Author Topic: Carburetor madness by Drew  (Read 49875 times)

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Drew Pojedinec

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Re: Carburetor madness by Drew
« Reply #30 on: November 10, 2017, 03:47:01 PM »
I need a beer.

Heo

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Re: Carburetor madness by Drew
« Reply #31 on: November 10, 2017, 04:36:08 PM »
you need to cut down carbs in your diet ;D
Have you ever worked with a S.U Carb? genius
construction that more or less unchanged since 1906
i love them. I think you cant make a carb with less parts

https://en.wikipedia.org/wiki/SU_Carburettor

« Last Edit: November 10, 2017, 04:38:25 PM by Heo »



The defenition of a Gentleman, is a man that can play the accordion.But dont do it

Drew Pojedinec

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Re: Carburetor madness by Drew
« Reply #32 on: November 10, 2017, 05:49:51 PM »
Not an SU carb, but very much the same are the carbs folks here run on junior dragsters.
Just a slide carb with a tapered pin that sits in a jet.  Open throttle and slide opens and pulls the pin out of the jet.
Doesn't get much easier really.

turbohunter

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Re: Carburetor madness by Drew
« Reply #33 on: November 10, 2017, 06:22:27 PM »
I thought I had a few carbs, jeez. :o
Marc
'61 F100 292Y
'66 Mustang Injected 428
'66 Q code Country Squire wagon


Dan859

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Re: Carburetor madness by Drew
« Reply #34 on: November 11, 2017, 01:53:25 PM »
You collect carbs like I collect guns ))

Drew Pojedinec

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Re: Carburetor madness by Drew
« Reply #35 on: November 11, 2017, 05:08:53 PM »
Not really collecting them.

I mean, I get requests for about 7 different sizes/types.  So I need to have at least one of each done at any time, right?  Well core prices fluctuate so when i see one within my range I snag it.  I have at least two of each laying around ready to be built due to this fluctuation.
So now we're up to 21 or more just laying around.  Of course there is a swap meet this weekend.  :P
Plus having ones around gives me time to experiment with different calibrations and come up with a recipe of sorts for each one.

Drew Pojedinec

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Re: Carburetor madness by Drew
« Reply #36 on: November 13, 2017, 05:37:37 PM »
No plating progress as of late.

Fixed Boxtop David's two 1850's he runs as 2x4's.  They run a good bit smoother than previously, they literally ate 2.5 days and probably 3 years of my life..... Just simple stupid issues, but a ton of them.
A 600cfm Holley, a 670 Holley, a 600cfm Quickfuel, an 850 Quickfuel, and a quadrajet all showed up today.....  This is all customer work so it takes priority over fun stuff.  The 850 I tore into first, was supposed to just have a blown power valve.  Looks like they pumped mud into it, I'll have to take it totally apart.  Had to order Q-jet parts as I don't keep them around.

I got some zinc brightener to add to my electrolyte bath, it should make the linkage a little bit shinier when zinc plated.  I also got some more soldering rods.  I need to fix 3-4 cracked baseplates with those.....  I've got the 5 carbs above to r&r but I'll probably get curious and try out that brightener.

Drew
« Last Edit: November 13, 2017, 05:42:20 PM by Drew Pojedinec »

Drew Pojedinec

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Re: Carburetor madness by Drew
« Reply #37 on: November 15, 2017, 05:47:27 PM »
Been home 9 days, 8 carbs built, 6 of which were for customers and went right back out.
Not all of the walk ins are in a hurry, so:
Started tearing down a 4779 that ended up here.  No hurry on this one, figured I'd clean it up really nicely.

Of course 50% of the way through I got the phone call and have to ship out in 48 hours, blah.

Anyway the pictures should be self explanatory.  If not, ask.

