Carb jetting
#2552053
09/19/18 08:04 PM
09/19/18 08:04 PM
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Joined: Jan 2007
Posts: 10,142 A Red State
SNK-EYZ
OP
I Live Here
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OP
I Live Here
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Posts: 10,142
A Red State
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I’m rebuilding a carb for Kayse’s 440 Dart.
What’s a good starting point for jetting for a Holley 830 double pumper.
The combo is 9.5 to 1, 509 cam, Torker intake, headers.
The carb was an old Carb Shop carb that had the power valves eliminated and 90 jets on the primaries.
I have to replace the metering blocks due to the parts that hold the jets being broken so I got new metering locks.
What’s a good starting point on the jets?
Kayse can't keep up at all now. lol
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Re: Carb jetting
[Re: sgcuda]
#2552092
09/19/18 10:17 PM
09/19/18 10:17 PM
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Joined: Jan 2007
Posts: 10,142 A Red State
SNK-EYZ
OP
I Live Here
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OP
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They're not billet, but these are the ones that I bought.
Kayse can't keep up at all now. lol
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Re: Carb jetting
[Re: SNK-EYZ]
#2552096
09/19/18 10:25 PM
09/19/18 10:25 PM
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Joined: Jan 2003
Posts: 15,439 Val-haul-ass... eventually
BradH
Taking time off to work on my car
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Taking time off to work on my car
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
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What brand are those?
EDIT: If those are Speedmaster/Procomp, you'll be better off getting your $ back and using old Holley blocks.
Last edited by BradH; 09/19/18 11:22 PM.
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Re: Carb jetting
[Re: SNK-EYZ]
#2552217
09/20/18 09:05 AM
09/20/18 09:05 AM
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Joined: Nov 2011
Posts: 287 PA
Harry's Taxi 2
enthusiast
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enthusiast
Joined: Nov 2011
Posts: 287
PA
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What's wrong with the speedmaster/procomp blocks?
'86 Maple Grove KOS Mopar low qualifier......true street legal with no power adders.
NOS-used when losing since 1940.
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Re: Carb jetting
[Re: Harry's Taxi 2]
#2552283
09/20/18 12:45 PM
09/20/18 12:45 PM
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Joined: Feb 2010
Posts: 1,645 Phila. Pa.
Mattax
top fuel
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top fuel
Joined: Feb 2010
Posts: 1,645
Phila. Pa.
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Brad - It sounds like the main jet threads are stripped. See top post. Not much depth for a helicoil or insert. Suppose it might be worth a try. What's wrong with the speedmaster/procomp blocks? I suspect one thing Brad's looking at is the emulsion and idle feed restriction. Easiest and most straightforward tuning will be setup like an old school Holley. This keeps the fuel most consistant. You can make the blocks you purchased similar to the original blocks. Some useful references and explanations here: https://www.tapatalk.com/groups/racingfuelsystems/stickies-f31/in particular the ones titled Relocating the Holley Idle Jet Emulsion Tuning Numerical Listing
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Re: Carb jetting
[Re: SNK-EYZ]
#2552290
09/20/18 01:12 PM
09/20/18 01:12 PM
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Joined: Jul 2006
Posts: 4,319 Puyallup, WA
StealthWedge67
master
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master
Joined: Jul 2006
Posts: 4,319
Puyallup, WA
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I’d set it up 100% per original settings, then tune from there. I’ve always felt that if you have to go much off the original jetting spec with a basically stock Holley carb, then there’s likely issues elsewhere that need to be found and addressed. I’d start questioning anything more than 4 jet sizes off spec., personally.
LemonWedge - Street heavy / Strip ready - 11.07 @ 120
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Re: Carb jetting
[Re: SNK-EYZ]
#2552301
09/20/18 01:41 PM
09/20/18 01:41 PM
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Joined: Jul 2004
Posts: 19,318 State of confusion
Thumperdart
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I Live Here
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State of confusion
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They're not billet, but these are the ones that I bought. Look like chinese crap and would steer away from those as I've tossed a few in the trash for having issues..........
