Showing posts with label Performance. Show all posts
Showing posts with label Performance. Show all posts

The Status Quo of Electric Cars: Better Batteries, Same Range





"The 2010 Nissan Leaf and Mitsubishi i-MiEV have exactly the same range as the 1908 Fritchle Model A Victoria: 100 miles (160 kilometres) on a single charge."

A very interesting article from Low Tech Magazine: https://solar.lowtechmagazine.com/2010/05/the-status-quo-of-electric-cars-better-batteries-same-range.html

Janus Design Updates

Here are two recent video updates showing the typical design process for developing a new Janus part. In this case, the part is an upgrade for our most recent model, the Griffin 250, a dual-sport style motorcycle in the tradition of the early "scrambler" style motorcycle. Scramblers were the first motorcycles built specifically for riding off-road and were the forebearers of today's dedicated dirt bikes. This component protects the frame rails and engine cases from debris and obstacles with could dent or otherwise damage the motorcycle in off-road riding conditions.



Three Days of Hammering

 Just over a hundred exhaust pipes

The new through-frame "cali" pipe with a number of cones for other models

The Paragon...

Here is a sneak preview of what I was doing in the few moments I wasn't working on my thesis this semester. MLM's Devin Biek and I have set out to design and build a custom moped frame from the 19" wheels and swing-arm up to the polished aluminum tank and seat. Oh, and the pedal shaft... Our inspiration comes from 60's & 70's 50cc GP racers with a flavour of 20's and 30's record breakers. Don't mind those EBR's they're just on there for the mock up. More to come in good time...

Design Precedents:
Early Triumph racers
'65 Honda 50cc GP racer
The 1937 Excelsior "Manxman"
Italian 50cc racers

The famous supercharged Zenith "Super Kim"
60's Minarelli 50cc GP racer
Ivan Wicksteed's Brooklands record breaking supercharged Triumph Speed Twin

60's & 70's GP racers
Harley Davidson board track racers

I love this shot. And those handlebars...


Moped vs. Pitbike



Not so good on the turns, but Devin's carefully built and tuned setup put out more power than the motorcycle. Isn't this track fantastic? I can't help but compare it to a sort of Brooklands for mopeds.

The Nordic Folkboat

Tord Sunden's Nordic Folkboat is a sailing legend. She was one of the few items of exceptional merit to emerge from the horror years of 1939-1945 when much of the world was experiencing the convulsions of war. Sunden's home country was Sweden, which had declared neutrality in World War II. In the early 1940s the Swedes organized an international competition for a new common Scandinavian class of sailboats. The organizers were looking for a cheap, fast, seawo rthy, one-design racing boat that could also be used for family cruising during weekends and holidays.

Nearly 60 designs were entered for the competition, but none was accepted outright, and Tord Sunden, then an amateur yacht designer, was chosen by the organizing committee to pull together the most promising aspects of the top four designs submitted.

The result was the nautical equivalent of the German Volkswagen, the people's car. She was named the people's boat, the Folkboat. But little did the organizers of the competition imagine how successful she would be Eighty orders poured in from all over Sweden before the final plans were completed.

Today, 60 or so years after the first Nordic Folkboat was launched, there are thousands of Folkboats afloat: wooden ones and fiberglass ones. The majority are in Europe, with Sweden leading the pack, followed by Denmark, Germany, Finland, and the Unite d Kingdom. There are about 120 in San Francisco, where the San Francisco Bay Folkboat Association administers the fleet, and where the Folkboat's wonderful heavy-weather performance is much admired.

Besides the Nordic Folkboats, all of which comply with the class's one design rules, there are thousands of near-Folkboats, close look-alikes such as the Contessa 26 (featured in the September 1999 issue), most of which attempt to increase her interior living space with more beam, a longer waterline, and a larger coachroof, while retaining her fabled seakeeping qualities and her classical good looks.

In 1966 Tord Sunden introduced a variant of the classic Nordic Folkboat that lacked the traditional lapstrake planking. It was carvel-planked and featured a shallower, self-bailing cockpit. She also was more luxurious below. She was known as the Intern ational Folkboat, but the Scandinavians regarded that description as misleading, and referred to her only as the "IF Boat." The term International Folkboat survived in the United States, however, and the International Folkboat Association of San Francisco Bay held sway over their racing and cruising activities there.

