World's Best Flowing Indian Heads

Kind of reminds you of the movie title "World's Fastest Indian" doesn't it? Sorry, nothing quite that cool here. Cool ....but not that cool. I recently finished work on a set of heads for an Indian PowerPlus 100 (that's the late model overhead valve engine, not the Flatheads of yesteryear). These were not the first of these heads I have done porting work on, but they were the ones I put the most time and effort into.

On the previous heads, I was strictly doing an "basic" porting job. I re-used the stock valves and simply worked with what was there. While I was still able to get a sizable increase in flow, for the valve size the results were disappointing (at least to to me). Thanks to Jeff Moll, one of the techs over at Fury Motors, on this set I was able to go a little further. Jeff not only sold the job to the customer, but he also provided me with a spare head for me to do preliminary experimentation on.

The PP100 (PowerPlus 100) heads were supposedly designed by a BIG name automotive firm who shall remain nameless to protect the guilty. Well, maybe not guilty; for all I know they may have been directed to design a lousy flowing intake port. If so, they succeeded with flying colors.

If you are familiar with the ports on Harley heads, then just picture the worst Shovelhead intake port you have ever seen and an average Evolution exhaust port blended into one head with a Twin Cam combustion chamber. Oh well, I guess it could have been worse. They might have used a Twin Cam intake port with a Shovelhead combustion chamber. Of course then they would have the Screamin' Eagle 103 open chamber head. Hmm.

Be that as it may, suffice to say, the PP100 has a decent exhaust port, a decent combustion chamber, and a really bad intake port. Now a bad intake port is one that flows poorly. A really bad intake port is one that not only flows poorly, but is missing material where it is needed to get good flow. Where Evolution and Twin Cam intake ports have a generous "hump" in the floor, the PP100 intake ports actually have a slight "dip" in the floor. Add to that the fact that each side wall of the intake port has a large "divot" across from the valve guide, and you have a head that is just plain begging "weld me ...WELD ME!"

A stock Indian PP100 intake port flows about 199 cfm at .500" valve lift, and about 206 at .600. Simply doing a standard porting job on this head using the stock valves will bump the flow to about 220 cfm at .500" and 234 at .600 (all of these flow figures are given at 25" test pressure). As a reference, stock Twin Cam heads flow about the same as the stock PP100 heads with a .100" smaller valve. Now if you increase the size of the Twin Cam valve to 1.900" (still .040" smaller than the stock PP100) and do a decent porting job, your flow will be about 243 cfm at .500 and 253 at .600". So, you can see why I felt the flow on a ported PP100 was disappointing, because despite gaining nearly 30 cfm, for the valve size it was dismal compared to a Twin Cam. In fact it is a little dismal compared to the 232 cfm at .500" lift that I can normally get from a Shovelhead (which incidentally uses the same valve diameter as the PP100).

As is most often the case with production heads, the PP100 heads suffer from the diameter immediately under the valve head being too large for the valve size. The easiest method to rectify this is to install a larger valve, which was the first step in working up the "spare" head. A 2.0" intake valve is enough bigger than the stock 1.940" to allow me to "get some shape" to the seat area. From there I went through and ported the head as best I could with no material added, which gave me 256 cfm at .500 and 259 at .600" lift. Now things are looking promising! Next some clay to add a "hump" to the floor, and fill in the side "divots" and we are in business. A test with the clay installed showed that it would be worth while to have the customer's heads welded up.

Since the weld came right to the intake seat, I cut the heads for a new oversize seat insert, just to insure that the welding in such close proximity to the seat would not cause it to fall out at a later date. After shaping the newly welded in material to match the clayed up head, the heads were ready for the flowbench again. 256 cfm at .500" lift and 272 at .600 were the final results. More than 50 cfm gain over stock at .500 lift and 65 cfm at .600. Not too shabby. 35 cfm better than a Screamin' Eagle Performance Head. Like I said, not too shabby. Are they the world's best flowing Indian heads? They just may be. Is there potential for more? How much do you want to spend?

So I will continue to offer a Super Street porting job on PP100

heads where I use the stock valves ($499). But now I will add a Bare Bones porting job with 2" intake valves and no welding ($625) and of course the Pro Street porting with 2" valves and welding ($1200) A little performance to fit most anyone's budget.

