EL Bonnie, Part 2: Never Easy

In my last post on EL Bonnie, I stated that the next step would be to mock the engine up to check/blueprint the breather timing. As is so often the case, easier said than done! My intention was to perform this quick and dirty, without regard to cam bushing clearances, but no such luck. I knew that I was dealing with an inferior aftermarket cam cover, and so at some point the bushings would need to be replaced and line reamed for proper fitment, but I thought I could get by with them for now.  The lineage of the cover was quite evident.  A certain company who will remain nameless to protect the guilty, reproduces these covers and puts them on their reproduction Knucklehead motors.  I have seen one other in the past; it too had damage to the bushings from misalignment.  One has to wonder how big a hammer it took to get one of these covers installed the first time.  It seems that S&S made the right call in casting their name into the covers they make, if for no other reason than to keep them from being mistaken for these gems. 

Did I mention that this motor is being done on a budget?  It has much in common with something I would build for myself in that respect; a lot of "spare parts" coming together,  in some cases those parts finding their way to the build based on availability and price rather than on fitness.

Before assembling the case halves for the mock up, I put the cam into the gearcase with the cam cover to ascertain how much it bound up in the bushings- the answer being plenty! Still thinking I could get this done quickly, I chose to line ream the cover bushing an extra couple thousands (the particular reamer I use for this operation is adjustable) since that would surely alleviate the bind and keep things moving. Wrong again! Apparently even the additional clearance was not enough to compensate for the mis-alignment between the case and cover. Time to re- think this.

After an appropriate bit of soul searching (to make the decision sound infinitely more dramatic than it actually was) it appeared to be the perfect opportunity to follow the old adage; when life gives you lemons, make lemonade!

The cam choices available are a (new) old Sifton 110 or an S&S FHP 420.  Both of them happen to be set up for a Torrington needle bearing in the crankcase rather than a bushing (the shaft for a Torrington will be approximately .0007" larger O.D. than one for a bushing).  That means that either the crankcase cam bushing would need to be reamed oversize (the original cam bushing had enough wear that it already fit) or the case would need to be bored for the larger outer diameter of the Torrington.  The bearing would have the added benefit of slightly less friction, so it seemed that the logical thing to do would be to use a Torrington on both ends of the cam.

Now, machining to install a bearing in the crankcase is pretty straight forward:  indicate in the existing hole and bore it to size.  The cover is an entirely different matter though, especially in this case, given there is good reason to suspect it was manufactured with the hole in the wrong place.  I decided to create a template.  I already had a 3/8" thick aluminum plate with the two dowel pin holes correctly located.  By installing the plate on the crankcase half and mounting it on the mill, I was able to indicate in the cam  bushing hole, and then going through the bushing hole, bore the aluminum plate. 

Indicating case bushing hole

Boring hole in template

Indicating template hole

Once I had a hole in the template, it was simply a matter of fabbing a couple extra dowel pins to align the cover to it.  Fortunately, at some point in the distant past I had built a fixture for holding generator cam covers level while installing and pinning bushings.  This made mounting the cover in the mill quick and easy.  Then, by indicating in the new hole in the template, I had the correct relationship between dowel pins and where the new cam bearing was to be installed.  BTW, the original hole in the cover checked as being only .006" off: I expected worse.

Boring cover for Torrington bearing

Once the new hole was bored and a bearings installed in both cover and case, another test fit with right case, cam and cover gave the results I was looking for: a totally free spinning cam!  Since I was in cam cover mode, I also tackled the pinion bushing.  I chose to go ahead and try installing a new bushing and line ream it, rather than going to extreme measures.  Kind of a "why go looking for trouble" approach, and in this case it paid off.  Another test fit with the cam cover bolted on the right case and the new S&S pinion shaft with bearings in place resulted in a very pleasant surprise.  Absolutely no binding even with only .0007" shaft to bushing clearance!  It appears that the cover manufacturer managed to get half of the bushing holes in the correct place.

Checking pinion shaft for binding

By the way, if any of those of you who are anxiously waiting for this motor are wondering, you may feel better knowing that the writing is lagging behind actual progress.

