Correct oil weight for UK-based '72 440

[theseoldcars]

I'm hoping someone can more accurately answer this oil-related question for me.

I live in the UK and the temperature ranges from about -5 to 25 degrees C (23F to 77F) across the course of the year, and perhaps a little extra either way.

My car had been parked for a decade and, given that it was an old motor with unknown history, I was all set to drain and replace with 20/50W mineral oil - the typical 'classic' oil here.

However, having read about how the top end is lubricated, I was put off that idea - 20/50 seemed a bit thick.

Eventually I just slung some 10/40 in it (which it seems to like), ran it for a bit and dropped it all out. I'm just doing this again, to get rid of all the junk (turned black almost immediately when it went in the first time, haha).

However, I'm wondering what would be best to settle on? A decent 10/40 with an additive? Plain 20/50? VR-1? It is available here, as I used it in my Firebird...

Thanks for your help.

[72Charger72]

Ive always ran 20w/50 in my 440 anything less just breaks down too quick.

[440]

I've always run 20/50 in all my cars but the climates I have lived in never really drop below 32f/0c.

[myk]

I was running a 10w40 full synthetic, but now I'll be switching to Brad Penn 10w40 'semi-syn.  20w50 seems too thick to me, and the Brad Penn has all of the ingredients needed so you don't have to pour in any additives...

[c00nhunterjoe]

There is no "correct" oil weight. It should be determined based on the bearing clearances in each particular build.  20w50 in my engine will risk blowing the oil filter off and bury the gauge past 100 psi. I run 10w40. But the engine in the race car is set up to run 20w50. So it is really a case by case basis.

[Dino]

I'm running high zinc 10W40 in temps ranging from 20F to 95F and it likes it just fine.  

[myk]

I'm running high zinc 10W40 in temps ranging from 20F to 95F and it likes it just fine.  

What brand oil is that?

[Dino]

I'm running high zinc 10W40 in temps ranging from 20F to 95F and it likes it just fine.  

What brand oil is that?

I bought a big jug of the stuff once and cannot remember the name. It was a green jug if I recall. It clearly stated it had a high zinc content though.

These days I have my mechanic do the oil change as he periodically checks the car out and fixes stuff I break. He's a mopar guy so he knows what to look for and has fixed numerous little things without charge. He gets his oil in bulk but he mixes a batch with a zinc additive, same stuff he uses in his 440 Dart.

If I ever go back to doing my own oil changes I'll probably go to Brad Penn...but unless he retires I'm going to have him do it. He charges me less than what it costs me to buy the damn oil!

After PA school I'm going to have to be careful working on cars. It's not good to serve patients with grease under your finger nails.   

If I end up doing surgery I might have to stop working on cars all together. Scary thought!

[myk]

Career first, I say.  When I hurt my hand changing the shocks on my Trans Am I couldn't play guitar for weeks.  I wasn't happy with that!

[Dino]

Career first, I say.  When I hurt my hand changing the shocks on my Trans Am I couldn't play guitar for weeks.  I wasn't happy with that!

Been there myself. Had a gig playing sax one night and had a flat tire on the way to the venue. One of the wheel lugs was kinda tight and I kept slipping off the wrench with my foot so I grabbed it with both hands and cranked it loose. In the process I slammed my hand against the ground and had to play a two hour gig with a hand the size of Texas. I looked like Hellboy! Didn't play anything for the new week or so.

[myk]

Damn.  I just had a flashback of the Incredible Hulk's television intro, lol...

[theseoldcars]

Thanks for all the feedback!

I think what I'll do, then, is carry on running the 10/40 for now - and start using it on the road, see what it does. If it looks like it needs something thicker, I'll swap it out to a quality 20/50W.

Cheers! 

[c00nhunterjoe]

If hot idle oil pressure is minimum 20 psi and cruise rpm is 50-60 you are fine. If it is below 20 at idle, step up a weight.

[theseoldcars]

If hot idle oil pressure is minimum 20 psi and cruise rpm is 50-60 you are fine. If it is below 20 at idle, step up a weight.

Cheers! I'll find out this weekend...

[BSB67]

Ive always ran 20w/50 in my 440 anything less just breaks down too quick.

Wow.  What breaks down?  Can you share the lab report?

[BSB67]

If hot idle oil pressure is minimum 20 psi and cruise rpm is 50-60 you are fine. If it is below 20 at idle, step up a weight.

This is a good general rule.

I usually run a 0-30 or 5-30 in my 508.  I'll run just about anything that is on sale in my stockish stuff with normal hyd valve spring pressure, and normal cam lobes.  Otherwise you should make sure you have zinc, IMO.