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 Post Posted: Mon Apr 30, 2012 11:22 am 
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I got a link to this thread from jmark some time ago and now i have been reading, and re reading everything i can. I'm ready to start, mine should be fairly easy since i'm starting with 8082hp but i will still have a few questions.


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 Post Posted: Mon Apr 30, 2012 7:32 pm 
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I have to move the ij down, right now it is .040 in the top. Should i drill it out, or is it ok for two .040 jets?


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 Post Posted: Mon Apr 30, 2012 7:45 pm 
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If you're gonna drill and tap for the bottom IJ location, then you need to drill the top one out. It's not OK to have two similar sized metering devices in a circuit.

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 Post Posted: Mon Apr 30, 2012 8:14 pm 
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Thanks, the lower hole was already to size, just need to tap when they get here with the set screws. Today i drilled the angle channel to .159, the PVCR to .081, iab to .078, mab .026, drilled out the brass in the ts, i need to plug one emulsion hole each circuit and tap a couple of holes.
The throttle blades close with no slot showing which seems good but it takes 2.5 turns to get the slot to appear on both primary and secondary from when adjusting screw first touches the arm, is this good?
Thanks


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 Post Posted: Mon Apr 30, 2012 9:40 pm 
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Well, considering that most of them are too long I'd say yeah, that's a good thing!! You can always make a short one long, but it's much more difficult to deal with making a long one work well.

Don't do anything with the T slots until you actually get that thing running on the engine. You'll need to have the blades (front and rear) set where it will idle so you'll know how much longer you need to make them.

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 Post Posted: Wed May 02, 2012 8:25 pm 
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Ok guys got everything done tonight and fired it up. I started with 8082 2 circuit and my idle and cruise was rich, i set my carb up to the specs here and its worse at idle. Can i just go larger on the iab? My screws are out 2 1/4 turns and it will kill motor if i screw one in. This is a pump gas 502 roller with 3.5 mufflers if that has any effect.


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 Post Posted: Thu May 03, 2012 4:59 am 
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T-slot??? How much is showing??? Did you set it then put it on?

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 Post Posted: Thu May 03, 2012 6:27 am 
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I have a .052 restrictor on and set the blades with a small amount of slot showing but it idled at 1500 so backed them off a bit, I will have to pull carb tonight to check how much slot is showing but doubt it's much.


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 Post Posted: Thu May 03, 2012 6:40 am 
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Do you have holes in the blades??

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 Post Posted: Thu May 03, 2012 7:33 am 
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No holes.


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 Post Posted: Thu May 03, 2012 8:24 am 
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driftbuster wrote:
Ok guys got everything done tonight and fired it up. I started with 8082 2 circuit and my idle and cruise was rich, i set my carb up to the specs here and its worse at idle. Can i just go larger on the iab? My screws are out 2 1/4 turns and it will kill motor if i screw one in. This is a pump gas 502 roller with 3.5 mufflers if that has any effect.


So have you driven it yet?

How does it act when you start it up cold?

I'd go smaller on that IAB, not larger. Drop down to an .074 on the IABs. An .074 will likely bring those idle mix screws back to around 1.5 turns.

Having said that, I'm having problems understanding why it's rich at idle? 2 1/4 turns out on the mix screws is not unheard of and you "should" be able to get it lean even with the .078 IABs? :-k

I would say to check the plugs but with the "rot gut" unleaded pump gas we have I'm not sure what to look for?

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 Post Posted: Thu May 03, 2012 8:52 am 
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Yes i got to take a short ride and at idle it was a eye burner but drove good till 2500_2800 cruise and you could hear hear it wasn't smooth but felt fine. The carb had 71 iab, 36mb and I think the ts was in the 76 range. Now the78iab, 26mb, and 52ts.


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 Post Posted: Thu May 03, 2012 9:07 am 
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Have you moved the idle jet down yet? It won't work as well until you do. Where is your timing on the engine?

If you are over 2 turns on the mixture screws you are likely too lean, when t-slot fuel is close the mixture screws usually end up between 3/4 and 1 1/2 turns out for best idle. Getting the balance of idle jet, idle bleed, and t-slot restriction can be touchy with some bodies. My suggestion is to put .040 IJ in the lower position, and start with about a .067 MAB. Adjust the mixture screws to get the best idle speed with the least amount out at operating temp. Bring the RPM up out of gear to about 2000 and hold it steady, put your finger over one or two of the idle air bleeds. You should se no RPM gain or a little loss. Let the car cool completely down and do it again, it should gain a little RPM when you put your fingers over the holes. When tuned correctly it will be a little cold natured, but that's OK. That's what chokes are made for, something we learn to live without on a performance engine.


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 Post Posted: Thu May 03, 2012 7:16 pm 
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Yes i moved the .o40 ij down. I put in the .067 iab and on a cold start it idled low but on its own till it warmed up and the idle came up. Seemed most responsive at 1 3/4 out on the screws. I pulled the carb to check the tslot and the throttle blade is even with the t slot but not exposing any. The timing is locked at 38, i pulled a plug and it was black after idleing. I also blocked the iab at 2000 rpm and got a slight drop in idle.


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 Post Posted: Thu May 03, 2012 7:39 pm 
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FYI my 1050 on a pump gas 434 SBC roller motor will not idle at all cold!! During warmup I'm patting the gas to get the pump shot to keep it running. Once heat is in it will idle fine but not until then.

With what you're saying it almost sounds like the IJ needs to be smaller but wait until jmark confirms this before you tear into it. If I remember correctly a few of of these conversions would up with an .035 IJ to get them right.

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