Subject: [TR] TR3 Oil Pump Lessons Learned

From: William Brewer <[email-masked]>
Date: Fri, 20 Dec 2013 13:11:57 -0800 (PST)

So I have two oil pumps for my TR3. One looks like the original 1960 oil
pump (from my last rebuild). The clearances on it are way out of spec. My
second pump is a nondescript pump that I bought new off of Ebay at a bargain
price. It has good clearances and made good pressure in my last engine, but I
found that the rotor isn't pinned to the shaft. Here is a list of
miscellaneous info that I have learned from the experience thus far:

1. I
tried to drill through the rotor and shaft to put in an allen head set-screw.
It dulled the Harbor Freight titanium coated bits immediately.

2. I took it
to work and gave it to the machinist. A cobalt drill bit in a mill wouldn't
drill through it. He said forget about trying to tap it as well.

3. For kicks
I put the newer oil pump cylinder in the original oil pump. The clearances
were out of spec. The pump housing didn't appear too worn. It is conceivable
that the original pump just wasn't made that well.

4. My second (newer) pump
had 8.8 mm metric bolts holding it together instead of British standard
threads like the original. That might be a warning sign.

5. I ordered a pump
rebuild kit from British Parts Northwest. It came with the pinned shaft. I
went to install it in the newer housing and the assembly (rotor and cylinder)
is 0.117" longer than the pump housing. I took it to work and turned it down
on a lathe to clearance.

6. I tried the pump rebuild kit in the original old
1960 housing and the cylinder fits very loosely and out of spec.

7. There is
a guy named Steve Yott who makes new oil pump rotors where the shaft goes
through the impeller and out the bottom of the oil pump housing. This supports
the shaft/impeller on both ends. Racers use this and some street cars as well.
It was a little outside my price range at about $250 + a new oil pump. It is a
good idea though and I commend him on his engineering.

8. I wouldn't use any
oil pump where the rotor isn't pinned to the shaft.

9. Knowing what I know
now I would have just bought a new pump from BPNW. I would still check it to
make sure that the impeller is pinned to the shaft.

     -Bill Brewer
   
 Tehachapi, CA

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