|10-13-2012 05:04 PM|
|10-13-2012 11:27 AM|
Just to answer Painted Jesters other question, this is for the street. And it doesn't need to be class legal. Truck does not get a lot of miles on it so not a daily driver; more like an experimentation/learning tool and fun driver.
|10-12-2012 03:19 PM|
Correct, relatively new (about 1.5 years old) Holley 600 w/vacuum secondaries. No adjustment possible on floats, needle or seat. has air/fuel mixture adjustment.
Has the provision for the ford kickdown (which I just found out in another thread where I asked what the lever besides the throttle was for).
Put the Holley work on hold until I get the 2500 stall 10" converter (current was 1500) in early next week. That should help with my stall problems (as noted by F-bird'88 in my other tread on the distributor).
|10-11-2012 03:45 PM|
Universal with a ford passing gear kick down? basic street carb no needle & seat adjustment except for bending the float arm?
|10-11-2012 03:37 PM|
transfer slot setup
Jester, he has a Holley 600 w/vacuum secondaries.
|10-11-2012 02:16 PM|
What model# carb are you modifying? Is it a Holley or a copycat? ( like Quickfuel? ) Is the carb new or used? And for what purpose Street, , Roundy Round, Drag Etc? Does it have to be class legal?
Maybe you mentioned it and I missed it? Or maybe you stated it on another thread I haven't read?
|10-09-2012 10:07 PM|
Well, the other thread was supposed to stick to just distributor type questions (re: mechanical and vacuum) and this one about holley type stuff but there is some overlap going on.
Anyway, that's why I'm here and asking questions, some items I'm fairly familiar with but others are new hat.
My cam is a Comp Cams 450 lift, 224 duration, 206 lobe centre. I had it running good at 800 idle with just primary screw adjustments but when I looked at the t-slot after pulling off the carb it was pretty large (didn't measure or write it down as I was going to go through the 0.020" setup procedure anyway). I will, for the record, reset the secondary to closed, adjust the idle with the primaries to 850 and then pull the carb and read the t-slot size.
The part I was trying to understand was the proper order of things when modifying a holley and then, in turn, doing each of these to ensure you have a properly running engine. I do understand there is some level of going back and forth but there must be some items that have to be done in order to get them correct. For example, you would never setup a holley until your timing is good.
Here is the list I have sofar of steps and the order they should be done in.
1. Get the timing fixed and correct
2. Verify that you have 4-7 psi of fuel pressure; ensure it is NOT higher than 7.5 psi as that can cause severe fuel control problems
a. If too high then install a fuel regulator and set to proper psi at 6.5 psi
b. If not enough then you need to replace the tank intake, pump and all the lines as they could be clogged.
c. At high rpm or WOT fuel pressure should not drop below 3.0 psi; if it does you need a higher volume fuel pump.
d. Ensure that the fuel filter is the large one and does not come close to heat or in contact with the engine itself. A large filter can transmit a lot of heat to the fuel.
3. Ensure you use a large 14"x3" open element air cleaner; it will offer very little resistance to air flow, thereby not causing the fuel to go leaner. All Holley carbs are initially calibrated using this type of air cleaner.
4. Check for manifold-to-head and manifold-to-carb vacuum leaks
5. Take out the Carb and take it apart. Write down:
a. Jet sizes
b. Actuation point of the power valve
c. Size of the accelerator pump squirter
6. Get the floats right
a. Primary with the level just barely below the sight plug, secondary the fuel level about .050" below the sight plug
i. My carb (Holley 600 w/vacuum secondaries) does not have adjustable so must leave as is
7. Make sure venturi butterflies and the choke plate open fully
8. Set the transfer slot as per procedure below
9. Set Idle mixture as per procedure below
10. Check off-idle circuit (tip-in) as per procedure below
11. Set your power valves as well as your PVCR’s as per procedure below
12. Set your jets as per procedure below
13. Tune your secondary’s
14. Set your accelerator pump
15. Set your fast idle setup (for when choke is on)
Where it says 'as per procedure below' I then have detailed steps (with pics) on how to do that from what I have learned (both from reading and by experimentation). I did read a lot of articles from reputable companies like Holley (which has a whole technical library) to car magazine articles and where I found corroboration then I put that in my procedure. If you want to read it let me know and I'll upload it for you to see.