Flat Track and Old Iron

Last fall a long time local flat track racer by the name of Billy Hofmeister approached me about doing some work on his iron XL heads and cylinders. Since I have recently seen a resurgence in interest in porting work on these heads, and have done a few sets in the last year, I agreed to take a look at his heads.

His bike is an original factory XLR which is now outfitted with a 1969 XLCH 900 which he runs in local races in the open class. Last time out he had a cylinder break at the base, possibly because it had been shortened in an effort to raise the compression. Another used set of cylinders was in order, as well as some headwork.

The heads he had been running had been ported previously, but without benefit of a flowbench. They flowed about as good as can be expected with no way to check the work. Over the winter, as time allowed, I installed 2" intakes and 1 3/4" exhaust valves and a full porting job. Along with the head work, I found a set of 11.0:1 compression pistons.

Nothing too exciting here, you might be thinking; and I would agree, but what may be more interesting is the coatings we will be using. Cast iron does a great job of holding heat. Just what you don't really need in an air cooled engine. It tends to lead to all kinds of annoying little things like seized pistons and valves and such. One way of combating this heat build up is by the use of thermal coatings on the engine parts. While this technology is not new (I recall that the fuel class bikes were using them 15+ years ago) I have not seen or heard much about it in regards to antique motors.

Seems like a natural, but truth be told, I may not have thought of it except for Joe, one of my customers for whom I recently finished a big twin Flathead stroker build. He had done research on coatings and had many of his engine components done. The whole idea behind ceramic coating is to put a heat barrier on the part to prevent combustion heat from "soaking" into the part. On his Flathead, we had the combustion chambers in the heads, the combustion chambers in the cylinders, the combustion chamber side of all 4 valves, the "back" side of the exhaust valves, and the exhaust ports ceramic coated. In other words, everything that is exposed to combustion temperatures. We also had the a teflon treatment done to the piston skirts.

Unfortunately, due to some issues with the company that did the coatings on his motor, (horrible packaging for the return trip leading to broken fins along with coating the wrong ports) I was not about to entrust any parts to them. Luckily there was a local alternative. I have been having piston skirts teflon coated by a local business for a number of years. When I asked him about ceramic coatings, he said he had done some a few years ago, and would order some fresh materials if I was interested. I was.

So with the start of the racing season only a week away for Billy, I needed to get his motor wrapped up. Last Saturday I had Billy drop off the bike so I could do a "mock up" with clay to make sure there were no valve to valve or valve to piston issues. Just a very small amount needed to be removed from the intake pockets to give a little more radial clearance for the larger valves. Thursday morning I dropped off the pistons, heads and valves for teflon on the skirts and ceramic in the combustion chambers, exhaust ports and valves. Friday morning I picked up the finished pieces and started assembly. New high performance valve springs from Kibblewhite were in order, since with the porting work, the engine should want to rev higher.

So as of this writing the bike sets on a lift in my shop with just the carb left to install. I, for one, am pretty anxious to see how much the performance is improved with the increased airflow, higher compression, and a cooler running engine!

When Shovelheads Ruled the World, Part 6

When I left off this story in When Shovelheads Ruled the World, Part 5 , we had just loaded up the dragbike to head to Farmington, North Carolina for the HDRA National Finals. That's a pretty good jaunt from Minnesota, so I had made special provisions. Yes, for the 4th race of the year, we had our 4th different tow vehicle. The year was 1985, and my wife and I splurged and bought a 1979 Dodge van just for the trip! To help with gas expense we bring along another local racer, Guy, with his Panhead that he ran in the Handshift Class. Guy has to be one of the most obnoxious people I have ever known, but hey, gas money is gas money! As I recall, Guy still had to put the heads back on his bike, so we loaded it in the back of the van so he could work on it during the trip. So it was just my wife Jane and I, Bobby, Guy, one other friend, Jim, and a Panhead in the van; the Shovelhead dragbike on our same little open trailer behind. Cozy might be a generous way to describe it.

Guy endeared himself to me forever by immediately demanding to know if I had tuned up the van because he didn't want to have to pay for any more gas than necessary, and complaining that he could hear an exhaust manifold leak, and that better not cause too much heat on his feet when he took his turn driving. Kind of took the wind out of my sails as I had felt like quite the hero for going out and buying a van for the trip. Turned out that Guy need not have worried about heat, because his driving was so bad that after one turn, the rest of us unanimously banned him from another turn behind the wheel.

