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By BudMan - 12 Years Ago
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Hi - I have a Ron Kellog built tri-power set-up that I am going to put on my 312. The two end carbs are Ford 94s and the center carb is a Holley 2100. The distributor is not a load-o-matic but a dual advance 57. My question is - where do I get the proper vacuum for the distributor advance? I read Teds 07 Feb 2010 article "Modifying the Holley 94 two barrel for late model distributor". Do the modifications Ted describes apply to a tri-power set-up? I know there are several forum members running tri-power. How are you getting distributor vacuum? Were Teds modifications done? What happens if I just hook the vacuum up to the vacuum port on the center carb? Thanks!
BudMan
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By The Master Cylinder - 12 Years Ago
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Budman, You should have vacuum hooked up to your primary carb, especially if you have progressive linkage. Does your Holley 2100 have ported vacuum for the distributor?
I myself have Stromberg 97's which don't have ported vacuum (well unless you have a rare ported vacuum base plate) so I am using manifold vacuum. In Ted's Test he used full mechanical advance.
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By lowrider - 12 Years Ago
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I used Ted's method on my tri-power. Worked great. Get a lot of head scratching from onlookers at shows.
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By BudMan - 12 Years Ago
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Ted's modification modifies the economizer valve opening to supply vacuum to the distributor. My carb does not have the economizer valve so I can't do the mod. Will intake manifold vacuum work? As I asked previously, will the normal vacuum port on the carb work? I'm getting ready to install this set-up and I could use a little help. Thanks!
BudMan
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By charliemccraney - 12 Years Ago
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Manifold vacuum should work. Several of us use that, with single carb and multi carb.
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By MarkMontereyBay - 12 Years Ago
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I am running a tripower setup on my 312. Same as you, with a 2110 as a primary carb. I use manifold vacuum now and it seems to help the idle with the Mummert 270 cam and the Fordomatic. I have Ted's post instructions for modifying the power valve circuit to ported vacuum and have intended on doing it for a long time. Lots of opinions on manifold vs ported vacuum but I will probably do the modifications for ported eventually.
I just reread your last post and it says your primary carb doesn't have a power(economizer) valve. Are you sure? In my case, the two outer carbs have base plates without idle mixture screws, no power valves and the power valve circuit filled in, and no choke plates. The center carb has the power valve and idle mix screws and choke plate.
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By BudMan - 12 Years Ago
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I found a throttle body with an economizer valve for $15. I think I will buy it and do Ted's modification then transplant the throttle body onto my Holley 94. I work rather slowly so it may be a few weeks before I get this done. Thanks for the input on using manifold vacuum. It seems to me that if one can use manifold vacuum, them one should be able to use the normal vacuum port on the carb. Wouldn't the vacuum be the same or maybe a little less than the vacuum from the manifold?
BudMan
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By MarkMontereyBay - 12 Years Ago
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The power valve (economizer) threads into the float bowl from under side the carb. Modern power valves hit the side of the float bowl when threaded in to place and interfere with the valve operation. I modified my primary carb gently with a Dremel tool to make room in the wall of the float bowl for modern Holley power valves. They come is several sizes so you will need to see what works for you. Trial and error is probably the way to pick the right one. You can get early style power valves from Charlie Price and maybe Speedway. Manifold vacuum holds the vacuum timing advance at idle and again approaching and at steady speed to improve gas mileage. Ported vacuum only allows vacuum advance approaching and at steady rpm/light engine load. The pros and cons of each have been debated epically for decades.
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By paul2748 - 12 Years Ago
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You don't need power valves in the end carbs. There is a Holley blank off piece that screws into where the power valve is. As mentioned, Charlie price has power valves that are modified to fit the 94's and seat right. He also has a nice gasket for it.
Actually, you can run the car ok without the vacuum advance. Mallory has made distributors that don't have it and th engine runs ok with out it. I had one on my flathead at it ran fine.
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By BudMan - 12 Years Ago
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Here is a link to Ted's article "Modifying the Holley 94 two barrel for late model distributors" -
http://www.eatonbalancing.com/blog/tag/holley-2100/
If I am reading the article correctly, the power valve is not used. Some carburetor modifications are made and the power valve is removed. A fitting with a hose barb on it is then screwed into the hole (after re-threading) where the power valve was. A hose is hooked to the barb and then to the distributor vacuum advance. None of my carbs have the power valve fitting. That's why I need a throttle body that has one to replace the throttle body on the center carb. Then I can make the modification.
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By MarkMontereyBay - 12 Years Ago
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Sorry...terminology mixed on my part. The Loadomatic Distributor Anti-Spark valve is what you are referring to, not the power valve. The term "economizer" is sometimes used to identify the power valve.
Check this photo link of the power valve:
http://www.heminutter.com/wp-content/gallery/carbs/img_3466.jpg
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By MarkMontereyBay - 12 Years Ago
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I checked my garage shelf and still have some 94 bases with the loadomatic (economizer) spark valve. You can have one for the cost of shipping if you need it.
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By Ted - 12 Years Ago
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Here’s the link to the thread that outlines the differences between direct vacuum and ported vacuum hookups to the distributor. Recurving the mechanical advance portion of a factory distributor or using an older mechanical advance only Mallory distributor can provide an ignition advance curve that does away with the vacuum advance while providing good driving characteristics and decent fuel economy.
http://forums.y-blocksforever.com/Topic44648.aspx
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By BudMan - 12 Years Ago
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MarkMontereyBay - I sent you an email regarding your offer. Please let me know that you got it. Thanks!
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By MarkMontereyBay - 12 Years Ago
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Got your email and sent a reply to your email address. I will ship one up to you. Happy Turkey Day.
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