[DeTomaso] Pure Power Oil Filters High Performance Motor Oil

[jderyke at aol.com]

In a message dated 12/18/09 3:52:54 PM, julian_kift at hotmail.com writes:

> On that a point worthy of note is that I understand installing a high 
> pressure spring in your oil pump can force a bypass filter into early or 
> constant bypass mode if pressure is too high. I do not know at what pressure a 
> std bypass valve is set to relieve at and suspect it may vary between 
> manufacturers.
> 
I think the stock Ford bypass spring is 70 psi, but Ford sells a 
high-pressure spring that opens the bypass at 100 psi. This, combined with a Wix 
filter with apparently defective threads and thick 20W50 oil allowed me to blow 
the filter clear off the block at 6500 rpms, half-emptying a10-qt oil pan & 
making me the least popular driver at that event- at least from the guys who 
then went out on track through 30 lbs of kitty litter and cement dust.
Another Nor-Cal owner ran that spring and found his hydraulic lifters 
floated at only 4800 rpms apparently due to the very high oil pressure. Replacing 
the 100-lb spring with a 'stock' one, the engine then could be revved to 
6800. Jacking oil pressures up with a spring or with a 'high-pressure/high 
volume' pump causes more problems that it solves IMHO. It loads the distributor 
drive gear pin much more as well.
With Chevy V-8s as in your Ultima, plugging the bypass port with a setscrew 
raises the oil pressures from 40 to about 60 psi, but if the filter plugs 
and doesn't have its own bypass, its possible to blow Chev filters off a 
block, too. My 2¢- J DeRyke (with a stock pump & spring in our 351-C)