Oil question

[mopar Joe 65]

What oil should I use in my 383 ? After I broke it in I used Lucas hot rod and classic 10w-30 high zinc but now I have to change it again and I was wondering if I should use something else? Not a big fan of synthetic. I appreciate any input..

 

[Davea Lux]

What oil should I use in my 383 ? After I broke it in I used Lucas hot rod and classic 10w-30 high zinc but now I have to change it again and I was wondering if I should use something else? Not a big fan of synthetic. I appreciate any input..

I use Valvoline conventional 15-40 all fleet in all of mine. Main thing is to use an oil with adequate zinc. Chevron Delo 15-40 or Shell Rotella 15-40 will also work. These are all diesel rated oils with extra zinc.

Dave

 

[mopar Joe 65]

Thanks Davea , I think I will try the chevron delo 15-40 If this new rear main seal leaks again I might just use crisco .

 

[300rag]

I used the Lucas exclusively.

 

[Gerald Morris]

I ran Motorcraft Diesel Engine Conventional Engine Oil 10W-30, for a couple years, being able to score a gallon from Walmart for ~$18, then Lucas hotrod/classic, then just added Lucas cam break-in zinc to 5 qts of Havoline. If I build an engine from the block up, with all seals for synthetic, I'll look into Royal Purple HPS, which lists 1200 ppm for ZDDP. The Motorcraft stuff has about the same.

I don't know if Rotella conventional STILL has a high zinc content or NOT. Does anyone know a RECENT authoritative reference to what they put in Rotella now?

 

[3175375]

Here’s what I found:

Does Rotella Have Zinc? (T1, T4, T5 & T6 Oils Explained)

 

[Gerald Morris]

OK, I looked up Rotella T4 here from 2023: Shell Rotella T4 SAE 15W-40 Heavy Duty Engine Oil | The Petroleum Quality Institute of America

Delvac doesn't look so good these days: Mobil Delvac 1300 Super | The Petroleum Quality Institute of America

Delo, at just 819 ppm, is lower yet: Chevron Delo 400 SDE SAE 15W-40 Heavy Duty Diesel Engine Oil | The Petroleum Quality Institute of America

The Motorcraft 10W-30 I ran still has 1206 ppm zinc, and they publish on the back of the jug. (Or did until verfy recently, as I looked at one earlier this year.) So I'd got for Rotella T4 or the Ford stuff if using diesel crankcase oil in my 383. We might do well to look into the detergent properties of our oils also. In this, I reckon diesel motor oils should be amply supplemented.

 

[Gerald Morris]

Here’s what I found:

Does Rotella Have Zinc? (T1, T4, T5 & T6 Oils Explained)

I looked at the article, and notice the author doesn't understand that ZDDP dissociates in solution, so that the phosphorus content will be proportional to the zinc content, NOT additive! Advertisers use this sort of fallacy when touting their wares, though I think this author erred inadvertently.

Stick w the PQIA or vendor data when available. I suspect most american authors use these sources for reliable data. Note how high dollar stuff like Amsoil isn't any better w.r.t. zinc content than far more modest sources. I see Lucas providing the MOST ZDDP of all the stuff sold in this country. One CAN put TOO MUCH ZINC IN THE CRANKCASE TOO!! IDK of the Lucas level of ~2600 ppm will catalyze corrosion or not, but this might merit study.....