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Stalling 1938 Studebaker? Any ideas?


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1 hour ago, SC38DLS said:

 t’s a flat head 6 cylinder 1938 - no valve cover!

Of course it does, it is just on the side of the block, and sometimes two of them. You have to remove them to adjust the valves.... Sometimes calles Side Covers, but you don't adjust the Sides.... English, what a language....😆

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The engine is running so timing has to be close to correct.  Does the dampener have a TDC reference mark?  I’m not familiar with the timing markings shown in your photo Dave and I can’t find any Motors Manual to help me out with the timing procedure.

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2 minutes ago, TerryB said:

when I’m zeroing in on TDC and turn the vibration dampener to find the top of the piston travel (compression stroke).  Then at TDC see where the points are opening and go from there. 

 

Right, find TDC for the #1 piston, and see where the pointer is in relation to 0 on the timing mark (on damper in your picture). If the pointer does not point at 0 when the #1 piston is at its highest point, something has slipped a tooth OR the vibration damper has slipped on the crankshaft or internally (common on rubber ring styles after years). If the pointer does point to 0, then gears, damper (dampener) are OK, look elsewhere for issues, and adjust timing by the book.

 

 

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5 minutes ago, TerryB said:

The engine is running so timing has to be close to correct.  Does the dampener have a TDC reference mark?  I’m not familiar with the timing markings shown in your photo Dave and I can’t find any Motors Manual to help me out with the timing procedure.

 

Right here in this Forum:

 

 

Should get you close. Notice the damper uses words instead of just numbers. 

 

Also here:

 

 

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Ok - I am getting lost with all the terms being used as I’ve tried to stay with the service manual for the 38 Commander 6 cyl  - different than the President  8 cyl. — that’s why I posted a pic of the manual page (also below). If I’m reading this correctly and understand what you all are saying ( same meaning in different words) wouldn’t the mark at IGN (chalk mark on mine) be directly under pointer when #1 was at TDC and the points should just start to be open?  If that is true isn’t that when engine should be in correct timing?  If the #1 is NOT TDC when pointer under mark it is either a timing chain jumped a link or was originally set up off a link which is why mark would have been before pointer. 
 

356A8C16-0A76-4FAB-A7A2-5DBF7084D207.jpeg

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At this point so much has been fiddled with that it is best to start from ground zero and work your way out.

 

I have never seen a car run well on modern fuels set at TDC at idle. All need 4-8 degrees advance this MAY BE the inch you are seeing.

 

Everything I know about your original symptoms scream "FUEL" at me.

 

Dunno if your cam is chain or gear driven but usually for a cam-in-block there are marks on the crank gear and the cam gear that line up. Once you know where TDC is a GOOD mechanic can generally set the cam by the valve position.

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What kind of a flathead does this dowel method work on? One with the spark plug hole over the piston I guess. Is the Studebaker made this way? I doubt it. Most flatheads of the mid 30s have the spark plug hole roughly over a valve.

 

To find true TDC on such an engine, first verify that the far side of the combustion chamber, furthest from the valves, is machined flat as part of the machined head surface, Most are. A picture of a head off of an engine like yours will tell the tale. Also verify that the pistons are flat topped over at the far end of the chamber. Most are when made for that sort of a head.

 

Get a large, long plastic zip tie, the bigger the better, and really long so it would be tough to drop it in the spark plug hole. Stick the zip tie in the #1 plug hole, head first, and run it over to the farthest side of the combustion chamber, at the far side of the piston. Slowly crank the engine over by hand with a wrench until it stops with the head of the zip tie stuck between the piston and the head. Make a very temporary mark with a pencil or something. then turn the engine over backwards by hand with a wrench until it stops again. Make another temporary mark. Get the zip tie out. The spot halfway in-between the two marks is true top dead center.

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Posted (edited)

Padgett I’m not a good mechanic that’s obvious because  if I was this would have been solved. At this point saying so much has been fooled with does nothing. Everything I’ve done is technically minor. Changing points and plugs, coil & condenser,  putting in a new  electric fuel pump and a new vacuum diaphragm should not and did not change a damn thing so in my book no harm no foul. The only thing technically that changed was rebuilding the carb and that was done by a pro. It was done based on everyone saying it’s a fuel problem. I’ve done every fuel test every person has suggested and not one has proven to be a problem. The only thing that does show up to be out of spec based on what or how I read the manual ( maybe I am not understanding it correctly) is the timing mark and that is why I am asking for help. Sorry if this seems like a rant I just don’t want to go off in another direction until this is answered. 
dave s 

Edited by SC38DLS (see edit history)
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Posted (edited)

Bloo we use the straw on a modern V8 not a flat head. I’m not about to start trying to find TDC by taking off sides of the motor then having to find gaskets etc. 

