What weight oil

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EDMOPAR

EDMOPAR

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What weight oil are you running in your small block engines, mine is a mildly built 72 340 with roller rockers, I used Penzoil 10w40 in my last 340. Thanks and have a great day
 
In a just purchased car I decided to try Castrol 20-50 in a 318, car is not a track car and my driving thoughts were that the summers are brutally Hot here in Texas. Bad idea, Good idea? Who knows but it was my idea, lol.
 
15w50 Mobil-1 extended performance, it is designed for flat tappet cams.

And has the extra zinc and other additives that a flat tappet requires to live.

And Walmart has it in 5 qt jugs for around $26
 
10w30 or 10w40 in the winter and 20w40 or 20w50 in the summer.
 
Hemioutlaw said:
In a just purchased car I decided to try Castrol 20-50 in a 318, car is not a track car and my driving thoughts were that the summers are brutally Hot here in Texas. Bad idea, Good idea? Who knows but it was my idea, lol.
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Main thing is to get the Zinc and Phosphorous that has been deleted in recent years, if you are running non roller cams. 20-50 is fine, I'm not sure about the Zinc and Phosphorous in Castrol, I assume GTX.
 
Great question....so what might be best in a magnum engine?
 
67dartgtgo said:
Great question....so what might be best in a magnum engine?
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I personally do not think there is a "best". Any good oil will do. Brad Penn Grade 1, Valvoline Racing, or Pennzoil GTP Racing oil were specifically recommended the last time I bought an Isky cam. I think the Zinc and Phosphorous is good for both flat tappet and roller. It seems more critical to keep cam and lifters from self destructing in a flat tappet engine. I personally do not feel the need for synthetic oil but others will and will also have their reasons. Talking about Oil in these forums is like dropping a live hand grenade.
 
66fs said:
Main thing is to get the Zinc and Phosphorous that has been deleted in recent years, if you are running non roller cams. 20-50 is fine, I'm not sure about the Zinc and Phosphorous in Castrol, I assume GTX.
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Yup if you run a flat tappet you need to make sure these are in your oil. most oils dont have this. I run SAE 30 in my antique tractors for this reason.
 
The reasoning for the heavy 20W50 with the hot temps is rational. But, you need to be careful the first time you use it; if the oil pump is worn, it may not be able to pick up that heavy weight; and you will damage a rod bearing at start up in < 20 sec or so. That wil be the main issue with 20W50: the start up lubrication will suffer, and that tends to be critical with all-around engine wear. If you are worried about the hot, temps, then ideally spring the $$ for a full synthetic of ligther weight; even with a lighter weight, it will retain better viscosity than a 20W50 petroleum when it gets really hot. Next best would be a synthetic blend of lighter weight.
 
I run 5w-30 full syn, it's never done me wrong.
 
20w stands for the Low temperature dynamic viscosity while the 50 stands for the High temperature specifications.

[ame]http://www.ideas4ag-ed.com/uploads/3/7/0/4/3704787/stan_toepfer_understanding_motor_oil_viscosity.pdf[/ame]
 
I like the 15-50 mobil 1 Synthetic Extended Perfomance , I find 0w and 5w weight oils make my valve train a little noisier , on the temp charts you will find 15w is good down to like -15 c { 5F } cranking and -25c { -13F } pumping and as a synthetic it flows well on start up .
 
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