Sooo, long story short, when I set the primaries to 0.020 and the secondaries to 0.020 then my idle was at 2200 with the fast idle off so then i adjusted the secondaries to give me an idle of 1050. I think I was closing them off slowly, can't recall right now.
It sounds like my next steps now are:
- close down secondaries and run engine to see what happens with tslot on primary set only at 0.020"
BTW, my idle air screws are currently reset to 1.5 turns; when I tried to work them before I did my t-slot adjustment they did nothing. no increase or decrease in vacuum until I stalled the engine going all the way closed so I left them and started at the t-slot procedure.
Sorry for the long email
|10-09-2012 11:14 AM|
If you have to open the transfer slot too much w/the curb idle screw- THAT is when you start to use the 2'ndary side to add bypass air to get the idle right. This is preferred by me to drilling holes in the primary butterflies. But this isn't required unless you have a fairly radical cam- so what are the cam specs?
|10-08-2012 11:22 PM|
It has a section about the idle slots and good info to help you understand a little about the other circuits !! You asked about your converter not being loose enough What that meant? I took for granted your knowledge is limited !! And your asking questions about the carb that are very basic ( no insult intended )
And once you drill the P.V.R. you can go back by installing a screw in bleed and drilling smaller ! ( not that you need that) But it tells me you didn't read the article very well or it didn't sink in!
|10-08-2012 11:03 PM|
I agree strongly!!!
|10-08-2012 09:26 AM|
Setting the t-slot "square" and then setting the curb idle using the secondary is NOT how it's done. I don't know how BS like this gets passed around and somehow becomes a fact.
I see you've got another thread running on all this. Good luck.
|10-08-2012 12:27 AM|
Never mind, found looser/tighter torque converter articles online so you are saying that I need a higher, numerically, torque converter. Ok, will look into that next.
|10-07-2012 11:29 PM|
I still don't get what you mean "torque converter is too tight", you mean 1500 vs 3500?
t-slot on primary was setup at 0.020 and left there, idling was adjusted on secondaries only so would it be on the transiotion circuit? I did confirm that fuel starts dribbling down the primaries at 1950 rpm so that should be the transfer from the idle to main fuel circuits is and is way above where I'm working.
Also, I have been keeping a careful eye on the timing the whole time I'm doing this. It is set at initial 18 degrees and the springs installed (2 mediums) cause timing to come in at 1300 (vacuum is disconnected and plugged). As noted above, I did see the mechanical come in when the secondaries were too open but when I get it down to 1050 idle it runs at 18 degrees idle so, in my mind fine.
I have not checked the timing out of gear vs in gear; will do that tomorow.
Cam specs are: Comp Cams 450 lift, 224 duration, 206 lobe centre
Painted Jester, that is one of the articles I have followed when building my own procedure. I have not yet gone as far as modifying the PCVR's, jets, PCV's, etc as I want to work through where I'm at first (once I drill there is no going back). Next step is the air/fuel mixture but first I need a stable idle based on idle transfer slots. Based on what I've been reading I should be ok but, like Cobalt327 says, there may be other factors involved I will need to study up on.
Thanks and keep the information coming!
|10-07-2012 12:30 PM|
This may help with your questions and save me a lot of typing!
|10-07-2012 10:19 AM|
If the engine has to idle so high that it's on the verge of (or is already) idling on the transition circuit, and the engine rpm drops way down when the transmission is engaged, the torque converter- if too tight- will cause the rpm to drop. This is uber common w/any sort of performance camshaft in combo w/a stock stall speed TC.
Another thing that can do this is if the mechanical advance is already adding timing at idle speed (very possible if you're idling at an abnormally high rpm), when it's put into gear, the drop in rpm causes the timing to drop as well. The result is the idle speed drops too much.
Have you checked to see what the timing does when out of gear compared to when in gear? What are the cam specs?
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