Timing on this thing can’t be that hard. I’ll go along with what’s in the book and then see how it’s running. Adjust based on that if it works great if not it will have to go into a shop with someone who knows how to get it right. 
Thanks for all the help from all who have read and posted. 
dave s 

Edited by SC38DLS (see edit history)
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16 minutes ago, SC38DLS said:

Ok - I am getting lost with all the terms being used as I’ve tried to stay with the service manual for the 38 Commander 6 cyl  - different than the President  8 cyl. — that’s why I posted a pic of the manual page (also below). If I’m reading this correctly and understand what you all are saying ( same meaning in different words) wouldn’t the mark at IGN (chalk mark on mine) be directly under pointer when #1 was at TDC and the points should just start to be open?  If that is true isn’t that when engine should be in correct timing?  If the #1 is NOT TDC when pointer under mark it is either a timing chain jumped a link or was originally set up off a link which is why mark would have been before pointer. 

 

Almost. UDC (Upper Dead Center) is 1930s lingo for TDC. UDC 1-6 tells you that it is TDC for 1 and 6. The IGN mark is ahead of TDC. As you turn the engine over, clockwise only to remove any slop in chains or gears, the points should break at the IGN mark, but the piston has not quite reached TDC. As you continue to turn the engine over, the piston will reach TDC at the UDC 1-6 mark.

 

If the timing is a little early, so points break just a little bit before you reach the IGN mark, I wouldn't be too upset. Someone may have advanced the timing to compensate for higher octane modern fuel. I still would refrain from moving that distributor until some definite problem has been identified.

 

 

 

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44 minutes ago, SC38DLS said:

Bloo we use the straw on a modern V8 not a flat head. I’m not about to start trying to find TDC by taking off sides of the motor then having to find gaskets etc. 

Timing on this thing can’t be that hard. I’ll go along with what’s in book and then see how it’s running. Adjust based on that if it works great if not it will have to go into a shop with someone who knows how to get it right. 
Thanks got all the help from all who have read and posted. 
dave s 

 

I wasn't the one who suggested taking a side cover off, and I am really trying to avoid going there, but it might be the next step if the distributor has already been moved. Verifying the TDC (UDC 1-6) mark as in my post above only requires removing the spark plugs, all of them so the engine turns easy with a wrench. This just lets you know where you are. If the marks on the balancer are way wrong, It has probably slipped somehow and that needs to be addressed even if it is not causing the problem. You need to know TRUE TDC in order to check any other timing (valve timing or ignition timing).

 

Edited by Bloo (see edit history)
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19 minutes ago, SC38DLS said:

wouldn’t the mark at IGN (chalk mark on mine) be directly under pointer when #1 was at TDC and the points should just start to be open?  If that is true isn’t that when engine should be in correct timing?  If the #1 is NOT TDC when pointer under mark it is either a timing chain jumped a link or was originally set up off a link which is why mark would have been before pointer. 

 

UDC is TDC. IGN is an advanced timing position, not 0, TDC or UDC (all different terms for the exact same thing, piston at Top Dead Center). Let's just call IGN 4 degrees advanced. Exact number does not matter, as Studebaker marked it properly for their (and the end user-you) operating conditions.

 

UDC 1-6 just means top dead center for both cylinders 1 and 6 happen at the same time. 

 

Therefore if the piston is at the top of it's stroke, TDC, UDC, etc, the pointer should point at UDC, not IGN. With the car running and a timing light hooked up, the pointer should be pointing at IGN, all other criteria in shop manual being met.

 

Yes, if the piston is at TDC and you see the pointer NOT on UDC, then something is wrong inside or with the vibration damper.

 

Yes, if the (engine not running) crankshaft is turned so the #1 piston is at IGN, then the distributor is rotated until the points just open is a good start for correct timing.

 

The mark on the damper IN OP 1-6 |  means where the intake valves on cylinders 1 and 6 just start to open (at the mark). This is only good information if the valve covers or head is off. You are not there yet!😉

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Does this car have a timing chain or timing gears?

