Oil Viscosities And Oil Pressure

[John Galbreath Jr.]

Have a question figured somebody on the forum can answer.

In the Solo Buggy, I run 10w-40 oil. The engine is a GM Performance HT383.

http://www.chevrolet.com/performance/crate-engines/small-block-ht-383.html

I run low oil pressure at idle after beating on it and raising the temperature above 210 (normal 180). I have the Autometer's gauge warning light set at 15 PSI. In this condition it runs about 9 or 10 PSI. I do not want to lower the warning light from 15 PSI. I had rather boost oil pressure.

My question is, if I change viscosities, can I boost oil pressure above my 15 PSI threshhold. Looking at this picture of temperature verses viscosities.

 

[TBItoy]

Re:

What oil are you running (brand/type).
You need an oil with a higher viscosity index, not necessarily a higher viscosity

 

[zukimaster]

Put a bottle of Lucas in it! sounds like the bearings have some wear in them, classic symptoms of low oil pressure when hot.

 

[wont work]

Do you have an oil accumulator? If you did it would help you cycle 3 or more quarts through the motor helping keep its viscosity.
Going to assume you are running non synthetic oil. If you are I am about to go back to regular oil because when my motor gets to operation temp the oil pressure is lower with the synthetic.

 

[Mr. leafspring]

my 2 cents I had same problem I was running 10w-40 with lucas and went to 20w-50 with lucas and haven't seen under 20 psi . since.. some may disagree but like I said that's my 2 cents !!!!!

 

[John Galbreath Jr.]

Re:

What oil are you running (brand/type).
You need an oil with a higher viscosity index, not necessarily a higher viscosity

I run this Valvoline.

http://www.valvoline.com/products/consumer-products/motor-oil/conventional-motor-oil/1

It has a viscosity index of 151.

So if I need a higher index, be better off with 5-30 (index of 168) rather then 20-50 (index of 121).

 

[John Galbreath Jr.]

Do you have an oil accumulator? If you did it would help you cycle 3 or more quarts through the motor helping keep its viscosity.
Going to assume you are running non synthetic oil. If you are I am about to go back to regular oil because when my motor gets to operation temp the oil pressure is lower with the synthetic.

I do not on Solo Buggy which is the conversation. I do run one on the 38 Special. There is not a good place to mount on either. I am running regular Valvoline oil, not Synthetic.

 

[John Galbreath Jr.]

my 2 cents I had same problem I was running 10w-40 with lucas and went to 20w-50 with lucas and haven't seen under 20 psi . since.. some may disagree but like I said that's my 2 cents !!!!!

That is what I was thinking, but according to TBItoy, that would be going the wrong direction..Still confused.

 

[John Galbreath Jr.]

Put a bottle of Lucas in it! sounds like the bearings have some wear in them, classic symptoms of low oil pressure when hot.

May try that. According to their spec sheet, it does increase oil pressure.

Key Benefits

Increase oil life at least 50% longer
Reduces oil consumption
Eliminates dry starts
Raises oil pressure
Increases power and miles per gallon

http://lucasoil.com/products/engine-oil-additives/lucas-heavy-duty-oil-stabilizer

 

[TBItoy]

That is what I was thinking, but according to TBItoy, that would be going the wrong direction..Still confused.

May try that. According to their spec sheet, it does increase oil pressure.

Key Benefits

Increase oil life at least 50% longer bullshit salesman statement
Reduces oil consumption high viscosity base + some seal swelling additves
Eliminates dry starts no such thing as "dry starts", unless you've never had oil in the motor
Raises oil pressure high viscosity base oil...
Increases power and miles per gallon and once again, high viscosity base oil "might" help with blow by...

http://lucasoil.com/products/engine-oil-additives/lucas-heavy-duty-oil-stabilizer

I was saying if you wanted to stay with the same viscosity, you would need a higher viscosity index (holds closer tolerance to specified viscosity over a wider temp range)

If it were my buggy, I'd run a 20w-50 full synthetic racing oil...

Cheap insurance IMO, and with a buggy, you are not (generally) subjecting it to what is hardest on daily driven engines (soccer mom cold start gunning it from stop light to stop light for 5 miles, then shutting the engine off).



from a lubrication engineer/chemist stand point, adding additives like Lucas to your oil is a Band-Aid/last resort for mechanical failure. mainly because you don't know exactly what mixture you are ending up with.

Basically the lucas is a cocktail of the additives that are already in motor oil, just concentrated and put in a high viscosity base. With oil additves, "more" is not necessarily "better"
You end up with a soup of a higher unknown viscosity and chemistry... You could accomplish the same thing by adding a quart of 85w-140 gear oil to your engine.



You are better off spending a little more $ for a high quality oil up front.

