High Revs and GC/30-Weight Oils

[kapps]

I'm also a fan of GTX 20w-50 in my old Brit ('70 Lotus Europa). 80+psi of oil pressure when cold which drops down between 60 and 75 when hot. It's geared just about the same as DCG's MGB.

I've also heard VR-1 is a good oil. I may give it a shot in the future.

 

[Steve S]

Quote:

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Someone needs to call all the Nascar engine builders and let them know. No wonder they have so many failures...

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Do you think the failures are from 30 wt oil?.

 

[SmotalChaos]

i think ill start using 75w-90 gear oil in my engine now

 

[BMWDriver]

Someone told me the earth is flat, must be true!

 

[insomniac]

Quote:

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Someone told me the earth is flat, must be true!

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No, it's not...the don't-rev-high-if-on-30-weight-oil guy told me so.

 

[just_me]

A thin oil pumps better than a thick one at any given temperature. Yes, some thinner oils will break down or shear, but many wont. and in today's motors, 30 is nto a thin oil.

A thicker oil, at lower temperatures, will simply not be able to pump sufficiently to feed a rapidly spinning motor. A thinner oil will.

Of course, very demanding stresses adn temperatures *may* call for a thicker oil with higher resistance to shear, but that is truly an extreme circumstance (like running flat out, full throttle, for hours on a racetrack)

Grant

 

[Towel_Rail]

Originally Posted By: itb76
Quote:
my civic revs 4300rpm at 80mph, so i guess i have to use 15W-50 oil

LOL

I thought my VW was bad. 3300rpm @80mph. It really needs a sixth gear.


My VW tops out at 80 MPH @ 3900 RPM. In fourth!

 

[G-MAN]

Originally Posted By: insomniac
Someone told me that if you're on a "thin" oil (30-weight or less), never hold your revs above 3K RPM for like more than 15, 20 seconds.

Ridiculous, I believe...but...decided to put this out and see what you guys have to say.

Let's see...Formula 1 uses custom blended oils in the 20 to 30 weight range and those engines spend 90% of the race turning 10,000+ rpm. Guess the races must be extremely short for that theory to hold up.

 

[Saab9-3]

I thought they used straight 5w, or 10w as per Dr.Hass papers.

 

[G-MAN]

Originally Posted By: Saab9-3
I thought they used straight 5w, or 10w as per Dr.Hass papers.


I don't think so. I think the blends are typically in the 7.0 cSt to 9.0 cSt range.

 

[73 BGT]

Originally Posted By: BMWDriver
Someone told me the earth is flat, must be true!


If you've ever drivin across Nebraska in the winter......

 

[d00df00d]

My '96 M3 spends plenty of time above 3k -- as much as it can within reason on public roads -- and has seen nothing but 30wt for the past ~40k miles (BMW 5w-30, GC, Motul X-Max). My last UOA was pretty darn good.