EL Bonnie

Some of fellows from over Wisconsin way have been scheming for several years to put a 1939 61" (model EL) Knucklehead on the great salt flats of Utah - better known as Bonneville. Joe Taylor, the owner of the "project," is joined by Tom Anderson and John Endrizzi in the quest to take home a record in the 1000MPSVG class at the AMA sanctioned annual BUB Motorcycle Speed Trials. For those of you not quite up to speed on class designations (I fit in that category too) the 1000 refers to the maximum displacement in cubic centimeters - hence a 61 inch Knuckle = 1000cc. The MPS narrows it down further, to a frame that is Modified/Partial Streamlining. The final piece of the puzzle is the VG which stand for Vintage Gas, limiting the engine to a production date of 1955 or earlier.

The trio does not walk into this endeavor with no prior knowledge of what they are getting in to; Joe and Tom have previous Bonneville experience racing under the Buell Brothers banner. This build will, however, be their first foray into the vintage side of land speed racing.

As may be expected, a project like this is not without its setbacks. Too small budgets are almost always an issue when regular guys take something like this on. A major setback in this particular build was the untimely death of the engine builder. That will definitely put a damper on a project!

Knowing the predicament that the Buell Brothers found themselves in, I had to weigh my morbidly obese workload against the possibility of being involved in a record setting endeavor. In the end, the deciding factor was this: given my penchant for high performance and knuckleheads, how would I feel if EL Bonnie set a record, but another engine builder's name was associated with it? What could I do but offer my service to build the engine?

Before going any further, it is important to note that a project such as EL Bonnie would be virtually impossible to complete without the existence of a company such as S&S Cycle. S&S has made the commitment to reproduce quality engine parts for these early motors. Witness the parts in the shot below; all from S&S, and all vital to transforming this dream into a reality.

As soon as Joe dropped off the engine, it became apparent that they committed no sacrilege by turning it into a racer. Nearly every square inch of the '39 cases showed evidence of welding repairs. If they could talk, these cases would probably have quite a story to tell. With Joe's permission, I decided it would be worthwhile to do some reinforcement modifications. I added a gusset to the left side of the left front motor mount (which showed evidence of at least one previous repair). Early Knuckle cases are also known to be weak on the left side in the cylinder spigot area. My solution was to weld 3/8" plate to that area, windowed just enough to leave the serial number pad intact.

Moving on to the the inside of the cases, windage is always a concern - at least to my mind. The "pocket" in the right side case quite obviously performs no function other than to save a bit of aluminum during the casting process, and I have always pondered what to do with it. What, if any, effect on windage this pocket has is any one's guess. On the other hand, when it comes to racing, I am a firm believer that the difference can often come down to a matter of adding together all the details. I've heard it before: "Do you really think that will make a difference?" My answer is usually, "We'll see." But the more honest answer is no ....but hopefully when it is added to the other dozen things that are too small to make a difference by themselves, it will!

A couple of thin aluminum plates cut to fit and welded into place smooth out the interior of the right case half. The next step toward minimizing windage was to polish the interior of the cases, including the gearcase. One of the final steps before final assembly on the case will be to treat them with TLTD, a oil shedding thermal dispersant coating.

Now you see it ...

Now you don't

So, if all the previous repairs had not distorted the cases, it was a good bet that with the welding I did, there was reason for concern! Besides, one of the keys to making this motor fast will be to keep the friction losses as low as possible. The first step to ensuring that was to mount the left case to the mill and indicate in the pinion shaft race hole (races removed). Once the indicator showed that it was centered in the hole, I gently installed the right case, torquing all the case bolts. Taking a reading from the indicator in the right side case race hole, I was far from shocked to find .012" runout. A +.025 race in the right case was the cure.

Next, with the cases still bolted together, I decked the bottoms of the motor mounts enough to insure they are true, and then did the same with the cylinder mounting surfaces. Before giving the mill the rest of the day off, I also machined the breather gear bore for the +.030 S&S gear, removing 70 years worth of damage in the process. Installation of the new crankcase races, and line lapping them to size pretty well brings us up to the present. Next is a mock up to blueprint the breather opening in the case and see what kind of piston deck height we are dealing with. To be continued ...