 

[mac5005]

You may want to give this thread a read. Just came up over in nc4x4 a few weeks back. Tons of info, to make a long story short, I just switched oils to rotella t6 5w-40. I made the switch due to the higher zinc and phosphorus content, and it's half the price of royal purple.

http://www.jeepforum.com/forum/f8/why-use-diesel-oil-my-258-a-2898938/#/forumsite/20623/topics/2898938

 

[mac5005]

On another note, every engine builder and old guy I've ever talked to all said the same thing about oil pressure and volume. You need a minimum of 10 psi per 1000rpms hot or cold to keep the bearings happy.

 

[TBItoy]

You may want to give this thread a read. Just came up over in nc4x4 a few weeks back. Tons of info, to make a long story short, I just switched oils to rotella t6 5w-40. I made the switch due to the higher zinc and phosphorus content, and it's half the price of royal purple.

http://www.jeepforum.com/forum/f8/why-use-diesel-oil-my-258-a-2898938/#/forumsite/20623/topics/2898938

When running diesel oil in a gas motor, you still want to change it on "gas oil" intervals.

The TAN # will get high (oil will become overly acidic) if ran for long periods of time because of gasoline blow by vs diesel blow by (and yes, ALL engines have blow by)




Full synthetic 5w-40 diesel oil is an acceptable "high performance" gasoline oil substitute, but that is not what it is really formulated for...

I ran it in my 22re when I was racing ECORS.

 

[throttlejunkie]

I've dropped the oil out of heavy equipment for years, the ones we ran Lucas in came out a lot thicker, the ones we didn't, ran out like water. That was enough to prove Lucas to me. This was with engines getting throttled up and beat hard on average of 10-12 hrs a day. If you have an engine with some wear on it Lucas is a wonderful product.

 

[John Galbreath Jr.]

I was wrong on the oil put in last. It is Amsoil synthetic 10w-40. It has an index of 156.

http://www.amsoil.com/shop/by-product/motor-oil/gasoline/sae-10w-40-xl-extended-life-synthetic-motor-oil/?code=XLOQT-EA

Learned some about viscosities here. Did not even know W means Winter.

http://www.upmpg.com/tech_articles/motoroil_viscosity/

But, still confused. Go with Amsoil 20w-50 (index of 165).

http://www.amsoil.com/shop/by-product/motor-oil/gasoline/sae-20w-50-synthetic-premium-protection-motor-oil/?code=AROQT-EA

 

[Mortalis5509]

Re:

I run Rotella t6 in my gas motor, street bike, and diesel motor. Almost everything I have, an oil sample is sent off to Blackstone labs for oil life and a pile of other things they can tell. My truck up to 10k so far and wife car is up to 10k on oil change intervals.

Sounds like you need an accumulater as well. They can be set up for pre lube. Look for places under the dash, side rails, or over the engine.

 

[redneckengineered]

John, Mast recommends Rotella 15w-40 non-synthetic in all their hand built motors as well as stock motors running their cam and electronics (like the LY6 in the 38). That's good enough for me. I know your 383 is not an LS but I'd run that and be done with it. Personally 10psi hot doesn't bother me all that much considering that 383 is probably idling at 500rpm and IIRC that motor has been around for a minute right?

edit: One other thing, I noticed a slight increase in pressure in my motor when I went from an AC Delco filter to a Mobil 1 filter. They're like $12 but whatever

 

[zukimaster]

I love Rotella oil, its cheap and good! that's what I run in my boat! and a boat engine is always under lots of stress!

 

[John Galbreath Jr.]

John, Mast recommends Rotella 15w-40 non-synthetic in all their hand built motors as well as stock motors running their cam and electronics (like the LY6 in the 38). That's good enough for me. I know your 383 is not an LS but I'd run that and be done with it. Personally 10psi hot doesn't bother me all that much considering that 383 is probably idling at 500rpm and IIRC that motor has been around for a minute right?

edit: One other thing, I noticed a slight increase in pressure in my motor when I went from an AC Delco filter to a Mobil 1 filter. They're like $12 but whatever

I agree 10PSI at idle it not bad, but I hate the warning light. Bought the motor new June 13, 2007 for the Single Seater Buggy. But, it is only driven on weekends, and half the time it is going down hill.

Not sure how an oil filter could raise oil pressure, but it is only a few bucks more.

 

[TBItoy]

Re: Re: Oil Viscosities And Oil Pressure

I agree 10PSI at idle it not bad, but I hate the warning light. Bought the motor new June 13, 2007 for the Single Seater Buggy. But, it is only driven on weekends, and half the time it is going down hill.

Not sure how an oil filter could raise oil pressure, but it is only a few bucks more.

Anything that creates a restriction creates pressure. The Mobil 1 filter probably has a tighter media, therefore more back pressure.