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John Moxon 
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Joined: March 07, 2004
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Location: Southampton U.K.
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 Posted: Fri Aug 13, 2010 3:47 am Post subject: Oil starved Judson Vanes - Cautionary Tale |
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Picture of Judson Vanes that have not received sufficient lubrication. This might seem a puzzle as the Marvel Oiler was working perfectly and the car running on a 3 mile downhill stretch and not under load.
The answer is the car was coasting with only high vacuum in the manifold and as the Marvel Oiler supplies inversely to vacuum, it virtually cut off the oil supply to the blower with the pictured results.
Solution, engage lower gear and give the Judson a blast occasionally on long downhill stretches.
Fortunately it doesn't seemed to have damaged the rotor or chamber from pictures I've seen.
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Snort
Samba Member
Joined: April 02, 2005
Posts: 1976
Location: Seattle, WA
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| Posted: Sun Aug 15, 2010 9:54 am Post subject: |
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| I wonder if it would be helpful to add a portion of MM oil to the fuel tank in addition to the vacuum oiler. |
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John Moxon
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| Posted: Sun Aug 15, 2010 11:32 am Post subject: |
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| Snort wrote: |
| I wonder if it would be helpful to add a portion of MM oil to the fuel tank in addition to the vacuum oiler. |
I had a Finnish guy send me pictures of his Beetle running with 1% 2stroke oil/gas mixture instead of lubricating the Judson with the normal Marvel Oiler.
I must say I wasn't convinced this alternative would work in the long term and he'd only put 100km on his Judson set-up at the time he emailed.
Perhaps I should find his email address and see if the Judson is still running.
Adding it to the fuel tank will disperse the oil and will be atomized as it passes through the carburettor before getting to the blower vanes. Normally the Marvel Oil is added directly to the blower after the carb and so I suspect in a more concentrated form.
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Judson Supercharger Information on The Samba
My 1958 Shorrock Supercharged Karmann Ghia
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Russ Wolfe
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Joined: October 08, 2004
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Location: Central Iowa
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| Posted: Sun Aug 15, 2010 12:17 pm Post subject: |
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Most 2 stroke engines run a richer oil mix than 1%, (about 4 oz of oil to 1 gallon of gas) but it goes through the crankcase after it goes through the carb, and then through a by-pass into the combustion chamber.
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John Moxon
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Peter_Plade
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Location: Denmark
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| Posted: Mon Aug 16, 2010 9:55 am Post subject: |
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Wow that looks crazy!
When I was running a Judson I drove through Kassel in Germany (that´s some pretty big hills) with no problems.
Can the vanes have been made from a wrong type of phenolic?
But good thing the rotor didn´t get any damage!
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John Moxon
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Peter_Plade
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Location: Denmark
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| Posted: Mon Aug 16, 2010 11:23 am Post subject: |
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Okay it was only a thought.
But again good thing that only the vanes was damaged, and nothing more expensive.
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Altema
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Joined: June 20, 2010
Posts: 2907
Location: Lower Michigan
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| Posted: Mon Aug 16, 2010 11:55 am Post subject: Re: Oil starved Judson Vanes - Cautionary Tale |
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| John Moxon wrote: |
The answer is the car was coasting with only high vacuum in the manifold and as the Marvel Oiler supplies inversely to vacuum, it virtually cut off the oil supply to the blower with the pictured results.
Solution, engage lower gear and give the Judson a blast occasionally on long downhill stretches. |
That's an ugly picture! The horror! Since the Marvel Oiler supplies inversely, seems like you could also make a manual vacuum release operated by a choke cable to give the Judson a live-saving dose of oil on a long downgrade.
Paul |
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John Moxon
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| Posted: Mon Aug 16, 2010 12:05 pm Post subject: Re: Oil starved Judson Vanes - Cautionary Tale |
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| Altema wrote: |
| John Moxon wrote: |
The answer is the car was coasting with only high vacuum in the manifold and as the Marvel Oiler supplies inversely to vacuum, it virtually cut off the oil supply to the blower with the pictured results.
Solution, engage lower gear and give the Judson a blast occasionally on long downhill stretches. |
That's an ugly picture! The horror! Since the Marvel Oiler supplies inversely, seems like you could also make a manual vacuum release operated by a choke cable to give the Judson a live-saving dose of oil on a long downgrade.
Paul |
The other Vintage Oiler available is The Ampco...and that doesn't operate inversely to vacuum. I've been told a lot of Judson owners use this oiler and it works well although I'm at a loss to understand how the flow rate is set to serve as a lubricator for the Judson.
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Judson Supercharger Information on The Samba
My 1958 Shorrock Supercharged Karmann Ghia
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kiwisteve
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Location: UK
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| Posted: Wed Aug 18, 2010 5:13 am Post subject: |
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ouch!  what about running a direct line from the main engine oil system John like the Shorrock or Pepco do. This seems too obvious a solution so I must be missing something. That way you can do away with the separate bottle and bits. cheers, Steve |
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John Moxon
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| Posted: Wed Aug 18, 2010 5:33 am Post subject: |
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| kiwisteve wrote: |
| ouch! what about running a direct line from the main engine oil system John like the Shorrock or Pepco do. This seems too obvious a solution so I must be missing something. That way you can do away with the separate bottle and bits. cheers, Steve |
The thing with the Shorrock and Pepco, is the vanes on former and interlocking rotors on the latter, don't run in contact with the chamber walls.
