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Judson on my 66 convert
Posted by: Mct66 ()
Date: October 14, 2010 02:12PM

1st time post. Here are pics of my 66 with Judson Sc installed. I've had it running
since about April of 09. Have slowly made tuning improvements over the months.
Runs pretty well even on 40 degree mornings.
Anybody currently running a Judson?? Maybe we could exchange tuning info.




Mike Tuttle
Omaha, NE

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Re: Judson on my 66 convert
Posted by: brocklanders ()
Date: October 14, 2010 03:10PM

Couldn't make that out, could you enlarge the pics a bit? winking smiley

Look great. would you say the trouble is worth it for the added power?

1968 Corvair 500 coupe 140 4 spd
Bowmanville, Ontario, Canada


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Re: Judson on my 66 convert
Posted by: Phil Dally ()
Date: October 14, 2010 03:19PM

Ask and you shall receive. cool smiley

Paso Robles CA-Unsafe at Any Landspeed-Sidewinders (SCTA Charter Member 1934)-CORSA Member-Central Coast Corsa-Ventura County Corvair-V8 Registry-Corvanatics-California Angels Fan Since 1978...World Series Champions 2002 & 9 AL West Division Titles-So Cal Gas Since 1974 Rehired as Contractor Seasonally-Vairy V8 (AKA SuperVair) ADE 506 Cube BBC/PG/QC L/M Coupe-148.253 MPH Landspeed F/BGALT Late Model Coupe-B&M Blown Methanol 3.1L Mid Engine Funco Sandrail-1965 Ugly Duck 110/PG Monza Coupe Parts Car-2013 Ford F250 Super Duty XLT Four Door Crew Cab Short Bed 6.7 Powerstroke-Grand Design Momuntum 350M Luxury Toy Hauler-When I Grow Up I'm Selling Everything and Buying a Vintage Triple Weber 911S Because I'll Never be Able to Afford the Miura!!!

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Re: Judson on my 66 convert
Posted by: B-Vair ()
Date: October 14, 2010 03:32PM

This thread makes me feel like Goldy Locks (SP?) spinning smiley sticking its tongue out

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Re: Judson on my 66 convert
Posted by: SpyderMan ()
Date: October 14, 2010 04:31PM

I have a Judson that I am about to install. I would love to know about your experience.



Sam Russell
Durham NC
1962 Monza Wagon
1964 Spyder coupe


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Re: Judson on my 66 convert
Posted by: Mct66 ()
Date: October 15, 2010 08:03AM

Sorry about the pic sizes, I will try again.


I am running a stock 66 110 ( originally powerglide) engine.
Msd6 & Pertronix 1, Accel 8mm wires and High output coil.
The accelerator linkage, choke hookups and pcv were all made from stock Corvair
parts. The carb has #52 main jets with the external adjusters. The power valve circuit has been modified to only see the supercharged side manifold pressure.
I have not been able to get a vacuum advance to work. I have even modified the
base of the carb to emulate porting on a 1 bbl rochester (no luck).
The performance of this set up is not overwhelming. You get a little more torque at lower RPMS, and you can also tell a little difference in the 40-70mph range. I only have a stock Corsa boost gauge, not that accurate. You maybe could get 1 to 2 PSI
on 164CID.
I overhauled the supercharger, so this set up is to get some revs on the unit and break in.
Over all, I would suggest a 145CID engine in some form to match the SC flow better. I am going to build a 145 with Turbo crank, Type 3 rods, and 140 Heads.

At any rate, the 66 is quite driveable, but idles around 900 RPM.

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Re: Judson on my 66 convert
Posted by: SpyderMan ()
Date: October 15, 2010 11:10AM

Do you think the high idle is because the carb leaves something to be desired? I am not planing on running the stock carb except for a mock up, I will be using a stock YH because of clearance issues.

How loud is it?

Sam Russell
Durham NC
1962 Monza Wagon
1964 Spyder coupe


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Re: Judson on my 66 convert
Posted by: SpyderMan ()
Date: October 15, 2010 11:16AM

One more question, doesn't the carb have a ported vacuumv for the distributor advance?