Basic design
The original design concept had a long, overhanging stern, like a 30-SquareMeter's. But that was later chopped off, probably because a long overhang adds considerably to building costs. The result was a much more seaworthy transom stern. The transom, h owever, was given a handsome rake so it would better match the moderate overhang of the bow, and thus the after end of the full keel also was clipped away to line up with it. That, together with the generous cutaway up forward, greatly reduced the wetted area of the keel without affecting its efficiency. Early critics thought the raked rudder would make steering difficult under some circumstances, but experience proved them wrong.

The first boats were, of course, built of wood. Their bulls were clinker-built, or of lapstrake construction, with each strake overlapping the upper edge of its neighbor below. This makes the boat strong and light. It also adds greatly to her looks by repeating and emphasizing the sweet lines of her sheer.

The first fiberglass Nordic Folkboats were legalized in 1977 and were exact reproductions of the wooden boat, including the overlapping strakes. They raced on equal terms with wooden boats and were forced by the strict one-design rules to use wooden ma sts.

The International Folkboats were regarded as a separate class, although their overall measurements and design were basically the same. They, too, were produced in fiberglass, but with smooth topsides and lighter aluminum masts.

Between 1967 and 1984, when production ceased, Marieholms Bruk, of Sweden, launched more than 3,400 International Folkboats, hitting an annual record high of 552 boats in 1975. After that, there was a steep decline in demand, although almost 1,000 were sold in the next nine years.

Production of fiberglass Nordic boats also continued apace, and a Danish boatbuilder, Folkebådcentralen A/S, of Kerteminde, has now built more than 900 Nordic Folkboats that are solid GRP replicas of the original wooden-hulled design, lapped strakes and all.

The Folkboat has a rounded underbody with fairly slack bilges, a combination that makes for slight initial tenderness but more than compensates for it with comfort at sea. After that initial tilt, she stiffens up considerably, so much so that she is ab le to race in winds strong enough to keep other classes in port. The topsides and the cabintop are low, offering little resistance to the wind and making no concessions to creature comfort below. The foredeck is uncluttered—there are only a hatch and a mooring cleat to stub your toes on—and convenient to work on.

The cockpit is a compromise between the needs of racers and cruisers—big enough for a racing crew, barely small enough for serious deepsea cruising. Some Folkboats have a deep cockpit that is more sheltered and more comfortable, but it drains into the bilge. Serious deepsea sailors will want the other version, a self-bailing cockpit that will not endanger the ship if it fills with water. The rudder hangs outboard of the transom, a simple, strong and easily accessible arrangement. The tiller sweeps across the after deck, but doesn't interfere much with the crew in the cockpit.

The engine is a matter of choice and depends on whether your boat is Nordic or International. Some boats have a well in the cockpit for an outboard motor of between 5 hp and 8 hp. Others mount an outboard on the transom. Still others prefer an inboard auxiliary, usually a single cylinder diesel. If you're planning an ocean crossing in a Folkboat, it would make a lot of sense to choose an outboard, and to keep it on the transom. If you find it interferes with your self-steering gear, you may have to hou se it in a well, in which case you can either leave it down, causing a little drag in the water, or remove it and store it below while you're on passage. The inboard engine makes more sense for weekenders or coastal cruisers who won't miss the valuable st owage space as much as the bluewater cruisers will.

Accommodations
It doesn't take long to describe the Folkboat's accommodations, although they, too, can vary according to whether she's Nordic or IF, and from builder to builder. On the IF boats, there's usually teak everywhere, and vinyl headliners. The hull is lined with padded vinyl, too, in place of the wooden ceiling. The V-berth has two berths more than 6 feet long, and the main cabin has two settee berths which are even longer.
Some boats have an enclosed head compartment, and others are supplied with a portabl e head. There's a rudimentary galley, and there may even be a small chart table. There's usually a hanging locker somewhere, and a few lockers and shelves scattered around the place, though not nearly enough for a long voyage. Nowhere is there sufficient room to swing a cat, and nowhere is the headroom more than 4 feet 8 inches.
The interior is bright and airy, though, especially with the companionway sliding hatch open, and seems very welcoming and protected in contrast to the exposed conditions of the cockpit.

The rig
The Nordic Folkboat is a Bermudian sloop with a wooden mast and a conspicuous fractional rig the forestay joins the mast about two-thirds of the way up from the deck. This makes for a small working jib and a large mainsail. It is, perhaps, not as effic ient as a rig with a larger jib, seeing that the jib does most of the work when going to windward, but it certainly makes for happier cockpit crews when the load on the jib sheets is small.

