6 cyl draw threw turbo

[hiy_po]

Looking for advice to setup my Quadrajet 17059596.
I have a 3.3litre 202 ci Inline 6 cyl Holden engine.
It kind of looks like a smaller version of your Chev inline 6's.
It runs a Rajay Turbo draw threw turbo system. I have a Quadrajet 17059596 It is modified to reference the power piston from after the turbo and has a one way so dos not blow into the power piston.
Some engine specs - After market Alloy head 12 port 1.5 ex 1.7 in 70cc chamber
.462 valve lift LC 112 with a 1.65:1 roller rocker
7cc dish tops 7.3:1 c/r
Ignition is via an ECU fully adjustable with MSD 6AL igniter and MSD coil Blaster 3
5 speed manual 3.08:1 LSD diff

My progress so far
FIRST Carb (Stage Two Ver 3)
________________________

Idle Down tibes 1.6mm 0.064' #52 top 1.2mm 0.046' #56 bottom
Idle Down-Channel Restriction 1.59mm 0.062' #52
Idle Discharge tube 3mm 0.118' #32
Upper Idle Air-Bleed    0.4mm 0.18'  (Air horn)
Upper Idle Air-Bleed    1.78mm 0.070' #50
Lower Idle Air-Bleed    2.2mm 0.087' #44
Idle Air By Pass throtle plate outlet 2mm 0.079' #47
Main Air-Bleed Airhorn 2.3mm 0.090" #43
Primary Jet 0.073
Primary Rod o.048
Custom: / (2-5) / 0.900' spring
ATP 2 turns up.
Secondary Metering Rods   0.044 inch tip “DA” code
Secondary hanger bracket B

Measurements in mm then thou then Index size if known.
My progress so far
FIRST Carb (Stage Two Ver 3)
________________________

Idle Down tibes 1.6mm 0.064' #52 top 1.2mm 0.046' #56 bottom
Idle Down-Channel Restriction 1.59mm 0.062' #52
Idle Discharge tube 3mm 0.118' #32
Upper Idle Air-Bleed    0.4mm 0.18'  (Air horn)
Upper Idle Air-Bleed    1.78mm 0.070' #50
Lower Idle Air-Bleed    2.2mm 0.087' #44
Idle Air By Pass throtle plate outlet 2mm 0.079' #47
Main Air-Bleed Airhorn 2.3mm 0.090" #43
Primary Jet 0.073
Primary Rod o.048
Custom: / (2-5) / 0.900' spring
ATP 2 turns up.
Secondary Metering Rods   0.044 inch tip
Secondary hanger bracket B

Measurements in mm then thou then Index size if known.

[hiy_po]

It runs but Idle is lean, Idle mix screws are 3.5 turns out and carb does respond to them, Touch throttle and goes rich.
Idle stop screw is about 2 and a half turns out.
0.067" #51 I think is what will work for IDCRs
I have two Upper Idle Air Bleeds 1) from throttle bore to Idle down channel on a downward slope.
2) In Air horn see attached pic.
Should I block the top ones?

I would need to know the specs in thousands of the following items.

The idle tubes (bottom or restriction at the end of them)? - 0.046' #56 bottom

Lower idle airbleeds? - Lower Idle Air-Bleed    0.087" #44

Upper idle airbleeds and location?  (There should only be one pair either just above the DCR's or in the airhorn, not both) - I have both see above Upper Idle Air-Bleed    0.18'  (Air horn)
 Upper Idle Air-Bleed    0.070' #50 IDC.

Main airbleeds in the main casting? - unkown look small in a brass bleed.

Main airbleeds in the airhorn? - 0.090" #43

if I am doing something that isnt the best, would like to hear about it.
Things that matter, Engine is low compression and is 10/12 Hg at Idle.
Is a 3.3 inline 6 cyl.
My aim. Get good fuel economy for long trips but have 12s AFR at WOT with Boost.
My theory
Need large jets and orifices to counter low vacuum, but 6cyl doesnt need the same amount of fuel as a V8 so highly sensitive but low volume supply.
Things I dont know and would like to,
The Idle tubes, should I be opening the bottoms of the idle tubes and leaving top of tube standard?
Will opening the Air-Bleed to the main circuit  in the venturi have more effect than opening the one in the air-horn?

[hiy_po]

My settings mm removed
Idle Down tibes  0.064' #52 top  0.046' #56 bottom
Idle Down-Channel Restriction  0.062' #52
Idle Discharge tube  0.118' #32
Upper Idle Air-Bleed     0.18'  (Air horn)
Upper Idle Air-Bleed     0.070' #50
Lower Idle Air-Bleed     0.087' #44
Idle Air By Pass throtle plate outlet  0.079' #47
Main Air-Bleed Airhorn  0.090" #43
Primary Jet 0.073
Primary Rod o.048
Custom: / (2-5) / 0.900' spring
ATP 2 turns up.
Secondary Metering Rods DA   0.044 inch tip
Secondary hanger bracket B
Needle seat 0.130

[hiy_po]

Main Air Bleeds (In the main casting) - 0.025"
Drilled my IDCR  - 0.067  #51
Measured the Main Air Bleeds in the Main casting while I had top off.I have a 0.026 Bit so am thinking will use it while apart. So upgrade that size -
Main Air Bleeds (In the main casting) - 0.026

[hiy_po]

Just went for test drive, mains are still rich and Idle mixture screws are 3 1/4 turns out, Throttle stop screw is about 2 turns out Idle is around 950 rpm and  close to stoich maybe 14.2:1 AFR.
I am noticing I dont seem to get a leaner cruise with some manifold vacuum, seems not much if any difference between driving at 4Hg and 1psi Thinking need to hit the main air bleed in the main body with the next drill size up.

