[Gach]

Originally Posted by 64speed

Only reason I am running 20/50 is builder said to. I am not married to any particular weight I just don’t want a failure because the damn filter exploded or something. I am using VR-1 or Lucas whatever I can find.

Thats what I figured.

[Gach]

Originally Posted by TB1

"it get to at least 100 degrees before moving or giving it any RPM it puts the high pressure alert on the DD RTX gauges and says I have over 100 pounds." this is a built in safety of the Dakota digital gauge set up, It states in the instructions that the transducers are rated for 100 PSI and the oil filter should handle way more than 100 psi before it bursts. As for the 20W-50 oil run what you feel will work best for the season.

Good information, didn’t realize that on the DD RTX

[Steve C.]

This thread reminded me of a conversation I had with a Valvoline Tech Rep.
At the time I was using their 10W-30 VR1 full synthetic racing oil.
He told me with clearances under .0025" they did not recommend the use of 20w-50 oil.

And somewhat related. When I was dealing with Mark at Luhn Performance regarding his custom built oil pumps
he told me that he had conversations with both Mahle and Dura-Bond engineers and he mentioned they tend to shy away from 20W-50 oil in street cars.
They would prefer 10W30 or 10W40. At the time I did not ask Mark and he did not offer a specific reason why, and I don't remember if it was related to bearing clearances or piston rings, or both.
It was just a passing comment made during a conversation regarding what weight oil I was using.

.
.

[chiphead]

There is some real world engineering that provides some insight. Modern cars have gone to thin rings and very tight tolerances, and very light oil. The 1.5/1.5/3mm LS ring pack has become a very popular one for performance work. Those are usually used with 5W20 to 5W30. Those oil rings are going to like the thinner oil, they're going to have to work harder to control 20W50.

So its not just the bearing clearances, the skirt to wall and ring pack also dictate what oil the motor will really be happy with. For the motor I built, I used the LS ring pack, .0025 main, .0021" rod, .0035" skirt, HR cam with lifter bore mod, oil pump set for 70 PSI with 10W30 oil. 7QT milodon pan and windage tray. So the whole setup is going to be happy with 10W30-10W40 oil.

1/16" high tension rings and looser bearings may like 20W50, but I'd still start it on 10W40 and see how it maintained pressures and controlled the oil.

[64speed]

I was using 5 quarts of VR1 and a quart of Lucas stabilizer but I am gonna run the 10/30 straight and see what happens

[Dragncar]

Shaeffers 10-30 7000 oil is on sale on Amazon.
9.75 $ a quart.
About as good a oil as you will ever find. Lots of folks swear by this stuff. Plenty saying their engine sounds quieter and gets a little better MPG.
Shaeffers is Americas oldest oil company. They do not recommend any additives at all. Their oil already has Micron Molly in it. Its kinda sticky like Lucas just like it is.
This is what I will run. My engine still has break in 10-30 in it right now.

https://www.amazon.com/Schaeffer-Man...s%2C209&sr=8-1

[steve25]

Sorry, I was wrong.

Top fuel cars run 70w oil with a special thickener .

[Kenth]

The how´s and why´s choosing the correct viskosity.

Don´t mind the Corvair, replace with any engine if you like.

https://www.widman.biz/uploads/Corvair_oil.pdf

https://www.widman.biz/Corvair/English/Links/Oil.html

[78w72]

Originally Posted by Kenth

The how´s and why´s choosing the correct viskosity.

Don´t mind the Corvair, replace with any engine if you like.

https://www.widman.biz/uploads/Corvair_oil.pdf

https://www.widman.biz/Corvair/English/Links/Oil.html

Very good articles, mentions why not to use too thick of an oil that causes more wear at start up & until the engine is at operating temp. Plus very good info on zddp and base stock oils too... too much zddp (above ~1300-1400ppm) like all the "hot rod" & racing oils actually cause more wear & deposits.

Without knowing the clearances of how an engine was built there is really no way to say what oil it needs, most builders will suggest an oil weight that provides adequate pressures for the engines use & operating situations, and most builders wont build a "street engine" to loose race type clearances. Didnt mean to start a "chit storm" my initial question to the OP was why he was using 20/50, if the builder said to use it thats fine, but the psi the engine runs at shows its doesnt need that thick of oil and as the articles posted say, too thick of oil has no benefit. Neither does crazy amounts of zddp some guys use.

Hope the 10/30 drops the psi to a more acceptable level.