In light of the above, undoubtedly the hi-light of the trip to North Carolina came when Jane started to make sandwiches. Guy, with his usual tact, demanded "Jane, make me one of those!" My wife is known by most of my friends to be pretty feisty, so we were all somewhat surprised when Jane complied without any comment. She got her revenge, though, soon after Guy's sandwich was passed back to him. His exclamation upon biting into a sandwich that included a slice of cheese still in the wrapper was priceless. The story of the cheese wrapper has become legendary among the old drag racers we know.

We arrived at the dragstrip sometime after midnight on Friday night. Of course the gates were closed, so the best we could do was find a field road approach to park on. No one got a comfortable nights sleep, but at least here the weather was mild. The next morning we were early to the track, and all set for a day of racing! Or were we? The first thing after unloading the Shovelhead, I opened my toolbox to double check all of the fasteners. What do you suppose was the very first thing to meet my eye but all four of the teflon wrist pin retainers!

That's right, in my rush to get the bike finished, I did the one thing I had been so worried about. I forgot to install parts, and here we were half way across the country! We were just very lucky that the retainers were in plain sight in the top of my toolbox! So, off came the heads again! No extra gaskets, so I would have to re-use what came off, but that didn't look to be a problem. In short order, I had the motor back together again, and ready to run.




With the modifications we had made since the last race, there was no doubt that the bike was faster. I believe that Bobby lowered his own 1/8 mile national record with the first pass. The competition was much tighter than at other races, with other bikes running times close to our old record, but thanks to our new found power, we still had a nice cushion.

Again Bobby was kind enough to let me make a pass on the Shovel during time trials. The fact that I ran in the 7.50's with my extra 45 pounds and inexperience showed that the Shovel really liked the new cam and higher compression.

Once again Bobby was able to breeze through eliminations with the most exciting moment being when the bike unexpectedly wheelied for the very first time. True, the front wheel came only about a foot off the ground, and Bobby didn't miss a beat, but it was such a shock to all of us, that it remains one of the hi-lights of the race. By the time our class eliminations were done, Bobby had won the Street Racer FL class, and set new 1/8 mile national records of 7.275 seconds, and 99.33 MPH.




Our performance in the run off between classes had yet to go our way at any of the races so far. Would this fourth time be the charm? We were sure hoping it would be. A little frustrating to have the quickest street class bike at three races in a row, and still get beat out for the "Street Eliminator" title. Tough part was, there was really no one to blame. Bobby's reaction times were consistently at least as good, and most times considerably better than the competition's.

As we checked the bike over to get ready for those final eliminations, everything was looking good. Since Bobby had just lowered the record in our class by about .04 of a second, we knew that he should be in pretty good shape in that regard since he would be indexed on the old record. The last thing to do just before we pushed the Shovel up to staging was to add a little more gas. And that's when it happened. One of those moments that seem that it should be inconsequential, but is locked in my memory forever. I was pouring as Bobby held the funnel. We both watched in disbelief as a minute piece of "fluff" from a tree lazily drifted down and into the funnel. Although it happened rather quickly, it was as if it was in slow motion. To this day I have to wonder if one of us might have grabbed it if we hadn't been taken so much by surprise.
We both saw it, then we looked at each other in amazement.

Such a small piece, what could it possibly do. I had no filter in the tank, nor in the fuel line, and it would not have been large enough to clog one anyway. Probably not large enough to even clog a jet! We may have had time to drain the tank, but it would have been cutting things pretty close. I made the executive decision and opted to ignore it and run the bike the way it was.

Soon we were in the staging lanes and time to start the bike. Only it wouldn't. I kicked, and kicked, and kicked, and kicked some more (I was in much better shape back then). Then Bobby kicked, and kicked, and kicked some more. When we lifted it off its kickstand, gas ran out the carb, so now we knew it was badly flooded. We both knew right away what had happened. Sure enough, our piece of "fluff" that had floated down into the gas tank, had made its way to the float needle and seat, and was keeping it from shutting off the flow of gas. We were about to miss our first round when in a fit of desperation we asked if we could start the Shovel on the rollers that were usually reserved for pro class bikes.

Now back in the "old days", rollers were the most common way to start your drag bike. Normally one set of them was set up near the front of the staging lanes. Picture a pair of giant rolling pins about 6 feet long mounted side by side with bearings on the ends and you have a pretty good idea of what rollers looked like. One rear wheel of a car or van would set on one end of the rollers and the bike's rear wheel on the other end. With the bike in gear and the clutch pulled in, the car would accelerate, getting the bike's rear wheel spinning at a good clip. Then when you popped the clutch on the bike, the motor would start turning. At that point when you gave it ignition, it would usually start almost immediately.

