what oil again

[grumpyvette]

Greetings All:
On my 40 over 350 engine, oil pressure great when starting up. After warmup, pressure falls. Here is my question: Currently have 10-W30 oil in motor. Due to change. Can I move up to a 15-40 without any ill effects to engine and will that help a bit maintaining oil pressure? Thought I read that somewhere here but not sure where? Looking to get through till Winter rebuild.
Thanks in advance for your help with this question, look forward to your replies.
Willow

theres a great deal of info posted on this subject on this site , a couple hours spent reading and taking a few notes would be helpful .
http://garage.grumpysperformance.com/index.php?forums/oil-and-lube-systems.54/
,its the quality of the oil, its additives and formulation that will provide most of the lubrication,protection to the moving surfaces and its the viscosity that provides the resistance to flow through the bearing clearances, its that resistance to flow that's being read as BACK pressure or oil pressure on your gauge, thinner oils like 10w30 tend to pump faster and cool better with the higher flow rates , and because most wear in any engine occurs during start-up before pressurized oil flow can force a protective film between moving surfaces the automotive manufacturers have, along with the conversion to roller lifter based valve trains, slowly graduated to the thinner and lower viscosity oils,because they realize the benefits.
As long as you have at least 15-20 psi oil pressure at idle once the cars up to full operational temps (generally 180f oil temps) youll be better off with the thinner synthetic oils that have a higher heat tolerance in many engines

http://garage.grumpysperformance.com/index.php?threads/which-oil-what-viscosity.1334/

http://garage.grumpysperformance.com/index.php?threads/basic-info-on-your-v8-lube-system.52/

https://540ratblog.wordpress.com/

http://garage.grumpysperformance.com/index.php?threads/oil-system-mods-that-help.2187/