|05-27-2013 06:03 PM|
Stpd Carb, stupid tuner.....(me)
650 works fine....no smoke, pulls hard....
For now the 750 sits.....will worry about another time.
Thanks again F-Bird....appreciate the help.
|05-26-2013 08:41 PM|
Transfer slots squared
Now sitting on my shelf....
Got pssd off and threw on my 650DP and will see how that works in the morning on my way to work.
idle is much snappier, mixture screws 1.5 turns out.
Haven't driven it till the morn.
If it isn't any better then I will have to go deeper I guess.
Thanks for the help with it and I will report back tommorow.
|05-26-2013 08:18 PM|
Whats the tune up on the carb now?
Smoke in exhaust at idle...are you sure there is not something blocking one of the idle wells in the metering block
Raw un emulsified un mixed fuel at idle or something.
Ignition issue?.... very odd...
|05-26-2013 04:21 PM|
I give up.....runs perfect, it could pass for fuel injection at this point, its snappy everywhere, no bogs or stumbles and pulls clean from every rpm......
Smokes and smells....behind me, cruising speed, its clean....but idling in the lane way, smokes, accelerating, smokes....def dark, def fuel....
|05-26-2013 12:20 PM|
OK, got a new vacuum guage, reset transfer slots front and rear, started over with mixture screws,
Vacuum is 18 in park, 15 in gear, mixture screws are very sensitive to tiny changes, they are both a little over 1.5 turns out.
Idle seems stable and has snappy response. Still very smelly exhaust, no smoke at idle now.
Going to go drive it now and see what i have.
Fine, I concede, I will pick up tune up parts this week lol....see if it helps.
|05-25-2013 08:39 PM|
No, Carb isn't flooding at all, it starts, it shuts off, it doesn't diesel or do anything unusual. Throttle response is now good across the board with no more stumbles or bogs.
Other then once the floats were set right I then had a lower idle.
This will allow me to open the secomdaries up and get front to back even.
Yes, the ignition is new, but its not "brand new" it was on the car last season with no issues. This is only become an issue since I switched over to the Holley.
I'm going to rest the transfer slots tommorow and see what changes. I didn't realize that having the rear closed and front open too far could cause any drivabilty concerns other then at idle.
The baseplate and metering blocks are over 20years old....not much drive time on anything but still old.....so maybe there's more to it then anything I'm doing or not doing.
Will try in the am and see if it helps.
|05-25-2013 07:15 PM|
I just got thru with another guy on a different forum that has been haveing way too much trouble getting his holley dialed in. Turns out the PCV was staying open at idle, instead of closed.
I must have posted 3 or 4 time for him to check the PCV valve...for the last 3 months.
I guess he finally got around to it....Pretty Billet PCV valve...Wrong vacuum level.
Just shows you its always the little basic stuff.
|05-25-2013 07:01 PM|
I guess I assumed you knew how to correctly set the float height on a holley. I thought every one did...
but now I bet the plugs are finished (black smoke)
Is the carb still flooding ? ( needle seat fault/dirt in fuel/fuel filter)
inconsistant float level
|05-25-2013 06:58 PM|
Adding ignition power to it will not fix a fault.
it is a better than 50-50 chance its the newest most rescently replaced electrical parts
that is the thing that is fubared. Always suspect the new part.
This is the first rule of electronics repair diagnostics. (it is always the most recently replaced part that is fubared)
The black smoke is not a "rich" issue.. it is a misfire issue. (ignition fault)
|05-25-2013 06:55 PM|
Slight wake up call here, remember when I had said it idled to high with the rear transfer slots exposed? Well with the floats set right that isn't the case, I can idle it down to a stall using the idle screw. So currently I have the rear slots closed but now I can actually open them up and get front and rear squared.
Will improper transfer slot exposure effect idle rich condition?
Will improper transfer slots effect things anywhere else? Just wanted to know if this could be my cause of my rich everywhere condition.
|05-25-2013 03:29 PM|
Will drill 2 blanks to 0.062 and replace the 75's with them and go from there.
Ignition is stock HEI, but directly from GM...and has less then 2000k on it.
So I'm not sure what ignition issue I would have that is causing a rich condition?
I may still have an old msd 6A kicking around....if so is it worth installing on such a mild motor?
|05-25-2013 02:20 PM|
A high speed air bleed of between .031 and .036 is fine.
get a 1/32" drill bit and a 1/16th " drill bit .. It is just that easy.
If you want to know the numbered drill bit equivelent of a given drill bit diameter in incheds or MM's
good search drill bit size chart and download the PDF.
The most you will need is a few numbered drill bits like a #72 (.025")
or a #51 (.067") you do not need all the air bleed sizes or all the numbered drill bit sizes.
final hone by hand as required.
You cannot tune high speed air bleeds by feel, smell or plug appearance or any other voodoo.
requires having the correct main jets first. requires dyno or extensive accurate track testing using a WB AFR meter
and accurate main jetting and timing, first. You can burn up a motor by getting it wrong.
on my car the .036" high speed air bleeds work just fine. .031" to .036" will be fine.
when the correct jets are used too (70-74 pri 80-84sec)
and the air cleaner installed (ya it matters)
You can do this whole job with what you got and a 1/16" and 1/32" drill bit and a simple NB heated afr meter/gauge/Voltmeter
|05-25-2013 02:04 PM|
FORGET the I read this that and other.
Start with a 70 primary idle air bleed.. drill 2 blanks with a 1/16th " drill bit .062" and hone to size.
WHY are you making this harder than required.
The 36 pri and sec high speed air bleeds are fine.
The 36 sec idle air bleed is fine. If it needs to be smaller than 36 solder it up and redrill with a 1/32" .031" drill bit.
now its smaller.
Just get the pri IAB right. start @ .062 (1/16th drill bit") this is not that hard.
forget the lean it down till it surges BS. The jetting will be between 70 and 74 primary and 80-84sec.
It is just that simple. The black smoke is a ignition issue.
I don't know why you bothered getting all these blank air bleeds when you are going to have to custom size tune them anyway.
The final primary IAB size wil be +/- .003 of what is in the stock carb body. start at .062" not that hard.
.075 is too big.
Stop trying to tune by feel and voodoo.
I don;t know who told you how to set a holley carb float level. It is just to the bottom of the bowl sight screw hole.
There should be no fuel dribbling out at all unless you bounce the car. EVER...anything higher is too high.
Stop the voodoo BS.... The jetting will be 70-74 pri and 80-84sec.
|05-25-2013 01:19 PM|
70 idle, 31 main on the primary,
28 idle and 25 main in the secondary.
But these bleed sizes will be richer across the board compared to what I'm currently running.
Right now I'm 75 idle, 36 main and
36 idle and main on the secondary
Bigger is leaner correct?
I was shocked to see the difference float level made.
I was going to start with opening up the fronts to 80 and 40
Secondaries to 42 on both primary and secondary
This should lean it out a bit for idle and high speed bleeds.
I have read to try and get it to a point where it has a lean surge while cruising, then go back a bit in bleed size.
What do you think?
Or should I try and take some jet out of it first? With the floats wrong I wasnt getting an accurate test before so I could go back and try 68/76 again and see how it feels and how the plugs look.
|05-25-2013 12:55 PM|
Do not use a 75 as a high speed air bleed. Use a 36.
What is the size of the primary and secondary idle air bleeds in the stock carb body?
Guestimate using a1/16th and 1/32 drill bit. or a straight pin that you can mic ,,etc.
This is your start point.
The final pri and sec IAB sizes will be very close the IAB sizes in the stock body.
Ya the float level matters.
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