69 N.O.X. RATT

Probably good stuff, thinking of using it in my 572, Mountainmotor ?

gerry72

Racing oils do not perform any better than non-racing oils. What makes an oil suitable for racing is that they can lubricate through racing fuel dilutions (read that as alcohol or nitro) better than street oils.

Why would you use such a heavy oil anyway? A 10W-40 is about the highest you would want to use unless you have very, very loose bearing clearances. And the 10 weight will give you better cold flow.

verskel

:iagree: .....I'm a big fan of Mobil 1. I'd go pure synthetic after the rings seat to provide max. protection to that awesome power plant ! - just my 0.02 cents. :D

page62

:iagree: These guys are telling it right! GM has recommended in Vettes for several years now. And Mercedes uses it so they can get away with 7500-mile service intervals. Racing oils are meant for one purpose: go 500 miles (or whatever) at top rpms -- then change the oil for the next race! :yesnod:

69 N.O.X. RATT

I think you guys are right for about 99% of the motors out there, but this will be a 1400 hp heavy nitrous 572, with a cam that will put over 700#'s of pressure on the lifters, cam, etc. The main component of protecting a motor like this is the level of zinc in the oil (as I understand it)

I ran full synthetic in my last solid rolller 454 with great results.

As far as the weight of the oil I am open to suggestions, I normally heat the oil before I start the car anyway.

gerry72

Well if that's how you see it then you should only use motorcycle oil (BMW oil preferred) since they have the high zinc levels you seem to feel you need.

verskel

The heavier weight won't help you. A mid-weight oil (10W40) has a better flow rate to keep all your parts coated & happy. As for the 700 #'s of pressure.........that's not the issue. What peak RPM's will you be turning to produce all this anticipated 'heat' ??? ....if it's more than 10,000 then you'll need the ZINC....if not ~ I'd still lean towards a more standard oil type. :yesnod:

Look at it this way.....a 1400hp 572 is no different than a 850hp small block 350. ;)


[Modified by verskel, 4:00 PM 3/12/2004]

Paul L

We may be into overkill here. A new Z06 uses Mobil 1 10W-30. What more is really needed?

Desertdawg

Why can't you break in a motor on full synthetic???

Doesn't chevy sell the new vettes with full synthetic Mobil 1 in the crankcase???

GDaina

[QUOTEWhy can't you break in a motor on full synthetic???[/Quote]

Synthetics are too slick, and the rings will never seat

That is correct, and the motors are broken in at the factory

Fevre

That is for flat tappet cams, roller cams can use dino. If you read the instructions that come with cams it states not use syn oil to break in the cam and it also states that syn oil producers agree. Plus you should change the oil with in 500 miles on a fresh eng so a good dino oil would save you some $ since you will be tossing it in a short amount of time.

GDaina

:iagree: The one thing about racing oils that conventional fossil oils don't do....the viscosity does not break down..and and that is another property of the synthetics as well....sythetic oil's viscosity will not break during extreme heat. You will loose some h.p. by using the racing oil, but for peace of mind, and I assume your 572 will generate extreme heat, much more that a 600-800 h.p. motor, I see no reason not to use the heavier oil.

I have a puny 533 with decent h.p. using 10w 40 Mobil 1

Larry3x2

I'm responding but hope I don't come across as a "Know it all" 'cause I don't but I'm a a mech engineer who worked in R&D for Castrol when we were qualifying synthetics for automotive applications. Originally, they were developed for jet turbines due to high temps carbonizing the mineral base stocks of conventional oils. the advent of turbos accelerated the need for synthetic as conventional oils would "cook" when the engines were turned off.
The viscosity, viscosity index and additive package distinguishes one oil from the others and the base oil package (which is often from common suppliers) is always the majority of the oils content on the order of 85%. Racing oils are definitely different! Dilution is one consideration but higher loads of anti scuffing, anti foaming and oxidation inhibiting agents and reductions in detergent dispersants mean more of the base stock is present to do the "heavy lifting". Use of a 20/50 in any engine toleranced for lower viscosities can cause bearing failures etc. because the thick oil may not flow into tight toleranced passages. The trend in racing today is to use the lowest viscosity oil possible to reduce pumping losses. Synthetics do have a place in normal engines but primarily because they last longer not because you can "feel the power", in fact most engines have more windage losses from the crank than the syn will provide. Dry or deep sump your engine go to a 20w racing oil to extract power from reduced oiling losses. Lastly, my compliments to Mobil for their superlative marketing job there is just not a discernable difference between retail oils from big name providers. I go by SAE test results, not magazine ads. PS even my own son insists on Mobil 1 !

Larry

79VetteMike

Good info Larry- I've always used Castrol 10W-30 on everything I drive. Are you the guy on the commercials dreaming of the hot girl waving the checkered flag and when they wake the dude up, he is drooling all over?