Annular boosters on a Tunnel Ram

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MomsDuster

MomsDuster

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Well Christmas came early here. Bit the bullet and picked up a pair of Proform main bodies with annular boosters for my tunnel ram. Looking forward to working through the retuning/learning process on these. Stay tuned, I’ll post updates as I move forward this winter.

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Because I love self flagellation, what diameter are the Venturii and how many holes are in the boosters?

TIA
 
Rat Bastid said:
Because I love self flagellation, what diameter are the Venturii and how many holes are in the boosters?

TIA
Click to expand...
1.385 at the top, but my tool hit the bottom of the booster so I’m thinking it’s just a smidge smaller, not much maybe another .01

1.674 at the bottom and 12 holes in each booster.
 
Ok for those interested I started working on these main bodies this am.

First I measured and verified the supplied air bleeds. .033 MAB and .070 IAB then the squirters, they all measured.033.

Next I drilled and tapped for transition slot restrictions. I use a 10-32 tap so I can use the brass for either TSR or Air bleeds.
I did notice that the transition slot passage had a shoulder inside that measured.086 so I’m assuming that if/when it comes time to tune the transition slot I have a starting point at smaller than that.

Then I sprayed everything down good with carb cleaner and blew everything out with air. Wrapped them back up and now it’s time to pull the carbs off FF the car and start the cleaning/swapping process.

Thinking I’ll drop 4 numbers on my main jets and maybe .001 on my IFR’s to start with and go from there.

Thoughts?

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Ok folks, got the main bodies installed. Unfortunately it’s too wet to go out and do any testing. She starts runs and idles fine. I kept the same tune in it except I dropped the main jets 4 numbers. Hoping for some better weather to move forward. Here at a couple before and after pics and a link to a video for those interested.


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You may need to go up .002-.004 on your MAB as those boosters will want to go richer, sooner than a down leg.

Just keep an eye on it.
 
Very nice main bodies. It does take some work. Some O2 sensors in the collectors will be helpful. I also run 8 EGT sensors as well. I have two Holley 1050 Dominators. have it tuned nicely for the street and strip.

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RB,
Post #7. So now the MAB needs to be bigger to delay the main system? Opposite of what you say in other posts......
 
I don't need to read it again. Once was enough. You actually got it right for a change in post #7; it is the other thread you got it wrong claiming bigger MABs start the system sooner....
 
Bewy said:
I don't need to read it again. Once was enough. You actually got it right for a change in post #7; it is the other thread you got it wrong claiming bigger MABs start the system sooner....
Click to expand...

Dumb ***. I’ll say it again. A bigger MAB starts the mains sooner.

If you understood what happens when you go from a down leg booster to an annular booster then you‘d understand what I said.

Since you already admitted you don’t work on Holley carbs (and it’s clear you know nothing of them) you should check out and keep quiet.
 
Rat Bastid said:
Dumb ***. I’ll say it again. A bigger MAB starts the mains sooner.

If you understood what happens when you go from a down leg booster to an annular booster then you‘d understand what I said.

Since you already admitted you don’t work on Holley carbs (and it’s clear you know nothing of them) you should check out and keep quiet.
Click to expand...
My understanding is, the annular booster is bigger and add a restriction. That in itself could cause it to go rich. Also, This is getting into why you've always said peak air flow doesn't always mean peak power. It's how the air and fuel are mixed. A better mixture can make more power at lower overall air flow numbers. ........and you didn't think I was payin attention.
 
Post #14.
RB

No moron, a bigger MAB starts the system LATER. Your describe this in post #7 which depicts increasing MAB size to lean out the mixture by starting the main system LATER.
Might come as a surprise to you but Holley carbs work the same as any air bleed/venturi carb, & if you know how brand X works, a Holley works the same way.

Do you ever get anything right? I never said I don't work on Holleys. I said I don't like Holleys. I have worked on plenty of Holleys, under protest.
 
Bewy said:
Post #14.
RB

No moron, a bigger MAB starts the system LATER. Your describe this in post #7 which depicts increasing MAB size to lean out the mixture by starting the main system LATER.
Might come as a surprise to you but Holley carbs work the same as any air bleed/venturi carb, & if you know how brand X works, a Holley works the same way.

