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oil pump drive angle not quite 47-49 degrees

Discussion in '"Stock" Alpine' started by mightyohm, May 28, 2019.

  1. mightyohm

    mightyohm Gold Level Sponsor

    I made a handy dandy template that has a line at exactly 47-49 degrees through the center of the distributor drive. The problem is, the marks don't line up no matter how I orient the pump! I tried moving it one tooth in either direction and this is the closest I can get. Has anyone else noticed that their pump doesn't quite match the angle in the Rootes book?
    I feel like I've seen this offset on every motor I've built, but I always thought it was my template that was off, not the oil pump drive. This time I'm pretty sure my mark is correct!

    IMG_6811.jpg
     
  2. mightyohm

    mightyohm Gold Level Sponsor

    Here's where the distributor winds up after setting the static timing to about 7 deg BTDC on cylinder 1. I put the dipstick in for reference. Last time I had issues with the distributor running into the dipstick when timing the motor. I'm tempted to clock the oil pump one tooth forward to rotate the distributor towards the block.
    IMG_6820.jpg
     
  3. sunalp

    sunalp Platinum Level Sponsor

    Jeff,
    That's just about where mine is, and the car runs fine. I've always looked at the diagram in the manual
    and kind of "eyed" it to where I thought it should be. So far ( knock on wood) I haven't had an issue
    with timing. I think you just need to be in the parameters of the range.

    Cheers!
    Steve
     
  4. mightyohm

    mightyohm Gold Level Sponsor

    Steve, thanks for the confirmation on the distributor orientation.

    I clocked the oil pump one tooth ahead and this results in the distributor being roughly parallel to the block at 10 degrees BTDC and the drive looks like this:

    IMG_6822.jpg
     
  5. DanR

    DanR SAOCA Treasurer Diamond Level Sponsor

    I believe you should go back to align with the distributor button in your PIC just before this....

    Edit: Change the "bottom to button"....
     
    Last edited: May 29, 2019
  6. Hillman

    Hillman Gold Level Sponsor

    The only difference between the two is the position of the dizzy (parallel to block or not). I'd use the one where it is parallel, but that's just me. It won't affect your timing. Just use either and set it correctly, the car will run the same, the only difference will be the distributor's orientation to the block.
     
  7. 65beam

    65beam Platinum Level Sponsor

    The body of the distributor and the vac unit don't have to point to the front. All you do is turn the body so the vac unit points to the back. All of my cars are set up this way. Makes it easier to use the dip stick too. 110_0594.JPG
     
  8. Tom H

    Tom H Platinum Level Sponsor

    You have installed the oil pump with #1 piston NOT at TDC firing, but at TDC exhaust. This is a common error, because the procedure for installing the timing chain puts the engine at #1 exhaust. You need to turn the crank 360 deg after aligning the timing chain marks, before your install the oil pump THEN you will find you can achieve the correct alignment.

    Tom
     
  9. mightyohm

    mightyohm Gold Level Sponsor

    I made sure to double check this, so I don’t think that’s the issue. I left the timing cover off when I installed the oil pump so I could easily check the timing marks. I installed the timing chain with the marks aligned, rotated the crank 360, and THEN installed the pump.

     
  10. Tom H

    Tom H Platinum Level Sponsor

    Jeff, are you sure you did not rotate the CAM 360? I have worked on many Alpine engines and discussed this issue with several guys on this site and ALWAYS have been able to get the shaft aligned according to the WSM. There is an odd number of teeth on the oil pump (11 ( or 13) teeth, I think). And the only reason you would not be able to align the slot is if the camshaft is 180 deg out when the oil pump is installed. Most common problem is that guys miss the offset of the slot and install the pump, but I see you have the "heavy side" toward the block and still not the right angle. Note that if you re-install the pump with the oil pump shaft rotated about 180 deg, you can achieve the proper angle, but with the heavy side wrong. Then crank the engine one full crankshaft turn and all will be aligned correctly and I'll bet you will have the #1 piston at TDC firing. You can verify TDC firing by looking at the valves, See this previous thread:
    http://forum.sunbeamalpine.org/index.php?threads/oil-pump-install.23799/#post-161497

    Regardless of the alignment you CAN achieve correct firing with different alignment of the dizzy and wires.

    Tom
     
  11. DanR

    DanR SAOCA Treasurer Diamond Level Sponsor

    Tom made a statement I can relate to... I did my alignment in error and learned to do as Tom says.

    Another mistake was attempting to install an oil pump that had different number of teeth.... Now that is a real mistake you certainly do not want to do..
     
  12. mightyohm

    mightyohm Gold Level Sponsor

    DanR,

    My oil pump has 11 teeth. I think this is correct for the 1725.

