> I'd be worried that such a mod might lower your oil pressure. Maybe it
> wouldn't be by much, but I'd be inclined to uprate the relief spring in your
> oil pump (in the TR7, this takes you from 60 PSI to 80 PSI), at the same
> time. In fact, the oil pressure upgrade alone should improve lubrication of
> the rockers.
Up-rating the relief spring will only effect the maximum permissible
for what you filter, and other components can stand. The DPO modified
valve in my car, and I had a Major oil filter blow-out. I was asking a
he could see any leaks, he had a look at the filter, and it blew off the
oil was splurged all over the place. I stopped the engine pretty quick.
The relief valve is only used when the engine is cold, and the oil is
thus can't get through all the oil ways so fast, so you get a back
the engine is warm, the oil can get through easily, so you can channel
all the oil
through the oil ways, and not use the relief valve. The oil pressure in
system is controlled by several factors, ultimately the back pressure
the oil ways in the system. Then the efficiency of the pump, and last
which dictates the MAXIMUM pressure, not the normal.
The amount of oil flowing through the system is dictated by the size of
and the pressure. Put the pressure up, and you get more oil flowing.
Put the size
of the output up but maintain the pressure and you get more oil
flowing. Put the
size of the output up, and keep the flow the same and you get less
The flow is dictated by the pump, which just raises the pressure until
of oil it can cope with is flowing through the system. So to get the
up you need a pump that can cope with both the flow and the pressure,
original one in the original condition, or a higher flow one in good
you add something that requires higher flow.
Sorry it's a bit long and rabbley, I could cut it too half the length if
Yellow '79 spit wired by a trained marmot