 

Whichever it has, the cam turns half as fast as the crankshaft, and so the cam has twice as many teeth. If you have a picture of the timing gears, you can count the number of teeth on the crank gear (or sprocket).

 

You can also then measure the circumference of the balancer with a fabric measuring tape, and divide by the number of teeth, and then you know how much distance on the outside of the balancer equals one tooth.

 

It is normal for the cam timing to run a little late on an old car due to gear or chain wear, but gear or chain wear will always be quite a bit less than a whole tooth.

 

Rotating the engine by hand, easiest with spark plugs out, watch what happens at the distributor as you are getting close to the IGN mark. The points should open at the IGN mark, or a little before if someone advanced the timing. Compare the distributor rotor position to the wires on the distributor cap to be absolutely sure the rotor points to either #1 or #6 while you are watching the points break. If the points have not broken, continue to rotate the crank until they do. Measure from the IGN mark to the spot where the points actually break. It should be considerably less than a tooth's worth if the cam timing has not slipped.

 

This only works if the distributor has not been moved.

 

 

Edited by Bloo (see edit history)
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1 hour ago, Frank DuVal said:

vibration damper has slipped on the crankshaft or internally (common on rubber ring styles after years)

 

My brother told me that it happened on his son's old truck.  The balancer had the rubber inner ring and the outer ring slipped.  They had a hell of a time of trying to figure out why they couldn't get it timed and running right.  

 

 

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8 minutes ago, Laughing Coyote said:
1 hour ago, Frank DuVal said:

vibration damper has slipped on the crankshaft or internally (common on rubber ring styles after years)

 

My brother told me that it happened on his son's old truck.  The balancer had the rubber inner ring and the outer ring slipped.  They had a hell of a time of trying to figure out why they couldn't get it timed and running right.  

 

Exactly. And if a rubber ring balancer has slipped, even if you make a new mark it will be wrong in a few minutes because it is still slipping as the engine runs. I don't think they had rubber ring balancers yet in the 30s, but not knowing what balancer (or pulley) design this Studebaker uses, it is impossible to guess if or how it might fail.

 

When you find the TDC mark exactly where it is supposed to be, then you know you can trust it as you continue to run the engine and troubleshoot.

 

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Valves are closed and piston is at TDC so dowel is at its minimum depth in the spark plug hole.  It helps to be close to TDC based on points and feel of compression in cyl.

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I've been really reluctant to stick my finger into this pie again, especially because you have so many well-qualified people advising you.  BUT....

 

1.  Dave, did you remove the dist when putting in new points?  (If so, you might be off a tooth)  Set points at 0.020 (MoToR repair manual, 1935-46).  Hard to get a good adjustment with dist installed in car, but easy to be off a tooth when putting dist back in.

 

2.  Did you check the *dwell* with points installed?  Should be 35 degrees.  (In other posts I explained that when I was in college, I had a 1950 Pontiac 6 with worn dist cam lobes that required point gap of 0.014 rather than the book's 0.020 to get the proper dwell.)  Dwell is what makes the car run well; point gap is a mechanical expression of how to get that dwell *assuming* unworn lobes.

 

I remain concerned about the very low vacuum at idle.  Consider this old "power tuning" technique of my youth:  Mark position of dist so you can go back if this doesn't work.  With engine idling and a vacuum gauge hooked up and visible, *advance* the distributor to maximum vacuum, then back the other way to reduce vac reading by one-half to one inch of mercury.  If you try this, please tell us what the highest vac gauge reading is.

 

 

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Posted (edited)

Grimy don’t hesitate to offer advice, I ask for help so I can get a good perspective on possible fixes. 
The distributor on a 38 Studebaker is of the variety that can only go on one way because of the way it hooks up with the oil pump. Can’t put it in wrong or even 180 off!  I did not take it out to put points in. The points are difficult to get gapped correctly as the have a screw and lock nut setup. 
The manual has a range for the points, I would need to check but something between 18-22. 
I have not been able to find a number for the vacuum setting. So don’t know if decent or not. The vacuum does rebound very quickly when I get off the gas. It goes from 15 at idle to 5 at full throttle and responds quickly when off gas. I tried the vacuum leak test and could not fine any. Tomorrow I will try timing again and see if anything changes. At this point I don’t think I am going to make it worse than it currently is. Can’t drive it now so might as well try to make it work or take it to someone who knows what they are doing. I do know it’s not easy finding someone who knows old cars in today’s world. Especially as we know almost no one since moving here. 
dave s 

Edited by SC38DLS (see edit history)
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The big + is it runs so everything is close to right.  The moving distributor with vacuum advance is my hangup. I would think there is some spring force to return the distributor to a fixed position when vacuum is not pulling on the vacuum advance chamber.  If that normal rest stop point is somehow not correct or repeatable then you can be chasing a moving target when trying to set timing.  Using an external hand held vacuum pump (mityvac) you should be able to connect to the vacuum advance chamber and observe how much and how smooth the advance changes when the engine is not running.  Dave has mentioned he is not sure if the vacuum advance is working correctly so my mind wandered off in this direction.