The Judson has friction heat to contend with as well as compression heat so the oil demand would be greater than the other two. The oil to the Judson also needs to be of a lighter weight (Marvel is about 5w).
I wouldn't like to make a great issue of the ugly pictures because it's not something you see very often on Judsons. It's more of a reminder than trying to say it's a usual scenario.
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Judson Supercharger Information on The Samba
My 1958 Shorrock Supercharged Karmann Ghia
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Altema
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Joined: June 20, 2010
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Location: Lower Michigan
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| Posted: Wed Aug 18, 2010 2:16 pm Post subject: |
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| John Moxon wrote: |
| I wouldn't like to make a great issue of the ugly pictures because it's not something you see very often on Judsons. It's more of a reminder than trying to say it's a usual scenario. |
That is why the picture was so shocking, I've never seen anything that bad happen to a Judson before. Glad the rest of it survived!
Paul |
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HouseofGhia
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Joined: February 17, 2005
Posts: 858
Location: Bellingham, WA
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| Posted: Wed Sep 15, 2010 8:43 pm Post subject: |
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| Altema wrote: |
| John Moxon wrote: |
| I wouldn't like to make a great issue of the ugly pictures because it's not something you see very often on Judsons. It's more of a reminder than trying to say it's a usual scenario. |
That is why the picture was so shocking, I've never seen anything that bad happen to a Judson before. Glad the rest of it survived!
Paul |
Actually, the Judson body did not survive, it was damaged beyond repair so another body had to be sourced for the rebuild.
This Judson was starved of oil. Look at the vanes...thay are dry as a bone. Since this was my first Judson, I was always concerned about the oiling, knowing how important it was. I had religiously checked the drip rate and was setting it to 4 counts per drip....about half the recommended setting. I had filled the jar full of oil and there is about half a jar left....so oil was getting to the Supercharger. I didnt keep any mileage records so I'm unsure if a half jar equates to the 400 mile estimation mentioned in the install instructions.
What I found frustrasting was that before I would take the Ghia for a spin, I would check the oiler....and it would not be dripping at all....so I'd open up the valve about a half turn and it would start dripping like crazy....I'd close it up a half turn back to the 4 count per drip rate....and then take it out for a drive. At the end of the drive, it would still be dripping at the rate I set it at. This happened quite a bit and always made me nervous.
George Folchi performed the rebuild, and reported that the oiler valve was about 1/4 turn from being completely closed! George said this knob normally should be a full turn to a turn and a half to set a drip rate of 4 counts per drip. I did not touch the setting after pulling the oiler out to send back, so this was the setting the last time I drove it.
So...it could have been the oiler, could have been my set-up...not sure.
I have the new Supercharger back in my hands and will get it installed soon. I'll report back if there are any differences I can see in how the oiler operates.
Note: George said he gets about 200-250 miles on a half jar of oil. I will be noting the milage this time.
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retrowagen
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| Posted: Sat Sep 18, 2010 11:04 pm Post subject: |
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Mike, was this the source of the mysterious sound we were trying to pinpoint in Angels Camp? (sigh... bummer.)
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HouseofGhia
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| Posted: Sat Sep 18, 2010 11:34 pm Post subject: |
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| retrowagen wrote: |
| Mike, was this the source of the mysterious sound we were trying to pinpoint in Angels Camp? (sigh... bummer.) |
It appears so. It seems that the oiler was not oiling. It wasnt a bearing as I suspected, but rather a dry supercharger. 
The new Judson is installed. I ran it rich for about 20 minutes at idle, then backed it down to 3-4 seconds per drip. It's a whole new experience. Its quieter, and it doesn't appear to be running as hot. At 3-4 second per drip, the adjusting knob is almost a full turn from closed as George instructed.
I'll never know for certain what was up....but I highly suspect the oiler.
I'm just glad to have the Judson back and installed.....
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Peter_Plade
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John Moxon
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| Posted: Sun Sep 19, 2010 9:28 am Post subject: |
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Yes good to hear it's up and running again.
I too found the operation of the Marvel Oiler pretty erratic. Not so bad once you set it and ran it over the length of a journey but when the engine cooled and had been standing at a show all day, I had to start from the beginning again to reset the flow rate for the journey home.
I had no mishaps over a period of 10 years so I suppose I can't really complain but the standard Judson instructions for setting the oiler is to set the flow on a warmed engine and check the flow every week...remembering in those days the car would have been used every day.
Over the 10 years I pulled the oiler apart and cleaned all parts quite a few times without ever getting it to run without constant attention. 
Maybe I was paranoid but when you realise what can happen if you ignore the oiler setting, it was a small price to pay for keeping things running smoothly.
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Judson Supercharger Information on The Samba
My 1958 Shorrock Supercharged Karmann Ghia
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HouseofGhia
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Location: Bellingham, WA
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| Posted: Mon Sep 20, 2010 10:01 am Post subject: |
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I started the ghia up this morning after it sat for the weekend....the drip rate is at 1 drip per second....so there was some change. I'm reluctant though to reset it to a lower rate.....There isnt any smoking, so I'm going to leave it alone for now....better more oil than less.
I will likely not be driving it much through the fall and winter, so I wont have much to report on, but I'll keep updating this post on how things are going.
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DANP85
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| Posted: Fri Aug 16, 2024 12:54 am Post subject: Re: Oil starved Judson Vanes - Cautionary Tale |
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| Do we have any update on how the Judson is going? |
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