- Thread starter C. Amick
- Start date
Jim Becker
Well-known Member
Yes, what Bob and Bob M said, with one little exception. Rotation direction for distributors is defined by looking at the drive end, not the end in your picture. So the one on the left is CCW rotation correct for a C. The one on the right is CW rotation.
Each shaft is stamped with the total advance and rotation direction. Part of that mark can be seen in the distributor on the right. You can see an "8" and part of what has to be an "R". This means 8 degree advance and right (CW) rotation. The 8 degree limit implies it is from a gas start Diesel. You can also identify distributors by a code stamped in the mounting flange. The Diesel distributor will probably be stamped either "C" or "H".
The stamping isn't visible on the distributor on the left. It is probably "30L" (flange code "J").
Each shaft is stamped with the total advance and rotation direction. Part of that mark can be seen in the distributor on the right. You can see an "8" and part of what has to be an "R". This means 8 degree advance and right (CW) rotation. The 8 degree limit implies it is from a gas start Diesel. You can also identify distributors by a code stamped in the mounting flange. The Diesel distributor will probably be stamped either "C" or "H".
The stamping isn't visible on the distributor on the left. It is probably "30L" (flange code "J").
Nebraska Cowman
Well-known Member
Are you sure Jim? The distributor drive reverses
the direction so it is the same on either end.
Unless you are talking about with the drive
removed. Confusing?
the direction so it is the same on either end.
Unless you are talking about with the drive
removed. Confusing?
Jim Becker
Well-known Member
Yes, it can be confusing. But I was referring to the distributor itself, not including the distributor drive assembly. The drive assembly reverses the rotation and cuts the speed in half. The distributor assembly consists of the parts shown in this illustration.
One needs to understand the meaning of clockwise/counterclockwise in order to avoid confusion from the "R" and "L" stamping on each distributor shaft.
/Electrical/Page-36.jpg)
One needs to understand the meaning of clockwise/counterclockwise in order to avoid confusion from the "R" and "L" stamping on each distributor shaft.
Bob M
Well-known Member
I think IH engineers define distributor rotation by looking at the DRIVE (input shaft) end of the bare distributor.
So the unit on the left in the picture - which turns CW as viewed from the distributor cap - is actually considered a "CCW" distributor.
So the previous answers to what each distributor can fit are still correct. It's the semantics of the definition distributor shaft rotation causing the confusion.
So the unit on the left in the picture - which turns CW as viewed from the distributor cap - is actually considered a "CCW" distributor.
So the previous answers to what each distributor can fit are still correct. It's the semantics of the definition distributor shaft rotation causing the confusion.
Jim Becker
Well-known Member
Except that the "8" means that distributor is correct for a gas start Diesel, not a 9-series gas engine.
One on the left is a clockwise distributor facing the cap end. Look how when the weights swing outward it moves the cam and shaft turning the rotor more clockwise to advance the time as the engine speeds up. Right distributor moves to advance when turning CCW facing the cap end. Or when facing the drive end if its what IH considered a complete distributor unit.
As already posted the number 8 showing on the right distributor indicates its almost certain to be a gas start diesel distributor.
On a C the shaft from the front of engine driving the distributor turns the same direction as the engine crankshaft. When it goes through the other gear set in the distributor unit the cap end of the distributor turns clockwise when facing the cap or drive end of a complete unit.
As already posted the number 8 showing on the right distributor indicates its almost certain to be a gas start diesel distributor.
On a C the shaft from the front of engine driving the distributor turns the same direction as the engine crankshaft. When it goes through the other gear set in the distributor unit the cap end of the distributor turns clockwise when facing the cap or drive end of a complete unit.
In answer to the original question, what the factory may or may not have called them is really a moot point. The distributor on the left is correct (in rotation) to the OP's machine.
<img src = "http://i167.photobucket.com/albums/u125/27Grainfield/IH/help1_zpsb2c2ab51.jpg">
<img src = "http://i167.photobucket.com/albums/u125/27Grainfield/IH/help1_zpsb2c2ab51.jpg">
Jim Becker
Well-known Member
Maybe except for the fact that every distributor shaft came from the factory stamped with either an "L" or an "R". If you want to say it backwards, you constantly face the improbable coding of "L" means clockwise and "R" means counterclockwise. I suppose you could insist that your truck came with four tires on top because you always stand on your head when you look at it.