Sam Russell
Durham NC
1962 Monza Wagon
1964 Spyder coupe


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Re: Judson on my 66 convert
Posted by: Mct66 ()
Date: October 15, 2010 12:51PM

Yes, I would say the carb leaves a lot to be desired. I have a Stomberg to
2GC adapter and may try that in the future. None of the ports on that
carb offer ported vacuum for a GM style vacuum advance.

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Re: Judson on my 66 convert
Posted by: SpyderMan ()
Date: October 15, 2010 01:49PM

Does it make a bunch of noise?

Sam Russell
Durham NC
1962 Monza Wagon
1964 Spyder coupe


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Re: Judson ported vacuum advance
Posted by: Andrew ()
Date: October 15, 2010 03:33PM

The instructions that came with the Judson say that the carburetor is "specially modified" for use with the supercharger.

After doing some research into how the stock Holley 2110 vacuum system worked with the Ford Load-O-Matic distributor and also checking a few carburetors that were likely the original ones that came with the superchargers, I believe I've found out what was done to provide ported vacuum advance to the Corvair distributor.

The stock Ford Load-O-Matics used a combination of ported and venturi vacuum to control the spark advance on 50's Y block Fords. They used NO mechanical advance. On the throttle arm side of the throttle body there is a small diaphragm valve that looks much like a power valve. It is called the Spark Timing Control Valve. If you remove the valve, you can see a hole that extendeds (on an angle) to the underside of the throttle plate. This is the ported vacuum port. On the body of the carburetor there is a threaded port that connects to the stock L-O-M distributor. If you look straight in thru that port you can see a tiny hole that opens up into the carburetor venturi. This hole in the venturi vacuum port. Both of these two ports are connected thru the body and throttle body with the STCV between them. The STCV valve has a diapraghm that is attached to a spring loaded seat. In the stock system, depending on throttle position and engine speed, the STCV controls whether the LOM distributor is getting ported or venturi vacuum.

To modify your 2110 carb to run a Corvair distributor you need to plug the tiny venturi port hole in the throat of the carb, AND break off the spring loaded seat of the STCV. Inside that threaded port there is a bore and 2 counterbores. The smallest of these opens up into the venturi of the carb. You only want to plug the port in to the wall of the carb. If you plugged the intermediate counterbore you will cut off the vacuum passage that connects down to the ported connection. The second part is removing the valve action of the STCV. You cannot just remove the valve and plug it, otherwise the ported vacuum passge will be blocked. Just pull out on the needle and seat of the STCV and cut it off with a pair of side cut pliers. That's it!

You can see a schematic of the vacuum passages here

[www.oldcarmanualproject.com]

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Re: Judson ported vacuum advance
Posted by: Andrew ()
Date: October 15, 2010 03:42PM

Sam,

If you use a YH, you may be able to find and use one from a 53-54 Corvette. They have a vacuum port on them.


Mike,

When you say "The power valve circuit has been modified to only see the supercharged side manifold pressure".... exactly how and why did you do this?

The area on the Judson manifold that is between the carburetor and rotor would always be seeing vaccum, at least a little, and never see pressure. Only after the rotor would it ever see positive pressure. I'm not implying that you have done anything wrong by making the modification that you have, I only ask because it sounds like you may have more experience with getting a Judson to run well than others have done before.

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Re: Judson on my 66 convert
Posted by: SpyderMan ()
Date: October 15, 2010 06:03PM

Andrew, don't you worry, I'm ported. LOL





Sam Russell
Durham NC
1962 Monza Wagon
1964 Spyder coupe


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Re: Judson on my 66 convert
Posted by: Mct66 ()
Date: October 16, 2010 07:31AM

