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1150 HP 2 Circuit conversion.
http://motorsportsvillage.com/forum/viewtopic.php?f=6&t=9316
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Author:  SGDCXCVI [ Sun Jun 24, 2012 1:56 am ]
Post subject:  1150 HP 2 Circuit conversion.

Well I have commited to doing this conversion, I got some Quickfuel metering blocks (34-10) they look nice.
I have read the sticky and the other relevent threads many times.
This is where I will start.
TSJ 0.052"
IJ 0.040"
EB 0.026" @ 1 & 4 - the metering blocks have five bleeds
IAB 0.065"
MAB 0.026"
KB I still need to measure what I have
Jets I'm thinking of starting at about 93/94

The main body (80556 1150 HP) has 0.170" booster pins with 12 hole annular booster.
I'm pretty happy with the transfer slots as they are.
I opened up the angle channel already to 0.161" - #20 drill

The PVCR came with blank bleeds which will be ok because I don't run a powervalve. Baretta started a thread about blocking the PVCR so to isolate the main wells from each other.

I just have to wait for some brass set screws to come in the mail, I went to a engineering supplies store here in OZ and asked about some screws.
The guy behind the counter almost had a brain embolism soon as I mentioned 6-32 & 10-32 brass set screws.
So if you guys see any problems with where I'm at, let me know.
Cheers Colin

Author:  scoop [ Sun Jun 24, 2012 3:21 am ]
Post subject:  Re: 1150 HP 2 Circuit conversion.

Colin,

I am running an 1150,but it is a 7320. Factory 2 circuit. I have mine on an 18 degree headed 427 ci SBC. Here is how I have mine set up:
QFT metering blocks part number 34-4
mab: .026
Iab: .067
e-bleeds .028 #1 and #3 #2 and #4 blank
tsj; .065
Ij: .040
pvcr: .055 front only rear blocked
power valve 3.5
jets: 90f 94 rear
A little t-slot showing below the blades.

Bob J

Author:  Beretta [ Sun Jun 24, 2012 6:28 am ]
Post subject:  Re: 1150 HP 2 Circuit conversion.

Colin, your going to need 3/16 set screws for the e-holes but you can also file down some 1/4 inch ones also...
On that metering block just be careful not to set them to deep and you will have to "spike' the threds to keep them from going in to far..

On the PCVR thing I tested last night during a race and it did make a difference blocking them holes if your not using a PV. It did balance the EGT's some ....So as you said go ahead and do it..

Author:  ss436 [ Sun Jun 24, 2012 6:56 am ]
Post subject:  Re: 1150 HP 2 Circuit conversion.

Colin where did your order your set screws from? Im in oz to and been looking around as well.
Steve

Author:  Beretta [ Sun Jun 24, 2012 7:03 am ]
Post subject:  Re: 1150 HP 2 Circuit conversion.

Steve Mcmaster carr will ship there also...

Author:  Ken0069 [ Sun Jun 24, 2012 8:50 am ]
Post subject:  Re: 1150 HP 2 Circuit conversion.

Beretta wrote:
Colin, your going to need 3/16 set screws for the e-holes but you can also file down some 1/4 inch ones also...


Barry, you are referring to the LENGTH of those set screws, right? :-k ;-)

Author:  Beretta [ Sun Jun 24, 2012 10:35 am ]
Post subject:  Re: 1150 HP 2 Circuit conversion.

Hey it was early and didn't get to bed till after mid night =; ...Yes 6/32 X 3/16 is what you want for the E-holes but like I said you can file down the 1/4" long ones to fit..Sorry for the confusion..

Author:  scoop [ Sun Jun 24, 2012 10:39 am ]
Post subject:  Re: 1150 HP 2 Circuit conversion.

Why not buy blank e-bleeds from QFT? That's what I used. Bob J

Author:  Ken0069 [ Sun Jun 24, 2012 11:03 am ]
Post subject:  Re: 1150 HP 2 Circuit conversion.

scoop wrote:
Why not buy blank e-bleeds from QFT? That's what I used. Bob J


PRICE! ;-) We don't have your money Bob. ;-) Remember, I'm cheap!