Folkboats not subject to the one-design racing rules usually have modern masthead rigs and aluminum spars. Many of the boats in the United States are rigged that way. If you're more, interested in crossing oceans than in racing around the buoys, the al uminum masthead rig might be preferable because it makes provision for double lower shrouds in place of the single after lower shroud that is standard on wooden masts.

The mast is stepped on deck but appears to be well supported by a massive deck beam and seems not to compress the cabintop as so many others do. Presumably, after more than 50 years of racing and ocean cruising, the builders of Folkboats have got it ri ght.

Right from the beginning, Nordic Folkboat owners agreed to race without spinnakers, to make thing easier for family sailors and shorthanded crews. But those gung-ho Finns couldn't stand it. Even though they couldn't compete internationally with spinnak ers, they raced with them among themselves.
"We simply think that sailing with a spinnaker is more fun, and that it makes sailing more colorful," explained a member of the Finnish Folkboat Association.

Performance
Any class that is still going strong after more than 50 years obviously has something good going for it. The Folkboat has several excellent features, not the least of which is her performance. For a full-keel boat, she is surprisingly fast and close-wi nded. Her PHRF rating is 228 for boats with outboard engines and 234 for boats with inboards.

On top of that, she's easy to handle. A picture of IF Boat 377 (Magnificent Obsession) published in Latitude 38 magazine in June, 1998, shows her rail down just outside San Francisco's G olden Gate in 25 knots and more. She has one reef in the mainsail and full working jib—and her tiller is being held dead fore-and-aft. No weather helm there.

The Folkboat is indeed revered for her ability to carry sail in strong winds, and no doubt her extra-heavy keel is largely responsible for this. The ballast ratio is an extraordinary 54 percent, which means the iron keel alone weighs more than all the rest of the boat. Little wonder that Folkboats were, and still are, so popular in the blustery San Francisco Bay area.

Her performance as a seaboat is legendary, of course. It wasn't just a coincidence that two of the six boats in the first Singlehanded Transatlantic Race, in 1960, were Folkboats. Valentine Howells raced in the conventional Folkboat Eira, while Colonel H. G. ("Blondie") Hasler sailed a much-modified Folkboat, the famous Jester, which had a standard hull but a flush deck with a central control point and a Chinese lug rig.

The long keel gives the Folkboat good directional stability, and this, together with her zesty performance and her easy motion, makes her a sensible choice for a singlehanded voyager or a young couple—and we say a young couple only because young p eople are more likely to be forgiving about the Folkboat's biggest disadvantage, her lack of interior space.

Known weaknesses
After nearly 60 years of production and real-life testing, there are no weaknesses left in the Folkboat that are not patently obvious, such as the cramped accommodation quarters. This is a very open, honest boat.

If you're contemplating buying one for a long voyage, you'll have to look for the wear and tear applicable to boats in general. Inspect the hull for the dreaded boat pox, if she's GRP, and be careful to locate any areas of rot if she's wooden. Dance on those fiberglass decks and tap away with your screwdriver handle.

As always, even if you think you know it all, it's a wise move to get a second opinion. Let a qualified surveyor check her out. It's your life that's at stake.

Owner's opinions
This is another boat people fall in love with so passionately that it's difficult to get an owner to say a word against a Folkboat. Her classic beauty alone is enough to still all criticism.

Yet the physical exploits of her devotees give us valuable insights into her abilities when the sole arbiter is the sea itself. Blondie Hasler's wooden Jester is both a good and a bad example of this. Good, because she crossed the Atlantic 14 times. Ba d, because she was eventually lost at sea without trace. But she was very old and she had suffered more punishment than a dozen normal boats.

From the waterline down, Jester was a normal Folkboat, but the rest of her had been greatly modified by her owner, who was much given to invention and experimentation. She was a very early model, and in fact sailed from 1952 to 1959 with Hasler's "lapw ing" rig before he threw that out and installed a junk rig for the 1960 Observer Singlehanded Transatlantic Race.

Hasler came in second in that race, a remarkable achievement. He was only eight days behind Francis Chichester's Gipsy Moth III a much bigger and faster 39-foot sloop that crossed the finish line 40 days after the start. Jester was driven hard, and was reduced in one gale to what Hasler described as "four reefs down."

