Gentlemen,
Just updating on my oil pump shaft "fix" as listed below. I manufactured the
oil pump shaft as described and it was a complete success, using the methods
described. As we all know, the pump shafts supplied with current replacement
rotor kits are extremely poor in manufacture and are 'soft'. Virtually mild
steel. The first rotor kit that I fitted saw the pump shaft worn 0.010"
within 2000 miles.
In manufacturing my replacement rotor shaft I encountered the following
manufacturing issues: -
1. The case hardened material made the machining of the tang slot difficult.
2. The retaining pin/or locking fastener between the shaft and rotor was
impossible to drill due to the case hardening of the shaft. I had to firstly
have a pilot hole spark eroded into the rod and then finish the hole by
drilling. Very carefully!
What I learnt: -
1. It would be far better to start with un-hardened material to manufacture
the shaft(s) and then have it hardened. What I made up on by utilising an
already hardened shaft material, I lost in extending the machining time due
to the hardness of the material.
I also manufactured a rocker shaft utilising the same material. It turned
out splendidly. But the guys that had to spark erode all the rocker oil feed
holes
said they weren't going to do another one for me in that way. Nearly drove
them crazy!
Regards
Peter Vucinic
TR-4
> From Peter Vucinic in Aug 2003:
>
> Many thanks to all those that contributed to my TR4 Oil pump shaft
problem.
> Much good information and ideas were bandied about. So, to this end I have
> decided on having my own pump shafts manufactured as follows: -
>
> 1. Staring with 1/2" linear bearing shaft material. Readily available 'off
the
> shelf', hardened, ground precision rod. Case hardened to a depth of about
> 1-to-1.5 mm. The material is difficult to machine. But it can be done.
> 2. Have the distributor shaft drive tang slot machined with a radius in
the
> bottom. This should be able to be accomplished using a ball nose milling
> cutter.
> 3. Use Greg Solow's idea of drilling and taping the pump shaft and pump
> rotor.
> 4. I am also looking at having the oil pimp body machined to take a bronze
> bush, at the rotor end.
>
> I have ordered the material(s) and I should have the finished product in a
> week or so. I will advise of the end result for those of you that are
> interested.
> Kind Regards
> Peter Vucinic
> WORKS-4
> TR-4
>
> From Kas:
>
> That shaft material sounds very much like what we call "drill rod". Cheap
> and available at most steel servers. Available in many diameters,.
>
> Reply from Peter:
>
> Kas,
> The material I am using is definitely not along the same lines as drill
rod.
> Linear rod is a precision ground, hardened bar used in such applications
as
> material handling/packaging equipment, where linear motion ball bearing
> units are required.
>
> I am getting the specification sheet for this material, but haven't seen
it
> as yet. Typical mechanical properties for this material will be similar to
> the below: -
> Hardened & ground - inch dimensions. Steel: Ck60 Surface hardness: 62
> Tensile strength: 550-750 N/mm
>
> Kind Regards
> Peter Vucinic
> WORKS-4
> TR-4
>
>
>
> At 10:20 PM 7/4/2004, Bill Babcock wrote:
> >Seems like I remember a thread about better pump shafts. This part is
> >obviously flawed. The stress in those sharp corners must be huge.
Likewise
> >the drive slot. Does anyone make an improved part with radiused edges?
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