Neither Bobby or I had any experience starting a bike on rollers, and the Shovel was not going to start easily. Despite all that, Bobby handled it like a pro, so with just a few words of instruction from the gentleman running the car on the rollers, he had the Shovel's engine spinning over. Not starting, just spinning over. Seemed like an eternity, but it was probably less than ten seconds of the engine spinning over on the rollers before it cleaned itself out and roared to life.

Now the trick would be to get the bike to the starting line without running it out of gas by leaving the petcock off too long, or flooding it again by leaving the petcock on too long. Ideally Bobby would turn the petcock on at just the right time so that the float bowl would be just reaching full as the lights turned green. We'll never know how close Bobby came to timing it perfectly, but he must have been pretty close. The Shovel launched fairly good, but flattened out pretty bad in midrange. The bike in the other lane, another Shovel (but with a turbo and nitrous) had us by a couple bike lengths by the end of first gear.





Each time Bobby shifted, the Shovel would go flat as it was pulled down in rpm's, but would start running clean and gaining ground as the rpm's came up. But then, just as Bobby was closing in on the other bike, he would have to shift, and loose the ground he had just gained. So once again we lost in the first round of the eliminations between class winners. In retrospect, I have little doubt that I never had the main jet quite small enough for the low elevation in the first place, or else the extra fuel in the float bowl wouldn't have given such similar results as being too rich in the Colorado Springs race.

So was this a lousy way to end the racing season? Not at all. I don't think any of us spent more than a few moments in disappointment. After all, Bobby had dominated his class at all four races that we attended. Along the way he set a total of four national records. Not too shabby for a couple of guys who just set out to see how their bike measured up!

And now for the GOOD NEWS!

If you have been following this blog, you may have noticed that I stated that I had yet to post a message on the gospel of Jesus Christ, and that I intended to do so. In my post entitled First, the Bad News I told you that I believe that in order to have any kind of understanding and appreciation of the good news of the gospel, that we first needs to see that we are guilty of breaking God's laws. In my second post on the subject, Just a Little More Bad News , I attempted to explain that being found guilty, we are under condemnation, and in realty should serve out our sentence in hell. Once a person is fully convinced that they are indeed guilty and deserving punishment, it is then proper to introduce them to the good news.

What wonderful, glorious good news it is! That God would lower himself to such an extent as to take on human flesh, live a sinless life, and then be sacrificed in our place! Once we understand the terrible condemnation that we have heaped upon ourselves through our sinfulness, then Christ's payment is so much more precious!

We can find the "gospel" spelled out very precisely in Paul's letter to the Corinthians. This is probably the clearest, most "compact" presentation of the good news in the bible. 1 Corinthians 15: 1-4 says "Moreover, brethren, I declare unto you the gospel which I preached unto you, which also ye have received, and wherein ye stand; By which also ye are saved, if ye keep in memory what I preached unto you, unless ye have believed in vain. For I delivered unto you first of all that which I also received, how that Christ died for our sins according to the scriptures; And that he was buried, and that he rose again the third day according to the scriptures:"

CHRIST died for our sins! Christ DIED for our sins! Christ died FOR our sins. Christ died for OUR sins! No matter which word we emphasize, there are many, many sermons that could (and no doubt have) been written on each aspect,

CHRIST died for our sins. Implicit in these 5 words are the fact of who Christ is. He is a man, and he lived a perfect, sinless life. He completely fulfilled God's law in every aspect; something no man before or since has even come close to doing. If he had not done this he could not have paid the price for anyone's sin, because he would have had to pay for his own. It is also necessary that he came and did this as a man, else he would not have been a suitable substitute for any other man. Just as we learn in Hebrews 10 that "... it is not possible that the blood of bulls and of goats should take away sins",, neither could any other creature be a substitute to pay for a man's sins. Not a lamb; not an angel; only another man. (That Christ is God incarnate is also clearly taught in scriptures, so don't get the idea that I would in any way deny Christ's deity). This explains why the bible teaches that Jesus was born of a virgin, that there could be no shadow of doubt cast on the fact that God was his father. But that Mary herself was a sinful human is shown in Luke 1: 46-47: " And Mary said, My soul doth magnify the Lord, And my spirit hath rejoiced in God my Saviour." A sinless person has no need of a saviour. But just as important is Mary's humanity. If she were indeed part of the godhead as some would suggest, then Jesus, being born of God the Father and Mary the Queen of Heaven, would not be a man. We would all be undone, because if Jesus was not a man he would not be a proper substitute to die for us.

