Help needed with Judson Supercharger

[SethThomas]

I installed a Judsun Supercharger on my 110 1966 powerglide (it has 95 HP Heads). It stalls every time I try to put it into drive (or reverse)

I get it started just fine and runs in Neutral about 1000 RPM minimum. It stalls out any lower. I bumped it up to 1500 RPM to compensate for the drive drop in RPM, and it still stalls when selecting a gear. I bumped it up again to 1800 and the same thing happens.

Timing is set at between 20 and 22 (factory spec is 24 for my car) and I'm concerned about going any higher with the supercharger on.

I'm honestly not sure what I should be adjusting. For now I'm assuming there are no vacuum leaks as all seals and hoses are new, nuts and bolts tight.

[KenHenry]

What is the carb and does it have ported vacuum advance? Is the 20-22* with the vacuum advance disconnected? Cool setup! One strategy for a low steady idle is low timing, a little extra throttle opening, and a rich mixture… Good luck! Ken

[SethThomas]

What is the carb and does it have ported vacuum advance? Is the 20-22* with the vacuum advance disconnected? Cool setup! One strategy for a low steady idle is low timing, a little extra throttle opening, and a rich mixture… Good luck! Ken

Carb is a Holley 2110. I've never dealt with one of these before.
Yes, 20-22 with disconnected vacuum and clamped hose.
Thanks for the advice :). I will try that tomorrow and report the results.

[PrismSky]

Could be due to the increased load from the supercharger, especially since you’re having issues when shifting into gear. You might want to check your idle mixture and fuel delivery your carb might need tuning to handle the extra air from the supercharger. Also double check the torque converter on the Power glide it might be struggling to handle the increased load.

[66vairguy]

Did the engine stalling in DRIVE only happen AFTER you installed the Judson Supercharger setup?

Post your distributor number. It will let us look up the mechanical advance rate. On some distributors you have to get the RPM down to 700 to set the "static" timing. If you set it an at RPM that is too high the distributor will already be in the advance mode so in reality your 20-22 BTDC at a higher RPM may be too little. Just something to check before getting into the carburetor.

[KenHenry]

I had the Holley 94 version of that carb on my Ford flathead. One thing to be aware of is that the threaded vacuum port on the rear of the carb body is not traditional ported vacuum. It is a blend of several vacuum signals designed specifically for the Ford loadamatic distributor. Second thing I see is that your pcv looks like it could pressurize the crankcase under positive manifold pressure, depending on how effectively it works as a check valve. On a draw through it might be better to position your vacuum source for the pcv between the throttle plate and supercharger (not between the supercharger and intake valve) . Ken

[jimbrandberg]

Does it have a Pertronix 2? They don't want to idle in a PG sometimes.

[SethThomas]

Distributor is a 1110319 for the 110's, So it wants 500 RPM for BTC timing setting? I would never be able to get this RPM that low even on stock 2 carbs (I idled about 650 - 700 in drive on my normal setup before it started stalling any lower. Neutral was about 1000). I do not know if this behavior has anything to do with the 1966 factory A/C setup I have with the 95 heads and 24 BTC timing plate.

Points Ignition and Bosch coil (1.5 ohm), with stock resistance in wiring.

The vacuum port on the Holley carb is plugged. There are 3 ports on the supercharger base/bracket. I have Vacuum advance on the lowest one by the intake. The oil drip is in the rear of the base, and on the same level as the 3rd port on the side between the Carb and supercharger (I figure the oil could have gone to either, they both tap into the same chamber).

The 3rd port was plugged, but I just tried switching it to the PCV with a longer hose as suggested by KenHenry, and there was no change in behavior.

I will try fiddling with the carb and timing a bit more.
If it is the torque converter, I would have no idea what I'm looking at. I never had to do anything other than stop a leak with the gearbox or drivetrain since I bought the car.

[66vairguy]

The 1110319 110HP distributor chart indicates the distributor starts to centrifugal advance (no vacuum hook up) between 600 and 1,000 RPM. The typical Corvair PG idles at 600 RPM in Drive and about 900 RPM in NEUTRAL.

A NON A/C 110HP engine had a static timing of 14 BTDC. The low compression heads A/C 110HP PG engines used a static timing of 24 BTDC.

While you have a low compression engine, you also have a supercharger on it, but you have the 110HP/140HP camshaft.

What to do? Noting the 95HP engines with a milder cam used 14 BTDC on the PG (6 BTDC on manual transmission) I'd try setting the timing to 14 BTDC and DO NOT USE THE VACUUM ADVANCE. Based on comments about the carburetor you are using I'd cap off the vacuum advance ports. On the Corvair vacuum advance DID NOT come into play at idle or under load/laceration. It was intended to advance the timing under light loads to increase fuel mileage. With it disconnected it will not affect how you car would normally run, just decrease fuel mileage at cruise.

