carb size
Post Fiend
Joined: Jun 2003
Posts: 8,209
Likes: 12
From: Black Hills of SD
Where do you get just a power valve? I mean besides whatever comes in a kit.
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Posting Guru
Joined: Apr 2006
Posts: 1,477
Likes: 7
From: NAMPA, ID.
Mikes carburetor parts or Carbs unlimited, but with the shipping costs involved, you can probably buy a complete rebuild kit from Auto Zone or O'reillys cheaper.
Post Fiend
Joined: Apr 2002
Posts: 19,311
Likes: 97
From: Waterloo, Iowa
True but depending on carb size, engine tune etc the kit may include a power valve that won't work correctly for his application.
Altitude especially, which he hasn't mentioned exactly but, he lives in Idaho. One of the key elements of carb setup is making sure that thing stays closed, except and only when under load, for power enrichment. I bet if he determined what valve he wanted Mike would swap it out in the kit? Mikes Carburetors has any size ya want for that matter. Holley power valves too, are identical for this purpose.
Check for the average minimum steady highway cruise manifold vacuum observed (with a vacuum gauge) and select a PV about 2" below this number.
Somebody should have made an adjustable power valve, with a set screw or something like that, and accessible without carb disassembly. Would have saved a lot of hassle.
Altitude especially, which he hasn't mentioned exactly but, he lives in Idaho. One of the key elements of carb setup is making sure that thing stays closed, except and only when under load, for power enrichment. I bet if he determined what valve he wanted Mike would swap it out in the kit? Mikes Carburetors has any size ya want for that matter. Holley power valves too, are identical for this purpose.
Check for the average minimum steady highway cruise manifold vacuum observed (with a vacuum gauge) and select a PV about 2" below this number.
Somebody should have made an adjustable power valve, with a set screw or something like that, and accessible without carb disassembly. Would have saved a lot of hassle.
Hotshot
Joined: Mar 2013
Posts: 14,255
Likes: 199
From: Phoenix, Az.
Ford sold them separate back in the day. Give me a tag number or application and I can see if there is any out there.
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Posting Guru
Joined: Apr 2006
Posts: 1,477
Likes: 7
From: NAMPA, ID.
True but depending on carb size, engine tune etc the kit may include a power valve that won't work correctly for his application.
Altitude especially, which he hasn't mentioned exactly but, he lives in Idaho. One of the key elements of carb setup is making sure that thing stays closed, except and only when under load, for power enrichment. I bet if he determined what valve he wanted Mike would swap it out in the kit? Mikes Carburetors has any size ya want for that matter. Holley power valves too, are identical for this purpose.
Check for the average minimum steady highway cruise manifold vacuum observed (with a vacuum gauge) and select a PV about 2" below this number.
Somebody should have made an adjustable power valve, with a set screw or something like that, and accessible without carb disassembly. Would have saved a lot of hassle.
Altitude especially, which he hasn't mentioned exactly but, he lives in Idaho. One of the key elements of carb setup is making sure that thing stays closed, except and only when under load, for power enrichment. I bet if he determined what valve he wanted Mike would swap it out in the kit? Mikes Carburetors has any size ya want for that matter. Holley power valves too, are identical for this purpose.
Check for the average minimum steady highway cruise manifold vacuum observed (with a vacuum gauge) and select a PV about 2" below this number.
Somebody should have made an adjustable power valve, with a set screw or something like that, and accessible without carb disassembly. Would have saved a lot of hassle.
Post Fiend
Joined: Apr 2002
Posts: 19,311
Likes: 97
From: Waterloo, Iowa
Once people start modifying a stock engine, especially cam, then stock power valve sizing goes out the window. How much manifold vacuum does your engine draw at idle? Do you plan on driving up into the high country?
The shop manual specs are a good place to start but that's about it.
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Laughing Gas
Joined: Mar 2013
Posts: 1,027
Likes: 5
From: Garner NC
Different jets is a sign of mass rebuilder having their hands on it at some point. Could be your booster venturi is also incorrect. They disassemble a bunch of 'similar' carbs, batch clean and then just grab parts out of the pile as needed. Fortunately, the 2100 is a very forgiving design.