Christ DIED for our sins. He suffered and died a cruel death on the cross. Worst of all he suffered the wrath of God, culminating in the declaration of Jesus just before his death "My God, my God, why hast thou forsaken me?" (Matthew 27: 46) Jehovah is a God of justice and judgement as Isaiah 53: 11 says: " He shall see of the travail of his soul, and shall be satisfied: by his knowledge shall my righteous servant justify many; for he shall bear their iniquities."

Christ died FOR our sins. As previously mentioned, Christ lived a sinless life. He had perfectly kept all of God's laws, so that he could be the spotless lamb of God, a blood sacrifice to atone for our sins. Christ died as a substitute for us. A perfect justice demands that a payment be made for offences. God is perfect in every way, including his justice. In order to fulfil perfect justice, Christ took the punishment that we earned by our breaking of God's law. Just as Jesus lived a sinless life in our place, he died to pay for sins in our place.


Christ died for OUR sins. Christ died because of our sins. It was the only way to satisfy God's justice without sending each of us to the hell we deserve. As I tried to emphasize in First, the Bad News we need to see our sins as personal, and just between ourselves and a Holy God. We need to see our sin as exceeding sinful! Our sins demand punishment. Jesus Christ took that punishment upon himself, that we might escape the judgement we deserve.


Christ died for our SINS. We are all sinners deserving punishment. I attempted to cover that in the two previous posts on bad news. Christ died not only to save us from the penalty for our sins, but as Matthew 1:21 says; "And she shall bring forth a son, and thou shalt call his name JESUS: for he shall save his people from their sins." This also is part of the good news. Not only are we saved from the judgement that our sinfulness demands, but we also are made free from the slavery to sin that we are under. Romans 6:14 tells us that sin no longer has dominion over us. That too is very good news!

Going a little farther in 1 Corinthians 15, we find the fact that Christ died for our sins is all according to the scriptures. When this letter to the church at Corinth was written, we did not yet have the New Testament. When Paul says "according to the scriptures", he is referring to the Old Testament. Jesus sinless life and substitutionary death was foretold in prophecy and foreshadowed in ceremonies throughout the Old Testament. The fact that Christ died on the cross for sinners is amazing. The fact that God revealed it beforehand through his word reinforces the truth of both the prophecy and of the act itself.

Continuing in 1 Corinthians 15; "And that he was buried, and that he rose again the third day according to the scriptures:" Christ's burial and resurrection too were revealed in Old Testament. Jesus himself tells us in Matthew 12:39-40: "But he answered and said unto them, An evil and adulterous generation seeketh after a sign; and there shall no sign be given to it, but the sign of the prophet Jonas: For as Jonas was three days and three nights in the whale's belly; so shall the Son of man be three days and three nights in the heart of the earth."

This resurrection from the dead of our Lord and Saviour is not only a glorious event, but it is our proof that God the Father found Jesus' sacrifice for sins to be acceptable. Acts 17:31 says : "Because he hath appointed a day, in the which he will judge the world in righteousness by that man whom he hath ordained; whereof he hath given assurance unto all men, in that he hath raised him from the dead."

Included in the good news is the fact that because Christ died for our sins, on the last day God will raise us up also. 1 Corinthians 6:14 says: "And God hath both raised up the Lord, and will also raise up us by his own power." We will be resurrected to live with and worship God throughout eternity!

Now perhaps all of this elaboration that I have attempted on the gospel as it is stated in 1 Corinthians 15 has only served to confuse the issue. The simplicity of the gospel is this: We are all sinners who deserve punishment, but Jesus Christ took that punishment upon himself, that we might escape judgement and instead have eternal life. God the Father laid all of this out in the Old Testament, and showed his acceptance of Christ's substitutionary sacrifice by raising him from the dead.

THAT is wonderful, amazing, glorious GOOD NEWS!

The Great Knucklehead Cylinder Controversy

Since the title of this blog is Knucklehead Theology, you are probably wondering why so little has been said about Knuckleheads so far. Not to worry, having owned and ridden Knuckleheads for over 25 years, and drag raced them for about 15, there is plenty to come.

