15% if that is what it truely is is only 1.8 lbs at idle and 4.5 at 2000 rpm. If that is what it is. Scratch my head in really wondering what's the purpose. I would truely check the results like bigsky did. If you are compelled to mod it, make sure what you did did do what you want. Harley enginners cold have done that if there was truelly a need or reason at no cost. One of my common used so called upgrades was a aftermarket spring, Harleys SE oil pump and cam plate with hydralic tensioners. The oil pressure on the hydralic tensioner on the inner shoe that still had the link chain went right thru that shoe in less then 20K.

The thing about cooking the oil on twin cams was a piece in Whicipeda on the enginering and developement of the TCs.

 

==============================================

" weather is hot, a stop lights, you will do a lot more damage with cooked oil. "

Well thats not true for all cases and here's why i say that.

It's when your running an oil cooler with twin thermostatically controlled elec cooling fans reducing oil temp up to 50deg f (like i have on my TC HD) that overheating the oil isnt an issue at all.

Sitting still in traffic @ lights in 95+ deg summer heat for 12-15mins oil temp max's at 235-238deg f which isnt an issue at all for quality semi blend or full syn motorcycle specific oil.

But prior to installing the oil cooler with twin elec cooling fans oil temp in same cond sitting still at lights for 12-15mins in 95+deg f summer heat oil temp would have been approx 285-290deg f on mt stock 09 FLHTCU w-96"TC.

BTW,with stock spring in oil pump on my stock 09 tc 96" oil pressure in summer heat went from 7-8psi @ idle & 35psi @ cruise (with no oil cooler) to now 17-18psi @ idle & 45-47psi @ cruise post installing oil cooler with twin therm cont cooling fans being the oily change/thing i did.

BTW,that 50deg f reduction in oil temp in summer heat not only inc hot oil pressure @ idle & cruise by 10-12 psi ,it also stopped detonation,stopped valve/lifter noise,motor now retains the pwr/trq/crisp throttle response it always lost in summer heat,hot restarts in summer heat like post fueling up are much easier/faster due to starter/battery/motor being less heat soaked,less heat is hitting riders,etc .

Thats because the oil in my HD's not being overheated/viscosity comprimised or sheered anymore due to the oil running 50deg f cooler.

and remember,when you cool oil 50deg f in summer heat that also means engine temp is aalso being reduced @ the same time too because the oil removes heat from the engine.

I also installed wards cooling fans that are designed to reduce heat in heads & upper cyls & thats it.

Installing those 2 cooling mods was some of the best money i have spent on the bike thus far that resulted in multiple positive improvements in engine perf & rider comfort every single minute & mile i am riding the bike especially when riding in temps of approx 75-80deg f & higher.

Happy motoring!

Scott