flathead oil

[29 special]

just finished rebuilding my 8rt does anyone use detergent oil in a clean flattie or is it best to stay with straight weight thanks

[paul2748]

Use detergent, it keeps the engine clean - 20/50 or 15/40 (Diesel) is my recommendation

[29 special]

thanks paul

[Binx]

Here we go again........

[Fibber Mcgee]

Am I the only one who gets nervous when I see the word oil in a post?

[19Fordy]

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I use Castrol 20W50 along with a bottle of STP that contains ZDDP. Some folks say that using synthetic oil is good also, but it tends to find "leaks" easier. Seems logical to me that if you have a nice new clean engine that you would wanto to keep it clean by using detergent oil. Regular oil changes are the key.

[G.M.]

Read this attachment to understand a little about oils and decide what you want to use. G.M.

[Ol' Ron]

The stock flathead does not have an efeective filter. Using a detergent oil keeps the grit,dirt and other unwanted stuff in suspension so the filter can remove it. A good 10-30 non detergent oill would be best, in my opinion. I also believe that a newly rebuilt engine should be run hard and not spend much time running without a load. After a few 100 miles you can drain this and use what ever oil you see fit for your application. I recommend 10-30 as this is what the Ford factory specs. I feel 20-50 is best used in old warnout engines to keep the oil pressure up.

[uncle buck]

Keep in mind that the feds have required the zinc additives to be removed for emission requirements on the oils of today. I have been told that the changes in the diesel oils have also reduced it too. Make sure to consider adding a zinc additive to whatever you decide for continued cam and lifter life. Lucas, Hiltons and all of the major cam manufacturers offer it. I also have been told that the racing oils still have zinc in them , as they are intended for off road use.

[29 special]

thanks for replies my plan is to use10w30 non detergent drain alitle out each qrt add zinc so it pours over cam lifters when entering motor then check out a detergent oil after break in .I always add zinc long after break in in new motors my first flathead rebuild though tom

[Old Henry]

Originally Posted by G.M.

Read this attachment to understand a little about oils and decide what you want to use. G.M.

CAUTION: That whole discussion is about oils for diesel engines. Gasoline and diesel oils have different additive packages because the contaminates in the crankcase are different. With a gasoline engine you get a lot of moisture and tar and with a diesel the oil becomes acidic and will collect more carbon.

Many oils will work well in either engine type but it's always best to use an oil specially formulated to the type of engine for optimal life.

You will see things like "API SG/CJ" on the oil container, that means:

API = American Petrolium Industry
SG = Spark ignition, grade "G"
CJ = Compression ignition, grade "J"

The second letter is the grade designator, in alphabetical order, and later = better.

All oils analyzed in G.M.'s article are C grades for compression ignition engines (diesel engines). Not as good as S grades for our spark ignition engines.

[Old Henry]

Here is a very exhaustive thread on the subject from two months ago: http://www.fordbarn.com/forum/showthread.php?t=60100

[TomO]

Most single viscosity oils on the market are detergent oils. You have to look hard to find a non-detergent oil.

The Multi-Viscosity oils give a more constant lubrication than the single viscosity oils.

[Old Henry]

Originally Posted by TomO

The Multi-Viscosity oils give a more constant lubrication than the single viscosity oils.

Before getting too committed to multiviscosity oils you should read this information about the down side of them: http://www.upmpg.com/tech_articles/motoroil_viscosity/

[flatjack9]

Of course you realize they are promoting synthetic oils. They say viscosity index improvers can break down under high temperature and high shear conditions. How long must they be subjected to these extremes before they break down? They say that when broken down sludging will result. I've run my engine on multi viscosity oils for nearly 20 years now and there is not even a trace of sludge in that engine. I don't think our flatheads are taxing the oils of today.

[Ol' Ron]

I think someone makes a break in oil, but I can't remember who.

[G.M.]

My engine broke in just fine with Castrol 20/50. In over 30 years since start up and driven hard for 110,000 miles there is no sludge, runs quiet and burns no oil driven in warm to hot weather. This was a diesel rated oil for about 25 years until they changed all oil designations about 6 or more years ago. G.M.

[FLA48]

I do not know what "Junior Member" means, but I have been operating flatheads since 1953 and have always used 30 weight oil, until this last rebuild. Some of the engines had over 150,000 miles on non detergent oil before the heads were removed for a valve job. I am now using 10W 30. As a side note, I can remember the Houston Police department had a 53 Ford with 250,000 miles without even having had a valve job.

[MuskegonFlatheadFan]

This is what I use.
http://www.penngrade1.com/Zinc.aspx

[Old Henry]

Originally Posted by FLA48

I do not know what "Junior Member" means.

It just means that you haven't posted over 100 times.