Tuesday, August 7, 2018

Under Pressure

[Wow, how time flies when you are busy living life and working for a living.  There have been an untold number of things I have had the urge to write about over the last several months, but could not seem to justify taking the time.  Some of those topics I consider very important, some interesting but not very important, and some perhaps just somewhere in between. This post is definitely not important (in the grand scheme of things), and probably only interesting to a limited audience, but you know what?  I am going to go ahead and write it anyway, if for no other reason than to see if anyone is still paying attention.]

A few weeks ago I had Billy's Iron Head vintage flat track bike here for a little maintenance.  It had been smoking pretty good the last couple times out, and that coupled with the fact that one of the recent races featured extended time spent at 8500 RPM meant it might be due for more than just checking the valve adjustment.  As it turned out everything was in pretty decent shape with only a fresh set of rings required.

Given that I would not have to spend very much time freshening things up, I took the opportunity to fabricate a custom breather system for the bike, something that has been on my "to do" list for some time.

As with most early Sportster engined flat track bikes, Billy's has a magneto and runs without a generator.  Now, having my "druthers" I would love to see the mag mounted in the generator position so it would be out of the way of the pushrods and carb, but that's probably not going to happen any time soon.  So with the generator gone, a gaping hole is left at the front of the motor; easy enough to seal off with a flat plate, but of course that leaves the breather system in a state of chaos.  In stock form, the large diameter washer which resides on the inboard end of the generator serves as as an oil separator allowing excess crankcase pressure to be relieved by way of a tube attached to the cam cover. Without the washer, the breather tube would tend to do a credible impression of the Exxon Valdez (if you youngsters are scratching your head, click on the link for a little history).  Okay, that may be a bit of an exaggeration, but without the washer you will get at least some oil out of the breather tube, something most tracks take a dim view of.

But of course you can't then plug off the breather tube unless you're willing to give up a bunch of horsepower and initiate oil leaks from every conceivable joint.  Okay, you got me.  Another slight exaggeration, but only concerning leaks from every joint; that plugging the breather will result in loss of horsepower is a given.  The temporary bandaid that went onto Billy's bike when he showed up with an rebuilt stock replacement engine last year was as simple as it was marginal.  An elbow in the generator block off plate with about  18 inches of 3/8" hose pointing up, along with an in-line PCV (Positive Crankcase Ventilation) type valve topped with a generic plastic automotive fuel filter. In retrospect, perhaps the filter should have been put in place between the fitting and the one way PCV which would have allowed the oil seperated by the filter to drain back into the engine, but its a moot point now.

The actual breather that I came up with was to a large extent  dictated by the scrap aluminum material that I had on hand (keeping in mind mine is an engine shop, not a fabrication shop). What I came up with is shown below.  Keep in mind that I stressed the part about material on hand.  With more to work with, I probably would have built it with the oil separating baffle before the umbrella valves to keep more of the oil in the cam cover rather than transferring to the catch can.  But, ...oh well, the first prototype of anything is seldom the best or final version.There is a drain plug on the bottom of the canister for easy draining, so it shouldn't be a problem anyway.


1st piece -machined a flat plate for a recess and drilled holes for umbrella valves

Umbrella valves installed in plate

Engine side of plate - center hole of each group mounts umbrella valve - other 4 holes for air transfer

The umbrella valves are from a late 80" Evo engine, which uses only two.  I calculated the cross sectional area of the transfer holes to insure that added together they exceed the area of the new breather outlet. Consider this: due to the common crankpin design of the 45 degree V-Twin engine there will be 90 degrees of crankshaft rotation where both pistons are descending in their bores at the same time.  That means that without a "breather" to alleviate the potential pressure, the air/oil mist in the crankcase will need to be compressed, at the price of the horsepower it takes to do the compressing.  As mentioned earlier, pressure will also tend to seek a way out, usually at whatever gasket has the least resistance.

