"Blueprinting" the Oil Pump


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Bob Lang is best known for his car building and auto-cross talents and he recently shared one of his tips with the Triumph Mail List...........he called it "Blueprinting Your Oil Pump" and he's found that it will raise your oil pressure 10 psi everywhere! If you're dropping your oil pan for any reason, you should take an extra hour and try his simple fix.

That's Bob Lang and his very cool Auto-Cross TR6

Here's the oil pump still in the engine with the arrows pointing to the part we'll be working on.

What it looks like out of the engine

And pulled apart with that red arrow still pointing to the piece in question.

Here you can see all the scoring on the face of that piece.

I ended up using just the 500 grit paper

You'll need something perfectly flat so I spent a buck and bought a 12" ceramic tile.
At first I used some regular oil but found it to be too thick.
Hold it nice and flat and work it back and forth and side to side......
The oil was a little too thick..........the 50 degree basement didn't help any!
So I switched over to air tool oil which is much lighter.
It took about 5 minutes to get to this.............
after looking like this!
Next up was to check all the specs..... this was my straight-edge
The rotor clearance shouldn't exceed .004" and I was right at .004"

The next two points to measure are the inner to outer rotor and the outer rotor to body clearances.

The inner to outer rotor shouldn't exceed .004" and I was at .003"
The outer rotor to body shouldn't exceed .010" and I was at .002"
I ended up writing it all in the manual with the date for future reference.

The thing to do is to give it all a thorough cleaning, multiple times, to make sure now of that sandpaper grit is left behind!

As I get closer to re-installing my engine I'll add more pictures on priming the pump and installing it.

The yellow arrow points to the Oil Pressure Relief Valve (OPRV) which I documented in another section on my site.  As part of this new work I replaced both the piston and the spring in the OPRV which is a very cheap fix. I forgot to take a picture of the recess in the gear Oil Pump shaft sits in. So look down in to the OP housing base (red arrow) and you will see a round piece with a recessed slot in it. The OP shaft has a corresponding "tang" that will fit in to that slot.

When you're assembling the OP back into the engine, make sure you rotate the inner rotor until that tang on the end of the shaft drops into the slot that's in the housing base. If you've done it properly the OP housing will sit flush with the housing base.

Here's the other end of the OP shaft as it normally sits in the inner rotor. This is nothing more then a pressure fit. If the bottom of the shaft isn't properly recessed in the slot and and you tighten the bolts holding the OP in place, you will force the housing down and push this shaft up into the inner rotor. Everything will look fine but the OP won't be engaged with the engine and will not work. If you've done it right, you will feel the shaft drop into the slot in the bottom of the housing base.

I used good old Vaseline for packing the OP
And I packed it up real full........ it'll will naturally dissolve once the engine is running.
And here it is back on the engine.