Going back to an original oil pump

[Alford]

My '53 Panhead has an aluminum shovelhead oil pump, which is not scavenging oil back to the tank. I don't know why.

If I decide to replace the pump with an original panhead one, which pump should I look for and what do I need to do to correct any adaptation that has been done?

Thanks,

Alford

[Bosheff]

It may not be possible to go back to the original pump. In certain situations, the case-half (pump side) must be modified to accept the later pump (-68 or -80). I am not totally up on this procedure, but if my memory serves me correctly, the passage ways leading to and from the pump on the case must be drilled/redrilled to accept the shovel pump. I would think it might be easier/cheaper to repair the existing pump, unless you are after originality. I'm sure someone else is more familiar with this than I am, so jump in and correct me if I am mistaken. As I remember S&S makes/made a drilling fixture for this purpose. It bolts to existing pump mounting holes and you just follow their holes and drill away. I may be mistaken. The mind ain't what it used to be.

[Bosheff]

Clarifying the above rant, the drill fixture is used to modify the case so you can use the later pump, not bring it back after it has already been modified.

[fourthgear]

Check the shaft keys ,all of them .

[NightShift]

Dear Alford,

If a hole has been drilled in your motor case, you can always plug it with a set screw.

'Spectful,

[Alford]

Here's a picture of the surface of my case where the oil pump mounts on my '53 panhead.

Any extra holes?

Both keys were on the shaft (I haven't looked at the other side yet)

[Bosheff]

If you're not sure about the case being modified, check it with the stock gasket (original gasket). This is a starting point.

[Bigincher]

On the S&S website, there are various instructions for the installation of thier different oil pumps. That talk of 'drilling' got my curiosity up, so I went looking. What I found was an instruction sheet that shows the engine cases of different years, before modification. Perhaps you can use the photos to compare to your case.
Here's a link, scroll down to page 7 to find the photos.
http://www.sscycle.com/admin/uploads/in ... 1-1041.pdf

[awander]

Those pictures kinda' scare me-notice how '73 and up don;t have a main oil supply hole?