Recommended oil my newly assembled engine

kenewagner

Registered User
I have read a dozen threads on brands and weights of recommended oils. Most recommend higher weight oils for high milages SCs. I just got my new engine combination together. It has a low milage (12,000) short block with my new heads. What is the recommendation for a low milage SC? Should I run Mobil 1 and be done with, or start it up with a good brand of oil & run it for a short time and than change to Mobil 1. What viscosity? Dont want to run into bearing problems like on my last engine. Looking for some imput. Thanks

Ken
 
I've always broke in my new engines on none synthetic oil.I like rotella made by shell actually for big trucks it's 15w-40 and has some additives that aren't in regular passenger car oils.Then after 500 to 1000 miles I switch over to castrol syntec 15w-50.This is what I run as far as oils go but everyone has there opinions.


Jay
 
Ken,

I'm not smart enough to advise anyone on what type of motor oil to use, but I can tell you what I'm using. Valvoline 20w50 Race Blend (partial synthetic) for spring, summer and fall, and Valvoline 10w40 for winter.

I've got about 30k miles on this motor and I drive the car pretty hard...so far so good.

David
 
Ken,
I would use 5-30 for newly rebuilt motor. I will probably use 5-30 for my motor when I get it back. You can use heavier oil, but just make sure the motor is warmed up before hammering it.

Good Luck
Ken
 
My startup oil for my 93 is 15w40 Shell Rotella, typically considered Diesel Oil. I figured with the roller lifters in the motor, a high ZDDP oil would be good for break in at a minimum.

Do you recall this post(from this thread http://www.sccoa.com/forums/showthread.php?t=90515&highlight=oil):
Disclaimer: I'm not a petro engineer nor an expert on engine oils.

However.

If you ask people who DO know, they will tell you the same things with only slight variation so after awhile you start to get the idea.

1) Do not use synthetic oil for break in! The increased lubricity of the oil will hamper ring break in. If you want your motor to last for 1,000,000 miles and take 20,000 miles to break in, well then in that case go ahead I guess. BTW, 15w50 is only available in synthetic so that means don't use 15w50 for break in.

2) Ford specified 5w30 oil for our cars for the purpose of increasing gas mileage, reducing emissions and possibly to improve cooling. That specification has nothing to do with the mechanics of what is going on inside the motor. The SC engine does not require a low viscosity oil even when brand new. The SC engine will TOLERATE 5w30 if you go easy on it. If you run it hard I can pretty much guarantee what will happen to it over time and non of it's good.

3) Many NEW engines require 5w20 oil. These are OHC motors that need a low viscosity oil to lubricate the top end of the motor on start up. OHV motors, as a general rule do not require this. Our motor is as old school as it gets when it comes to lubrication requirements. I would not run lighter than 10w30 oil in an SC. There is no requirement in the SC engine for 5w30 oil.

4) Oil viscosity. Perhaps an engineer will chime in, but as I understand it the lighter number (the 5 in 5w30) represents the oil's true weight. The bigger number reflects the oil's ability to retain viscosity at operating temperature. This higher number is typically achieved with the use of viscosity enhancers which are NOT oil. The more viscocity enhancers an oil has the less lubricating it can do. A wide spread in the 2 numbers is not typically desirable. Keep in mind that synthetic oils by nature will comparatively speaking be capable of a wider range of viscosity with less viscosity enhancers than standard oil due to their superior molecular composition. There is a 15w30 oil available for racing. This represents a heavier base oil with less modifiers which will perform like a lightweight 30 oil under heat and load. Many racers recommend and use this weight of oil but remember, what is great for a 1300hp drag motor isn't necessarily good for a street SC that sees a wide variety of conditions.

5) Detonation. I do not believe that Ford engineers expected SC's to suffer prolonged detonation over their life times. However, that it occurs is a fact and so dealing with it in the end is our job. If you ask an engine builder or engine designer how to deal with detonation you will get a dumb blank stare as they consider you an idiot. You are not supposed to "deal" with detonation, you are supposed to eliminate it. In a perfect world we would do so. However, the reality is that most SC's detonate regularly and so we end up having to deal with it. It is the held opinion of at least one engineer and engine builder that running a higher viscosity oil than is exactly required for lubrication may provide some "cushion" on the rod bearings during the detonation events that destroy the bearings. The fact that I was able to run my motor with detonation AND worn out bearings without damage or failure lends credence to that belief. I realize that personal experience is not acceptable as scientific evidence, but some of us are having success where others are not. Take that for what it's worth.

6) I still recommend Mobil 1 15w50 for an SC motor with 80K miles or more on the bearings or one with less miles that may have wider than stock clearances.

If you disagree with anything I've said that's no problem. Do what works for you.

