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Re: Removing power valve [Re: fast68plymouth] #2663446
06/07/19 11:35 AM
06/07/19 11:35 AM
Joined: Jun 2006
Posts: 660
Virginia
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varunner Offline OP
mopar
varunner  Offline OP
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Joined: Jun 2006
Posts: 660
Virginia
This must really be an odd ball carb. On mine the only thing the x channel in the main body feeds is the hot-idle compensator on the side on the body, which is plugged. The only passage from the vacuum space behind the PV, goes down thru the body and lines up with the passage in the base plate that was covered. Arrow in the picture points to it.

The second pic shows the vacuum space as being wet. That doesn't seem right. The PV is new, gasket is new and I've been careful how the gasket lines up

yes I did try the 4 hole gasket with the re-surfaced base plate, gasket looked drier after disassembly, but not much of a difference in the idle

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Re: Removing power valve [Re: Clanton] #2663448
06/07/19 11:36 AM
06/07/19 11:36 AM
Joined: Jun 2006
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Virginia
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varunner Offline OP
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varunner  Offline OP
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spacer was a 4 hole. I'm now going with a new open spacer and matching gaskets.

Re: Removing power valve [Re: varunner] #2663548
06/07/19 04:31 PM
06/07/19 04:31 PM
Joined: Jan 2003
Posts: 14,479
So. Burlington, Vt.
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fast68plymouth Offline
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Sorry, total brain fart on my part.

The PV gets its signal from that hole at the bottom of the cavity, into a hole in the baseplate,(just like yours), but the hole in the typical “universal carb” baseplate has a little “v” channel to get vacuum when the 4 hole gasket is used(see pic).

I don’t know what I was thinking about with the cavity in the center of the carb and the PV confused

(Looking at your pic with the 4 hole gasket in place...... it still doesn’t appear as though the gasket “sealed off” that front cavity.
It would only need a leak with as much area as the size of the hole from the base into the PV cavity).

You sure those extra screw threads from the bottom aren’t interfering with how the PV slides into the cavity?

You could still try plugging the PV.

Measure the PVCR, calculate the area.
Calculate the area of the current primary jets.
Add the two areas together.......calculate what size hole that equates to..... install jets with that size hole.
That’s as good of a starting point as you can get without wet flowing the carb.

You should check the gasket surface for flatness on the front and rear of the main body.
I’ve seen them pretty warped in the past, which caused all kind of problems with several aspects of the carb function.

“Back in the day”........ when we’d send carbs out to have them “done”, milling those surfaces was always part of the process.

714BC6EF-5191-4770-81AB-D8DD3791846D.jpeg

68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads
Re: Removing power valve [Re: fast68plymouth] #2663555
06/07/19 04:47 PM
06/07/19 04:47 PM
Joined: Jan 2003
Posts: 14,479
So. Burlington, Vt.
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fast68plymouth Offline
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Make sure the metering block gasket looks like it’s not leaking around the “tube” that feeds the accelerator pump nozzle.

On your carb it appears to be a cast “standpipe”.
The more common arrangement was to have some of the top of the cavity filled in that area, which provided a broader area of support for the gasket.

You may want to verify that you’re using the “correct” metering block gasket, or at least see if it uses a generic gasket or something a little more specific to that carb.

44E3CE33-F22C-4045-8AB2-470ACAEFB245.png

68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads
Re: Removing power valve [Re: fast68plymouth] #2663572
06/07/19 05:40 PM
06/07/19 05:40 PM
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Posts: 660
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varunner Offline OP
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Thanks Dwayne, I will continue to measure and inspect this bad boy. Another carb will be here in 2 weeks, so I'll be able to swap it out.
cheers

Re: Removing power valve [Re: varunner] #2664011
06/09/19 12:30 PM
06/09/19 12:30 PM
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Posts: 660
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varunner Offline OP
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Think I've fixed this issue. Gaskets were leaking bad on both ends. I re-surfaced both ends of the body where the fuel bowels go. Amazing how bad a shape they were in once I started working on them. I will never build a carb without doing this. I also plugged the vacuum port in the vacuum space as a test in case it was still leaking. The vacuum space is dry on both ends now and spark plugs are also dry. Still a little fuel in the intake, not going to worry any more about that. I'll see how it runs. On to the next problem..