I can probably buy a box of 50 6x32 set screws and drill'em myself for what you pay for 2 from QFT. I've got about 7 boxes of set screws in my carb box now in various sizes.

Author:  SGDCXCVI [ Sun Jun 24, 2012 5:20 pm ]
Post subject:  Re: 1150 HP 2 Circuit conversion.

scoop wrote:
Colin,

I am running an 1150,but it is a 7320. Factory 2 circuit. I have mine on an 18 degree headed 427 ci SBC. Here is how I have mine set up:
QFT metering blocks part number 34-4
mab: .026
Iab: .067
e-bleeds .028 #1 and #3 #2 and #4 blank
tsj; .065
Ij: .040
pvcr: .055 front only rear blocked
power valve 3.5
jets: 90f 94 rear
A little t-slot showing below the blades.

Bob J


Bob,
where your at looks close to where I'm going to start except for the TSJ. I guess I as long as I start small, I can go bigger.
When I got the QF metering blocks I also got some blank 6-32 bleeds from them, so I'm ok there, they won't go in to far.
The ones I need are without the flange for the IJ.

Steve,
I ordered them from Superflow Carburettor Systems on Ebay. Put air bleed in and they come up. It's like 10 e-bleeds, for less than 8 bucks, what ever size you want.
Shipping is $ 3 bucks.
Cheers Colin

Author:  SGDCXCVI [ Mon Jun 25, 2012 7:28 pm ]
Post subject:  Re: 1150 HP 2 Circuit conversion.

Thinking about what scoop/Bob J wrote and reading the sticky again, I'm thinking I might be starting too small on the TSJ.
Anybody have any thoughts on that?
Cheers Colin.

Author:  Ken0069 [ Mon Jun 25, 2012 7:45 pm ]
Post subject:  Re: 1150 HP 2 Circuit conversion.

Colin you're not likely to hurt that engine running it lean at part throttle. That's the reason we start out RICH up top on the mains and LEAN down low at part throttle. Just make sure you have what you need to make changes if needed.

IMHO starting out a little lean on the T slots and working up is easier than starting out rich and having to drill more set screws with smaller holes. ;-) I'm cheap, remember? =;

Author:  Scott Smith [ Tue Jun 26, 2012 1:17 am ]
Post subject:  Re: 1150 HP 2 Circuit conversion.

No load off idle and light cruse can be 14 to 16 AFR no problem.

Author:  SGDCXCVI [ Wed Jul 11, 2012 6:16 am ]
Post subject:  Re: 1150 HP 2 Circuit conversion.

Well I got the conversion finished. Using the QF metering block made it real easy, I only had to drill the cross feed and lower the IJ and drill some bleeds.
The longest part was waiting for some brass set screws to arrive in the mail, superflowcarbs on ebay came thru for me there. Side note Mcmaster Carr won't ship to Australia, I tried.
So I'm going to wait to the weekend to start it up to get idle and transfer slot exposure sorted.
I will do a telemetery session on the Racepak. I can move the o2 sensor around a couple of the primarys. So I will have some data to share.
Unfortunetlly it's Winter here so I won't get to the track for a while.
One of my mate is building a 500 something cube Mopar and he has a 1050 3 circuit carb, it's red and shinney (not QF) and he doesn't beleive in the 2 circuit deal. He's heading to the dyno soon, so I'm going to give him my carb to try.
I had my engine on the dyno earlier this year and I know that my carb (prior to the 2 circuit conversion) was 10 better thans his carb.
I want to say thank you for all the help so far, with out it I wouldn't have attempted this.
I will try and attach some photos.

Image
Image
Image

Author:  Beretta [ Wed Jul 11, 2012 6:39 am ]
Post subject:  Re: 1150 HP 2 Circuit conversion.

Looking good Colin, You want to mark your Speed screws where full closed position is and then crank them open to where there is a square T-slot is showing.
This makes it easier to see where you are when doing the first start up. That way you will know it you will need some by-pass air or not...
Another tip is to remove the acc-pump cams after you get some heat in it as that makes it much easier to make adjustments to the idle...
Good luck!! and again Nice job =;

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