:)
 
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I have personally had no issues at all breaking it motors with a synthetic oil however why waste your money. I'd use a standard 10W30 for initial breakin. Call me super paranoid but I generally change the oil with less then an hour time when breaking in a new engine. The next change I generally do in a day or two.

After that I'm a tad less conservative

Also a 10W30 is a good weight to run on a newly built tight motor...After initial breakin use a synthetic..Before then its not worth it due to costs alne
 
I have read most of the post on oil by doing the search and agree with most of what I have read here. My short block has 12,000 miles on it already so I am not concerned about break in. I was concerned about the little debre floating around inside on start up, the kind everyone has even when taking care that everything is clean on assembly. I was thinking of running it for a short time after start up and draining the oil, (parinoid after the antifreeze in the oil, head gasket blown thing) than adding Mobil 1. I beleive now I will just add the Mobil 1, in 15w40 weight, start it up and run it awhile than just change the oil filter and top it off. I was concerned that the 15W40 would be a little stiff for a low milage block but Neibert has no problem running 20W50 (and I have the same red spark plugs he has) than I shouldnt have any problems either. The car will see no winter driving and will get drove hard often. I cant afford to keep buying bottom ends so I want the right oil from the get go. Thanks for all the imput

Ken
 
The way I see it, it’s not rocket science. Ford recommends both 5w-30 and 10w-30 with this one distinction. If you live in extreme heat where you regularly drive in hot weather (100 F or 38C or more), it would be your better choice to use 10w-30.

A break-in period is applicable to new engines. You should use the recommended oil and not drive the car at the same speed consistently (change speeds often) until after it's broke in.
 
Some clarification on the weight of oil (sorry Dave, but your wrong in the clip above). A 5w30 oil behaves like a 5 weight oil at low temperatures ( 40*C) and like a 30 weight oil at high temp (100*C or 212*F). If there's a 'W' in the weight, that means it meets a min and max viscosity for the weight specified at low temp, sometimes also referred to as 'Winter' weight. No W and it only meets the min. The 2nd most important spec in an oil is the Viscosity Index. This is the amount of change by temperature. Low VI means alot of change, high VI means less change. A more stable viscosity is better.

When the factory specs an oil for a certain car, they factor in the expected performance range of the motor, expected life and fuel mileage requirement. 5w20 oils are spec'd for motors with VERY tight bearing clearances, low tension rings, and VERY tight piston clearances usually with coated piston skirts. Running 20w50 in a motor spec'd for 5w20 will probably result in high oil consumption since the rings can't control the heavy oil.

In a stock SC, with stock rings and bearing clearances, 20w50 or 15w50 is a bad idea. It offers no benefits at all, only drawbacks of higher oil consumption and lower gas mileage. Oh, and the motor will make about 5-10 hp less with 20w50 than it would with 10w30. On a stock motor, 10w30 would be the only thing to run south of the Mason-Dixon line. North of that, 10W30 in the summer, 5w30 in the winter. At operating temp (200* oil temp) 5w30 and 10w30 will be almost EXACTLY the same oil. It's not my opinion, it's a fact. If there's a 30 there... it's 30 weight oil at 212*F. Doesn't matter if it's 5w30, 10w30, 30w30, -500w30... if it's 30, it has to meet the requirements of being a 30 weight oil at 212*.

In an engine that's been rebuilt, all bets are off. Then you have to do your own spec based on how the engine was built. Mine was built with 25% higher bearing clearances, 30% thicker rings and forged pistons with no coating. I've run 5w40 Amsoil synthetic in it since 1500 miles, changing it once a year or at 8,000 miles. It's around 50,000 miles now and still holds 70psi oil pressure at 2000 rpm and 35 psi at 900 rpm idle hot (220* coolant temp). If I didn't run 5w40 Amsoil, I'd run 10w40 Durablend or some other synthetic.

Film strength of oil has absolutely nothing to do with viscosity. Thick 20w50 oil offers no additional film strength over 0w20 assuming adequate film thickness is maintained. Putting 20w50 in a motor that's 'tight' for 0w20 would result in insufficient film thickness and increased wear. The thick oil wouldn't be able to flow out in the .0005" piston-bore interference fit (not kidding) with todays engines and coated skirt pistons. Oil pressure would be ridiculously high costing HP and MPG and oil pump drive wear. Most of oil flow would bypass back into the pan. Same with putting 0W20 in a motor built for 20w50. 0w20 would blow through the sloppy clearances like water and film thickness would be compromised resulting in increased wear. Oil pressure would also be way low and a super high volume pump would be needed to make it work.

Oh....pushrod engines with sled fulcrum rockers need more oil in the top end than roller follower OHC engines. A roller cam OHC engine can run with almost no oil in the top end. Valve springs wouldn't like it, but wouldn't really hurt the came. Our rockers and pushrods would turn black in about 10 minutes from over heating and friction.
 
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