I just received this response from Richard Good.
John,
I just had a some other inquiries about the need for the external line
and the possibility of it dropping oil pressure. This was my response:
On an engine with needle bearing roller rockers I usually end up
restricting the external line with a 3/32" roll pin in the end of the
hose fitting. In one case there seemed to be plenty of oil coming
through the internal channel so I eliminated the external line. I like
to keep a good supply of oil to the top. Don't starve the top end to
keep oil from sucking down the guides or blowing out the rocker cover
vent. Use valve seals and an oil separator to keep the oil where it
belongs. Also, check the oil pressure in the main oil gallery before
concluding that the external line has dropped the overall pressure. The
gauge may show a reduced pressure if it is connected to the tee
supplying the external line while the main gallery is showing a higher
pressure. The flow through an unrestricted external line may be enough
to reduce the oil pressure a bit at idle but at higher revs there should
not be a significant drop in pressure.
Richard
John Mitchell wrote:
> Hi Richard, I just received my engine back from the builder. It has
> your roller rockers, valve guides and seal, and the head cut for 9.5
> to 1 CR, GP2 cam. This is a street engine and was wondering if it's
> necessary to use an external oil feed for the rockers? Thanks in
> advance John Mitchell 76 TR6
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