Now, if one is willing to take the time, they might calculate the amount of air displaced by the downward motion of the pistons that needs to be moved through the breather system, and then factor in the amount of time available to do that at, say 7500 RPM and apply that to estimate the needed cross sectional area of the choke point (smallest orifice) in the breather system.  No, I'm not going to do it either, but barring that, it is at least a good idea to increase the size over stock.  The I.D. of a standard 1/8" pipe x 3/8" hose barb fitting is only .265" which calculates to only .055 square inches. That seems awfully small.  The outlet pipe on my completed breather assembly has a 1/2" O.D. (to take a breather filter) with a .380" I.D. for a cross section of .113 square inches, or double the stock size.  Still seems a bit marginal when just looking at the cross section, but it has to be an improvement.  Oh, and by the way, I did calculate the cumulative area of both the baffle(oil separator) holes and the holes at the umbrella valves to be sure they would not be a "choke" point.

Finished assembly

Orientation of umbrella valve plate when assembled

Tack welded in place oil separator inside canister


Installed on bike - breather filter not installed.

Before I go, one other think to consider.  Some of the breather fittings that go onto a Twin Cam motor are ridiculously small.  First of all, the heads are only tapped for a 3/8" - 16 tpi (thread per inch) bolt so there is little to work with (even the smaller cubic inch Evo motors were tapped 1/2" - 13 tpi) but some of the breather fitting that go into those holes have a through diameter of only .145" which works out to a cross sectional area of only .017 square inches per head or .034 for what are often 103 cubic inch or larger engines.  Its a testament to how well all the gaskets and o-ring in the engine work to keep (what I assume to be) all that excess crankcase pressure on the inside.



Tuesday, April 3, 2018

The Goliath Controversy




So there is a controversy concerning Goliath?  Who knew?  And no, this is not about the famous double engine Harley drag bike of the same name...
Some time ago I took the liberty of leaving a comment on Cross Examined, a Christian apologetic blog that I sometimes peruse during lunch.  This site seems to attract an abnormally persistent brand of alleged atheists who seem to have far more spare time than I can dream of, and they use that time to attack everything posted there. 

In the course of a little back and forth in the comments section, I pointed out to a fellow commenter named David that he was named after a man who is known as “a man after God’s own heart.” That seemed to set David (who, for clarity, I will refer to as Dave for the remainder of this post) off into a tirade.  Anyone who has spent time listening to debates between Christians and the “apostles of atheism” (as I like to call them) will be familiar with the common plan of attack: a verbal barrage of every Old Testament action which violates their personal morality.  This form of attack can best be translated as: “God is just a figment of your imagination and I HATE him!”   In fact, this scatter gun approach to argumentation is one that serves them well, both in formal debate settings and comment sections, in that it becomes impossible to answer every charge in the time available (even the self-employed need to limit their lunch break). 

However, Dave ended one of his tirades with this:
“… One additional bit of data Lee, the story of David and Goliath (1 Sam. 17) was not in the original text. It’s just one more piece of propaganda in favor of David and his line. It is demonstrably a later interpolation in the text and contradicts 2 Sam. 21:19. Thankfully, 500 years after the fact, similar to how Fox News shills for Trump, the chronicler shows up to spin David into Goliath’s killer and Elhanan into the killer of Goliath’s brother Lahmi. That’s right, Goliath the Philistine giant with a good Philistine name just like the other Philistine giants had a giant brother with a Jewish name that means “my bread”. LOL!”  - from a comment on the blog post What Christian Parents Should Learn from theNormalize Atheism Movement

Everything else contained in Dave’s comments were standard, run of the mill arguments about the immorality of the Bible which have been answered over and over by better men than me and easily found if one really wants an answer. But I don’t believe that I had ever seen this particular argument before, so wanted to look into it and give an answer (1Peter 3:15).    So, it’s been a long time coming, but I finally took the time to reply to this accusation.

The texts in question, along with 1 Samuel 17, are 2 Samuel 21:15-22 and 1 Chronicles 20:4-8. The claim that 1 Samuel 17 was not in the original text of the Hebrew Tanakh (what we as Christians call the Old Testament), is at best a spurious one, and at worst libelous.  Since the books of 1st and 2nd Samuel were very likely penned by at least several authors (“holy men of God spake as they were moved by the Holy Ghost” - 2 Peter 1:21) at the very least one would need to verify at what point the words were gathered into one book before claiming any one part of it to be a later addition.  Nowhere does the Bible make the claim that Samuel himself was the author of the two books which bear his name. A reading of 1 Chronicles 29:29 suggests that the books of 1st & 2nd Samuel were compiled using documents written by Samuel, Nathan, and Gad, which in no way makes it any less inspired sacred scripture.

