In answering another thread I was thinking on something. I'm sure all of us here have heard of using oil flow restrictors in mechanical valvetrain engines of other makes ie. chevrolet race engines.
Since there are mechanical VW's could a high RPM VW engine benefit from a restrictor in the head to keep more oil flow to the main/rod/IM bearings in a high load/heat/RPM application ie. a really tuned out 1.6td? I imagine the required oil flow for a mech. VW head is really low as many old mech. VW's have or have had very poor oil pressure/flow due to badly worn IM shaft bearings that have been run for a long time and no damage to the valvetrain usually results. It may be a way to keep that high cold start oil pressure after it warms up, actually, why is it that it drops like that? I know that all VAG engines do it but why, it has to be something as other brands only drop a little pressure as they warm up.
I am just curious and since it is not widely used and documented, it is probably of little consequence.
Isn't it the loss of viscosity in the oil as it heats up that leads to the loss of oil pressure? It is thinner hot.
Castrol syntec 5w50 is your friend
I am aware of the visc. change with temperature, its just a wide swing in pressure from cold to hot.
Even my hydraulic 1.6 has a wide sweep of pressures at the head from hot to cold.
Cold could easily peg 80psi at the head.. when warm drops to near 13-14psi at hot idle.. little low, but its got 700,000+ kms on it