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Re: Removing power valve [Re: varunner] #2664045
06/09/19 02:22 PM
06/09/19 02:22 PM
Joined: Jan 2003
Posts: 14,479
So. Burlington, Vt.
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fast68plymouth Offline
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Joined: Jan 2003
Posts: 14,479
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If you plugged the vac port to that cavity....... the PV def won’t work like that.

You going to try it without one?

When is the next outing?

Got your nhra number yet?


68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads
Re: Removing power valve [Re: fast68plymouth] #2664077
06/09/19 04:43 PM
06/09/19 04:43 PM
Joined: Jun 2006
Posts: 660
Virginia
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varunner Offline OP
mopar
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The plug was only in there as a test in case the re-surfacing didn't work. It's out now. I also put the PV back in. I do a final test tomorrow. VMP has an all day TnT next friday, planning on running that. #1358 G/SA

Re: Removing power valve [Re: varunner] #2664092
06/09/19 05:11 PM
06/09/19 05:11 PM
Joined: Jan 2003
Posts: 14,479
So. Burlington, Vt.
F
fast68plymouth Offline
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fast68plymouth  Offline
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Joined: Jan 2003
Posts: 14,479
So. Burlington, Vt.
Good luck at the TnT.

G/SA......12.00 index.

Shouldn’t be too hard to get it to go .40-.50 under.

I don’t know what your best speed has been so far(of course, I’m sure the carb hasn’t worked right on any passes)........ but I’d say you’re looking for 113+.

You said it had 60’d a 1.50 already....... so that part seems good.

Too bad that carb situation wasn’t sorted out before the motor was on the dyno.


68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads
Re: Removing power valve [Re: fast68plymouth] #2664115
06/09/19 06:34 PM
06/09/19 06:34 PM
Joined: Jun 2006
Posts: 660
Virginia
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varunner Offline OP
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Thanks, appreciate the help.

I just added 115 lbs to make G weight.

So I have only made 12 passes total since the motor/car was finished. I'm lucky enough to have 3 tracks within 2 hrs, VMP, MIR, and RD, but we're had a bunch of rainouts.

Best pass was 11.79/111 at MIR, 1.56 60ft.

I had a 1.50 60ft at VMP, with a 15 mph headwind, 1/8th mile et was the same as what I did at MIR.

I have 2 goals before August when 3 divisionals happen, Galot, VMP, and the rock.

1) get the carb jetting close. I have read somewhere, wish I could find it again, that with this intake the carb needs to be staggered jetted. I think I read that in an old mopar book, wish I could find that.

2) decide on if I foot-brake it or 2-step. Most people say and I agree it will be faster foot-braking it. I think I will be more consistent on the starting line with the 2-step. so the question is how much difference will there be. If it's a couple tenths, great, foot-brake it is. If it's .05 then I'll stay with the 2 step. This could take a while.

Re: Removing power valve [Re: varunner] #2664146
06/09/19 08:17 PM
06/09/19 08:17 PM
Joined: Jan 2003
Posts: 14,479
So. Burlington, Vt.
F
fast68plymouth Offline
I Live Here
fast68plymouth  Offline
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F

Joined: Jan 2003
Posts: 14,479
So. Burlington, Vt.
You should try the weight in and out at the TnT, since which way is farther under.

Both F and G have a ton of cars....... but I think G has more.

Depending where on the ladder you are..... .05 can be a few spots on the sheet.

My advice on the jetting is...... get something like an Autometer A/F gauge in the car, so you can keep track of what does what with the jetting.


68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads
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