But of course, the claims of later additions, redactions, or changes nearly always are the opining of self -styled experts who have one thing in common: unbelief. All of their “scholarship” is built upon the presupposition that there is no God, and that the Bible is a collection of fables.  Keywords that reflect the pedigree of their findings include “generally agreed”, “the consensus is”, “scholars agree”, and my personal favorite “according to modern scholarship”.  In fact, Dave’s statement that the description of the battle between David and Goliath as recorded in 1 Samuel 17 “is demonstrably a later interpolation in the text and contradicts 2 Samuel 21:19” is, in itself, a fine example of an interpolation based on a presupposition (if we follow the definition of interpolate as being “to alter or corrupt by inserting new or foreign matter”).  Namely the presupposition that the Bible is not true.  For those of us who side with Jesus Christ in affirming the Old Testament narrative as truth, there is nothing here to suggest a real contradiction, let alone a 2500 year old conspiracy to beef up David’s “street cred.” 
  
To drill down a little deeper into Dave’s claims, let’s look at the verses which do appear to contain a contradiction.  Keep in mind that I am no scholar and have no training in the original languages, so I am open to honest correction.

Samuel 21:19  And there was again war with the Philistines at Gob, and Elhanan the son of Jaare-oregim, the Bethlehemite, struck down Goliath the Gittite, the shaft of whose spear was like a weaver's beam. 
1Chronicles 20:5  And there was again war with the Philistines, and Elhanan the son of Jair struck down Lahmi the brother of Goliath the Gittite, the shaft of whose spear was like a weaver's beam.

It is very possible that two simple and understandable transcription errors explain any confusion.  One is that since the Hebrew word for Bethlehem actually contain the word Lahmi, it is easy to see how part of the word Bethlehem could have either been inadvertently left off while being transcribed or not even an error at all but only a shortened version of the word for the town. For example, if a biker tells you they are riding to Daytona in March would you need them to clarify that they mean Daytona Beach Florida or would the context give you enough information to know where he meant?

The Hebrew words in consideration are:
לַחְמִי
 בֵּית הַלַּחְמִי

And are written in English like this:
lachmiy or Lahmi
beyth hallachmiy or Bethlehem (bold added)
I believe a close look at the first characters of the Hebrew, even when transferred into English letters sheds a lot of light.  Remember, Hebrew reads from right to left unlike English text.

Note that “Bethlehemite” is included in the description of Elhanon in 2 Samuel, but missing from 1 Chronicles.  The description “brother of” is included in 1 Chronicles, but missing from 2 Samuel. It would seem (to me at least) that the best explanation is that 1 Chronicles 20:5 is correct that is was the unnamed brother of Goliath who was slain by Elhanan, but a part of the word Bethlehem was lost in transcription, causing Lahmi to be assumed to be a name rather than a short version of Bethlehem which should have been applied to the description of Elhanon who was from Bethlehem.
As for the missing “brother of” in 2 Samuel 21:19, in Hebrew characters it would look like this:  אָח

A modern example might go something like this; suppose I copied a letter from my great grandfather written to my mother which contained this sentence: “I decided to pay to have my dog bred.”  But, in copying it, I inadvertently copied it as “I decided to pay to have my dog red.”  Oops.  Small mistake, but it changes the meaning.  In fact, the way I actually copied it might lead anyone reading it to assume my great grandfather was going to buy a dog was named Red.  How important was the copying mistake?  Not very.  In fact my copying mistake would have had about the same impact on the Gospel of Jesus Christ as does the possible mistake in copying that might have been made in these two Old Testament texts.
 