72 Dart 470 n/a BB stroker street car `THUMPER`...Check me out on FB Dominic Thumper for videos and lots of carb pics......760-900-3895.....
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Re: Carb jetting
[Re: Harry's Taxi 2]
#2552336
09/20/18 02:37 PM
09/20/18 02:37 PM
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Joined: Jan 2003
Posts: 15,439 Val-haul-ass... eventually
BradH
Taking time off to work on my car
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Taking time off to work on my car
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
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What's wrong with the speedmaster/procomp blocks? To quote Dominic, who has certainly had his hands on more carbs than I have: "... chinese crap and would steer away from those as I've tossed a few in the trash for having issues..." Even the fancier billet version isn't a good product. More examples of cheap offshore copies that aren't even GOOD copies. I think Mark Whitener commented that by the time you've checked and corrected all the passage sizes with these things, you would have wished you'd bought better parts to start with.
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Re: Carb jetting
[Re: Mattax]
#2552830
09/21/18 01:28 PM
09/21/18 01:28 PM
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Joined: Jan 2003
Posts: 15,439 Val-haul-ass... eventually
BradH
Taking time off to work on my car
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Taking time off to work on my car
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
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Brad - It sounds like the main jet threads are stripped. See top post. Not much depth for a helicoil or insert. Suppose it might be worth a try. I wasn't trying to suggest that the OP use the old damaged blocks, but to get set of standard Holley blocks before he starts trying to tune it. Sorry for any misunderstanding.
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Re: Carb jetting
[Re: BradH]
#2553329
09/22/18 07:04 PM
09/22/18 07:04 PM
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Joined: Feb 2010
Posts: 1,645 Phila. Pa.
Mattax
top fuel
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top fuel
Joined: Feb 2010
Posts: 1,645
Phila. Pa.
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Brad - It sounds like the main jet threads are stripped. See top post. Not much depth for a helicoil or insert. Suppose it might be worth a try. I wasn't trying to suggest that the OP use the old damaged blocks, but to get set of standard Holley blocks before he starts trying to tune it. Sorry for any misunderstanding. Well I read more into it than you intended. No biggy. Everything posted is relevant and should be helpful.
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Re: Carb jetting
[Re: Mattax]
#2553501
09/23/18 04:21 AM
09/23/18 04:21 AM
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Joined: Jan 2007
Posts: 10,142 A Red State
SNK-EYZ
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I Live Here
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OP
I Live Here
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Thanks for the replies. What I had on it were Carb Shop metering blocks like this. They are designed to be able to change the jets without taking off the fuel bowl. My problem is that one of the jet holders is broken in half. Those are the brass hex's you see going in on an angle on the top of the metering block. This means the jet isn't in the proper place and fuel gets by it that isn't metered by the jet. Since apparently they went out of business in 1996 and parts aren't available that's why I'm changing the metering blocks. I've got a buddies 850 double pumper on the car right now and it has 82 jets in it. I'm going to start with 78's on the primaries and 80's on the secondaries and see how that works on my carb.
Kayse can't keep up at all now. lol
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Re: Carb jetting
[Re: SNK-EYZ]
#2553656
09/23/18 02:52 PM
09/23/18 02:52 PM
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Joined: Feb 2010
Posts: 1,645 Phila. Pa.
Mattax
top fuel
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top fuel
Joined: Feb 2010
Posts: 1,645
Phila. Pa.
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Might be worth posting something on the RFS forum. Its not a high volume of activity there, but higher than normal percentage 'collect' interesting things like that. In fact there's a couple of threads there about the Carb Shop and Rapidjet blocks. BLP made a version very recently. Troy Patterson was always promoting the Weber version, although I hate suggesting contacting him. Before doing that, see if with some collective knowledge, we can determine which if any of the metering tube/jet holders interchange. Mark and a couple of others also have some insight into their pecularieties during high flow. I think they are pretty neat idea, and the carb shop's version was close to the same thickness as an original Holley block. Pretty slick IMO.
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