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The automatic advance has a setup that only allows it to move so far - approximately a max of 12 degrees. It has a spring that returns the lever when the gas petal is released and vacuum is back up to max. If you see the metal bracket below the diaphragm and going over to the distributor it is a two piece bracket. That limits the distance it can move. The spring is inside the top of the diaphragm where the vacuum tubes connects. Pretty neat simple process. 

57C116F5-6720-464B-9E26-7D6CC4563685.jpeg

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"18-22" sounds like degrees of dwell and is how long the points are closed. Back in the day we used a dwell-tach to check dwell, still have one but is 12v. Can also read dwell with an ignition analyzer (Have a Heathkit that probably still works). O'scopes are nice.

 

However sorry to repeat but "Everything I know about your original symptoms scream "FUEL" at me. " You need an SME.

 

 

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42 minutes ago, SC38DLS said:

The automatic advance has a setup that only allows it to move so far - approximately a max of 12 degrees. It has a spring that returns the lever when the gas petal is released and vacuum is back up to max. If you see the metal bracket below the diaphragm and going over to the distributor it is a two piece bracket. That limits the distance it can move. The spring is inside the top of the diaphragm where the vacuum tubes connects. Pretty neat simple process. 

57C116F5-6720-464B-9E26-7D6CC4563685.jpeg

Thanks Dave, interesting setup!

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Posted (edited)

Padgett I have no idea what an SME is. 
The 18-22 is a feeler gauge setting but as I said I need to check book to be sure that is correct. Too many numbers bouncing around in my head regarding the car and readings/settings in the last few days. 
 

Edited by SC38DLS (see edit history)
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So if I knew how to do it safely I would connect a vacuum/fuel pressure gauge to the line fuel going to the carb and drive around until the running problem starts happening and observe the fuel pressure when it happens. I’m thinking 3-5psi is typical.  I believe Bloo had mentioned this too during the discussions.  Motorcycle riders like me know the feeling of the fuel supply dropping off and having to switch over to the fuel tank’s reserve setting. The engine slowly fades even as you give it more gas. Once the reserve flow kicks in and the fuel bowl fills everything goes back to normal.

 

 

Edited by TerryB (see edit history)
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Back in the day if you really wanted to check everything out, you needed one of these:

 

sunsleuth2.jpg

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I really doubt the timing all of a sudden changed, so I wouldn't mess with that just yet. 

 

I had a similar issue on my 1939 V8 LaSalle and racked my brain as it sure seemed to be fuel related.  It behaved similarly....would idle fine and run fine at higher rpms but as soon as you took it for a drive and put some load on the engine it would start dying out it as you tried driving faster. It turned out the spring pressure on my point set (which was new) was very low compared to the old set.  I looked up the specifications and did my best to measure the spring load and it showed low. I put a NOS point set in and problem solved.

Scott

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One of the benefits of being in the same house since the early '80s with lotsa storage space (do need to get rid of a Whole Bunch (tm) of tires).

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3 hours ago, TerryB said:

connect a vacuum/fuel pressure gauge to the line fuel going to the carb and drive around until the running problem starts happening and observe the fuel pressure when it happens. I’m thinking 3-5psi is typical.  I believe Bloo had mentioned this too during the discussions.

 

That works well if you suspect trouble with the fuel pump. What I suggested way back when was hooking it with a tee to the inlet side of the mechanical pump to look for a restriction. A mechanical fuel pump will suck a whole bunch of vacuum if the fuel pickup or line is restricted.

 

Edited by Bloo (see edit history)
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Posted (edited)

It has both the electric and mechanical pump. The electric is switched on at startup and running at speed as mechanical can’t keep up when doing 50-60 especially on a hill. I have check flow between mechanical and carb and the flow seems very good. That of course is being done in garage stationary not moving. So moving maybe the mechanical is sucking up the vacuum. If it was bad wouldn’t it be pushing fuel into the oil?  
 