    Tom,

    Yes, I rotated the crank 360. I triple checked the alignment of the gears and verified that I was on TDC #1. I don't have the head installed, but I verified this in two ways - since I had the timing cover off I could set the timing marks in alignment and then rotate the crank exactly 360 degrees. I also checked that both cam lobes for cyl #1 were facing DOWN (away from the lifter bores) - this ensures that cyl #1 is really TDC in the firing position. (And just in case there's any confusion, cylinder #1 is the one closest to the front of the car and the radiator, correct? I'd hate to have screwed that up all these years!)

    If anyone wants to try the template and see how their pump lines up with the Rootes spec, you can download an updated version here. Just cut out holes for the two bolts (to aid alignment) and the smaller hole in the center to clear the pump drive. (I just updated it again to show the larger side of the drive as the shaded side.) Make sure you print "actual size" and don't try to scale the drawing. This can be tricky depending on the printer driver on your computer. The long dimension of the template should measure exactly 3.25" when it's printed at 1:1 scale.

    https://www.dropbox.com/s/6fdakw1ecn39j9a/oil_pump_drive_template_20190529.pdf?dl=0

    Thanks for all of the tips and help. I'll check everything again today.
     
    Last edited: May 29, 2019
  13. Tom H

    Tom H Platinum Level Sponsor

    Wow! That is a puzzle. It seems you DO have the engine at #1 TDC Firing, based on the cam lobe positions. The only explanations I can think of is 1) the the oil pump gear has the slot machined offset to the wrong side. or 2) the timing chain if off by a tooth or two. My suggestion, assuming explanation #1, would be to install the oil pump approx 180 deg rotated such that the proper angle is achieved but with the slot on the wrong side. Then install the dizzy with the rotor 180 deg wrong, and shift all the wires in the cap 2 positions. This will put the dizzy in the normal orientation at normal timing. And yes, # is at the front.

    Anyone have a better explanation?? I have never seen this condition before.

    Tom
     
  14. mightyohm

    mightyohm Gold Level Sponsor

    I rotated the engine 360 degrees (to TDC #4) and now the pump lines up with the template. Now I'm really confused.

    IMG_6831.jpg

    Strangely, this block also calls the rearmost cylinder #1. Isn't that supposed to be #4?
    IMG_6832.jpg
     
  15. mightyohm

    mightyohm Gold Level Sponsor

    Is there a possibility that the angle given in the WSM is wrong? Maybe it's not supposed to be 48 degrees but something close? How many folks have actually measured with a template?

    I just noticed that the angle spec was removed from the later Hunter manual (WSM 149) and it just shows the picture (with no angle). I wonder if Rootes found their mistake and decided to remove the numbers in the later manual?

    It would be helpful if someone with a correctly timed motor could print out the template and take a picture showing their oil pump drive for comparison.
     
  16. Tom H

    Tom H Platinum Level Sponsor

    I don't think we need to use the template. Here are a couple photos where you can see the angle is pretty much as stated in the WSM. (or you can measure the picture).

    But Jeff, Something is not making ANY sense here. Your first two photos show the heavy part of the slotted shaft at the upper left , but not aligned with the expected angle. Then you say you rotated the crank 360 deg. Soooo the shaft should rotate 180 deg. Clearly it rotated something other than 180 or it would have the same angle but swapping heavy side. Do you have a mismatched oil pump shaft or cam. I think some engines had different number of teeth on the cam/oil pump.

    Tom
     

    Attached Files:

  17. DanR

    DanR SAOCA Treasurer Diamond Level Sponsor

    Jeff, Is that the original engine or one of the "new" engine from Iran?

    If you removed it from the car do you by chance have any prior pictures you could refer to?

    I have never seen a 1725 engine with those cylinder markings....
     
  18. DanR

    DanR SAOCA Treasurer Diamond Level Sponsor

    Just noticed the engine is marked with "FRANCE"
     
  19. Tom H

    Tom H Platinum Level Sponsor

    See this thread about cam and pump teeth
    http://forum.sunbeamalpine.org/index.php?threads/1725-oil-pump.26162/#post-178836

    It seems unlikely but somewhat possible that the shift is a result of overturning the crank and then backing up the rotation and the timing chain slack allows the crank to return to TDC and the cam does not move as much.

    Try turning the crank a couple full rotations and see if the cam / dizzy drive turns too much. You say the oil pump shaft has 11 teeth. If the cam has 12 teeth then the oil pump shaft will turn (180 X 12/11) degrees for each full rotation of the crank.
     
    Last edited: May 29, 2019
  20. DanR

    DanR SAOCA Treasurer Diamond Level Sponsor

    If you mismatch the oil pump and the cam you can easily grind some teeth off one or both of the parts (Cam & Pump).
     

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