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Posting Guru
Joined: Apr 2006
Posts: 1,477
Likes: 7
From: NAMPA, ID.
Well OK, but we're talking about power valve selection, not jet.
Once people start modifying a stock engine, especially cam, then stock power valve sizing goes out the window. How much manifold vacuum does your engine draw at idle? Do you plan on driving up into the high country?
The shop manual specs are a good place to start but that's about it.
Once people start modifying a stock engine, especially cam, then stock power valve sizing goes out the window. How much manifold vacuum does your engine draw at idle? Do you plan on driving up into the high country?
The shop manual specs are a good place to start but that's about it.
Hotshot
Joined: Mar 2013
Posts: 14,255
Likes: 199
From: Phoenix, Az.
Different jets is a sign of mass rebuilder having their hands on it at some point. Could be your booster venturi is also incorrect. They disassemble a bunch of 'similar' carbs, batch clean and then just grab parts out of the pile as needed. Fortunately, the 2100 is a very forgiving design.
They were only trying to help MPH. I remember reading how you have made a point to keep it as originally designed. BUT, not many do keep it totally stock.
Rasputin53 had a good point. The two different jets might only be part of your problem. PLUS, you have to consider the age and mileage of your engine and our current gas is not close to how it was when our trucks were new. So what the Engineers did originally should be a good start for you but not necessarily the end result. True if it were my rig I would start out with 55 jets. But I would have bought some 56 and 57 at the same time to save freight eventually. Run the 55's for a while. Get to know how it feels. Read your plugs. I have a sneaky suspicion they will read lean. Then I'd go with the 56's 1st.
My $.02.
Laughing Gas
Joined: Mar 2013
Posts: 1,027
Likes: 5
From: Garner NC
Two jet sizes is still a very close performance window. I would not think you would really be able to tell the difference except in mileage over a full tank. I made the jets for my wife's Mustang (43F) just to have the original size in there. It had a 50 and a 52 and ran plenty rich no matter what. It did have the correct booster. That is on a 289. Fortunately for me, my 360 had the untouched stock carb.
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Posting Guru
Joined: Apr 2006
Posts: 1,477
Likes: 7
From: NAMPA, ID.
Well, mine had a 52 and a 55. The 55 is OEM. I'm starting with 2 new 55 jets. We'll see what happens. I've noticed my venture is stamped 1.21. My carb is stamped 1.23. I don't know if this is a mismatch or not. I'm awaiting an answer from Mikes carbs. My truck has a lean surge at part cruise so this is step one.
Post Fiend
Joined: Apr 2002
Posts: 19,311
Likes: 97
From: Waterloo, Iowa
The shop manual specs will indicate the codes or letters on the booster, too. If Mike can't help here's a pretty good site on drilling down into carb trivia, he has some of the books.
Ed's Carburetor website, traffic isn't real high but he will answer questions
http://www.network54.com/Forum/88781
Ed's Carburetor website, traffic isn't real high but he will answer questions
http://www.network54.com/Forum/88781
Hotshot
Joined: Mar 2013
Posts: 14,255
Likes: 199
From: Phoenix, Az.
[QUOTE=mrpotatohead;17124914] I've noticed my venture is stamped 1.21. My carb is stamped 1.23. I don't know if this is a mismatch or not.
[QUOTE]
For tag number C8TF-Z the original venture cluster was part number C7AZ9A523K. It was stamped "B". That was replaced by D1PZ9A523V. Which was stamped "PV".
D1PZ9A523V:
Bob Allen Ford
913-381-3000
Good luck with these guys. When they are the "only game in town" like right now they up their price a bunch. You might ask them the last time they sold this part number. If a LONG time ago it might help you get a deal.
[QUOTE]
For tag number C8TF-Z the original venture cluster was part number C7AZ9A523K. It was stamped "B". That was replaced by D1PZ9A523V. Which was stamped "PV".
D1PZ9A523V:
Bob Allen Ford
913-381-3000
Good luck with these guys. When they are the "only game in town" like right now they up their price a bunch. You might ask them the last time they sold this part number. If a LONG time ago it might help you get a deal.