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D4600 Flywheel Positioning
D4600 Flywheel Positioning
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16 years 5 months ago #18097
by bboaz
Rebuilt a 4600 motor for a 5R D-6 (rings, sleeves, valves, heads) using the same bearings, so I did not remove the crankshaft or the flywheel. Will not start. Some black smoke as it seems to be firing once and a while, but lots of white smoke. New fuel filters, and all the air bled out of the system. Fuel pressure about half way up on the gauge. Took the transfer pump off yesterday and surface ground the main housing and bottom plate to remove all end clearance in the gears where they had worn into the housing. Should go all the way to green now. All injector pumps are pumping except #2,which I took out to see what wrong with it. In the process I broke the adjustment screw with the clip, which holds the end of the Pump Plunger. I have a new one ordered. In the process of getting the flywheel positioned to replace the screw of the plunger I discovered the flywheel seems to have been rotated 120 degrees out of position. This means 2 &5 on the flywheel are really 1 & 6: 3 & 4 are really 2 & 5: and 1 & 6 are really 3 & 4. Will the flywheel rotate exactly 120 degrees out of position if it is two sets of holes off???? (6 bolts divided into 360 degrees equal 60 degrees times 2 bolt holes equal120 degrees) With the side cover off of the injector pump rotating the engine brings the injectors up in sequence with the firing order only one mark off. This has also made my lifter setting off 120 degrees since I set the valves in the firing order turning the flywheel to each timing mark to set that particular intake and exhaust valve at .012.
This should be the primary reason it will not run. Valve adjustment 120 degrees off.
To keep from getting confused, I wrote the new numbers in magic marker next to the stamped numbers on the flywheel Can I leave the flywheel where it is and readjust valves with the new numbers and hopefully make this motor run? It would be a lot of work to pull the motor and change the flywheel.
Today to confirm my thinking, I put a dial indicator on the Number 2 lifter in the fuel pump housing and rotated the engine watching the timing marks on the flywheel. As I approached the marks for cylinders 2 after going through the entire firing order (two revelations of the flywheel) the numbers on the dial indicator started going up indicating number 2 cylinder was coming up on compression to fire at TDC. Prior to reaching the timing marks the dial indicator peaked at 2.71 then dropped back 0.010” in the 2 inches of travel at the edge of the flywheel to line the timing marks up with the pointer. This tells me the fuel is injected a few degrees before TDC. Short of pulling an injector and putting the dial indicator through the prechamber and checking piston rotation, can I pretty well assume the flywheel is 120 degrees out?
Replacing the lifter screw that holds the bottom of the plunger for the injector pump, SJ stated in one of the discussions that it is set at 1.734 inches for the 4400 engine. Is it the same for the 4600? Where on the lifter screw is this measurement taken from? Is it the top or to the bottom of the lifter yoke? Also this should be from the top of the housing to the lifter screw measured with a depth micrometer. Correct? Is this setting is done with the flywheel marks not the maximum lift of the lifter. The lifter I measured today dropped down 0.010 from maximum lift when the timing marks lined up.
Am I on the right track and will it work. Thanks for any comments or suggestions
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16 years 5 months ago #18100
by ccjersey
You're right on the 120* out. No problem, lots better to be 120 out than 60, at least you have a mark to line up. Adjust the valves on the cylinder of each pair (1-6, 2-5, 3-4) that has NOT just had the exhaust close and the intake opening as you went to the mark.
Set injection pump lifter when you reach the mark (which is TDC). Do not back up to get right on the mark, only go normal rotation and stop on it, if you go past, go back a long way and come up on the mark again so you take out any wear/slack in the gears when you set the lifter. Make sure to set the lifter that has just risen or you will break things as you rotate it around to get the others done.
Timing dimension for D318 is 1.736, not sure about the D4600. there should be a flat on the top of the lifter yoke that the pump plunger engages. Measure from top of pump housing to this lifter yoke flat top. D318 book says that lifter should still be rising after TDC, not falling before TDC as you indicate. Are you sure you are rotating the engine the correct direction (clockwise standing in front of the tractor looking at the radiator). You may also have a mistimed pump drive gear or perhaps a worn lobe on the pump camshaft if they all don't show that same drop.
D2-5J's, D6-9U's, D318 and D333 power units, 12E-99E grader, 922B & 944A wheel loaders, D330C generator set, DW20 water tanker and a bunch of Jersey cows to take care of in my spare time:D
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16 years 5 months ago #18104
by Old Magnet
The 1.734 in. measurement is correct for the D4600.....measured from the top of the injection pump housing to the bottom of the yoke.
This measurement gives you the proper built in advanced injection point.
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16 years 5 months ago #18111
by SJ
Cat finally wised up starting with the the D330 & D333 and other later engines at that time by positioning one of the flywheel bolt holes off center so you couldn,t get it on wrong.When setting the lifters they will just be starting up from the bottom position when your on the timing mark to set it. bboaz in your case your not on the correct marks but if it,s as you say with another set of marks the process is the same as all have suggested.
