? 3 94's on my 303" Olds?

I'm going thru my 3 deuces after reading everything I can find in the archives etc. on how to set up a 303" Olds with an Edelbrock 180 degree manifold for 3 Holley 94 carbs and progressive linkage. First off, I have two carbs labeled
model 91-99 and one labeled 59. I have measured the venturi actual size of the 59 by putting a series of sockets in it, the closest fit being an O.D. of 29/32". Haven't measured the others yet. What are they from?
Here is what I plan:
Middle carb- leave in choke, idle circuits, 51 main jets and add 6.5 power valve. largest throw on accelerator pump linkage.
End carbs- remove choke and fill holes with JB weld, idle screws turned all the way in (won't really matter) with tiny circle shaped solid gaskets replacing the fiber washers to block the circuit before transfer ports, where the mixing bar rests on the body after crossing the venturi. remove linkage to activate accelerator pump. 51 main jets. 4.5 power valves.

I notice that the well has a ridge in it that conflicts with the power valves as one tries to screw them in. I am using modern valves which I've machined to have a flat seat (they have a radius while the early ones don't). Is there enough meat that I can safely relieve upwards (continue the full bore of the well) about 3/8 inch of the carb body to make room for the br*** "nuts" that stick up from the valve? (these appear to set the preload of the valve, and I'm not sure I should change these....)

The engine has a mild isky cam, dual exhausts, hot coil with transister breaker, outboard oil filter conversion and a fuel pressure regulator set at 3 psi. the car is a 53' Super 88 with a dual range hydramatic which I figure weighs about 4000 pounds. I have run this car with 3 deuces for 25 years but have never been satisfied with the induction set-up....Help me get it right!
Thanks

 

All are 94's... .94 size, 15/16.
91-99=1939--1941, 59 is '46-8 and universal replacement for older models.
VERY similar carbs.
Consider as a tuning point comparing operation with idle p***age blocked ans unblocked, leaving the actual idle holes closed by screws. The off-idle circuit is often very important as venturis and mains are largely inop until airflow reaches a high level...in other words, LATE on a multi setup. Try open and closed on the circuit at the nozzle bars. Also, leave in all pump parts and remove only adjuster link, as you may find you need pump shot to cover venturi delay as secondaries open. Pay close attention to the tiny bleed holes in the bar...they are oft still plugged after lots of cleaning. You can clearance enough to clear the late adjuster nuts on the PV.
Do you have pics of your machining on PV's?? I've just started getting the wrong ones in recent NAPA kits and have been thinking about this.

 

I have a question for you. You said you've had this setup for 25 years and never been satisfied with it, why?????????????????

The 91-99 carbs are off 39/41 Ford/Merc p***anger cars. The 59 is off 46/48 Ford and 47/48 Merc p***anger cars.

On the primary carb I'd start out with 52 jets as a base line, just a preference.

Using JB weld on the choke shaft holes (for the secondary carbs) really isn't needed. The thing that looks cool is using 22 rifle casings, they fit really nice and look cool.
About using these "solid" gaskets to block fuel before the transfer............are these gaskets steel or ????, and will they hold up to the gas???? Why not just use the JB Weld to fill the idle adjustment screw holes and the venturi holes............is a more long lasting fix for turning these secondaries into dumpers than trying to use gaskets. I would also replace the throttle plates with 12 degree for a better seal and quicker release. I would also look at the primary carb throttl plates and replace them with 5 degree if needed (Ford factory specs were 4 degree).

About using a power valve on the secondaries after you've plugged the idle circuit and removed the accelerator pumps........if you truly want these secondary carbs to be dumpers you will need to plug the power valves. I would also start with 50 jets in these carbs as a base line.

This ridge that conflicts with the power valve area that you are talking about machining, don't as there isn't enough meat in that area, and as mentioned above, power valves are not needed in the secondary carbs anyway.

One of the single most important part of making a 3 deuce setup work is rebuilding the carbs correctly. Lap all mating surfaces flat, flat, flat..................setting floats (making sure that the floats don't have pin holes in them and that they will actually float), and making sure the throttle shafts are tight and not worn..................if they are replace them with new shafts or put oversize shafts in. These shafts are br***.............they wear long before the cast base will.............................IMHO

 

I would leave the choke plates in the secondaries, they are functional.. They direct the air down. Your primary is the only one that will operate as a choke..
Duane.

 

Yes, what were your issues?? Idle, off idle, transition, where?/
Most common are issues at secondary opening, when many systems go directly from one carb working at high flow to 3 working without enough airflow to pull in gas til RPMs go up more.