[hiy_po]

Where I am at

Idle Down tibes  0.064' #52 top  0.046' #56 bottom
Idle Down-Channel Restriction  0.067' #51
Idle Discharge tube  0.118' #32
Upper Idle Air-Bleed     0.18'  (Air horn)
Upper Idle Air-Bleed     0.070' #50
Lower Idle Air-Bleed     0.087' #44
Idle Air By Pass throtle plate outlet  0.079' #47
Main Air Bleeds (In the main casting) - 0.026
Main Air-Bleed Airhorn  0.090" #43
Primary Jet 0.073
Primary Rod o.048
Custom: / (2-5) / 0.900' spring
ATP 2 turns up.
Secondary Metering Rods DA   0.044 inch tip
Secondary hanger bracket B
Needle seat 0.130
Float setting 0.240.

[Cliff Ruggles]

Not sure why your LIAB's are .087".  That is HUGE and will cause a pretty big leak-path and reduce "pull" on the DCRs's, idle tubes,etc.  Then you have two pairs of upper IAB's?

That will require a big idle tubes and DCR's, and probably not the best set up for the little 6 cylinder engine.

You only need one pair of upper IAB's.  I'd rather see the LIAB's reduced to .070", block off the UIAB's in the main casting, and open up the UIAB's in the airhorn to .040". 

Then you can use small idle tubes, and much smaller DCR's and bring in PLENTY of fuel at idle and to the transfer slots for improved off idle transition. 

A few Q-jets were used on smaller CID engines, specifically the Pontiac OHC in line 6's from the 1960's.  Those carbs have very small idle tubes, DCR's, and tiny IAB's.  They work quite well on those engines and I'm sure the factory used the smaller specs for a reason.......Cliff

[hiy_po]

OK that will give me something to do tomorrow. Will try and make those changes.
My thinking was I have very low vacuum at Idle so need things open up big to get the fuel flowing.
I will try peen the LIAB closed a bit and redrill to 0.070 If I cant peen them maybe try to melt some lead into the holes and redrill.
I can lead fill the UIAB in the main body, blocking them and resmooth and drill the holes in the Air-horn to 0.040
I was just experimenting but can see why I joined because I do need some guidance.
And you are correct about it pulling hard. It looks like my AFRs are close but it  just kept picking up speed evenly it is missing the hard pull. The push back in the seat is not there.
Once I have it to your specs will test it again and re think the Idle tubes and IDCRs
Thank you for taking the time to read and comment.

[77cruiser]

Rather than trying to peen them smaller get some 6-32 brass setscrews for the lower bleeds 8-32 for the DCR.

[hiy_po]

Well I tried to peen, was getting to awkward and difficult, so lead filled it, the lead fell out when I drilled it. so yes it is now fitted with a Brass bush. I have one in but looks like I am going to have to make it smaller as it looks like its blocking half the passage.
Those Brass grub screws are incredibly hard to get in Aus. Something so simple you can walk into a corner shop and buy are not available here. I have searched EBay and online, I have found suppliers in USA but this is the message I get when I try to order them

Cancelling Your McMaster-Carr Order on 10/06
Contact photo
From   McMaster-Carr
To   hiy_po@hiy-po.com
Date   2019-10-07 21:26
Message Body
Hi Adam,
Thank you for considering McMaster-Carr for your purchase.  However, we will not accept orders from your location due to the cost of complying with US export regulations.
Andrew
Have found another place as well with branches in US and Canada, I cant even get an account because I am in Aus.
And our dollar is incredibly weak, what costs $US10 costs me $AU60 delivered.
I have one other Question is my carb an 800 CFM casting?? Looks like it has the lumps.
Tried to take a pic but turned out blury. Took some othe pics of progress.

[hiy_po]

800 CFM cast main body ??

[tayto]

have you tried going to a local machine shop and seeing if they have or can get the hardware you need? I would do this before looking online personally.

[hiy_po]

I dont live near a city, I live rural WA about 4 hours out of Perth. Its an hour away to nearest machine shop and they can supply grub screws but not in Brass.
I can not get Brass 6-32, 8-32 or 10-32 cup point set screws locally or online.
Only way I can get them is if Cliff wants to sell me some or someone wants to send me some, I will quite happily pay for a bag of 50 of each.
I may be needing a new set of Gaskets as mine are looking very used so maybe if I order some gaskets can order some screws as well.

[hiy_po]

I need the next step in setting up this idle circuit as its Idling very rough and have no control at all with Idle mixture screws. Seems to be running richer as well. I do notice when secondaries kick in it pulls harder. But need some idle control back please. My guess is smaller bleeds are pulling more threw the big IDCR and Idle tubes. But will wait to hear it and what sizes are recommended.

[77cruiser]

Her ya go everything you need.

https://www.mcmaster.com/brass-set-screws