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16 years 2 months ago #20182
by bboaz
I finally gave up and pulled the engine back out of the frame. Pulled the heads, pan, and front timing gear cover. The flywheel is in the correct position. When 1&6 line up with the timing mark 1&6 are top dead center. In one position with 1&6 lined up the timing marks “C” on the crankshaft, and “C” on the cam gear are together as the picture shows in the book. Turn the flywheel one revolution and line 1&6 up again and the “C” on the crankshaft is back in the same place as before yet the “C” on the cam gear is 180 degrees opposite. Am I correct in saying when the “C’s” are together number one cylinder is firing and when they are apart number 6 is firing? With the “C” together as in the picture and the “C” and the “P” lined up on the accessory gear and the idler gear this motor should be in time. Should number 1 Fuel Injector Pump Lifter be coming up when the “C’s” and “P’s” on the idler gear and accessory drive gear get lined up or at this point shouldn’t the lifter be just about at the end of it’s upward stroke and starting to go back down? I still have to adjust the Fuel Injector Pump Lifters because they were adjusted thinking the flywheel was 120 Degrees out of position. Once adjusted as each timing mark comes up on the flywheel, the corresponding Fuel Injector Pump Lifter should be coming up. At what point in the upward travel of the piston on compression stroke should the Fuel Injector Pump Lifters start their upward stroke? What I am seeing now is the piston strokes and the Fuel Injector Pump Lifters are not matching up. The timing marks are lined up yet as number one cylinder is top dead center and the flywheel marks are lined up it looks like number 5 Fuel Injector Pump Lifter is at the top of it’s travel. Is there that much advance in the Fuel Injector Pump Lifters? Am I reading too far into this situation? I have put too much money and time into this engine for it not to run
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16 years 2 months ago #20188
by Old Magnet
WOW,
Sorry to hear you are having so much trouble.
Yes, when all the timing marks are aligned you are set to power stroke #1 cylinder which should be at top dead center. The lifter should start to rise on compression stroke and be at the 1.734 in. position at the top dead center mark. A check of the correct position is the lifter still rising as you turn a few degrees past the TDC mark.
Remember that the injections pumps are numbered 1 to 6 consecutively starting from the front but the actual firing order is 1-5-3-6-2-4
The camshaft turns at 1/2 crankshaft speed so your 180 degree would be normal.
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16 years 2 months ago #20199
by ccjersey
Advance on the injection pump stroke would only be around 15 degrees. (D318 is 15) This would be around 3 inches travel on the outside of the flywheel rim ahead of the TDC marks.
I gave away my D4600 book, so I can't tell, but do you have a complete set of 4 marks between the accessory shaft gear, the idler gear and the cam gear which align all at one time?
The D318 book shows a one piece double gear on the cam with the accessory drive idler running on a smaller outer gear that does not mesh with the crankshaft gear. Also shows that the idler gear marks are not straight across from each other so that they would both align with the cam and accessory drive gears only at the 1-6 piston TDC.
No problems with these and no substitutions of gears etc, then the only possibilities are a sheared key or twisted accessory drive shaft.
D2-5J's, D6-9U's, D318 and D333 power units, 12E-99E grader, 922B & 944A wheel loaders, D330C generator set, DW20 water tanker and a bunch of Jersey cows to take care of in my spare time:D
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16 years 2 months ago #20201
by ccjersey
Do you have any history on this tractor before you tore it down? Looks like there would be some evidence of prior attempts at repair or history of failure.
Or was it "running when parked"
D2-5J's, D6-9U's, D318 and D333 power units, 12E-99E grader, 922B & 944A wheel loaders, D330C generator set, DW20 water tanker and a bunch of Jersey cows to take care of in my spare time:D
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16 years 2 months ago #20206
by bboaz
Thanks OM and CCJERSEY for your comments. I have readjusted the Fuel Injector Pump Lifters Where I had thought things were 120 degrees off. As the piston for the firing cylinder approaches top dead Center and the timing marks on the flywheel line up the Fuel Injector Pump Lifter for that cylinder starts up. Here I set the 1.734 with a depth micrometer. As I turn the flywheel to the next mark (i.e. set number 1 turn to the next mark to set 5 in normal firing order) the Fuel Injector Pump Lifter for number 1 cylinder continues to rise through the power stroke of that cylinder. Is this correct. It seems the cylinder is firing late. The way this is set it makes the majority of the fuel injection process take place during the downward stroke of the piston in the power stroke. Maybe I expected to see more of an advance (BTDC). Does this sound right for the Fuel Injector Pump Lifter travel in relationship to the piston travel?
I measured one of the Fuel Injector Pump Lifters prior to readjusting and the measurement was 1.906. This would be .172 low. Would this make the fuel injection for that cylinder even later? If so could this be an explanation why there was lots of white smoke and would only fire once and a while.
Not much history on this tractor other than it set for about 20 years collecting water in the cylinders. There was lots of rust and corrosion to clean up. Don’t know if it ran when it was parked or if that was the reason it was parked.
If this all sounds correct, maybe it is time to put everything back together and see if it will run.
Thanks for your help.
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16 years 2 months ago #20207
by Old Magnet
Hi bboaz,
Yes, if your lifter setting is 1.906 your timing is way late.
Yes, the lifter should continue to rise from the 1.734 in. setting.
According to my fuel injection handbook for the D4600 the timing is 25 degrees before top dead center. (15 degrees on the D318)
I'm including a picture of where lifter measurement should be taken as there seems to be some confusion and I just received a couple of PM's asking for clarification.
Did you actually pull an injector and verify TDC indexing, preferably with a probe and dial indicator??
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D4600 Flywheel Positioning
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