 

Now, I am not an engineer, but have been working with turbocharged-carburated engines quite a bit. I think that you are right, but the plates and shafts also introduce turbulence into the top of the carbs which can theoretically upset metering. The laws of physics say that the turbulence will continue for 9 times the length of the orifice that it went thru, so with a 94 or 97 that would be a long way down..... Now if you put a screen over the mouth of the carb, with, say 1/16" holes, the turbulence would be less by 9/16" down. I see lots of guys doing blow thru supercharging and turbocharging who bring their boost in at right angles to the carb and wonder why they can't dial in the carb.....I like to make carb hats that "caress" the air into a straight line as it gets to the carb, and then process the air further with screen. An adequate plenum will help too. Maybe it's just armchair ideas, and in practice is meaningless when dealing with something as crude as a 94.......
thanks

 

I did the three deuces 25 years ago, when I was not as fussy about how to run three together, with no idea that the end carbs were different. Gas was cheaper and I ran with only mechanical advance. Just accepted that the carbs would leak, and figured that if a rochester 4 barrel was good to go on 6+ psi, that those old 94's would be happy that way as well. Complicating my understanding was the vacuum lost to a leaking Treadle-Vac power brake ,the Isky cam and leaking vacuum driven windshield wipers. The kickdown to the ****** was also in limbo after changing to three deuces, and there was no manual to refer to on that..... I guess the main problem was bog when I tromped on the fast pedal, which I attempted to address with the accelerator pump linkage and by bringing in the progressive linkage to open the end carbs quicker. I understand now that tromping the pedal suddenly created a situation unlikely to convince gas to enter the engine.......

 

That's why you should consider the off-idle, keeping it in service and perhaps enlarging the idle jet that controls it. It is capable of functioning maybe 1,000 RPM before the venturis activate.
On a flathead single Ford says the off idle is still feeding in overlap with jet at 1600 or so. Here we have a not very large engine with three open. Part of the prob is that you are going from a fully activated single to suddenly 3 trying to digest the same amount of air til revs build. You have the off idle and the pumps available as different sorts of crutch to keep gas moving til the venturis get on the job fully.

 

So, just screw in the idle screws on the end carbs, and don't block the circuit after the nozzle bars. Maybe keep the pumps functional on a low throw linkage setting. Any idea how much to open the idle jets? Can I do this with my tiny drill bits, or is this a purchase only job? Also, I've noted that some plug the little U shaped groove between the intake ports in the carb base. What does that do?
Thanks

 

Test with and without off-idle circuit blocked...I think it will be better open, as it will likely be the only thing working at start of opening up. Then if still bogging, TEST with more gas through that route before drilling. You can add in extra gas to test by choking at time of bog, perhaps also by temporarily opening up the secondary idle screws for road test (obviously you'll have to do a quick step to get it lit and moving with them open)
If drilling out idle jet seems indicated, there ain't no map...just get a set of the tiny numbered drills and move up a step at a time.
Messing with these circuits won't affect main circuit (I'm ***uming it works at cruise and at full throttle?) as total flow possible is still controlled by the main jets...this is sorta how the poorly controlled idle circuitry and the well controlled main circuit can successfully cooperate in the idle to 1500 or so range as ventuis slowly activate.

 

You will need to maintain the idle capibility of all 3 carbs if you plan to have a smooth transition from the center carb to all three. If you disable the front and rear idle circuits you lose the additional fuel that is supplied along with the transition ports to prevent stumbling. Also the experts( Jere Jobe )says to leave the power valves operational but install ones that open at much lower manif. vacuum 3.5 to4.5in. Since late model HolleyP.V. will not work due to not seating properly, you will need to use modified ones. Contact Vintage Speed Charlie Price @ 772-778-0809.Vero Bch Fl. He is supposed to have them.He deals with this situation reguraly and should be able to give advise

 

The transition off-idle capacity would seem to me to be necessary unless engine is severely under-carbed and can bring in main circuit at very low rpm. As I mentioned, Ford stated that a 221 with single 94 carb was still transitioning part off-idle/part main at 1200 or so RPM!
Lots of people seem to think main jets do everything...they can't, and at many times in actual driving they are actually not feeding anything at all via venturis...

 

Bruce is correct and also remember that the 94 has an idle and transition circuit, and you can have fuel flow from both of these circuits well into the higher rpms. Manifold vacuum is what pulls fuel from the lower parts of the carb, where the idle and transition slots are. In the lower parts of cruise, your idle and transition slots will be providing a small amount of fuel. Any time you see manifold vacuum, the idle feed and transition slots will be flowing fuel, because of the vacuum under the throttle plates, even if it is a very small amount. For this reason it can sometimes be a little difficult to fine tune a tripower setup that still has these circuits on the secondary carbs.
At least this is the way I've looked at 94's for the past 45+ years.

IMHO

 

Path: All gas for main and both idle circuits starts out p***ing through main jet, so no combo of feeds can exceed that total. Both idle and off-idle then are fed through tiny hole ib idle jet. Idle circuit cuts that amount way down via screws, off idle is ultimately limited by idle jet. If progressive with throttles closed on end carbs at idle, close idle feed with screws, leaving off idle feeding. Main circuit will start feeding some gas in overlap with off-idle, then take over, PV adds supplemental enrichment needed at full throttle. PV can also only actually deliver when venturis are active.

 

"so no combo of feeds..." to clarify, that doesn't include power enrichment...PV feeds at venturi, is adding gas metered at orifice in casting and not by mains, obviously.