Build update 2

[85lebaront2]

I don't have a picture of one handy, but the bottom of the booster venturii has what looks like a miniature hoop skirt on it to increase the vacuum signal. So instead of two 390 cfm 2 barrels back to back, you have a 345 cfm primary side and a 390 cfm secondary side.  

Main venturii size is still the same.

[Ifitaintbroke]

That makes sense as a smaller venturi provides better vacuum signal and therefore (usually) better throttle response. They just achieved the same goal a different way. I've had to explain to people many times that bigger carb does not equal more fuel. An 850 double pumper on a mostly stock 302 in an F-150 is not a good idea. I know someone who did that and it ran like garbage.

[mat in tn]

too many don't know what a carburetor does. it feeds the air with fuel vapor. and in doing this, it allows the engine to run as it can. it does NOT make the engine do anything. if the engine cannot provide enough cfm velocity for the Venturi, then it will not get the fuel.

[85lebaront2]

Mat, we had a parts store that once sold an Offenhauser 360 intake, a Holley 850 cfm carburetor and an Accel distributor to a young USAF enlisted man with a 1957 Chevy 283 with a Powerglide. When it didn't run worth a crap they sent him to my shop (we were the Holley authorized warranty center). When we told the kid is was a totally impossible combination to get to work, the store that sold it (part of a group of loosely affiliated stores with one extremely rich partner in common) called and was extremely angry with us for telling him the truth instead of covering for them.

[mat in tn]

but 850 cant be too big . the 283 came with dual quads right

[85lebaront2]

Not with a Powerglide.

[mat in tn]

when I was a kid, I went through my learning curve like all the others. even had an 1850 with a machine screw with nut in the secondary slot. haha. don't do it! a good friend built great chevys and built a beautiful 55 two door post and put a 454 w a Doug Nash five. we went out on a "run" and stopped for what they now call a test hit. launched like a boss until he forced open the secondaries and then it fell on its @&&. he then said that he needed to adjust the track screw and I was stunned. he was my father's age and built award winning cars and even this 19 yr. old kid had learned that doesn't work.

[85lebaront2]

Let's see, at 19 I went in the Marine reserves to avoid being drafted into the Army (this was in 1965). When I returned from my 6 months active duty, dad gave me a choice, find a car or take over the payments on the 1964 Falcon he had bought while I was at PI. I ended up with the Falcon, a 260 V8, 3 speed fully synchro with factory AC. It didn't stay stock long, first change was a BW T10 and the needed floor tunnel and shifter.

Then Jahns 10.5:1 pistons, Lunati hydraulic cam, Hedman Headers and dual exhausts, later i built a C4 for it. Then an Offenhauser 360 intake and a Rochester Quadrajet for a 1966 Buick Riviera. Later I bought a Ford performance tri-power kit from Beach Ford in VB VA. I finally ended up getting rid of it after I bought a 1966 GT350.

[mat in tn]

I wasn't even born yet!

[ArdWrknTrk]

This is what my truck is wearing ATM

[mat in tn]

by the looks of it, it has been used for quite some time.

[ArdWrknTrk]

The white dust?
Or the rest of the corrosion?

[Ifitaintbroke]

I may just have to break down and find a new or newer carb. I love rebuilding carbs, and my mindset had always been "why buy a new one for $500 when you can find a used one for $20 and rebuild it". But, I'm now starting to understand why nobody does that anymore. I BLAME ETHANOL!

[mat in tn]

I'm rebuilding carbs somewhat regularly. it happens every time we get one in that set too long. my only complaint is that it takes far more time for the "must be ordered" kit to arrive than it takes for me to do it. even I forget to run my standing vehicles often enough. sad to say but many who have these old carb vehicles that sit for extended periods have them fixed then put them back up and don't use stabilizer either.

[ArdWrknTrk]

I blame the "it can be tuned from the front seat with a laptop (or even a phone app) in real time"
Rather than the carb itself.
I used to have four boxes of Holley tuning parts!

Technology marches on.

Would try to design an emissions system around vacuum operated controls, to meet today's emissions standards?

For that matter (if fuel mileage didn't matter) it's a lot easier to make power with ethanol than gasoline.
You just have to make it at 9:1!
Look at any drag strip or race course.
Look back at the days of Gran Prix race cars making 1100 HP in qualifying trim.
Look at the fiery accidents, with no flames apparent.
The '70's were a great time to be young at Watkins Glen.

[mat in tn]

yeah the invisible flame haunts me. I just don't like it.

[Ifitaintbroke]

I may play with it some more today. I've also got to figure out what's going on with the power steering. It's shooting out the pump end of the pressure line, but only when the wheel is turned. That would be because the line pressure is highest then.

[mat in tn]

you may have a mis match of parts. there were two or three different end fittings used across the years and the fitting which screws into the pump through the reservoir has to match it. some had a seal at the end, and some had an o ring in a groove.

[85lebaront2]

Dead on Mat, Ford went to metric fittings with the O-rings in 1985. If any of the components are wrong (US vs Metric) making them seal becomes mission impossible.

[ArdWrknTrk]

But purchasing the correct pressure line solves all the problems, because the steering box didn't really change....💡