Today I would like to talk a little bit about Knucklehead cylinders. We have all heard the horror stories of broken Knuck cylinders. And it is my guess that there are nearly as many theories as to why they break, as there are those stories. I am not going to claim to have the definitive answer, only theories of my own. This is one that I would love to have comments from others with their own thoughts.

The first time I saw a knuckle cylinder break, was while attending Motor Cycle Mechanics school at Hutchinson Area Vocational Technical Institute in about 1979. One of the other students (a Triumph guy) had brought in a Knuck chopper to work on for a friend of his. The engine that he had was a 61", but it had cylinders that were bored out to 74" plus. I don't recall exactly how much plus they were, but it would not surprise me if they were +.060 or +.070.

That is not unusual to find, but it does leave you with very low compression. There are no 74" bore pistons that are made for a 61" stroke (at least not that I have ever found), which leaves you stuck running normal 74" pistons. The only problem with that is due to the difference in wrist pin location and stroke between them, the 74" piston will be nearly a 1/4" lower at TDC than a 61" piston. (61" is 3 1/2" stroke/ 74" is 3 31/32")

Don't know if it was the owner's idea, the student's idea, or the instructor's idea, but someone's solution was to shave material off the base gasket surface to get the pistons closer to the top. I winch just thinking about it now. One wrinkle was that before the engine was assembled, another student bought the bike! The results were predictable. After the new owner finished assembling the engine, during initial start up, one backfire while kicking broke the cylinder off at the base! As a side note, the new owner bought a set of used 61" cylinders which were also at a 74" bore. He rode the bike for one season, and then sold me the knuckle engine when he bought a new "crate" Shovelhead motor. I ran that engine for many years and many, many miles with that ultra low compression.

The next time I had occasion to see an "exploded" knuckle cylinder, was a case of being in the right place at the right time. I happened to pull up to a stoplight behind another knucklehead. As the rider attempted to pull away in a quite normal manner, his front cylinder lifted. Of course I pulled over to see if I could lend a hand. This was in about the mid 1980s, so my memory is less than clear, but I do believe that the part of the piston which unfortunately was now in full view, was badly scored.

Fast forward about 10 years. While not a knuckle, the next broken cylinder that I remember seeing shares some similarities. This was on an old Pan/Shovel stroker belonging to one of the owners of the shop I worked for at the time. It had a set of +.070 stock cylinders. This one I took personally, because I had recently bored the cylinders. This one too had a badly scored piston skirt. (I believe that the scoring was due to the cylinders being powder coated after boring them which may have distorted them)

Soon after this, another acquaintance on his knucklehead had a cylinder explode while accelerating from a stop sign. As best as I can recall, this also had a badly scored piston. (I do not believe that I had anything to do with building that motor)

It should be obvious by now that all but the first incident that I related had one thing in common (at least if my memory serves me). That, of course is that in each case the broken cylinder was accompanied by a scored piston. As far as I know, they all shared one other thing in common; a large overbore on the cylinders.

Somewhere along the line a customer brought me a set of +.060 Knuckle cylinders to check for him. Looking at the bore I found something quite interesting. The bore had actually turned blue between the fins. Honestly, you could see where the fins were from the inside because the spaces between them was blue! For years after this I avoided boring Knuckle cylinders more than +.050. I just knew that if the cylinders were thin enough to turn blue like that, they had to be on the verge of exploding.

I am not so sure anymore. Over the years I have had the pistons score badly on my wife's 61" Knuckle numerous times, for numerous reasons. At least one set can be chalked up to the manufacturer. I saved the little instruction sheet that came with the pistons which called for .001 clearance. A couple more sets of identical pistons gave similar results. Then another set of identical pistons came with a similar little instruction sheet which called for .003 clearance. Oops! Another set went because we went for a weekend trip with a group of friends when the engine was fresh, the weather hot, and the speeds excessive. Another I attribute to a burned out head gasket sucking air. Well, you get the idea. But no matter how many pistons we scored with that 61", the thick cylinders held up fine.

Maybe I should point something out here. When I speak of a "scored" piston in a Harley, it is in reality a piston that has seized. The reason that in most cases the engine does not stop, is because of the extreme weight of the Harley flywheels. If pistons "scored" like this in any other motorcycle engine the motor would be stuck tight. Understanding that this piston scoring phenomena is actually a piston seizing phenomena should really shed some light on the broken knuckle cylinder issue.