Christ, the Church, and Marriage

Wives, submit yourselves unto your own husbands, as unto the Lord. For the husband is the head of the wife, even as Christ is the head of the church: and he is the saviour of the body. Therefore as the church is subject unto Christ, so let the wives be to their own husbands in every thing. Husbands, love your wives, even as Christ also loved the church, and gave himself for it; That he might sanctify and cleanse it with the washing of water by the word, That he might present it to himself a glorious church, not having spot, or wrinkle, or any such thing; but that it should be holy and without blemish. So ought men to love their wives as their own bodies. He that loveth his wife loveth himself. For no man ever yet hated his own flesh; but nourisheth and cherisheth it, even as the Lord the church: For we are members of his body, of his flesh, and of his bones. For this cause shall a man leave his father and mother, and shall be joined unto his wife, and they two shall be one flesh. This is a great mystery: but I speak concerning Christ and the church. Ephesians 5:22-32 (emphasis added)

As shown at the end of the above passage, marriage is a symbol or picture of Christ and his relationship with the church. That would seem to help explain why there are so many dead set on destroying that symbol today. This passage in Ephesians is given to help us understand Christ's relationship to the church by holding up a biblical marriage as an example. Sadly, in the wicked world in which we live, the average marriage bears little resemblance to what scripture tells us it should look like. Still much truth about the nature of the church can be found here, such as Christ is the head and the church is subject to him. Christ loves the church and gave himself for it. He uses the word of God to clean and sanctify the church to make it holy, and even that there is an intimacy between Christ and the church that will be found only in that relationship.

If you are a Christian, this should lead you to a couple of conclusions. One is that your own marriage should reflect the values presented in Ephesians 5 so that it does not present a distorted image of Christ and the church to the world. The second conclusion a Christian should draw is that the church they belong to also should reflect the values presented in Ephesians 5 in it's relationship to Christ, so that it does not present a distorted image of marriage to the world.

126 Drag Motor - Another Update

Well, it seems that I have neglected to take as many pictures as I might have, but the engine has actually progressed since the last installment. A mock up to check valve to piston clearance revealed two things. The first was that the hunk of clay I have been using for probably 20 years for this purpose, has finally become just a little too hard. I read somewhere that plumbers putty also works well for this, and since I still had some left over from a drain repair last year, I gave it a try. Didn't like it. Even with a little grease on the valves, the putty didn't want to remain stuck to the piston. Happily, a call to my lovely wife caught her in the midst of shopping - what are the chances of that? Now I am the proud new owner of 99 cents worth of fresh Chinese made modeling clay! And yes; she did look for the American made version without luck.

The second thing that the mock up revealed was that the valve pockets in the pistons needed more clearance. The intake pockets were deep enough, but needed more radial clearance for the 2.125" diameter valves.

A trip to the mill took care of that, but the exhaust valves were another matter entirely. Not only did they not have enough valve to piston clearance, they actually touched the piston preventing a full revolution. This is a pretty unusual situation, and as such, it was unforeseen by me. And since it was unforeseen, I had already taken material from the inside of the piston domes to lighten them. Not knowing how much material would need to be removed from the valve pockets, but knowing I did not have much to work with, I chose to sink the exhaust valves deeper instead. I started by going .080" deeper to see if that gave at least some clearance (and it did), and then went back and cut the seats again to give a finished clearance of .100". A new pair of custom exhaust valves with shorter overall length have been ordered to put the stem protrusion back into a rocker geometry friendly state. Incidentally, the exhaust pockets also needed a little more radial clearance than they came with, despite the fact that I did not increase the exhaust valve size.

As I hinted at in my last post, the flywheels were cut down a fairly radical amount, making the balance trickier than usual. Normally when balancing flywheels, the counterweight section of the flywheel is the heavy spot, and one simply drills holes at the heavy spot to bring it into balance. When the flywheels start to get very narrow, the "counterweight" shrinks. With big bore pistons it is easy to come up with a situation where the "heavy" spot in balancing is on the crankpin side - not the place you want to weaken by drilling balance holes. After I had lightened the pistons as much as I felt was safe, that was still the situation I was faced with. Rather than creating a "swiss cheese" effect in the crankpin area of the flywheels, however, I used an end mill to "skim" the required weight. After multiple trips between the mill and the balance table, the flywheels came into balance with no holes drilled whatsoever. Sorry, but I neglected to take pictures.