Jim, you are missing my point. I don't WANT to be different than the OEM folks, nor argue with you.
The OP didn't see/notice the L or R markings, and asked "which was the correct distributor". (NOT "what do the marks I never saw mean".)
I answered his question, along with the note that they turn CW when viewed from the back of the engine. That is TRUE and not a "diss" of the factory nomenclature, is it???
If someone asked what in which direction the firing order goes, would it be better to say "clockwise, looking at the distributor cap" or "left"?
Bob I agreed with you. But after more investigating even some IH information gets confusing.
C parts book and some others has listed CC for the distributor. Others don't say in the parts book. Other IH information lists a C,H, ETC as clockwise or the same as a magneto ID so they would be the same direction from both ends if the distributor was compete with the drive.
Some parts list the distributor as a Unit including the drive end and the distributor without drive end a assembly. Some call the complete thing a assembly.
Going to admit I don't know the correct sure answer. Long as I know what direction they go, don't guess it maters.
Whatever the correct definition its easy for me to remember that the ignition drive or hydraulic pump on the A through 450 gas turns the same direction as the engine crankshaft. Gas start diesels and W9 through 650 gas turn opposite the crankshaft. Then just think about the ignition unit gears reversing that.
C parts book and some others has listed CC for the distributor. Others don't say in the parts book. Other IH information lists a C,H, ETC as clockwise or the same as a magneto ID so they would be the same direction from both ends if the distributor was compete with the drive.
Some parts list the distributor as a Unit including the drive end and the distributor without drive end a assembly. Some call the complete thing a assembly.
Going to admit I don't know the correct sure answer. Long as I know what direction they go, don't guess it maters.
Whatever the correct definition its easy for me to remember that the ignition drive or hydraulic pump on the A through 450 gas turns the same direction as the engine crankshaft. Gas start diesels and W9 through 650 gas turn opposite the crankshaft. Then just think about the ignition unit gears reversing that.
Janicholson
Well-known Member
I have been looking at Distributor rotation instructions on line for 15 minutes. Not one of them indicates the direction as though the distributor was out and being looked at from the drive end. All are from the point of view of the cap.
I believe we need to agree that the counter intuitive position taken and embedded at IH when the first markings were put on (whether mag or dist)is used by them and that the markings are as such.
I will continue to indicate CCW or CW as rotation of the rotor in that direction when looking at it.
I believe I have always done so.
IH could have made everything simple by changing the diesel drive direction so it matched the Geas direction but had a different mount so it was incompatible. If I refer to a distributor markings or question I will point out the meaning of the lettering used by IH on the components. Jim's Thinking. Peace and Harmony.
I believe we need to agree that the counter intuitive position taken and embedded at IH when the first markings were put on (whether mag or dist)is used by them and that the markings are as such.
I will continue to indicate CCW or CW as rotation of the rotor in that direction when looking at it.
I believe I have always done so.
IH could have made everything simple by changing the diesel drive direction so it matched the Geas direction but had a different mount so it was incompatible. If I refer to a distributor markings or question I will point out the meaning of the lettering used by IH on the components. Jim's Thinking. Peace and Harmony.
rustred
Well-known Member
after looking again at the left dist. I am starting to agree with bob. I am picturing it turning clockwise in my head and its starting to make sense. the shaft turns clockwise, then the weights fly outward to advance the points.
before I was picturing it turning ccw. so the advance arms were rubbing on the shaft arms. it makes more sense now I think for it to turn cw.
I am going to open a gas and diesel dist today and satisfy my curiosity. post some pic"s of each also.
yes I know gas do turn cw and diesel ccw.
catch ya later.
before I was picturing it turning ccw. so the advance arms were rubbing on the shaft arms. it makes more sense now I think for it to turn cw.
I am going to open a gas and diesel dist today and satisfy my curiosity. post some pic"s of each also.
yes I know gas do turn cw and diesel ccw.
catch ya later.
Jim Becker
Well-known Member
You are missing my point as well. True, the OP didn't ask about the markings. Whether he had seen them or not, he is/was likely to see them as soon as he pulls a couple more parts out of either unit. He never asked which way the distributors turned either. He just asked which one was correct for his C.