Add to this, some anecdotal evidence from my 74" Knucklehead. I have run it for many years at +.050. I never was willing to bore to +.060 for the above mentioned reasons. Each time I have had it apart, I have honed it to bring it back to straight and round. I think that the last time I put it together it was with about .008 clearance on a set of high compression cast pistons. Never a bit of problem, and I run it very hard!

So here is the big question. Are the stock Knucklehead cylinders just too weak to be safe when bored much oversize? Or is the real culprit the mechanic that set them up too tight, causing it to seize? Well, before you go blaming your local mechanic, keep in mind that he probably sized your cylinders to specifications. Its not really his fault if factory specs give bad results, particularly if he does not do many Knuckleheads. Furthermore, too tight set up specs is only one possible reason for your pistons seizing. Anything that adds too much heat, or removes too much oil can give the same results. (think timing, idling in traffic, oil breakdown, etc.)

Are the "cheap" reproduction cylinders prone to breaking too? I really don't know. Some would say that they are. Part of the problem is that most of the information we have will be anecdotal (I can't believe that I am actually going to use that word twice in one day). Since a failure like this tends to be catastrophic, most who experience it once will be leery of taking any chances of it happening again. My guess is that if you had a +.070 break on you once, you would be sure to replace it with one as close to standard as possible rather than making some adjustment and using another +.070.

Well, it looks as though I am going to have to make this into two posts. In the second half I will offer my thoughts and attempt to offer some solutions. In the mean time, I would love to hear from any of you who have had Knuck cylinders break, and the circumstances.

Just a Little More Bad News

In my last post under the label Theology , I wrote a piece called First, the Bad News , concerning the necessity of understanding the bad news of scripture, before you will be able to appreciate the good news (gospel). Unfortunately, just a realization of the bad news, that you are a dirty rotten sinner (just like me) is not the whole story.

The "little more bad news" is, of course neither little in the amount that it is news or in the amount that it is bad. It is both big news, and very bad news. The "little more bad news" is that there is a penalty for breaking the Law of God. Just as our earthly governments set forth penalties for wrongdoing, so the Almighty God also has set forth penalties for breaking his commandments. A big difference is that here in this world we often "get away with" breaking laws. Often we can break the law without anyone ever knowing. Often we are not caught "red handed" and so are given the benefit of the doubt. Often the full penalty of the law is not brought to bear on us, because we are deemed to be a first time offender, or because there are extenuating circumstances.

Not so when it comes to Jehovah's laws though. He sees all of our sins, and knows all of our sins. You are not able to slip anything past God. Even your sins that no other person on earth know about. Psalm 139:1-4 says "O lord, thou hast searched me, and known me. Thou knowest my downsitting and mine uprising, thou understandest my thought afar off. Thou compassest my path and my lying down, and art acquainted with all my ways. For there is not a word in my tongue, but, lo, O LORD, thou knowest it altogether." Each of us has been caught red handed by God!

And God, being a totally righteous judge will hand down a perfect judgement. Every sin, every transgression of his law will be punished as it deserves. And there is a judgement coming! 2 Peter 2:9 proclaims "The Lord knoweth how to deliver the godly out of temptations, and to reserve the unjust unto the day of judgment to be punished:"

What is this day of judgement all about? The book of Revelation gives us a pretty good description of what will happen. Revelation 20:11-15 says: "And I saw a great white throne, and him that sat on it, from whose face the earth and the heaven fled away; and there was found no place for them. And I saw the dead, small and great, stand before God; and the books were opened: and another book was opened, which is the book of life: and the dead were judged out of those things which were written in the books, according to their works. And the sea gave up the dead which were in it; and death and hell delivered up the dead which were in them: and they were judged every man according to their works. And death and hell were cast into the lake of fire. This is the second death. And whosoever was not found written in the book of life was cast into the lake of fire."

Does God "grade on the curve"? Can a man's good deeds outweigh his bad, thus allowing him to escape paying the penalty for his sins? Not according to James 2: 10 "For whosoever shall keep the whole law, and yet offend in one point, he is guilty of all." Guilty of all! A just judge will not allow the guilty to go free. Just as we speak of paying a "debt to society", so must the sinner pay a debt to God.

No, this is the "little more bad news"; All of our sins must be payed for in full. Every last one of them. Bad news and more bad news! But if all of this bad news is causing you to despair, then maybe you really are ready for the good news. I know that I am anxious to get to the good news, and will in my next post on this subject.