[jhein]

Originally Posted by Kenth

The how´s and why´s choosing the correct viskosity.

Don´t mind the Corvair, replace with any engine if you like.

https://www.widman.biz/uploads/Corvair_oil.pdf

https://www.widman.biz/Corvair/English/Links/Oil.html

Excellent information. Thanks for posting that.

[Gach]

I would lose the quart of Lucas. Totally unnecessary when and if you go back to VR-1
20-50.

[geeteeohguy]

Originally Posted by Kenth

The how´s and why´s choosing the correct viskosity.

Don´t mind the Corvair, replace with any engine if you like.

https://www.widman.biz/uploads/Corvair_oil.pdf

https://www.widman.biz/Corvair/English/Links/Oil.html

Thanks, Kenth! This is one of the most comprehensive oil articles I've read in the past 25 years. Great stuff here.

[scott70]

Been running 15w 40 in all my pontiac stuff since the 80s. Right now I run cenpeco 15w 40. Always good pressure.

[Jay S]

Originally Posted by 64speed

I was using 5 quarts of VR1 and a quart of Lucas stabilizer but I am gonna run the 10/30 straight and see what happens

Which VR1 are you running, racing or full synthetic?

My guess…Just switching to a VR1 10w30 racing from a VR1 20w50 racing will change it probably 20 lbs cold @40*F, and 5 to 10 once hot. Valvoline says you can mix them also, a 50/50 mix would be like a 15w40, a 50/50 mix would cut those numbers in half. With the Lucus it could change more, maybe 30 cold and still 5 to 10 hot. Lucus HD stabilizer will add quite a bit of cold pressure. Lucus HD stabilizer is designed to keep the oil from thinning out at higher temps, it works opposite on cold temps. It has it’s place, cold temp start ups with thicker oils and low Viscosity index’s are not ideal at all. I think the index rating for Lucus HD stabilizer is down around 100 to 110, very thick when cold, but does not thin as much when hot. The VR1 20W50 racing Viscosity index is in the 120s, also very thick cold. VR1 10w30 racing, VR1 10w30 synthetic and VR1 20w50 full synthetic all have an index rating of about 150, and work a lot better for cold start ups. Fwiw

[grivera]

Originally Posted by Dragncar

Shaeffers 10-30 7000 oil is on sale on Amazon.
9.75 $ a quart.
About as good a oil as you will ever find. Lots of folks swear by this stuff. Plenty saying their engine sounds quieter and gets a little better MPG.
Shaeffers is Americas oldest oil company. They do not recommend any additives at all. Their oil already has Micron Molly in it. Its kinda sticky like Lucas just like it is.
This is what I will run. My engine still has break in 10-30 in it right now.

https://www.amazon.com/Schaeffer-Man...s%2C209&sr=8-1

I know it’s not your testimonial -

I imagine it’s very difficult to measure an increase in fuel mileage from an oil brand.

[64speed]

I put the 10w30 in and it dropped 20 PSI cold and about 5-10 hot. Great trade off cause now I don’t have to wait 2 days to drive off cold till it warms up.

[Gach]

Originally Posted by 64speed

I put the 10w30 in and it dropped 20 PSI cold and about 5-10 hot. Great trade off cause now I don’t have to wait 2 days to drive off cold till it warms up.

As long as its VR1 which has a additive that keeps a Coating on moving parts.

[Dragncar]

Originally Posted by grivera

I know it’s not your testimonial -

I imagine it’s very difficult to measure an increase in fuel mileage from an oil brand.

I get it. Hard to measure.
I am putting it in my Tundra and kind of doubt the computer is going to tell me of a MPG increase.
My High Port stroker will be getting it too.
They are a very interesting oil company for sure. 175 years in the business, longer than anyone else and family owned.
No corporate nonsense.
You can call them up and talk directly to their tech folks.

[78w72]

Originally Posted by Gach

As long as its VR1 which has a additive that keeps a Coating on moving parts.

Which additive is that? Do other oils have this additive or only VR1??

[Gach]

Originally Posted by 78w72

Which additive is that? Do other oils have this additive or only VR1??

Its been #1 racing oil sold, for years and why so many engine builder’s recommended it…. has zinc and no detergents. Anti foaming agent. I’m probably not going do a good job on explaining it, which would leave the door open for debate, this guy is and engine oil expert. I’ve been using it for years. Here’s the link.

https://youtu.be/W48nygk1mlc?si=_zLpzlFfMyxQJiNS