Once you introduced the unasked and potentially confusing designations of CW and CCW, it seemed appropriate to anticipate the question that was likely to be generated when he (or some later reader) notices an "L" stamped into a "clockwise" distributor or an "R" stamped into a "counterclockwise" distributor.
He didn't ask about firing order either. If he had and I had answered. I would have said clockwise. But somebody plugging wires into a cap isn't going to see the "L" and "R" stampings anyway. If someone is digging deep enough into a distributor to be able to see those marks, they need to know what they mean. This is especially true in a case like this where he has 2 VERY different distributors and is trying to fish enough good parts out of both of them to put together one functioning distributer.
I never thought it was inappropriate to anticipate a likely follow-up question and respond with an answer so the OP has a chance to see the added information when he looks at the responses. Maybe I am wrong on that point as well.
Here is another set of photos with the internals removed. The left one reads 25L and the right one reads 8R. They are not interchangeable. I'm not going to be able to switch out the internal components like I wanted to do. Notice the difference in the hole patterns.
Parts just won't line up with the holes.
Parts just won't line up with the holes.
Jim Becker
Well-known Member
The difference in the hole patterns correspond to the L and R markings. With opposite rotation, the hole patterns are mirror images of each other. One hole in the one on the left is larger than the corresponding hole on the right. The size of this hole determines the limit of the centrifugal advance (25 vs. 8 ). A peg on the back side of the cam sticks into this hole to limit the movement between the cam and the shaft. The original C distributor had a 30 shaft but many were changed to 25 when the engine was upgraded with Fire Craters etc.
By the way, the number on the shaft corresponds to crankshaft degrees. Movement at the distributor is half as much.
By the way, the number on the shaft corresponds to crankshaft degrees. Movement at the distributor is half as much.
Thanks for the sketch. Do you know the purpose for the plug that is the side of the the distributor casting? You remove it with a screwdriver. I used to think it was a place to install a grease fitting to lubricate the distributor shaft. I realize now that the hole doesn't go all the way through the brass sleeve that the distributor shaft runs in, so no grease can reach the shaft unless you were to drill a hole in the side of the sleeve.
Bushing material lets the grease soak through, just enough grease is put in until it exits the hole on the other side of the grease hole.
Distributor with L-25 may be from a 400 or 450 tractor engine.
Look on the distributor base where the clamps go. Stamped in you may find the letter N followed by a letter for month. Jan.=A, ETC. Next a number for the year built. Maybe a 4 to 8. 1954 to 58. Next would be a serial number. Or if the unit has a different first letter than N post the info.
What parts do you need? Looks like the weight post is loose on the gas.
I will check the numbers and letters on the base flange. Yes, the 25L plate is not any good. So I used the hole pattern on the 25L plate to drill another set of holes in the 8R plate. I think this will work? There wasn"t much that I could use on the distributor that I bought. The splines on both the gears were stripped in addition to the 25L plate being bad. The mounting holes in the cams from the 25L distrubutor are also badly worn, but I think they are usable.
Yes I have drilled the # eights to use on a gas before when I needed a different advance and also a good rotor shaft or also a housing with serviceable bushing. That way you can make the hole to the max advanced wanted. Placement of the hole is critical on placing the weights on the right swing arc to the cam. Will also change the advance rate from original with little changes.
Think I didn't say the first letter on the base can ID the original advance and intended use. May not be what's found now though. First letter was called the distributor symbol.
Interestingly the list I have that id's a N symbol gasoline says its a CW distributor. Doesn't specify the direction viewing from.
400,450 parts book doesn't specify the rotation direction. Older parts books for like A or C say CCW for a distributor turning the same direction as a 400 gas.
Jim Becker
Well-known Member
H = 8R and N = 25L agree with original codes/markings.
Edit: After posting this, I see that D Slater already replied with the same (modern view, it was on the next page).
I put the reconditioned distributor in the tractor and can't seem to get it to fire. I have power at the points. I put a new set of points and condenser in it. I checked the coil wire distributor post to make sure it wasn't grounded. I switched out the coil for one that I new was working. The points and condenser have been in the original package on a shelf in my garage for about 15 years. Could it be the condenser? I didn't get the distributor shaft completely straightened and the point gap varies a little, but the points are breaking. Any suggestions? I am out of ideas.
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