Oil pressure will vary even on a rebuilt engine
due to the fact that the oil pressure relief valve is normally never looked at on a rebuild .
Also depends on whether you have a much older engine with the separate ball , spring and seat .
These were often replced by the newer one piece cartridge type .
However , the success of the newer oil pressure relief valve was often dependant on how the bush/seat was removed from the block .
Sometimes the block bore was scored and this let oil past the sealing "
O " ring on the newer cartridge oil pressure relief valve ,
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On most of the engines used where the newer cartridge oil pressure relief valve was fitted as standard it is possible to nick the very thin sealing "
O " ring on insertion of the cartridge .
Slight wear/tension on the internal cartridge spring also comes into play between different cartidges .
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Tickover differences of 50 to 100 revs can also alter the reading .
If you have 40 to 50 psi at tickover keep a close eye on the reading at higher revs as you might blow the
connecting plastic tubes off {
if fitted }
Personally I do not fit the oil pressure gauge to any of my Reliants due to the chance that the tubes might blow and you loose the oil pressure .
I go by the electrical switch putting the light out .
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Right , I am away to bed now to dream of the Torrey Canyon
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