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 Post Posted: Sun Nov 06, 2011 4:26 am 
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Hi All,
I've just finished bolting the carb back on the car, but ran out of time to fire it (the neighbors have an infant that sleeps in a room that's close to my garage, and I didn't want to upset the neighbors).

Anyway, the purpose of this thread is two-fold:
a) the keep an online record of my carb settings =;
b) ask a couple of questions re: settings and tune.

The combo is a .030 over 440 block with Indy aluminium main caps and a Callies 4.25" crank (505"), Oliver billet rods and Diamond pistons, giving a compression ratio of 10.4:1. On top is a pair of E'brock heads with some minor work, Indy rockers, and a 0.587/0.593 287/294 cam, under an M1 intake and 1050 Dominator.

Firstly, I lengthened the transfer slots until they were just exposed under the closed butterflys. I installed .0595 TSRs.
I have the quickfuel 34-105 metering blocks (with the 3 E holes per side). I blocked the middle of the 3 E holes and enlarged the angle channel to 0.159.
PVCRs were opened to 0.089 and IFRs to 0.040. I've left the IFRs in the 'factory' spot (up top) as I was concerned that I couldn't tap the lower idle feed without the tap walking all over the place. How has everyone else tapped that spot?
I jetted 86 primary and 93 secondary (as they were the closest jets i had to 85/95).
I opened the IAB up to .078, but my MAB is currently 0.040, as it turns out I have neither a blank bleed nor a small enough drill bit (#60 is the smallest I have).

How can I best compensate for the larger MAB?

Cheers!


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 Post Posted: Sun Nov 06, 2011 5:33 am 
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damned67 wrote:
How can I best compensate for the larger MAB?
poke some wire in it.


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 Post Posted: Sun Nov 06, 2011 12:41 pm 
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Quote:
Firstly, I lengthened the transfer slots until they were just exposed under the closed butterflys. I installed .0595 TSRs.


How far off were the slots? I wouldn't have touched them yet.

It's not a 4150 you don't need slot exposed with the blade shut.
Actually with the blade 100% shut you shouldn't see any slot. The blade will not be 100% closed when it's running so now you will probably have too much slot exposed.


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 Post Posted: Sun Nov 06, 2011 7:59 pm 
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shrinker wrote:
damned67 wrote:
How can I best compensate for the larger MAB?
poke some wire in it.

Certainly makes sense.


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 Post Posted: Sun Nov 06, 2011 8:03 pm 
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Scott Smith wrote:
It's not a 4150 you don't need slot exposed with the blade shut. Actually with the blade 100% shut you shouldn't see any slot. The blade will not be 100% closed when it's running so now you will probably have too much slot exposed.


You're probably right. This historically seems to be what happens when I try to modify/repairs things on my own ](*,)

I just followed this from "Tuning A Holley Dominator Transfer Slot": http://www.motorsportsvillage.com/forum/viewtopic.php?f=6&t=3811
Quote:
You should see a tiny bit (.020 or so) of the T slot below the closed butterflies. If not, then you will have to lengthen them a little to get there. Quality Control on the newer carbs isn't as good as it was on the old ones as I didn't have to do anything to mine. Tuner says he took a small file and ground the flat sides smooth to fit into that groove then used the edge to file that slot longer. Let's hope yours isn't horked up either so you won't have to!


Hopefully I haven't cocked it up too much.

Cheers!


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 Post Posted: Sun Nov 06, 2011 8:33 pm 
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Worst case scenario is that you "might" have to drill a hole in the butterflies near the idle dumps to keep from opening them up too much at idle. This isn't "the best" way to do things but it is a band aid that can be applied to make things work correctly.

FYI, some "pro" carb builders drill and tap the top of the air horn next to the carb stud and put air bleeds in'em (one on each side, front & rear) instead of drilling the butterflies. Maley wasn't a big fan of that and preferred to have a small hole in each butterfly near the idle dump tubes instead if that had to be done.

But lets see how it does BEFORE we get too concerned about that part. ;-)

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 Post Posted: Sun Nov 06, 2011 8:34 pm 
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I had said somewhere that that needs to be edited!!! What you need to do is set the speed screws to where .020 or so slot is showing and then see if it will idle...Then at that point a couple of holes will need to be drilled in the butterfly's...

Slowpoke (Donee) told me how he did this and I copied it and it does work well for getting it to idle when working by yourself and the more you get the IAB and mixture screws tuned the less air you need..
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 Post Posted: Sun Nov 06, 2011 8:59 pm 
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You can usually get small drill bits at a welding supply shop, our Ace hardware has a welding section that has them. Order 10-32 brass set screws from McMaster-Carr to use for air bleeds, you can get the 61-80 drill bits from them as well.

And take the time to thread the idle feeds at the bottom, it is worth the effort. Use a 6-32 bottoming tap and keep it oiled, go slow and go just deep enough for the set screw to go just flush with the bottom of the milled slot. You don't want to go all the way through with the tap.


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 Post Posted: Sun Nov 06, 2011 9:14 pm 
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FYI, WD-40 or kerosene is the best lube for machining/tapping ALUMINUM! That's one of the things I leaned in my 30+ years as a machinist. ;-)

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 Post Posted: Mon Nov 07, 2011 5:46 am 
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It was hard to find bottoming taps local here so you can also use a regular tap and just grind the taper off the end and
now you have a bottoming tap...

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 Post Posted: Thu Nov 10, 2011 4:31 am 
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OK, so I'm rich at idle, probably due to my transfer slots now being too long ](*,)
I can get it about right with the idle screws about 1/2 a turn out, but would prefer a bit more control from the screws.
What's going to be the best way to achieve this? Opening up the idle air bleeds or down sizing the IFRs?

That said, I stalled out (flooded, I think) stopped at a set of lights when I took it for a trial run, so I should replace the needle and seat assemblies (the car has sat for extended periods of time, now and in the past) before I too concerned about being too rich.

Cheers!


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 Post Posted: Thu Nov 10, 2011 9:23 am 
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May be some trash has gotten into a needle seat. I'd check that and reset the float levels to make sure they aren't leaking by. It's also possible that the "O" rings on the needle seat are hard or cracked so you might want to look at those also. The viton needles usually last a good long time.

And yes, I wouldn't mess with anything else until you resolve the flooding issue.

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 Post Posted: Sun Jan 08, 2012 2:41 am 
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I'm back!
Sorry all, took a three week holiday to Thailand with my Girlfriend, then been distracted by the holiday season.
Anyway, I'm now back trying to sort out this dominator. I replaced the needle and seats today, so will take it for a drive in the next few days to see if the flooding situation is gone, then it's back to tuning.

Cheers!


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 Post Posted: Sun Jan 08, 2012 6:31 am 
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go up .005 on the IAB for starters.


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 Post Posted: Mon Mar 26, 2012 10:46 pm 
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Back again. Been driving the car a bit now, figured if I've already washed the rings out, then what harm can I do?
Anyway, latest is that I've managed to relocate the IFRs to the bottow well. I opened the IAB up to 0.082. I dropped the TSR from 0.0595 to 0.055 and put in 83 primary jets.
Result: It gave me more 'room' on the idle screws (now closer to 1.5 turns out than 0.5 turn out). Off idle transition still drops to low 12s/high 11s, but seems to cruise in the low 13s.

I've just ordered some #61-80 drill bits, they should be in my hands in the next couple of days.

Of course, now my LM-1 seems to have bit the bullet (either the sensor or the unit). I hope it will keep working until the weekend, where I can take a log for your perusal to help guide me in the next tuning step.

Cheers


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