The other Folkboat in that race, Eira, came in fourth out of six in 63 days. Eira was knocked on her beam ends, and Valentine Howells put into Bermuda to replace a chronometer he had lost and to repair some damage.

In 1963, Adrian Hayter circumnavigated the world alone, sailing halfway—from England to New Zealand—in Sheila II, a 32-footer. But he completed the New Zealand-to-England leg in a Folkboat called Valkyr. Mike Bale also sailed from England to New Zealand in a Folkboat called Jellicle, and had a crew for part of the way. In 1975, a 55-year-old Australian grandmother named Ann Gash sailed around the world singlehanded in a Folkboat called Ilimo. She chose the east-to-west route via the Panama Ca nal, but had the boat shipped for part of the way, from Ghana to England.

More recently, a British Folkboat called Storm Petrel was completing an unusual circumnavigation in 1998 with solo sailor Tony Curphey aboard. It was unusual because Tony's wife, Suzanne, was also making a singlehanded circumnavigation aboard her own b oat, a 30-foot Seadog ketch called Glory. They had originally set out separately, not knowing each other, but they met in New Zealand and got married in the Solomon Islands.

Tony's Folkboat often beat Suzanne's Seadog into port on subsequent legs of their tandem voyage and regularly clocked up 130 miles a day in the trade winds. Their plan, once they had completed their solo circumnavigations, was to sell their boats, buy a bigger one, and carry on cruising—but together this time.

There are undoubtedly many other Folkboats that have sailed around the world and around Cape Horn, singlehanded and crewed, whose names have not been recorded in the annals of small boat sailing. There was a time, 50 years ago, when such voyages were r are, and records were kept of individual exploits. Now that they are more commonplace, nobody seems to be keeping the tally, which is a great pity. Perhaps the Internet will one day find a place for the Roll of Honor of small boat circumnavigations; if it does, the Folkboat will surely feature prominently.

Conclusion
According to Marek Janiec, a member of the Swedish International Folkboat (IF) Association's technical committee, there are about 2,000 IFs in Sweden, and the market price there for a boat in excellent con dition is about 60,000 Swedish kroner, or $7,400 U.S. There are about 4,000 IF Boats scattered throughout the globe, which makes it the biggest deep-keel racing class in the world.

"In Denmark, the price is 20 percent to 30 percent higher, and down in Europe, still 20 percent more."
So—would you score a financial coup by going to Sweden, buying a cheap Folkboat, and sailing her home? Probably not, although it's a very attractive plan, in any case. Secondhand International Folkboats sell on the West Coast of the United States for between $10,000 and $14,000, so the savings are not substantial in actual dollar terms if you factor in travel and accommodation charges. A brand-new fiberglass Nordic Folkboat costs about $40,000 in Denmark.

Wherever you buy one, a Folkboat represents good value for a boat capable of carrying one or two people around the world, albeit in cramped surroundings. Besides that, if you have any finer feelings at all, you'll have to agree that she's one of the mo st beautiful boats ever made to go to sea. Just looking at her riding to anchor in her own reflection in a tropical lagoon will make your heart leap with delight.

Text from The Nordic Folkboat: Little Beauty with a Big Heart by John Vigor.

Also, a here is a link to Sea Room a film featuring the Folkboat about the 1976 St. Francis Yacht Club's Woodie Regatta in the San Francisco bay.
 

This little Folkboat was built between 1964 and 1965, probably in one of the original Scandinavian Folkboat shipyards. She is in very good condition and was sailing earlier this summer, but could definitely use some love and attention. Her exterior varnish is a bit shabby and the electronics haven't been used in a while. She is possibly the only Folkboat on the Great Lakes. Equipped with riding lights, fog horn, oil lamp, lit binnacle, and four berths, she should make a fantastic cruising boat, or even enter some races with an appropriate handicap... I am sure there will be many more stories to come from adventures on this little beauty. 

Variator Tuning

As I described earlier, the Shanghai Shuttle can't quite hit the power band of the new pipe. This is because the variator is opening too quickly, making the gear ratio too tall to allow the bike to get into the pipe's power band. In order for the bike to hit the power band in the highest gear ratio of the variator, the variator must gradually open throughout the range of the power band.


A variator works on the principal of centrifugal force. As the rpm of the crank (and thereby the variator) increase, three weights (in a Honda Hobbit) are forced apart on ramps which in turn force the variator to close. As the variator closes, the belt running between the two angled plates is forced further out on the pulley. This changes the gearing of the bike from short to tall, or from low to high.