I replaced the electric pump not the mechanical as everyone was saying it was fuel starved and I had a spare pump in the trunk. Didn’t hurt to replace it so I knew it was good. Maybe I’m nuts for that thought. 
 

Edited by SC38DLS (see edit history)
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Posted (edited)

I’ve replaced points, plugs, condenser, rotor and cap in the past if they were pitted when an engine started running rough. Easy an inexpensive to do and has never hurt doing it. I did the fuel electric pump and coil after multiple suggestions from the forum. The same with the carb rebuild. The vacuum advance diaphragm was because the readings were so low. 
The only one of these fixes that was a major change was the carb rebuild, otherwise they were all just parts switches which if the ok’d part was bad that should have fixed the part. None of these are big changes and unfortunately none solved the problem so were any of them necessary? 
Maybe and maybe not but did any hurt? I don’t think so but what do I know. 
 

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5 hours ago, padgett said:

"18-22" sounds like degrees of dwell and is how long the points are closed.

 

Not for a six cylinder engine....   Six cylinder point dwell is in the range of 30 to 35 degrees. 

This series of Champion engines has a point gap of 20 thousandths. So 18-22 is thousandths of inch gap.

 

47 minutes ago, SC38DLS said:

I have check flow between mechanical and carb and the flow seems very good.

Seems is not quantitative. Need numbers. Like filling a bottle with fuel while the engine runs on the fuel in the carburetor (fuel line disconnected from carb and inserted into container of known size ) and timed for exactly 15 or 30 seconds. Or running the electric pump into the container for a measured time. Then you will know how many gallons a minute of fuel you are actually getting to the carburetor. Of curse, if the flow gets low only at higher engine load then this test is not good. Then the fuel pressure gauge is  a better test. 

 

Does the car actually stall, like in stops running while moving down the road? I would carry the tools to remove the top of the carburetor on the side of the road and see if it is out of fuel. Only if the test could be done safely in traffic. i.e. route that allows car to stall and ability to coast safely to side of road where it can be worked on safely! No need to add getting hit by passing cars while under the hood.....

 

1 hour ago, SC38DLS said:

So moving maybe the mechanical is sucking up the vacuum. If it was bad wouldn’t it be pushing fuel into the oil?

 

If the mechanical pump ruptures a diaphragm, then it will put fuel into the oil. But, if the internal check valves fail (typically there are two of them, one on each side of the diaphragm), then no fuel in oil, but restricted flow output.

 

Have you done the test of hanging a small gas can under the hood and gravity feed the carburetor? A small one quart lawn mower tank will work. Just don't drive far! Boat tanks work well for testing, if you can find a place to safely install it for the test drive. For these you plumb it through the fuel pumps.

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SC38DLS if after doing all of the repairs/replacements/adjustments  you have outlined and you are confident that they have been done correctly and the problem persists I would go back to checking for vacuum leaks including the inlet manifold gasket.

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I had a Volvo P1800 that did the very same thing. A Volvo mechanic told me to remove the gas tank and thoroughly clean it, and especially clean the pickup inside the tank, I thought, "Nah, it couldn't be anything that simple". But after several more weeks of frustration I pulled the tank and cleaned it out and cleaned the pickup filter. Started and ran fine after that for the rest of the time I owned it, several years. There was a bunch of grit and rust in the tank that, after a few minutes of driving would collect around the pickup filter and cut off the fuel supply. Not sure if the Studebaker has the same type of setup in the tank or not, but I would definitely clean the tank.

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I have not timed the amount of fuel coming out of the line into a container. I will setup the pressure test today. 
The car does not totally shut off or die when driving it. 
If possible I will figure out how to setup an auxiliary gravity fuel feed can. Traffic is not a problem as I barely get out of the driveway of our house in a neighborhood. 
I have done the vacuum leak check a couple of times and have not found or do I hear a leak. 
It may take a day or two as one if the pups is having problems and is going to the vet today. They are 15 and sisters and they are more important than the car right now. 

 

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I had a old (large) lawn tractor plastic gas tank I used as the external gas feed.  Bought it for a few dollars at a lawn mower repair shop.

 

Yes, take care of the pup!

D08AF1D4-1DB9-40FE-B6BF-2FC663511244.jpeg

Edited by TerryB (see edit history)
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  • Peter Gariepy changed the title to Stalling 1938 Studebaker? Any ideas?

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