Friday, February 22, 2019

Righteous Lot

Many of you may recall the Old Testament narrative about Lot, who with his family fled from Sodom and Gomorrah just as those cities were about to be destroyed by God. Recently I read a post by someone intent on proving that Lot was a righteous man.  Well, I cannot argue with that sentiment since it is clearly stated in 2 Peter 2:6-8.

And turning the cities of Sodom and Gomorrah into ashes condemned them with an overthrow, making them an ensample unto those that after should live ungodly; And delivered just Lot, vexed with the filthy conversation of the wicked: (For that righteous man dwelling among them, in seeing and hearing, vexed his righteous soul from day to day with their unlawful deeds)  

Okay, so what’s the problem, you might ask.  Well, its just here.  Recalling the events as recorded in Genesis 19, God sent two angels to warn Abraham’s nephew Lot that the city of his abode would shortly be destroyed.  When they, as men in appearance, entered Lot’s house the men of the city came and demanded that Lot turn them over to them:

And they called unto Lot, and said unto him, Where are the men which came in to thee this night? bring them out unto us, that we may know them.  And Lot went out at the door unto them, and shut the door after him,  And said, I pray you, brethren, do not so wickedly.  Behold now, I have two daughters which have not known man; let me, I pray you, bring them out unto you, and do ye to them as is good in your eyes: only unto these men do nothing; for therefore came they under the shadow of my roof. (Genesis 19:5-8)

The problem, of course, is how to reconcile Lot’s action in offering up his daughters to be gang raped in place of his house guests and still be called righteous by the apostle Peter.  Now, I can do it rather easily, (and I will in a moment) as can many Christians who have a firm grasp of scripture, or are willing to take a moment to consider the case.  However, the author of the aforementioned post was forced to read all sorts of missing details into the narrative to square it with his theology, particularly his soteriology. (Soteriology is a 12-dollar word for the doctrine of how one receives salvation)

You see, when your religion teaches that it is your own actual righteousness that saves you, rather than the righteousness of Christ Jesus being counted as yours, then you will have to find a way to excuse or explain away the sin of those who the Bible calls righteous.  But for the true believer, it is quite simple. Lot was called righteous in the inspired word of God for exactly the same reason that his uncle Abraham was called righteous.  For what saith the scripture? Abraham believed God, and it was counted unto him for righteousness. (Romans 4:3)   and again,Even as Abraham believed God, and it was accounted to him for righteousness. (Galatians 3:6)

But of course, once again, if your religion teaches that it is your own righteousness that saves you rather than the imputed righteousness of Christ, then you will also find yourself looking for a “work around” for the rather clear teachings given through the apostle Paul mentioned above.  In fact, you may need to find a way to explain away his entire letter to the Galatians.

However, by God’s providence, just as I started to write this article I came to this Old Testament admonition during my daily Bible reading which further clarifies the matter:  When I shall say to the righteous, that he shall surely live; if he trust to his own righteousness, and commit iniquity, all his righteousnesses shall not be remembered; but for his iniquity that he hath committed, he shall die for it.  (Ezekiel 33:13)

So, while those of us who put our trust in Christ’s righteousness and not our own self-righteousness can ponder whether Lot’s actions in offering his daughters to the mob was morally reprehensible or acceptable given the circumstances, we don’t have to make him out to be someone more than what we are; sinners saved by grace!

Friday, February 1, 2019

Valve Potential Flow

We all fall prey to it occasionally; working on a project in which we have a preconceived idea of the results, but when you come near the end, they appear disappointing at best.  What did I do wrong? Can I fix it? When is “it will have to do” good enough?  Or, the ever-present option: do I need to start over?

But then sometimes when you find yourself in such a position, you need to take a moment an re-evaluate those expectations you had when you started. 

To make a long story short, I recently ported a set of head castings that I don’t often deal with, using smaller valve sizes than what I would normally select (for reasons I will not go into).  Once ported and flow tested, I was left wondering what I might have done differently.Then I remembered the actual valve sizes involved and it occurred to me that perhaps I expected more flow than I should have given the “smallish” valves.

For years I have had a chart that I produced for my own use, utilizing information from SuperFlow’s instruction manual for common valve sizes which provides “maximum potential flow” for the given valve size.  When I consulted the chart, I realized that I was dealing with a valve that was not on my chart.  The good news, however, was that once I did the math, I found that my work was completely up to snuff. 

But of course, never one to take small victories and move on, I decided that it might be a good time to update my chart.  And when I say update, I mean completely re-vamp it, put it into Excel and make it “interactive” so that with absolutely minimal input, all the data will be calculated for any valve size. So, if you have Microsoft Excel on your computer, you should be able to follow the link and download the “chart” and add valve sizes as needed.  

If you do not have the Excel program on your computer, you should still be able to download the chart though you will not be able to add sizes and will be limited to the valve sizes that I have listed.
This chart enables you to input the valve head diameter along with the stem diameter and everything else will be calculated for you.  Column A is a short description of where the valve is commonly used.  Column B is the valve head diameter and column C is the stem diameter.  Once the figures are entered into columns B & C, the rest of the fields will fill in automatically.  Column D gives the result of subtracting the square of the stem diameter from the square of the head diameter.  For the most part this figure can be ignored (though it is used by the program for further calculations).  Column F is the net valve area (which takes the area displaced by the stem into account).  From there the columns alternate between the potential flow at the given “valve lift to diameter ratio” and then what that valve lift is in inches. 
A quick word about lift to diameter ratio.  Many of those who do porting work find it most convenient to test flow at every .050” or .100” of valve lift, while others do all their testing at lift to diameter ratios. In the Harley industry, the lift to diameter ratio is not used often, though the concept is simple. The ratio is the derived by multiplying the valve diameter by a percentage; commonly 10%, 15%, 20%, etc.  This is expressed as: .10d, .15d, .20d, (you get the picture).  In other words, a 2.0” diameter valve would have a .25d lift of .500”.   The lift to diameter ratio has a couple of advantages, in that it allows one to compare the flow efficiency of two ports using different size valves rather than just the raw CFM of flow (where the larger valve will nearly always show up as the winner). This would be handy in a shop that ports a wide variety of head types. Also important, though often overlooked is the .25d flow.  At .25d (where lift = ¼ of the valve diameter) the “curtain area” of the valve is equal to the valve head area.  At that point, the amount of valve lift is no longer the primary deterrent to flow.  In porting, this has important implications when deciding what portion of the head needs improvement.

Hope this may be of use to some of you …