20w-50 oil

ripmf666

Active member
Sep 20, 2006
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Wentzville Mo
the factory oil pressure gauge is accurate (it doesnt "lie" like some people might say the coolant temp gauge does) but its best to get an actual digital "number" reading with the tech 2 or efilive



You can not trust this reading. The Tech2 gets it's info from the same sensor as the factory gauge. If you want a true ready you will go old school and run a mech gauge from one of the oil ports on the block and have a aftermarket mech oil pressure gauge to read
 

duratothemax

<--- slippery roads
Aug 28, 2006
7,139
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Wyoming
I'm skeptical of this claim. Is this like seat of pants meter stuff. I fail to see how changing oil grades helps the turbo spool better. Enlighten me, please. No KB style breakdowns either. ;)

that was a complete joke. Of course changing oil isnt going to make it faster or help turbo spoolup. :p: Im surprised it took several posts for someone to catch on and comment on it. :D :joker:
 

duratothemax

<--- slippery roads
Aug 28, 2006
7,139
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Wyoming
I'm my humble opinion the LB7's have a better bottom end an I think that's why they hold better oil psi. IMO

"better bottom end"? like how? I completely disagree. If you have an LLY short block sitting next to an LB7 short block can you tell the difference? Because I sure cant....... :confused:

Unless its an early 01, you can tell those apart from 02-05 short blocks because they are missing an extra mounting boss on the side of the engine next to the block heater.
 
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wdino73

Member
Sep 25, 2009
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Versailles, Ky
"better bottom end"? like how? I completely disagree. If you have an LLY short block sitting next to an LB7 short block can you tell the difference? Because I sure cant....... :confused:

Unless its an early 01, you can tell those apart from 02-05 short blocks because they are missing an extra mounting boss on the side of the engine next to the block heater.



Easy big guy I said in my opinion, I thought that the lb7's bottom ends were strong then the lly's, easy
 

duratothemax

<--- slippery roads
Aug 28, 2006
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sorry I completely didnt mean it to sound like that. :) :eek::

no, LB7 short blocks are the same as LLY's. Seeing as the LLY came after the LB7 im not sure why GM would make it weaker... ;)
 

Diesel Pilot

Hat? Suitcase? 50 BMG?
Aug 9, 2006
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Pickerington, OH
that was a complete joke. Of course changing oil isnt going to make it faster or help turbo spoolup. :p: Im surprised it took several posts for someone to catch on and comment on it. :D :joker:

Damn Ben, that's the second time in a week you've got me with the sarcasm. I need to start paying more attention. :thumb:
 

wdino73

Member
Sep 25, 2009
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sorry I completely didnt mean it to sound like that. :) :eek::

no, LB7 short blocks are the same as LLY's. Seeing as the LLY came after the LB7 im not sure why GM would make it weaker... ;)


No worries Ben I was just given you a hard time, :thumb:
but I always thought the LB7 bottom end would hold more hp, so I just thought saying that it would hold more oil psi, but hey I've alot to learn, an I always enjoy your thread, no disrespect I was just funnin' with u.;)
 

sweetdiesel

That's better
Aug 6, 2006
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Thailand
"napa performance" generic-whatever 20w-50.

Run a good oil weather it be with good dispersants for water and diesel soot

or a good shear strenght our oil heats up a ton in the diesel and then breaks down! I bet if you ran better oil u would find it held up and gave u better pressure after long hauls or hard runs


Just my opinion
 

duratothemax

<--- slippery roads
Aug 28, 2006
7,139
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Wyoming
I would have run something better but it was the only "heavier than 15w-40" oil I could find right away. We have had a nasty heat streak the past week and I HAD to do something ASAP to at least get a couple more psi hot at idle and get rid of that ever so faint knock. Like I said it was 16 tops hot at idle and like 41-42 hot at 1800rpm. Just about as close to minimum allowable spec as you can get. :(

This heavier napa-whatever oil will at least hold me off and keep a couple more pounds of hot oil pressure in the engine until I order some good 20w-50 oil online.

couple guys from what Ive seen/read have good luck with that cenpeco (sp?) stuff so Ill order some tomorrow.

when I build another engine the first thing on the list is either an LML oil pump (at the least) or one of curtis's new oil pumps with the regulator built in. I dont want to mess around with the current aftermarket oil pump because my truck IS a daily driver and it will see 0* cold starts during the winter...
 

sweetdiesel

That's better
Aug 6, 2006
10,390
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Cen-pe-co is great oil I did a lot of tests on it at work

I wouldn't run a dpr oil pump again though may be different on a lly but not on a lb7 jmho
 