Now, unless your standard of accuracy for the copying of texts which were first written down over 3000 years ago is that of a photocopy, these minor discrepancies occurring at some time during the long ages of copying and re-copying are pretty insignificant.  After all, what would you have had God do: strike a scribe dead just before he made a mistake? That may have decreased the number of textual variants, but it would have also greatly decreased the number of scribes willing to reproduce scripture. In short, I find myself in agreement with the Chicago Statement on Biblical Inerrancy, which says in part:

“Article X. WE AFFIRM that inspiration, strictly speaking, applies only to the autographic text of Scripture, which in the providence of God can be ascertained from available manuscripts with great accuracy.”

and

“Article XI WE AFFIRM that Scripture, having been given by divine inspiration, is infallible, so that, far from misleading us, it is true and reliable in all the matters it addresses. WE DENY that it is possible for the Bible to be at the same time infallible and errant in its assertions. Infallibility and inerrancy may be distinguished, but not separated.”

One thing is quite sure, when a person stands before God Almighty and says he could not be sure whether or not Goliath had a brother named Lahmi, it will probably not be accepted as a good excuse for rejecting the entirety of His word.

Wednesday, March 28, 2018

Indoor Flat Track 2018, St. Paul


We were treated to some of the most exciting racing action ever last Friday evening at the inaugural IFT (Indoor Flat Track) event at the Minnesota State Fairgrounds Coliseum held in conjunction with the Donnie SmithBike Show.  Having spent all day Thursday AND Friday helping with the set up for the bike show over at RiverCentre in downtown St. Paul, I was quite tempted to just skip the races and get a good night’s sleep since we still had another two days to go manning our booth at the show.  Fortunately, Jane saw it as an opportunity to get the old deadbeat (me) to take her out on what, by stretching the definition to the limit, could be called a date.  So, a quick 50-minute drive from the bike show to our house, and then another quick 50-minute drive back to the fairgrounds found us seated in time to still catch a couple of the semi-finals. ( And what a great wife I have to give me that little push I needed!)

Of course, I knew that Billy Hofmeister planned to have his “Lee’s Speed Shop” modified Iron Head 900 Sportster in the competition, but I had no idea who he had lined up to ride it, or the number it would carry or even the name of the class it would complete in.  In fact, his bike has a fresh paint job on it this season with lettering on the tank that is a bit harder to pick out than it has been in previous iterations. That meant I really had my eyes peeled to identify Billy’s bike. Each race started just below where we were seated so I couldn’t’ really get a look at them there.  

So here we are sitting in the stands next to Brian Klock and some of his friends, watching one of the last semi-finals and I keep thinking that the #101 bike running in second place might just be Billy’s, but they are moving fast enough that for the life of me I can’t read the lettering on the tank or even tell for sure that it’s an Iron XL.  What’s more, I didn’t want to sound like I was starved for attention, so I kept my mouth shut to those around me about my suspicion that it might be the bike with my porting. 

When the rider of the 101 bike came underneath and won the semi on the very last turn, and the crowd went wild in reaction, I knew it was time for Jane and I to make a trip to the pit area to find just who we should be cheering on.  Of course, I was pretty hyped to find that it was indeed Billy’s bike carrying the 101 number plate, with rider extraordinaire Mac McGrew giving the crowd the biggest thrill of the night, …at least up to that point.

E.J. Ebensteiner Photo


So, back to our seats where I did my level best to act as though I was still modest as I let everyone know that the excitement we had just witnessed could be linked (no matter how tenuously) to my porting.  But the show wasn’t over yet.  As Mac lined the old Sportster up for the finals in the Pro Hooligan class, we all expected quite a show, but no one could foresee just how that show would unfold.  At the very start of the race, going into the first corner in the middle of several other bikes, somehow Mac wound up on the ground and separated from the bike.  

Apparently neither he or the old Iron Head were quite ready to call it a night just yet though, because Mac quickly picked up the still running Sportster and pointed it toward the rest of the pack.  A 10-lap race on such a short track doesn’t allow much time for making up ground, but over the next bunch of laps Mac worked his way up from dead last all the way to second place, when he caught his handlebar on another bike, sending the Iron Head into the wall and breaking the front wheel.  Not quite a fairy tale ending, but definitely some of the most action-packed racing one is likely to see anywhere!

Congratulations and a big thanks to Mac McGrew and Billy Hofmeister for all the big shots of adrenaline!  That performance was the talk of the bike show for the rest of the weekend.