Would there be any issue running 10w-30 in an engine recommending SAE 30?

 

simple answer is no, there is no issue using multi vis oil

personally i use single weight but that is just me.

 

since we are on the subject what is a good weight to run in a stock original 352? supposed milage at 70K... And what brand do you all run i have always been a castrol gtx guy.

 

if using conventional oil i would get the zinc additive for your flat tappets regardless of miles

 

I have been running 10W40 then 30 after the 40 became harder to find for close to 50 years now. Most of that was Havoline, then it got hard to find.





John

 

Jowilker/Bill W,

I picked up some quarts of 10W-40. I just did a partial rebuild (valves, seats, springs, heads resurfacing, intake cleaning and pressure test). I would like to not do that again for awhile. Do you think 10W-40 is too thick for a summer only driver? I think I will be driving it only 200 miles a month.

 

I run 15w40 in the summer, 10w30 in the winter.

 

just rebuilt my 390 with alot of help from my son-in-law and his dad. It has been recommended I use 10W-40 in summer and 10w-30 in the cold weather. I tend to use Pennzoil.

 

How could it be too thick? 10W-40 is a multi vis with a wider working range than 10W-30.

The multi vis oil is formulated for just that purpose ie: thicker in the summer, thinner in the winter, throughout the vis range from 10W to 40W and points in-between.

 

I should have clarified Greg, I was refering to pressure issues.......

 

Scout Pilot you are fine with the 10W-40 in the summer, you can run heavier weight oils in the summer as the heat thins them out, you will notice a jump up in oil pressure, and how long it takes to warm up.. but not that much different. The Ford manual that I have suggest's 10W-30 for all FE"s year round, but I ran mine on 10W40 before I rebuilt it. Since then I have only used 10W-30 with Zinc Additive, which helps to protect the cam shaft, and flat tappets...You can find it at most auto shops or high performance shops, it is referred to as break In additive. The additive helps to keep the heat, and wear down. which is beneficial especially in the heat of the summer... As far as brand of Oil, it is personal choice... My father worked for 3 oil companies engineering oils and fuels.. He always said, only Pennsylvania grade Oils as they are the best (Highest Zinc Content, and most resistant to viscosity break down)....ie; Pennzoil, or Quaker State, or such... He also like to buy the American oils... I have learned to not waste your money on Synthetics for an FE.. it is basically wasted money. Actually a few FE re-builders I have spoken to discourage the use of Synthetics. Again it is all up to you and what you are comfortable with, as compared to what you can afford..

 

What is bad about synthetics? Just wondering 'cause I've only heard good about synthetic.

 

Synthetics have a tendency to soften the older style rubber gaskets, according to a few rebuild mechanics I have chatted with. and prolonged exposure causes Seal and gasket failure. They also said that in the older Engines with lower tolerances the Synthetic is just a waste of money. The last point was that the Synthetic oils have smaller molecules, which can actually pass by the Rings much more readily causing excess oil burn, which will eventually lead to plug fouling... Now this is just the Statements of a few Engine rebuild shops, but they all seemed to be in agreement on it. I have a tendency to trust these guys, since they see the end results of poor choices...

 

Addendum: I contacted my Engine rebuilder.. re; Synthetics.. he said definitely do not use during BREAK IN, as the Rings will not seat properly.. apparently the synthetic which greatly reduces friction which is counter productive during break in.. as it is the cross hatching in the Cylinders that helps to seat the Rings. He said it could be used after 5-10 thousand miles of engine use, but at the cost difference he said why bother as there is no great benefit in an older style V8, compared to the potential problems..

 

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