[Healeys] Oil Pressure

[Bob Spidell]

Aren't the cam lobes slightly sloped from edge-to-edge as well?


On 5/11/2020 4:50 AM, Michael Salter wrote:
> Richard is,as usual, absolutely correct in that the lifters are very 
> slightly convex on the base however it is not that which makes them 
> rotate rather that the fact that the lifter bores are slightly 
> displaced from the centerline on the cam lobes.
> In many Healey engines that I have disassembled however it is quite 
> apparent that at least some of the lifters have not been rotating as 
> evidenced by the rectangular shape of the witness mark on the base. By 
> measuring the position of the rectangle one can confirm that the 
> displacement is about 1mm as I recall.
> I've never been able to determine why some lifters fail to rotate as 
> they seen quite free in the bore.
> Regarding the idea that the engine has to be turning at 1500 RPM to 
> throw oil up to the cam I totally disagree with that.
> Even 600 RPM is 10 rotations a second .... hmmmm.
>
> M
>
> On Sun, May 10, 2020, 7:25 PM richard mayor, <boyracer466 at gmail.com 
> <mailto:boyracer466 at gmail.com>> wrote:
>
>     The lifter faces are not flat. They have a crown so they rotate in
>     the bores as the cam lobes move across them. At low RPMs the
>     lifters do not rotate so much. It is absolutely essential on
>     initial start up that the lifters are rotating so the cam and
>     lifters can properly bed in. This is accomplished if the engine is
>     reving at least 1500 RPM.
>

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