When Shovelheads Ruled the World, Part 5

Three races; three class wins and two national records. Not a bad start for a couple guys who only started out to go to one race to see how they measured up. So why would they be thinking about making their bike faster? I guess that just comes down to the basic reason anyone is involved in any kind of racing.

With only the National Finals left in the season, I suppose it was only natural for Bobby and I to try something to go really fast at the last race. Bobby was the ideal partner in this respect. No sooner had we discussed the possibility of more modifications, than he was on the phone researching it.

I am not sure who he called first, but I suspect it was Jim Leineweber. He gave us some specs for distance between the valves while they were on their seats to see which of his larger cams would fit. Jim was probably also the one who suggested higher compression pistons. Lacing up a wider rim to spread the rear tire out and get more rubber on the pavement we figured out ourselves.

A call to Axtell Sales down in Des Moines got us a set of higher compression pistons for the Shovelhead stroker. I wish I could remember with any certainty what compression ratio they where supposed to be. They may have been 12:1. That doesn't sound quite so radical in today's world of efficient combustion chambers, but at a time when the most common modification to a Shovelhead was to put in low compression pistons (7.2:1) it was enough to really get your blood pumping just thinking about it! And beautifully machined forged pistons they were. You could almost feel the horsepower just holding them in your hands!

The cam that we settled on was a Leineweber L5. More lift, more duration, even more power! This was a much more serious race for us than the previous ones had been, so once the parts were in, Bobby sacrificed a couple weeks of riding on the street so that I could get his motor ready.

But first, I tackled lacing the new wider aluminum rim to the rear hub of the drag bike. Again , Bobby had come through by calling around until he found a suitable rim. A wide 18" rim was almost unknown in the Harley world back then, at least in our little corner of the universe. Normally a simple job, lacing this rim was a little more challenging since it came with 40 dimples, but no spoke holes drilled. Nothing my handy Black and Decker 3/8 inch electric drill couldn't handle though; that and a good eyeball that is.

With a week to go before we left for the finals in North Carolina, I got the bike finished. The motor was out of Bobby's Low Rider, new cam and high compression pistons installed, and back into the rigid frame. I think in was a Friday evening when I had it ready to fire up. I pushed it out of my garage, and fired it up.

By the next Friday night we planned to be on the east coast ready to race, so I didn't see any point in babying the new parts. I revved the motor....maybe even a little more than my judgement told me I should. The engine sounded strong, but almost immediately it came to a sudden grinding halt. What had I done?!? I felt like someone had punched me in the stomach. Obviously something had gone terribly wrong. Was it from my over revving? Had I made a mistake when I assembled the motor? What now?

So off came the heads again. The valves in one head were a mess; one broken off and the other bent and folded over; the piston far beyond salvage. All of the damage was in one cylinder, but it sure didn't look as if we would be going to the finals!

As I took the engine apart, it became clear that the initial source of the damage was not the valves hitting the piston, or even the valves hitting each other. To this day I am not exactly sure what the cause was. If I had not revved the motor so high, would that have just delayed the "incident" until Bobby was on the strip?

My first instinct was to throw in the towel, but after talking it over with Bobby we decided to at least see if it might be possible to fix the motor in time. Our Matco Tools dealer, who had helped us out with some cash before the Iowa race in exchange for putting his sticker on the bike, offered to pay for a new piston if we wanted to try to fix it in time for the finals. That was enough to seal the deal. We got another piston coming, a couple of valves, and found someone who was willing to replace the damaged valve seat for us on short notice.

Time was running out, but it looked as though it might all come together for us. As soon as I got the head back from having the new seat installed, I did a standard 3 angle valve job on it. In retrospect, I hate to think how much flow we lost from that, but hey, sometimes ignorance is bliss!

Our original plan was to leave right after work on Thursday night, but now I would be re-assembling the top end right after work. The modified plan was to be loaded up and to leave from our house as soon as the bike was ready. I decided that it would be best to actually hear the engine run before we loaded it up, just in case I had neglected something. The last thing I wanted to do was to get to the east coast and find I had left a critical part in my garage in Minnesota.

As the clock neared midnight, I tightened the last few bolts, and a couple of kicks later the engine was running. We probably didn't let it run for more than 10 seconds before I shut if off and we loadeded the bike up. Against all odds we were on our way to the HDRA National Finals in Farmington North Carolina!