float settings. In my demon manual it say to adjust my float settings around the center line mark. Alittle above or a little below is ok.

http://www.barrygrant.com/fromBarryG...0Manual-08.pdf

An i am also reading in other places that using a demon carb for street only use the fuel level should be set at the 1/4 mark or first line.

http://www.gnetworks.com/v4files/bar...aintenance.pdf

Which setting are you guys going by ??

EvilCartman

iTrader: (1)

My front is about in the middle and the rear is a little higher. Probably a little too high for street because it likes to try and die sometimes after a quick turn of the steering wheel pulling into my driveway.

84 z28

I have both primary and secondary set at the middlle. I have another thread going on about a pig rich condition and im wondering if its the floats set to high or its a air bleed/Idle feed restrictor situation. The only way I can get my car to idle is to open both primary and secondary idle speed open more than the .020 thats recommmended.

xpndbl3

iTrader: (5)

more timing at idle would fix that probably.

84 z28

I have a mech advance distribtor. Its all in at 37 degrees.

dwint

i thought i had a float issue but when i took the carb off my butterflies were open way too much.i put them at twenty thousands raised the idle and turned the mixure screws in to three quarters and it never ran so good.my floats are in the middle

84 z28

Thats the thing. My Floats are in the middle of the sight plugs pri and sec. My idle screws are 3/4 out from seated. And the only way to get my car to idle is to open the butterfliys more that the .020 on both the primary and secondary which i believe is causing my rich condition they have to be open that much thou are the car wont run. But since I see that more people are running there cars at the middle of the sight glass I guess playing with the air bleeds/idle feed restrictors is the only way to go.

xpndbl3

iTrader: (5)

great, but you need to add more timing at idle, which means restricting the amount of total advance so it'll still be 37 total, but only have maybe 10 or so mechanical, so initial timing at idle can be much higher.

84 z28

And how am i suppose to accomplish this ?

Thomas Aquinas

iTrader: (14)

Are you running a vacuum advance distributer? I had my mechanical advance at about 14-15* and then I had about an extra 15* of vacuum advance at idle. So around 30* total at idle (which was about 800rpm for me). Depending on what cam you are running will tell you how much vacuum you have at idle. I needed an adjustable vac. advance can.
It sounds like your carb settings are pretty close.

84 z28

I have no vacuum on my distributor.

Thomas Aquinas

iTrader: (14)

What are the cam specs? You might need to fully lock out timing on the distributor.

84 z28

.

xpndbl3

iTrader: (5)

a cam that big needs timing locked out. if you have questions how to do it, use the search feature it's come up before on locking them out.

84 z28

All i see is threads about locking out vacum advance distributors.

xpndbl3

iTrader: (5)

i didn't even spend 5 minutes searching old threads here.


https://www.thirdgen.org/forums/tech...hlight=tie+zip


read the whole thread and you'll figure it out.

lukn4trbl

That cam is MASSIVE for a 355 cube motor.

You will need to do some extensive carb mods and also jack-up the initial
like everyone is stating.

Starting off with at least 20 degrees initial would be fine, and you could
also lock out the distributor with that much duration.

Vacuum advance wont work well with that overlap; at least not manifold
reference. You should use mechanical only due to the pressure variance caused by the cam (lope).

For the carb., look to the idle feed restrictors, and idle air bleeds. They
MUST be changed/modified. You can't run out-of-the-box carbs on
heavy cam'd engines.

The power valve must also be changed to at least 2 points lower than
the idle vacuum reading. I'm going to guess that setup will have about 5 in./hg. at idle.

The stock power valve is 6.5 which is already too high.

Float levels are not your problem.

YOur carb needs some major tuning to get it setup. I'd suggest going to
a speed shop if yuo're not keen on some of these circuits.

MY-92-RS

iTrader: (3)

I am a fan Big cams I am running 256/ 264 int/ ext duration at .50 lift in my 377
The MSD dist is set up for 20 degrees initial than all in at 2600 rpm 38 degrees the carb has a 4 inch vacuum power valve – throttle plates at 20 thousandths
floats center bowl idle is 850 rpm 7" vacuum with a nice lope !!!

84 z28

So let me get this right. I have to zip tie the weights down when there out ?

xpndbl3

iTrader: (5)

you zip tie the advance mechanism so that it no longer is able to move. this way timing is locked out all the time, your other choice would be to weld some of the slot shut so that it doesn't have as much travel or the final choice is just a simple tack weld on either side to lock it in place that way. the tack weld and the zip ties can all be undone, welding the slot will be a permanent solution. it's up to you all 3 choices will work fine and are needed on your car.

84 z28

Thanks for the help i appreciate it. Now im trying to understand what this does to the distributor so bare with me. Once the advance mechanism cant move any more and my timing is set at say 37 degrees all in. Is the distrubutor stuck on 37 degress all the time or will this still come down at idle.

five7kid

iTrader: (14)

It will stay at the same advance regardless or RPMs. You may have starter kick-back issues.

Exactly what kind of distributor are you using?

84 z28

Its a proform hei racing distributor. I do have a high torque starter if it that helps any.

five7kid

iTrader: (14)

Earlier you said, "I have no vacuum on my distributor." Does that mean you don't have a vacuum advance mechanism on the distributor, or you don't have vacuum hooked up to the vacuum advance mechanism on the distributor?

Personally, I've never run locked-out advance. I do have an MSD Digital 6 box, which has a start retard function available to prevent starter kick-back when running locked-out advance.

84 z28

I have dont have a vacum advance mechanism. Just a straight up mechanical distributor.

http://store.summitracing.com/partde...5&autoview=sku

How much do those msd digital 6 boxes go for and is it a pita to hook up?

five7kid

iTrader: (14)

Can't tell from the description, but the MSD distributors come with advance lock as well as advance tailoring parts.
$320 from Summit. It isn't too hard to hook up, just need to understand the type of system you're wanting and what you want the box to do for you. I bought it primarily for the 2-step rev limiter, I haven't tried the start retard yet (might do that soon).