0W oil in new engine

[1965Mustang]

I just finished rereading all the old posts on what weight oil to use. Finally got my new 302 efi roller engine installed and running in my 65 Mustang. I understand the break-in methods and the 10 psi per 1000 rpm thinking. I have decided to run a 0W20 oil after the short initial break-in. From my limited understanding the 0W is for cold starts. Does this apply to the hot months also? Still a 0W oil for year round use? At 2,000 rpm I should have 20 psi, but at idle I will have less than 10 psi. Is this enough to keep the engine from excess wear? Do i run the same weight when I ocasionally take it to the strip or autocross?
Thanks

 

[oggb]

0w-20 is a no-go in that engine. It might work, considering it's a roller engine, but I'd go with 5w-30 anyhow.

 

[Lead Shoes]

It really depends on how tightly it was rebuilt, I wouldn't run 0w20 at the track unless you know the motor can survive on 20 weight.

 

[tomcat27]

0W-20 is not just for winter; it's for most modern engines with modern tolerances. as far as your engine, I'd check with the builder. On my rebuilds my builder specs the oil and also warranties the engines for 100k.

 

[Bandito440]

Yeah... Unless fuel economy is more important than wear, 5w-30 or 5w-40 is what I would use. You don't need 0w in North Carolina for cold starts.

Did any literature accompany the motor? What is recommended or required for warranty purposes?

 

[LargeCarManX2]

Use Mobil 1 0w40, it's a zero weight when its needed and a 40wt when needed...that's a simple explanation

 

[dave1251]

Originally Posted By: JRed
0w-20 is a no-go in that engine. It might work, considering it's a roller engine, but I'd go with 5w-30 anyhow.


I would not go that far especially since the 5W-30 would like shear into a 5W-20 anyway. You will need to measure the correct oil pressure at operating temperature to guide you to the correct viscosity.

 

[tommygunn]

Sure, but for all intensive purposes if you're going to the strip, or autocross, I'd say stick to a decent 5W-30 at least.

The hot, heavily loaded engine will love you for it which is the conditions at a hot track.

And yeah, the lower the first number, the better, problem is your oil could potentially be more shear-prone because of extra modifiers to make it work so. Thats why most lawnmowers like straight 30, not 5W-30.

My $.02

 

[dave1251]

From what you stated on the Orginal post that you wish to have 10 PSI per 1K RPM. For some engines that is sufficient but for others that will be low pressure, consult other builders and engineers for your 302 to find the correct minimum oil pressure and make you decision from there.

 

[dave1251]

BTW the original recommendation for 1968 Mustang with a 302 was 10W-30 from what I read. I hope we where able to help you out. I believe that after nearly 45 years any oil you use will be better for your engine by leaps and bounds.

 

[jorton]

I don't think 302 was back spec'd for 20 weight.

Mobil 1

 

[FiremarshalRob]

no way I'd run or race 0w-20 in that motor. just me though.

 

[A_Harman]

Is this an EFI 302, such as in an '80's 5-liter Mustang? I don't think that engine was ever spec'ed for 20-weight oil. I say go with a 5w30. You could use a 0w30, but in North Carolina there's no need for it.

 

[OVERKILL]

IMHO, 0w40 is the best choice for that engine based on my experience with it.

 

[dparm]

A heavy 0w20 *might* work but I am inclined to recommen some sort of mid-30 weight. Use an oil pressure gauge to verify.

 

[Propflux01]

Once an engine has been rebuilt and or modified from its original intent and specs, all of the original manufacturers specs go out the window. Everything then becomes trial and error. I understand that some racing engines use a light 20w to run for track position, then go a # higher to do the 500 mile race, seems those motors don't blow up, and that sounds like the type of strip action you would be doing. I would run the 0w as long as you have good hot pressure it should be fine. Is the oil pump stock or high volume?

 

[CATERHAM]

If you have an oil pressure gauge installed you could run a 0W-20 oil grade. The 10psi/1,000rpm rule is a very rough guide that applies more to high rpm's than low. Look up the OP spec's for your engine and go from there.
A light 0W-20 is especially good for the Strip and Auto Crossing since the oil temp's are usually below normal when you're hammering it.

 

[Boss302fan]

I would use 10W30 VR1 in your engine... I have plenty of experience with 302's... LOL.

 

[mechtech2]

I'd use 5-30, and maybe an x-40 if you get her really hot [oil temperatures].

The 10bs/1000RPM thing is only a rough guide.
Remember, Chevy had no pressurize oil to the bottom ends of their 6 cyls until about 1953.
For all intents and purposes, they were splash oiled like a lawn mower.
Zero pressure at all RPM! [of course hydrodynamic pressure was still achieved]

 

[OVERKILL]

Originally Posted By: Boss302fan
I would use 10W30 VR1 in your engine... I have plenty of experience with 302's... LOL.


Why VR1? It's an HO roller motor.