Keep in mind reducing the timing results in a lower idle speed and the carburetor will have to be adjusted to set the desired idle speed. Just my suggestion to see if it improves the situation. Feel free to ignore.

See attached article on your 110HP/PG - A/C engine by Bob Helt

[SpyderMan]

I am not sure why but Judson did not want the PCV hooked up the way you have it. Here is the 63-64 service bulletin about correct routing. I have the original instructions as well if it would help.

[66vairguy]

I am not sure why but Judson did not want the PCV hooked up the way you have it. Here is the 63-64 service bulletin about correct routing. I have the original instructions as well if it would help.

As others said -- YOU NEVER WANT the PCV system hooked up to a pressurized source. The stock Corvair system uses manifold vacuum AND the air cleaner. Often a mystery to folks on how it works. The Judson folks just hooked the crankase vent up to the aircleaner. That is fine, but you tend to get more oil mist up to the aircleaner compared to the Corvair system and at idle there may not be enough air flow into the air cleaner to prevent fumes from leaving the air cleaner. The Corvair system worked well to ensure crankcase fumes did NOT get into the engine compartment. Those fumes contain carbon monoxide and you DO NOT want that getting sucked into the engine fan and blown into the engine compartment via using the heater!!!

See Corsa West article ---

[SpyderMan]

Yes now that I look at of course that is the reason.

Back to the idle in drive issue, a Judson will run fine without the belt. Have you pulled the belt off to see if there is any change?

[Nashfan]

I installed a Judsun Supercharger on my 110 1966 powerglide (it has 95 HP Heads). It stalls every time I try to put it into drive (or reverse)

I get it started just fine and runs in Neutral about 1000 RPM minimum. It stalls out any lower. I bumped it up to 1500 RPM to compensate for the drive drop in RPM, and it still stalls when selecting a gear. I bumped it up again to 1800 and the same thing happens.

Timing is set at between 20 and 22 (factory spec is 24 for my car) and I'm concerned about going any higher with the supercharger on.

I'm honestly not sure what I should be adjusting. For now I'm assuming there are no vacuum leaks as all seals and hoses are new, nuts and bolts tight.

What happens when you go to 26 degrees and close the throttle some more to bring the idle speed down? You may need to do something different for timing control (like going to programmable) or use a Safegard for boost retard, but for now just see if it cures the stalling by going to stronger timing and less throttle opening to get the idle speed down. My EFI turbo uses 28 degrees at 1000 rpm, and 29 at 750, and typically is around 18-19 inches of vacuum.

[SethThomas]

I am not sure why but Judson did not want the PCV hooked up the way you have it. Here is the 63-64 service bulletin about correct routing. I have the original instructions as well if it would help.

This did the trick

I removed the valve connection and the idle dropped a bit and I can now select gears.

Now the new problem is being massively rich and a little rocky at neutral, but being great in drive. Fixing Neutral brings up the RPM too fast with what I tried so far (like around 2000 RPM!). The Idle mixture screws don't seem to help neutral at all. I turned both all the way in wile playing with it, and it still poured out black smoke.

It seems to me the automatic choke isn't working properly either. The first time I thought nothing of it, but for the third day in a row I couldn't start the car cold because it was open. I had to close it manually to start. It feels really stiff. It seems to open up ok while warming.

Idle in Drive very steady just under 1100:


Idle in Neutral 1200 - 1400 too rich:

[SpyderMan]

Is the choke hooked to the passenger side exhaust manifold like the instructions say? Any chance it is binding? Do you have the oiler set one drip every four seconds at idle? I would still be interested to see what it does with belt off.

[SpyderMan]

The vacuum port on the Holley carb is plugged. There are 3 ports on the supercharger base/bracket. I have Vacuum advance on the lowest one by the intake. The oil drip is in the rear of the base, and on the same level as the 3rd port on the side between the Carb and supercharger (I figure the oil could have gone to either, they both tap into the same chamber)

The vacuum advance needs a ported vacuum source. The instructions have it hooked to the carb with a short piece of brass or copper tubing. The oiler is the only thing that should be hooked to the ports in the base. I would just keep the vacuum advance unhooked for now. It is there to improve economy while cruising, turbo cars do not use one.

I will try and look at my two Judson carbs and see if they have the tubing attached.

Do you know how much pressure your fuel pump is putting out? It could be overpowering the needle and seat.