Mike_S

OOPS!
Nov 18, 2009
803
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Idaho
Run a good oil weather it be with good dispersants for water and diesel soot

or a good shear strenght our oil heats up a ton in the diesel and then breaks down! I bet if you ran better oil u would find it held up and gave u better pressure after long hauls or hard runs


Just my opinion

I bet it was good oil that he was running to begin with. For whatever reason, he has low oil pressure when the engine is at opperating tempreature. I'd be willing to venture a guess that no matter what brand the oil is, a 15w/40 oil is gonna be a 15w/40 oil no matter whos name is on the bottle. One brands addatives and dispersants may hang in there longer than another's, but they all start out as a 15w/40 oil.

no matter what, a 15w/40 oil will never (ever) produce more oil pressure than a 20w/50 oil given the same opperating conditions.
 

sweetdiesel

That's better
Aug 6, 2006
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I bet it was good oil that he was running to begin with. For whatever reason, he has low oil pressure when the engine is at opperating tempreature. I'd be willing to venture a guess that no matter what brand the oil is, a 15w/40 oil is gonna be a 15w/40 oil no matter whos name is on the bottle. One brands addatives and dispersants may hang in there longer than another's, but they all start out as a 15w/40 oil.

no matter what, a 15w/40 oil will never (ever) produce more oil pressure than a 20w/50 oil given the same opperating conditions.

who cares what they start at? Check the vis of your oil after pulling a trailer or making a pass at the track:eek:

if your looking for a good oil in a 20-50 try a bike shop if you want crap go to wall mart the choice is yours!
 

BoiseRob

Active member
Oct 12, 2007
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Ben,

Look for Mystik 15W-50 HDEO oil at a tractor supply or farm store.

Here's a link...

http://docs.mystiklubes.com/msds_pi/M20003.pdf

FWIW, I've been running Delo 10w30 since February with Schaeffer's 15w40 on the shelf waiting for the temps to get consistently around 100 degrees. It hit 100 yesterday but Boise's temps are dropping back down into low 80's by Friday. I will change out the 10w30 when it stays hot or if we take the trailer camping which will be sometime after July 4th...
 
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BoiseRob

Active member
Oct 12, 2007
392
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63
do they even make an oils that comes in 20w-50 that is CJ-4 rated?
AMSoil is the only brand i could find that did have that kind, but its also a synthetic.

Mystik's 15w50 has a Viscosity at 100°C, cSt of 19.2. FWIW, straight 50 weight has a Viscosity at 100°C, cSt of 20.5...
 
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Mike_S

OOPS!
Nov 18, 2009
803
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Idaho
who cares what they start at? Check the vis of your oil after pulling a trailer or making a pass at the track:eek:

Oh, you mean like after its hot? Yeah, all oil thins with heat...no matter what brand it is. Only thing that changes that significantly is changing the initial viscosity of the oil.

if your looking for a good oil in a 20-50 try a bike shop if you want crap go to wall mart the choice is yours!

I wouldn't run oil designed for a bike in my truck if someone paid me money and gave me the oil too. That oil is designed to be changed in very short intervals. The addatives do not last long atall.

...
 

THEFERMANATOR

LEGALLY INSANE
Feb 16, 2009
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ZEPHYRHILLS, FL
Geez, and I was getting a little concerned over my LB7 dropping down to 30 psi at a hot idle on a 100 degree day with 5W40 ROTELLA with a 600 idle(680 idle will hold right at 40 even hot idle). I guess my LB7 must be a fluke off as it holds some pretty high oil pressure no matter what oil I run or how hot out it is. Cold she slams right up to 70 at idle and drops down to 35 at idle when hot at 600 RPM's. After 1000 though she tends to hold 45-50, and even on a 100 degree day towing she will still go up to 65 or so when I get on it even with the 5W40 oil. 15W40 was even higher oil pressure, but she spins over MUCH better with 5W40.

Another thing to consider is changing brands of oil. I know when I build engines for customers(all gassers) I run 10W30 VALVOLINE for break-in then switch to 5W30 or 10W30 CASTROL GTX after a 500 mile break-in period. On every engine so far I have seen a noticeable increase in oil pressure going from the VALVOLINE to the CASTROL oil of the same viscosity. I know I used WAL-MART oil one time to flush out an engine in a JEEP that was ran as a submarine and it would only hold 5-7 PSI of pressure at idle, but when I dumped it out and went to the CASTROL it went right to 18-20 at idle. Also using STP oil treatment(the small blue bottle) will generally yield a 5-8 PSI increase in idle oil pressure on every engine I've used it in.
 
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