Worried About Oil Pressure ... Thats Too High? But Thinks It Low?

[Grumpy]

Hi all.I have a `65 Chevrolet Impala.I brought it with a 283 and turbo 350 trans in it and running well.I had the trans serviced and the shop found lots of plastic looking strips and stuff in the pan?? Put it back together and i got a quote to fix.Too costly. I got a performance 350 turbo trans ex USA. Put it in with a good friend that has a workshop and a very fussy work ethic.Couple of years goes by and strange oil pressure,pull the engine pan and the thrust surface badly worn on the rear crank journal.We put in a re-built 327 that we put together.
Ground the crank,new rings gaskets etc...2 years on and i have noticed my oil pressure has dropped when hot and when sitting idling in gear the oil pressure drops to 25-30 pounds-out of gear 50 pounds! Long story sorry! Is my crank being eaten? Can a transmission cause this again.We were very careful to set the torque convertor clearance!I even had a transmission shop check the clearance!
I am using a Autometer electric oil pressure gauge. Thank you for any input before i pull the engine pan!We put in a High pressure or volume pump.Can`t remember!! I am using 10-40 weight oil.Just worried that it has suddenly dropped that amount! Hot idle usually 50psi and 60mph is about 70psi...

your oil pressure is a bit too HIGH, to be ideal, and that does nothing to reduce wear ,
it should be no more than 30-35 psi at idle and 45-55 psi at cruise speed (60-70 mph).
Id suggest use of 10w30 weight synthetic oil, as the change to a thinner viscosity may resolve the issue,
and it looks like having a high pressure or high volume oil pump is not required.
all the higher oil pressure and thicker viscosity oil does is increase wear on the distributor and oil pump drive gear and cam gear interface,
thinner oil flows faster absorbing heat and transferring heat more effectively away from moving surfaces like rings and bearings.
a sudden drop in oil pressure might indicate a problem, like a bearing wear issue
,bad oil pressure sensor, or gauge, defective oil filter,
or oil passage plug coming loose but you certainly still have more than adequate oil pressure,
still sudden changes warrant close inspection to locate the cause/
Id start with an oil change to 10w30 with a new higher quality oil filter
Id also cut open and inspect the existing oil filter
an oil pump pick-up coming loose or a defective oil filter are suspect but not the only potential issues
http://www.magnet4sale.com/n42-3od-x-1id-x-1-2-neodymium-rare-earth-ring-magnet/

change the oil, and filter, and slap a big magnet on the base of the oil filter
http://www.magnet4sale.com/n42-3od-x-1id-x-1-2-neodymium-rare-earth-ring-magnet/

and a couple high heat tolerant magnets,
that of course does nearly nothing, for you,
if you insist on purchasing their low price line of cheap oil .
vs selecting the more expensive and significantly better made,
but more costly product line
obviously buying an oil filter can opener tool, and doing some close personal inspection of what your dealing with won,t hurt.
http://www.summitracing.com/parts/sum-900510/overview/
http://www.homedepot.com/s/paint+filter?NCNI-5
almost any auto paint store and most hardware stores sell these disposable throw away paint strainer filters , that cost about 20-35 cents each, or a bit less in bulk packs, honestly I don,t see why most guys don,t invest the dollar it takes for a magnet and a couple filters

heres a helpful diagnostic tool,(the oil filter cutter pictured below) and yes I still cut open the oil filters and inspect the filter element on my cars oil filter [/color]
http://garage.grumpysperformance.co...king-how-other-people-might.11959/#post-56957

http://www.summitracing.com/parts/pro-66490/overview/

http://garage.grumpysperformance.com/index.php?threads/thrust-bearing-face-wear.15017/

http://garage.grumpysperformance.co...haft-thrust-bearing-trashed-in-1-2-hour.5141/

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

http://garage.grumpysperformance.com/index.php?threads/oil-filters.11189/#post-54673

http://garage.grumpysperformance.co...ilter-you-sellect-does-make-a-differance.117/

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

http://garage.grumpysperformance.com/index.php?threads/installing-an-oil-pump-pick-up-tube.1800/

High volume Melling pump in my warmed over hydraulic valves SBC. Hot idle around 20#, 45-50 at 2,000. 10/40 high mileage Valvoline.

that simply means your engines clearances are larger allowing more oil flow with less resistance,
GAUGE PRESSURE simply is a measure of RESISTANCE to rapid OIL FLOW volume

keep[ in mind your oil temp should generally be in the 180f-250f range, ideally 180f-215f

 

[Grumpy]

http://www.motorchecklab.com/get-my...tCBSL-FiIhoy2BALHZNeQoqLbzTDF1YEaAvV6EALw_wcB

http://www.motorchecklab.com/engine-oil-analysis-testing-kit/

btw you can send samples of oil (drain it hot and don,t pour out of oil filter)
to recognized analysts, and for a moderate charge they measure metallic content,
and oil condition, acids, ash dirt, etc.
aluminum=piston wear
Babbitt & copper = bearing wear
iron = rings, bore, valve,s rocker etc.

$30 to get the oil looked at may sound high,
but its much cheaper than pulling the engine apart and re-assembling it,
if you only suspect something might be wrong and you've had no other issues or noises
personally ID replace the oil and use a good oil filter and get a sample of oil analyzed
before you drive the car much if any further if you suspect issues, or before you pull it all apart
but if your obviously going to need a refresh/rebuild, well then dive in,
learn a few things along the way,
and take accurate measurements visually inspect, all components,
replace what you think needs replacing,
and youll feel much better after youve had it rebuilt.
even if your wallet won,t