Do you ever get anything right? I never said I don't work on Holleys. I said I don't like Holleys. I have worked on plenty of Holleys, under protest.
Click to expand...

Is that what I said in post 7? Is that REALLY what I said?

Read it again and see if it sinks into your block head.

A bigger MAB starts the booster sooner and makes the fuel curve go leaner at high flow.

Thats exactly what I’ve said from the beginning. And that’s the FACT.

Go read NACA 49. No wait, have someone read and explain it to you. You can’t learn on your own.
 
RB,
You can keep repeating your BS until the end of time....& it will still be wrong.

For those wondering about how the AB works, it is pretty simple, but not simple enough for RB.

If you suck liquid through a straw into your mouth.....& then put a small hole in the straw above the liquid level, you have to such harder to get the same volume of liquid into your mouth.
Your mouth suction represents the pressure drop across the booster. In the carb, the increasing pressure drop is created by more air speed [ more rpm ]. Increasing the hole size in the straw will require even greater suction [ rpm increase ].
So a bigger AB will start later [ higher rpm ] & vice versa. The bigger AB will also lean the mixture [ Rat got something right ]. MAB size thus controls when the main system starts.
 
Bewy said:
RB,
You can keep repeating your BS until the end of time....& it will still be wrong.

For those wondering about how the AB works, it is pretty simple, but not simple enough for RB.

If you suck liquid through a straw into your mouth.....& then put a small hole in the straw above the liquid level, you have to such harder to get the same volume of liquid into your mouth.
Your mouth suction represents the pressure drop across the booster. In the carb, the increasing pressure drop is created by more air speed [ more rpm ]. Increasing the hole size in the straw will require even greater suction [ rpm increase ].
So a bigger AB will start later [ higher rpm ] & vice versa. The bigger AB will also lean the mixture [ Rat got something right ]. MAB size thus controls when the main system starts.
Click to expand...



Damn dude. Just damn. At LOW AIR FLOWS the MAB acts like an emulsion bleed, adds air to the column of fuel, which changes its weight and viscosity, which in turn makes it easier to get out to the booster.

Disregard my last post in the ignition thread.

You ARE that stupid.
 
Here you go. Another example of being exposed as a knave and a liar.

You want to argue with Taylor, by all means go ahead.

The Internal Combustion Engine in Theory and Practice.

Charles Fayette Taylor

Volume 2: Combustion, Fuels, Matériels, Designs.
Revised Edition 1985.

Chapter 6: Carburetor Design and Emissions Control: Complete Automotive Carburetor, page 205.

See number 2.

For those who don’t have the book I’ll post a picture of number 2. Bewy has the book. He can look it up.
 
If you don’t have the book…a third grader can grasp this concept.

A bigger MAB starts the mains SOONER and leans the fuel curve at HIGH AIR FLOWS.

A smaller MAB starts the mains LATER and richens the fuel curve at HIGH AIR FLOWS.

Taylor explains it and Bewy argues it. Who to believe? I chose Taylor because it matches my testing.

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RB.
Brain surgeon. Did you actually bother to read your own info, the highlighted section?????

It says NOTHING, NOTHING, NOTHING about air bleed SIZE, SIZE, SIZE & start of the system, only that the air bleed promotes greater fuel flow at lower velocities.....& nobody, least not me, is arguing that point.
Talk about dumb & reading into things that do not exist....
My description of AB operation in post # is CORRECT.
 
Bewy said:
RB.
Brain surgeon. Did you actually bother to read your own info, the highlighted section?????

It says NOTHING, NOTHING, NOTHING about air bleed SIZE, SIZE, SIZE & start of the system, only that the air bleed promotes greater fuel flow at lower velocities.....& nobody, least not me, is arguing that point.
Talk about dumb & reading into things that do not exist....
My description of AB operation in post # is CORRECT.
Click to expand...

Yeah, I need to hold you F’ing hand and wipe your nose too?

Do they teach algebra down under? I’m asking because evidently they do not.

I can’t do EVERYTHING for you.
 
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