http://www.carcraft.com/techarticles...eet/index.html

 

So soft progressive linkage opens the secondaries sooner?

 

So follow me here a sec. If the rear secondaries are opening earlier at opening slower. How about running a rear power valve and the soft progressive linkage. At part throttle the main secondary jets would manage the fuel flow, but if I mash the throttle the power valve opens and allows the fuel through.

Just thinking out loud. A soft linkage device is about 25 bucks.

 

On hood height:

An ecklers high rise hood has 4.625" clearence at this point of measurement

As you can see my bar clamp is roughly 4" from rail. So the tallest hood I can get from a catalog gives me 4.625" and the L88 hood gives me 4.125" clearence.

As you can see from this picture I have 1.875" additional clearence to the top of the bar:


A couple of other measured dimensions.
My edelbrock performer 600 is 3.375" tall by my measurement
My holley Dominator is 3.25" tall. (The safety plate will take up the extra difference in carb height so it is a wash)

So realisitically with my dominator carb and a flat bottom intake with a 2" filter can(there is no drop base for a 14" aircleaner on a dominator) would be around the same height off of the carb flange as this set up.

I can use 4.2+1.875 = 6" manifold height

So with an L88 hood I am restricted to a 6" tall manifold, and with the high rise hood I could use a 6.5" manifold. (leaving around .125 fudge factor)

So at a minimum I would have to use the ecklers high rise hood to clear the intake, carb, and air cleaner.

 

They used to call it the *super soft* linkage. It's the slowest opening one available. That's what I put in mine. It keeps them closed until you need them.

The rear section of mine if basically stock. No PV...big jets. Typically 82/95 jetting plus pri PV.


JIM

 

So I took apart my metering blocks. Very interesting. No PVCRs. That is definitely a problem.

So I think I am going to have to get a pair of billet metering blocks from AED or quick fuel. Though the picture of the quick fuel billet block as no provision for a power valve.

Or I can get my holley 750 and disassemble that bad boy and figure out the 2 circuit conversion. TIme to take it apart.

check out the difference!

 

Just look at the holes in the 750 an drill some in the 1050. No need for a new metering block. Just follow the passageways all the way through.

JIM

 

Spending a quick minute with the gaskets and different metering blocks. It appears the only real passage difference I can tell is that it reorders the airbleeds. and so 4 holes in the mainbody aren't used.

 

I think I am going to have to buy an ear irrigator and dribble water through various circuits in the main body and determine where they go. Since other people have made this work I shouldnt be too far off. Just need to make sure I am blocking off the right circuit.

 

So I traced some holes in the main body.

Here is what I found:

The hole marked T is the transition circuit, the hole marked I is the Idle circuit, the 3rd is the intermediate circuit.

Up at the top are the High speed air bleed, the idle air bleed and the unused airbleed(x'ed out)

Now in a regular dominator carb the air bleed I have labeled IAB would typically be the intermediate airbleed and the x'ed out airbleed would traditionally be the idle airbleed.

In the next picutre you will see how a 4150 gasket lines up to the dominator mainbody


As you can see it lines up perfectly absent the dominator intermediate circuit, and the above airbleed order changes.

 

So there are 3 sets of annular boosters:

Holley 34-34 - Dominator HP Annular boosters
Holley 34-9 - Old style Annular boosters

And

34-36 - THis is a specially designed booster to restrict the carb down to 750cfm.

 

Here is a fun article on booster design.
http://www.popularhotrodding.com/tec...ech/index.html

 

So here is the pressure drop across a couple of common venturis:
http://www.ajdesigner.com/venturi/ve...fferential.php

(all based upon 180cfm flow and a density of 1.16Kg/m^3)

Holley 650: 4043 Pascal
Holley 750: 2334 Pascal
Dominator: 1090 Pascal

So lets look at what this means: I need a booster that will provide 3.71 times the gain as a holley stick booster, and/or 2.14 times the gain as a holley down leg booster.

Not quite sure how to figure that out.

Lets look at Jim's old 427 we basically keep the same values in the calculator and adjust the CFM to 216 from 180 and the pressure change would be 1569 Pascal.

Lets look at his 540 and up the CFM to 273 and we get 2504 Pascal, which is a little better than a 350 with a 750cfm carb on it.

 

So I guess-t-mate that the pressure drop across my holley 750 booster is 22557 Pascal with 37 CFM going through the booster

I guess-t-mate that the pressure drop across my Dominator booster is something like 11918 with 48cfm going through the booster

This leads me to believe that my dominator booster needs to have its typical .875" outside diameter with a .4375" interior.

That is of course if I was comparing apples to apples.

 

So I was thinkin on my drive in. Bernoullis principle operates on 2 pressures 2 areas flow and the density of the fluid.

So this got me thinking. I know the pressure change at the venturi, I can calculate the pressure change I want at the booster, and I know the area of the booster OD. So I should be able to calculate the ID of the venturi based upon that information.

If that works I need a venturi inside diameter of .445