[Richie Hoffman]

I must be wrong we run 20/50 in everything haven't had any problems yet.

[1972RedGTO]

My 400 is exactly the same. 30 to 40 at idle, 80 on the highway.

[Cliff R]

About all the 80lb oil pump is going to do for you is to rob some power from the engine and put additional stress on the cam gear, distributor gear, and timing set.

More time should be spent by the engine builder to make sure the clearances are correct, and that you take steps to keep the oil pick-up tube covered at all times (get a better oil pan).

Even on really high HP applications we use the stock Melling pump with 60lb spring in it, zero issues to date at any power level, even full race stuff pushing some of these heavy cars into the 9's at the track year after year after year.

The Pontiac oiling system is excellent, or at least good enough for these engines w/o any additional help, and there is no need for more pressure considering the film strength of modern lubricants.....IMHO......Cliff

[78w72]

i agree with cliff & others that say too thick of oil is not good for an engine, high oil psi does not mean it is lubricating better. flow = lubrication or an oils ability to keep parts seperated by a film, & flow increases cooling. pressure at the bearing entrance does not equal flow. 20/50 oil is usualy used for all out race engines with bigger bearing clearances that allow that oil to flow properly. street engines, which the majority of these cars here have, are not built like a race engine, bearing clearances are on the tighter side, useing 20/50 oil in your street engine is just causing extra stress on cam/dist gears & oil pump drives but more important is causing more wear especially at start up & robbing a little power.

having 40psi at hot idle is simply not needed, general rule of thumb is 10psi for every 1000 rpm. why would you want or think you need more psi than that? more psi is not better in this case. the most important thing for oil to do is to lubricate & cool the engine & it does that by flow. more flow= more lubrication & cooling... a thinner oil, within reason, is how you get more flow. psi does not = flow. period.

i love reading these oil threads, so many misonceptions & flat out misunderstandings about things like zddp, oil weight, psi, etc etc. proper oil weight, as mentioned by a few people above, is dictated by bearing clearances & pressures when running, not what someone tells you without taking in to account the engines purpose or the climate its operated in. just because a "mechanic" or anyone says you need to run this oil or that weight because thats what his grand daddy told him 40 years ago does not mean its true. & if someone says use 20/50 oil for a street car, regardless of the engines specs or climate the engine operates in, they are probably just a little out of touch on todays oils & what different engines need.

butler builds all kinds of engines from 400hp street engines to 1000hp+ race only engines, i highly doubt they all need 20/50 oil... i have a butler stroker kit in my 500+hp STREET engine, my local builder who did the short block builds all kinds of engines from 350hp street engines to 1500+hp blower engines, from drag race cars to truck pulling & circle track & is one of the most reputable engine shops in the area... funny he suggests 10/30 oil for my engine, & only uses thicker oils in dedicated race applications. he must be crazy!

save the thick 20/50 oil for race applications & use a more appropriate thinner oil for your street car. a 400hp engine driven on the street is not a drag race engine & does not need race only oil & 40psi at idle.

[old66tiger]

In the article posted, butler claims "the amount of time it takes pressure to climb to 60 psi or more can put the bearings at risk on a quick-revving, high-performance engine.".

FWIW...One of the reasons Ferrari and other fast revving engines use lighter oil. 0W-40 is gaining a ton of traction. Flows like a banchi when cold and has the 40 weight properties when warm. I am a huge fan of synthetics. More consistent oil pressure across the board.

Sent from my LG-US996 using Tapatalk

[JSPONT]

Unless you put together your own engine, own dial bore gauges and know every clearance in your engine, don't just guess and put any old oil in. Listen to the builder.
That being said not all 10-30 20-50 5-40have the same pour values either. 4 different 20-50 oils by different manufacturers can have a different pour value, which will alsoeffect how it gets thru the motor cold.
Do what works and has been working for ya. my .02

[Formulajones]

Originally Posted by JSPONT

Unless you put together your own engine, own dial bore gauges and know every clearance in your engine, don't just guess and put any old oil in. Listen to the builder.
That being said not all 10-30 20-50 5-40have the same pour values either. 4 different 20-50 oils by different manufacturers can have a different pour value, which will alsoeffect how it gets thru the motor cold.Do what works and has been working for ya. my .02

Yep I mentioned that. Seems people still stick to the old 20w-50 is too thick scenario without looking at the oil properties and additive packages. They've come a long way since the 1960's.

When I break an engine in I see the same thing and just went through this in the last couple weeks with a Pontiac engine. When I broke my engine in, cam run in etc...., I did it on 10w-30 break in oil. It still had 40 psi hot idle oil pressure. I changed it to a 15w-40 with a bottle of EOS for some more run in time on the street. Oil pressure still the same. When I switched to 20w-50 Amsoil synthetic, the oil pressure doesn't change.
Quite frankly, even my engines here with stock oil pumps have a hot idle oil pressure readings of at least 30-35 psi. I've never had any engine idle hot with 10psi or less unless it had an internal problem that needed a remedy, lol. Usually the culprit was worn cam bearings, or the engine was just flat worn out. They will run without issues like that, because I've done it, but I'm not going to sit here and tell someone it's okay or it's normal, because it's not. There is an underlying issue as to why that's happening.