As for the rest of the motor, the inside of the crankcases (including gearcase) were treated to an oil shedding coating, as were the flywheels once the balancing was complete. Again, I neglected to take pictures.

Once trued, the flywheels were installed in cases and the oil pump and gearcase assembled. As I await delivery on the custom exhaust valves, final porting work is the next order of business. The intake ports, as mentioned in a previous post, have had the floors welded up. Due to the large valve size (2.125" vs. the 2.0" the heads came with) a larger port opening size was in order. The port diameter that I chose was 1.900" (89% of the valve diameter). This of course required major modifications to the intake manifold, which included relocating the flange bolts. I will try to include some pictures when the heads are nearer completion.

Fortunately the owner gave me a bit of a reprieve on finishing up this motor, which has been a real blessing since I have a boatload of other work that needs to be finished up soon, not the least of which is a motor that is headed for the great salt flats dyno in Utah. Now, with that "teaser" I had better abandon the keyboard for more productive endeavors.

Memorial Day 2012

Memorial Day is the one day each year set aside to honor our nation's fallen soldiers. As is our custom at Valley View Baptist, the worship service closed with a patriotic hymn in honor of the occasion.  The hymn chosen this year was "God of Our Fathers."  I found it quite inspirational and wanted to bring it to your attention. 

The lyrics were written by Daniel C. Roberts for the occasion of the nation's centennial in 1876.  The music, a tune named "National Hymn," was written by George W. Warren specifically to go with the lyrics of "God of Our Fathers."  The following is a rendition from bobf72450's You Tube Channel.

Enjoy the music, but please remember to pray that our country might return to it's Christian roots.




Note: In the interest of accuracy, I believe that referring to this as The National Hymn is a mistake arising from the title of the tune, since to the best of my knowlege it has never had any official sanction  ...but perhaps it should.

KHS Chopper Class Open House and Knuckle Shuffle

Question: Where is the place to be on the weekend of June 1-3 if you are a big fan of vintage motorcycles






Answer: The Kennedy High School Chopper Class Open House, and a supporting event, The Knuckle Shuffle.


Every year the Chopper Class opens its doors to the public to showcase both their shop and the projects to which Kevin Bass' students have applied what they have learned. This year that open house will take place on Friday, June 1st.


But it doesn't end there. One of the guys at S&S Cycle came up with the idea of helping to support the KHS Chopper Class by staging a little get together in the sleepy little town of Yuba Wisconsin, just down the road from S&S. Group rides to Yuba begin on Saturday June 2nd from various locations throughout the Midwest (check the link for one near you). Last year's inaugural event was a rousing success, and this one looks to be a repeat. Money raised from the event goes to support the KHS Chopper Class.

This is a great little event combining a chance to support a worthy cause (keeping kids in school and teaching them useful skills) with some great riding through the scenic Wisconsin countryside, and an old fashioned biker get together. Or as the Knuckle Shuffle web site puts it "Hollister 1947 without the riot."

And did I mention the raffle of an S&S 93" Knucklehead motor .....?

Mother's Day 2012

Most of us remember the story of how the baby Moses was set adrift among the reeds at the edge of the Nile River. Since this weekend is Mother’s Day, I would like to consider his mothers part in this story. But first, here is some of the background to the story.

