Sorry dude oil pressure just doesn't work how you think it does. You think its a closed loop system but in fact it is not. OIl pressure is measure at the beginning of the run not the end, so you wouldn't be warned that cylinders are being starved of oil by the pressure dropping. What usually makes the pressure drop is a low oil level. Well heres some links for the benefit of people interested in learning something. http://blog.mechguru.com/machine-design/open-loop-vs-closed-loop-hydraulic-system/ http://en.wikipedia.org/wiki/Oil_pump_(internal_combustion_engine) http://www.machinerylubrication.com/Read/532/around-around-where-oil-goes-in-your-engine (this one actually explains at one point how an engine gets oil starved)
Duuhhh.... I know it's not a loop and dependent on engine, the pressure point can be near the pump(most Ford V8) somewhere in the middle(most inline 6cyl or the old Y block Ford V8) or even at the end(Cleveland V8 and many of the GM engines)... Anyway if you think a engine is going to loose all its oil pressure at say 40psi from the pump to end of the last gallery(maybe 8-10 ft of passages) you really are uninformed...
Good advice there ^. I run 2 oil weight spec's every year dependent on temps and engine design/operation parameters. Thicker for the summer.. thinner for the winter based on the fact that I don't actually prefer to increase startup wear.. I spin my motors every little chance I get(stock or not).. and mileage can be improved slightly by not going overboard with viscosity. I use conventional oil on cheaper.. "I could care less" motors(unless they burn oil in which case I usually run synthetic and hotter plugs).. and synthetic on just about everything that I want to last me 2 lifetimes.. small equipment included. The beauty of synthetic is that I get to run a slightly thinner viscosity while still managing the same film schear strength.. as long as the oil pressure variance stays acceptable. As a rule.. I also run slightly thicker viscosities as the miles start to add up and extra part clearances start to drop oil pressures and/or increases noise over the years. IMHO... choosing oil simply by viscosity range is tougher and more misleading than ever before simply because a thicker oil can actually have less protective(and cleaning) qualities than a thinner one in many cases. And to make matters worse.. it only robs you of power and mileage in the process. So, while we all might like to believe that our motors need racing quality oils?.. it's simply not true and many of those so called superior oils actually break down quicker than another supposedly inferior oil when used in your grocery getter. It's all in the additive packages these days and viscosity has definitely become the minor partner there. PS. also keep in mind that the factory spec's were created by testing the oils that were available at that particular time so could only really ever be used for general rules by todays standards. Driving style will also have an impact as well if the RPM's are kept higher more often and for longer periods of time(such as aftermarket gear ratios, manual shifting, and lead foots would incur).
We can run cooking oil in our engines? The little banter I see on this sight is ok. No different then bench racing at the track.....just dont forget to show each other a little respect
I changed mine tonight been running 10w40 trying to get some better fuel milage but tonight went back to 20w50 with a quart of 5w30 gain of 15 psi at idle oil pressure and 20 at road speeds just something to consider my engine is pretty healthy as far as condition with 130k
In my 200 I6 I have always run straight 40wt. oh...diesel oils have more sulphur but are fine if not better than others.. My choice is Chevron Delo 400 40 Wt. Delo 100 40 Wt I use in my crude Perkins diesel, and all Detroit 2 stroke diesels (they carbon up with Delo 400) Delo 400 in modern diesels. Shell Rotella is the same as Delo 400 (chevron) Multi grades break down faster than straight weight oils.. I might use a multi weight if I lived were it froze at night, but I'm in So Cal not the frozen boonies. What I dont get about synthetics, and maybe someone knows; how are synthetics ok to leave in so long when the oil gets so dirty after a year?? I understand they dont break down so fast but what about the dirty oil??? The filter doesnt get everything.
The main thing the filter is there for is to catch large debris that would cause major turbulence and eventual blockage, then theres usually a magnet in the pan to catch large metal fragmentation or mild grind-off. Usually the debris that gets left is small enough to not matter. Also you are supposed to change the filter between oil changes.
The color of the oil isn't really important, the question is how much of the protective additive pack remains... Only real way to know is have a used oil analysis performed, which is going to cost approx same as a 5qt oil change(assuming you buy it on sale)... If your engine dirties the synthetic quicker than std oils, it probably has some sludge built up that was left behind from the older oils that's now being cleaned... Generally with good ring seal(not necessarily a '70s engine's virtue), synthetic oil can remain in a engine two or more years (this assumes a limited use of maybe 3-4K per year), but only if the engine is fully warmed each time(at least 20-30 min)... This will remove water vapor that form especially in colder weather... If your engine has any leaks, it's possible they may increase with synthetics, Valvoline used to recommend against synthetic in older engines...
oil use I use 15W-40 in my 70 maverick 200ci I6.Yes it is for diesels but works fine for gas cars too.The Key is the oil grade on oil containers most cars needlike a SG grade, diesel engines need a higher grade like SJ so that the diesel fuel doesn't break it down so quickly. The higher grade in a gas car works great.