The picture on the right shows the variator in the closed position during high rpms. Notice how the rear variator, described in the picture as the "driven pulley," is open. This variator does not contain weights but rather a spring which is tuned to take up the slack of the front variator or "drive pulley". The benefit of a variator is that you essentially have an infinite number of gears between low and high gear which means, on a well tuned bike, maximum torque throughout; from low to high end.

However, if a) the variator closes too quickly the bike will drop out of the power band and be unable to reach maximum rpms, or b) the variator changes too slowly the power band can only take place within a limited range of the variator, meaning that you could top out well below your top gear.

The solution to this is to tune the variator to close later by lightening the weights in the front variator or by putting a stronger spring in the rear variator. If done correctly not only will you shift later, but the shift or variation will occur over a much wider range. Today I started by lightening the weights. There are three weights in a Hobbit variator. I weighed each of them on a triple beam and the average was about 14.8 grams. I found a drill bit that looked about right and drilled out the center of each weight taking off approximately 5 grams. 

The disassembled variator with a weight on the scale.


Drilling out the weight

A comparison of the weights before and after lightening.

With the freshly tuned variator back on the bike there was a noticeable difference. The variator opened much more gradually and wound up into the beginning of the power band at around 35 mph, but once again, shifted too soon to carry the bike through the variator while in the power band. As the picture above shows, there isn't enough material to take out any more weight. The next option is to either find lighter aftermarket weights, or even better, to find a stiffer rear variator spring to keep the variator from closing so soon. The good news is that there was a definite improvement, and there is plenty of room for more modification. Upgrading to a larger and more tunable carb will also really help. I took the bike out today for a trial run, and even without hitting the power band I was able to make high forties. On the downhills I could get into the power band and that was fun. It will be interesting to see how this Cali pipe performs on a variated bike once it's dialed in.

Variator images courtesy Just Gotta Scoot.

MLM Performance Exhaust

I made a post earlier about MLM performance expansion chamber exhausts, and another about how they work. I just got mine back from the welder last night (our welder apparently does pretty good work even after 12 beers) and bolted it up. My variator is opening way too soon for the bike to hit the pipe's power band and it feels like I am running a bit rich. I will either drill out the variator weights I have, or get some lighter ones so that the variator will open at more like thirty or thirty-five miles an hour and not fifteen or twenty like it is now. Nonetheless, I can feel the pipe wanting to hit the power band; it just doesn't have the rpm's. I have more pictures of the details such as the header flange I fabricated and the rear hanger, but in the meantime, here are some pictures of the basic process:
 
Pieces of laser-cut 18 gauge steel ready to be rolled into the cones of the "Cali" and "RevRun" pipes.

Devin can usually get about fifty cones out of a single sheet of steel. When we get the stacks of oddly shaped steel back we take them to various conical jigs made of either maple or steel, depending on the curvature and tightness of the cone, and basically beat them into shape with rubber mallets. It took me about a week to finally begin to understand how the metal would react to the impact and where exactly to direct the force of the blow.

The rolled cones ready for welding.

 After the cones are rolled we send them off to the welder who welds the ends together. Then we take them back to the jigs and true them up to fit together perfectly and then tack-weld them together creating the basic form of the exhaust. At this point they are nothing more than five variously shaped cones tacked together.

 
What happens if your hit your hand and not the sheet metal when rolling the cones...

 Then it is back off to the welder for the whole pipe to be welded up. When we get it back we then mock it up to a bike (in this case a Honda Hobbit) making sure that the header clears the center-stand and provides a clear flow of gases from the cylinder through the chamber. We also tack the hanger and perforated tube in the appropriate position. Then it goes back to the welder again.

 Here is the pipe getting the rear hanger, header flange, and silencer  welded in place.

 Jim, the welder TIG welding my pipe while smoking a cigar after a twelve pack of Mich Lite. 

He warned me that his welding might not be up to par, but I told him I had complete faith in his abilities (which I do) and he didn't let me down.

Here is my old stock exhaust. It is the little box down there under the magneto.

 And here is the bike with the new pipe...
I have yet to see how and where the pipe hits the power band, but the sound of the pipe is amazing. It is surprisingly quiet; barely louder at idle than the super-silent stock exhaust, but when you open it up it really sounds good, with a wonderful purr when you let off the gas. The bike is already going a bit faster than stock, even without hitting the power band. The pipe should clear the side cover once I work with it a bit. More updates to follow...