Drew Pojedinec

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Re: Carburetor madness by Drew
« Reply #38 on: November 15, 2017, 06:42:26 PM »
After cleaning it like 400 times and waiting for the loctite to fully set I dip it to get color

15 seconds in Phosphoric acid
wash in wash bucket number 1
wash in wash bucket #2
wash in wash bucket #3
Submerge in olive dichromate 30 seconds
wash in bucket #1
wash in bucket #2
wash in bucket #3

and I give you......
The poor man's Holley HP

turbohunter

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Re: Carburetor madness by Drew
« Reply #39 on: November 15, 2017, 06:51:03 PM »
Gotta say that looks darn nice.
Marc
'61 F100 292Y
'66 Mustang Injected 428
'66 Q code Country Squire wagon


Drew Pojedinec

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Re: Carburetor madness by Drew
« Reply #40 on: November 15, 2017, 08:25:50 PM »
Thanks Marc.

Now that I'm out of the shop and bathed, I'll add some info:

Pic 1 Wretched 4779 core
Pic 4 I ground down a punch to fit inside of the booster entrance.  There is a thinner section, hammer away and hope it breaks out cleanly.  Sometimes you aren't so lucky and have to work to break the pieces out.
Following pics are me cleaning up the edges, and polishing.
Now.... really, the guys at Holley are pros, I mean the engineering staff has spent decades learning what they know.  It would be foolish to think I know more than them, so I'm not changing the shape or size of the venturi, entrance, or exit.  Really I'm just blueprinting and cleaning up stuff.  The kind of detail that a large production company can't afford to do, but some dude in his shop is willing to spend a few hours for an extra 25cfm.
Due to this being old and in this case obviously an old racer's carb, there was damage, scratches, etc.  I'm not fixing these, and so even when polished, some deep scratches will remain.  I don't want to enlarge the venturi, simply blend and relax the airflow.

Further down is a picture of the tools needed to install a booster.  Green loctite, a swaging tool, booster, etc.
Swage tool is critical.  The one I have is from BLP (AED sells them too).  I can install straight leg, downleg, and annular boosters with this one.
If you really want to clean up the main body, it's kinda hard to do with the booster in the way.  You cannot reuse the boosters.

I show a comparison of the stock .140 downleg, with a .152 Stepped booster.
Testing has shown they both see the same signal, but the stepped booster flows more AND atomizes better.  I use the stock .140 with 600cfm carbs as they simply don't require additional atomization due to the small size.  I really like the stepped on 750cfm and larger carbs.

I've seen a leveling tool for sale after installing the boosters, you use it to make certain that it is perfectly level.
I guess that makes sense, but I do it with a snap gauge.  To me it seems the distance from the minor diameter to the booster skirt is much more critical as that is where the greatest air speed and fuel draw will occur.  I imagine that the skirt being further away on one side than the other that it'd pull the fuel to the closer side..... this would obviously impact distribution.
The boosters I install were perfectly centered in the venturi.  You have about 5 minutes to force them around with e screwdriver before the loctite fully hardens.
I hope in the future to build a flow bench so I can test each venturi and match them all.  I think this would help balance the carb greatly.  (I'd also like to get a milling machine so I can stop taking everything to my neighbors).

That's about it.
Dp

hvywrench

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Re: Carburetor madness by Drew
« Reply #41 on: November 15, 2017, 09:43:45 PM »
I'm another one that reads and appreciates all the information.
Thanks for putting it all up, its an interesting process and I'm and actually understanding most of it due to all the pictures.
The finished carb(s) look great.
Bill

Drew Pojedinec

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Re: Carburetor madness by Drew
« Reply #42 on: November 16, 2017, 05:56:05 PM »
Last day home and I'm probably supposed to be doing yard work or some other mundane work......

Along with the theme of "poor man's HP"  I drilled, tapped, threaded all the adjustable stuff, ie pvcr, ifr, iab, hsab, emulsion bleeds etc.  I set everything back to the stock spec, but being able to change these things kinda goes with the whole feel.

Drew Pojedinec

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Re: Carburetor madness by Drew
« Reply #43 on: November 26, 2017, 04:48:18 PM »
Posting pictures for John on the Network54 site:


WerbyFord

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Re: Carburetor madness by Drew
« Reply #44 on: November 26, 2017, 07:40:05 PM »
Excellent Stuff Drew thanks for posting.  ;D