If you do some research on oils for the Kent, you will find some useful information.
Here is a pretty good thread:
http://www.apexspeed.com/forums/show...light=oil+dyno
#1 ask your engine builder. It's worth it to invest in a phone call or an email.
Art Smith did some research on the dyno and found some interesting things.He found the oil temperature above 200F during operation gave the most significant improvement in power. He recommended the oil should be fully warmed before the car goes out on track.
He found that 0W-20 gave the best power when fully warmed. If you are running 20W-50 you are giving up significant power from parasitic drag.
He also advised to use his advice and 0W-20 at your own risk.
For Valvoline VR1 Synthetic:
http://www.valvoline.com/pdf/vr1_synthetic.pdfThe viscosity of 20W-50 is 20.8 centistokes at 100C (212F).
The viscosity of 5W-30 is 10.8 centistokes at 100C (212F).
Therefore 20W-50 synthetic has twice the viscosity than 5W-30 and greater parasitic drag on the rings and bearings.
For Valvoline Racing 10w-30 conventional:
http://www.valvoline.com/pdf/vr1_racing.pdf
The conventional oil is a little higher initial viscosity at 40C, but the same at 100C
Art did further work on the bottom end and shared it with the world if you are willing to read and put in some basic labor:
Power can be gained from careful attention to the inside of the block with the pan, windage trays, scapers and how the oil drains from the head and block into the pan. The same with improving vacuum in the crankcase.
http://www.apexspeed.com/forums/show...t=sump+scraper
Synthetic oils have a flatter viscosity vs. temperature curve, particularly in cold weather. Most oil companies publish their technical data if you are willing to look for it. They either have their own certified labs or they use one.
My own humble experience? I have no brand preference. I have been using several brands of synthetic 5W-30 race oil with at least 1000ppm of ZDDP. I don't use an oil cooler(I plan to install an oil/water cooler to get the oil up to temp). Oil temp after a race on a 100 deg day was always below 230F.
I got 60 hours of racing and test days with no sign of unusual wear on bearings, cam or tappets at 25 and 50 hour inspections. Unfortunately I exceeded the fatigue life of the crank from too many hours and too many overrevs.
Regards,
Dan