Oil

[whitea62.7t]

After reading , lanlubberstsea's post about and oil filter causing low oil pressure , and responses about him using 20w50 .
I wanted to know what the amazing engine builders on this forum use and recommend for Oil., brand and weight?
I have an 89 Mustang 5.0 that i run Castrol 5w50 in , due to the fact they were known for having weak oil rings  and it seems to use A LOT less oil running it
And an 04 Audi A6 2.7T with k04 turbo and build that i run Mobil 1 euro blend
 Sean

[Drew Pojedinec]

I'm not "expert enginer builder" but I've been in an engine or two
I run 5w30 royal purple in both of my engines (390 and 429)
I run Motorcraft FL1A filters in the 390 which is lower performance and FL1A HP in the 429.

390
cold idle: 40psi
hot idle: 18psi
5000rpms: 65psi

429
cold idle: 70psi
hot idle: 60psi
5000rpms: 80psi

[blykins]

Most of my stuff gets Valvoline VR1 non-synthetic 10W-30.  This depends on bearing clearances, the application (street, drag race, etc.) and your climate. 

[whitea62.7t]

I drag raced a 1968 cougar with a 390 , we put 352 heads on it that were cut for CJ valves
and i always ran Mobil 1 and Motorcraft filters
Miss that car

[jayb]

I like to use Valvoline VR-1 straight 30 or 40 weight for oil, and Mobil 1 oil filters.

[Jackal]

I've seen recommendations for 10w30, 10w40, straight 30, and either VR-1 or Rotella, or your favorite brand with zinc additive. Some say 5 quarts, some seem to say 6 qts. No question on the filter, I will use a Motorcraft FLA1.

Couple of questions, I assume 10w30 would be better for a tight motor and 10w40 for an older build? Is straight 30 more for the nostalgic motor head or valid reasoning?

Would one be better off running VR-1 (synth or non -synth) 10w30 by itself, or something like Motorcraft 10w30 synth-blend with a bottle of Lucas Oil zinc?  If adding zinc, is it 1 bottle + 5 or 6 qts. or do you pull the oil quantity down equivalent to the amount of zinc to be added?

[jayb]

Generally you want a heavier weight oil when you have larger bearing clearances, so heavier oil in an older engine makes sense.

I've been using straight weight oil in my higher HP engines because I'm not sure I trust the multi-viscosity oils ability to get to the higher viscosity level that is advertised.  After carefully measuring and setting bearing clearances, I want to be sure that the oil is at the viscosity I want.  Probably just me, though...

[fekbmax]

I second the straight weight in hi hp and hi rpm engines.  Even in street Fe's I always liked the straight 40.
A far cry from when I pop the hood on my 2010 mercury that calls for 5w20 .

[shady]

I just put a GM crate motor in my chev bucket van & gm recommends 10-30 or 10-40 for their hp motors. I thought 10-40 was antiquated. I guess not. While not a big GM fan, this is a 350 4 bolt, roller cam, all new complete sans water pump & intake for $2050 from jegs. how do they do it? In my old 352 I run 15-40 rotella & a shot of STP with a motorcraft filter.

[whitea62.7t]

OK , this maybe a dumb question to you veteran engine builders,
But why the high zinc content?
especially if you are using new modern blocks and heads

[Joe-JDC]

Zinc helps the lifters and camshaft from wearing each other in tappet configurations.  Roller camshafts don't require the high concentrations of zinc.  Joe-JDC.

[Joe-JDC]

After reading , lanlubberstsea's post about and oil filter causing low oil pressure , and responses about him using 20w50 .
I wanted to know what the amazing engine builders on this forum use and recommend for Oil., brand and weight?
I have an 89 Mustang 5.0 that i run Castrol 5w50 in , due to the fact they were known for having weak oil rings  and it seems to use A LOT less oil running it
And an 04 Audi A6 2.7T with k04 turbo and build that i run Mobil 1 euro blend
 Sean

I don't know where you have heard that 5.0s have weak oil rings, for they will sometimes go over 200,000 miles without a re-ring, and don't use oil.  I have been building and racing 5.0 engines since '86, and I have never heard of weak oil rings in the 5.0.  Joe-JDC

[Nightmist66]

I just put a GM crate motor in my chev bucket van & gm recommends 10-30 or 10-40 for their hp motors. I thought 10-40 was antiquated. I guess not. While not a big GM fan, this is a 350 4 bolt, roller cam, all new complete sans water pump & intake for $2050 from jegs. how do they do it? In my old 352 I run 15-40 rotella & a shot of STP with a motorcraft filter.

Unless the clearances are huge, I can't see why you would need that combo unless it is just your preference. That must be like molasses, lol. I can't stand STP or Lucas, it's just too thick IMO.

[shady]

lotsa miles & the Scientifically Treated Petroleum has lotsa zinc. b4 the 62 I only used stp for engine building & the occasional oil hogs. BTW the late 80's 5.0 used low tension rings that were kinda oil hogs from new. ford would re-ring them for you if they consumed more than a quart in 500 miles. they ran good & they ran forever & by the time you had a 100k on them they usually quit using oil. I had a 90 5.0 lx bought new & it never used oil so they must have been redesigned by then, but 88s & 89s were notorious oil users.

[whitea62.7t]

Mine is an 89 140k ordered it new , always ran castrol syntec 5w50 never had an oil use issue .
Buddy of mine had the same exact car and used a qt every 1k miles