I am surprised to see that you made the modification to a cast iron pump. Beyond Glen's description the only online mentions of it I found involved the aluminum pump bodies of the later 4-cylinders.
Regardless, I understand what you are saying and that you didn't see a lot of improvement. The issue my 1500 is showing indicates that the block probably has excessive cam journal bearing clearance and the pump cannot deliver enough flow at low RPM to maintain "higher" pressures. The longer rotors of the 6-cylinder pump may provide increased volume (and therefore pressure) at low speed while a carefully adjusted relief valve should just return the excess oil to the sump when off idle. Will it be worth it? I may never know. If the oil pressure stays above 25 PSI or so in the spring and summer it probably isn't worth messing with.
Perhaps with the full race engines the pump blueprinting also involved selecting from multiple rotors and housings for minimal clearances. Lacking a stack of pump parts I am resigned to using the few parts I have at hand. I should mention that my pump clearances were checked and endfloat adjusted... my 1500 pump just isn't delivering enough at idle for the component clearances elsewhere in the engine.
Glen, the "noises" will indeed be separate threads if justified at all.
Doug L.
--Previous Message--
: Stock pump blueprinted worked fine in
: full race engines that saw 8500 rpm for
: years. I did try the GT6 pump mod and
: never saw a benefit. Whatever. Attached
: are pictures of that type of
: modification on an actual oil pump.
: Back to lurking...........
:
: http://public.fotki.com/jr2dad6888/oil-pump/11092014-002.html#media
:
: http://public.fotki.com/jr2dad6888/oil-pump/11092014-001.html
:
Responses