The Judson is a draw through type supercharger. The "pre" supercharged part
where the carb is mounted sees basically normal vehicle vacuum values. The power
valve sees these values and makes mixture enrichments based on this. The supercharger can produce positive manifold pressure very quickly when the accelerator is stepped on. The power valve may not react as fast, or to the
time or level that more fuel is needed when positive pressures occur.
On the 2110 carb, the power valve circuit operated by a port on the throttle
body base, to the power valve in the main body, and then if I remember correctly,
goes to the upper carb body to run the original 2110 choke pull off, which I
do not use. I simply plugged the port in the throttle body and the choke pull off
port with gas resistant epoxy. I then drilled a small hole into the isolated area,
and put in a small tube to fit the rubber hose I am using. I then route this back
to the supercharged side of the manifold. I did use small hose clamps off a turbo
to secure the hose. These hoses can blow off under positive pressures.
Now the power valve tracks the supercharged side of engine operations.
I got this idea from a Holley carb book, specifically referencing draw though
supercharging concepts.
Now for the disclaimer: I don't suggest doing this unless you have a decent understanding of this carb, and maybe have some spare parts. None of the mods
I tried resulted in some type of dramatic performance enhancement, but I think
this one actually helped.
As for the vacuum advance:
I couldn't mod this carb to get ported vacuum, but I tried things similar to
what Andrew has posted. On my 66, I don't think this would have helped.
The next engine (145cid) I am building will have an adjustable MSD timing computer
and a pressure switch that activates timing retard under positive manifold pressures. Someone else may have better luck with 95Hp or 80Hp heads and lower
compression with a stock distributor setup. I think with modern pump gas (going to
15% ethanol in Nebraska) computer components are going to be needed. Also, the
EPA is warning they are considering going California emission requirements in Omaha, but that's another story.
Mike Tuttle

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Re: Judson on my 66 convert
Posted by: SpyderMan ()
Date: October 16, 2010 03:42PM

Hey Mike I still want know how loud you think it is. LOL

Sam Russell
Durham NC
1962 Monza Wagon
1964 Spyder coupe


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Re: Judson on my 66 convert
Posted by: Mct66 ()
Date: October 18, 2010 07:07AM

I think it might be slightly louder, but its hard to tell.
I have an older set of Clark's headers with straight though steel packed mufflers.
You can hear a slight metallic sound from SC rotation. The air cleaner I have
also gives slight valve noise on acceleration. The inverse oiler really helps
valve lubrication once you have run it for a while. I used to get slight lifter
noise on start up after sitting a week or two. Now, it starts quietly every time.

Good luck

Mike Tuttle

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Re: Judson on my 66 convert
Posted by: SpyderMan ()
Date: October 18, 2010 09:31AM

Thanks Mike.

I just got mine back together after a rebuild and have been wondering if it was going to make a ton of racket.

How often do you need to refill your oiler? I am on the hunt for one and am wondering if I should pony up for one of the big cans.

Sam Russell
Durham NC
1962 Monza Wagon
1964 Spyder coupe


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Re: Judson on my 66 convert
Posted by: Mct66 ()
Date: October 18, 2010 10:48AM

I don't think you will mind the noise. I have the 2 quart oiler, and have only
topped it off once. It goes quite a while. If you get the adjustment per the
instructions, I'm pretty sure you will get in the 1000 mile per qt range.
Also, I think space might be an issue on an EM.
I have 2 EMs, a 64 500 and a 64 Monza I am trying to get on the road. The Judson
will most likely land in the 64 Monza. EMs are my favorite, but I owned 2 LM
since the late 80s. I am the second owner on the 66 convert. Bought it in 89.
There are not a lot of good Corvairs around here, so I usually purchase when the
opportunity allows. Garage is full now, but I always have wanted a wagon.

Mike Tuttle

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Re: Judson on my 66 convert
Posted by: SpyderMan ()
Date: October 18, 2010 03:08PM

It is going to be supper tight in the wagon but I am up to the challenge I think. I will have to put the oiler in the right side fender well so it is going to be hard to get to for filling I may just go with the bigger one to give myself a longer refill cycle.

Sam Russell
Durham NC
1962 Monza Wagon
1964 Spyder coupe


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Re: Judson on my 66 convert
Posted by: alexanderwoelfel ()
Date: January 07, 2018 10:49AM

Hey Mike,

Thanks for posting this thread on my Judson topic the other day. I think I have my linkage question resolved.

Anyways I wanted to ask if about your setup. Mine will also be going on a 164CID motor like yours. Were you able to use the harmonic balance with your unit? I have read that if installed on a late motor the balancer needs to be swapped for the older style non-balanced crank pulley. I have been trying to find out if I use a harmonic balance if the belt will align properly.

Best,
Alex

1962 Monza Convertible



Assistant Editor
Los Angeles, California

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