Hobbit Performance Exhaust

Just got finished mocking up one of the MLM "Cali" pipes I built with Devin to my Honda Hobbit yesterday. I fashioned my own header flange (who needs machinists anyway?) and figured out a rather ingenious rear hanger supported of the bottom of the sub-frame. Pictures to follow. 

In the meantime here she is:

Since this photograph was taken I have mounted the old headlight off my Puchavus to the front forks, installed a different carb and purchased the 21mm intake for the bigger 21mm PHBG I will be getting to go along with the new pipe.  Lets just hope the Chinese clone bottom end I'm running holds out...

Velocity Stacks and Garden Tractors

I experienced the unexpected thrill this weekend of a garden tractor pull in Shipshewana, heart of Indiana Amish country. While there were of course no Amish entrants in the event, the gray-hatted boys seemed quite interested, gathering around the machines as they prepared for their run in front of the adjustable weight.

Thrill might be a bit of an exaggeration; tractor pulls in general usually attract a very specific audience... That said, large tractor pulls are certainly a bit more exciting with a lot more power accompanied by massive wheelies, but my appreciation of small engine tuning was well rewarded with velocity stacks galore, massive carburators, and homemade exhaust systems--even if they were all four-stroke.

 
While most of the smaller tractors retained there starters, all of the more powerful machines required this interesting dolly mounted starter. Since tractor engines are longitudinally mounted this device was simply wheeled up next to the tractor and a belt run from the electric motor mounted at the top of the dolly. The car battery at the foot of the dolly kicks over the started and the tractor fires to life, while the belt slips harmlessly off.   

Replacing the Replaced Crank Seal, Again


I mentioned in an earlier post that I was rebuilding my Honda PA50II engine as it was showing signs of a bad seal: no idle, overheating, and other inconsistencies. While your replacing a seal it's usually a good idea to replace the bearings, especially if your running a kit. Honda cranks are pretty tough and I don't think performance versions are readily available, so I'm sticking with the stock crank. I ordered new bearings and bought a set of seals off a friend who also has a kitted PA50II. When I opened the cases (for which I had to make a special clutch-puller out of a Honda axle nut welded to a pipe with a M14 nut a bolt at the other end), I found the magneto side seal had completely worn through and that the seal spring was in contact with the crank. This was definitely the problem. 

Here is the bad magneto-side seal:

The split cases with existing bearings and seals:
 

I removed the old bearings, cleaned the cases inside and out and installed new bearings by heating the cases in a toaster and placing the crank (with bearings installed in a freezer) and then lightly hammering them together with an added layer of Yamabond.

 

After I had installed the new bearings and seals and almost reassembled the entire engine I realized that the stator plate has a little lip which requires that the magneto side seal be recessed in the cases about 1/4 inch. I hadn't realized this when I installed the seal, so I tried pressing the seal further into the cases. 

Well, I pushed it too far... Needless to say, I had a much worse case leak on my hands.

This was all in October.  I took a break... and about three weeks ago I cracked the cases again to reposition the seal only to find that the seal had been destroyed by the inexplicable PA50I worm gear on the crank (don't ask me why I have a PA50I crank in PA50II cases because I don't know).

The destroyed seal: 
 Regardless, the seal was done, so not wanting to leave my cases open for too long, I put the old seal that I thought wasn't bad back in. 

Apparently that seal was bad too...

So, I ordered another seal, and fresh cases gaskets from Treats along with a Malossi 21mm intake so I can run my 21mm PHBG carburator (off the Puchavus) as soon as I find it... I cracked the cases again, replaced the seal at the correct depth and reassembled the engine.
Variated cases are beautifully simple:

While I had the cylinder head off I noticed the piston was wearing around the edge, probably only at quite high RPM's because the damage was very light. I took a Dremel and cut a deeper squish band into the head.

Here's the damage, I'll try posting pictures of the modified squish band later:
 
The new engine runs very well, with some minor overheating that I think is a result of poor timing... I'll get to that later. In the meantime the carb is leaking... Ah, mopeds!

My current setup is a 70cc Polini cylinder with stock 12mm carburator and stock exhaust with notched stock variator. If I can get the overheating issues cleared up I expect to see 45mph at The Bourbon Bandit's Whiskey Business.

Next up 21mm PHBG carb and Motion Left exhaust.