The children of Israel, who had originally come down to Egypt in order to survive a famine, eventually found themselves as slaves rather than just foreigners. But the Israelites continued to increase in numbers to the point that they were seen as a threat by the Egyptians. However a careful reading of Exodus chapter one reveals that the Pharaoh was not so much concerned that the children of Israel were becoming strong enough that they might overthrow his armies and take over the country, but rather he was concerned that they may become strong enough to escape from their captivity and leave Egypt. No more slave labor - can't have that. For this reason Pharaoh put out a command that every son born to the Israelites should be killed by casting it into the river. This is where we will pick up the story in Exodus chapter two.
Exodus 2: 1-10

And there went a man of the house of Levi, and took to wife a daughter of Levi. And the woman conceived, and bare a son: and when she saw him that he was a goodly child, she hid him three months. And when she could not longer hide him, she took for him an ark of bulrushes, and daubed it with slime and with pitch, and put the child therein; and she laid it in the flags by the river's brink. And his sister stood afar off, to wit what would be done to him. And the daughter of Pharaoh came down to wash herself at the river; and her maidens walked along by the river's side; and when she saw the ark among the flags, she sent her maid to fetch it. And when she had opened it, she saw the child: and, behold, the babe wept. And she had compassion on him, and said, This is one of the Hebrews' children. Then said his sister to Pharaoh's daughter, Shall I go and call to thee a nurse of the Hebrew women, that she may nurse the child for thee? And Pharaoh's daughter said to her, Go. And the maid went and called the child's mother. And Pharaoh's daughter said unto her, Take this child away, and nurse it for me, and I will give thee thy wages. And the women took the child, and nursed it. And the child grew, and she brought him unto Pharaoh's daughter, and he became her son. And she called his name Moses: and she said, Because I drew him out of the water.
　
It is interesting that in this passage, the name of Moses’ mother is not even mentioned. As I mentioned earlier, this story of Moses is a familiar one for most Christians. When we consider the story, we can’t help but put ourselves in his mother’s shoes. And yet how many of us even know her name? Later in the book of Exodus (6:20), her name is given as Jochebed.　
　
Now, can you even imagine what this was like for Jochebed? She was expecting a baby, and she knew that if she delivered a boy, then there was a death sentence on him. And indeed it was a boy, so she did the only thing she could do. Jochebed hid the child for as long as she could, which the bible tells us was three months. Can you imagine what those three months were like for a mother. The joy of having a newborn son tempered by the terror of being discovered. We have to assume that if the child had been discovered, it would have been his death.


Its not so hard to see how Jochebed took the risk of hiding Moses for those three months, stressful as it must have been. After all, what other option was there? A mother’s love for her child comes naturally. But what she did next showed not only love, but it showed ingenuity and faith. The bible does not tell us how Jochebed came up with her plan to make an ark and place the baby Moses in it near where Pharaoh's daughter came to bathe. We can only speculate that she was led by God to do so. After all, Moses was the one chosen by God to lead his people out of slavery in Egypt. And if Jochebed was led by God to place her baby into that tiny ark, then she still needed faith that God would protect her son through it.

But then comes the best part of the story. Because Jochebed put her faith in God to protect her baby, God allowed her to act as the nursemaid for her own child, and to be paid for it to boot! When we think about the faith that it took for Moses’ mother to place her baby in that tiny little ark and set it afloat in the river, it is something to marvel at. But, when you think about it, many mothers exercise that same type of faith. They care for their babies from the time that they completely helpless. They do their best to teach that child to care for themselves. As the children grow, they teach them about God the Father and about Jesus his Son. They do their best to see their children develop a relationship with Jesus. But eventually, when those mothers have done all they can, they have to just let those children go, putting their faith in God, that he will watch over them, just as Jochebed did.　
　
Of course there is another area of faith that applies to all of us, not just those who are mothers. That is the matter of putting our faith in Jesus. But just what does the phrase "put your faith in Jesus" mean? I think most of us have been around long enough, and know ourselves well enough to understand that we have each fallen short of God’s law. What we often don’t realize, though, is just how badly we have offended a holy God. If we consider the penalty paid though, it helps put it in perspective. Our sins are so offensive to God that it required the death of his only son to pay that penalty. Do you think your sins are just a little thing, and yet it took the death of Jesus Christ on a cross to pay for them? Once you do understand how serious your sin is, that is where faith comes in. Faith that Jesus paid for your sins. Faith that the payment was acceptable to God the Father. Faith that you are an heir to the promises of the Bible.


If you have never before done so, won’t you ask God to forgive your sins, and put your faith in Jesus the Christ?