Sunday, September 29, 2013

Machine Tool Spotlight - Hardinge Lathe

The lathe in my shop is a Hardinge Model DV/DSM-59, a fairly common and simple machine built in the 1940's and 50's. It is known as a "second operation lathe", and was primarily used as a production machine, rather than a toolroom machine.

These machines are not equipped with a leadscrew or provisions for auto-feed or screw cutting. While this can be limiting for certain operations, it also makes them extremely versatile to set up for production. My machine included a compound slide, quick cross slide, 6-position turret, and a standard tailstock. These all slot into the same bed, so the machine can be set up using any combination.

6-Position Turret


Compound Slide and Tailstock
Until I bought it, this lathe had apparently never left upstate New York. I purchased this it from a fraternity at my university. They in turn had acquired it from the student shop at RPI sometime in the late 70's who, if the plaque on the turret is accurate, had bought it from Eastman Kodak in Rochester.


Disassembled for travel

Saturday, September 21, 2013

Machine Tool Spotlight - Vintage Vertical Mill

I previously posted some pictures of my milling machine, while being used to machine out the welds in my BSA Bantam case. I acquired this mill for free several years ago, but it required a total restoration before I could use it. Unfortunately, I didn't take any "before" pics.

After Restoration and Recommisioning
This machine is a home-shop vertical mill, manufactured by the "Burke Machine Tool Company". I cannot locate any product literature or its exact product number, but its design and castings are remarkably similar to those used on the Burke Model 1:

Burke No. 1 Advertisement circa 1905
 This advertisement is from approximately 1905 so I would guess my machine is roughly the same age, although at some point it was modified from common belt drive to an electric motor. I found this machine while cleaning out a storage barn. The roof had suffered some major damage and was actually missing directly above the mill, so it had been sitting in a damp atmosphere for 30 years, and in essentially open sky for a further 6. The drip plate was full of rusty water, all the paint had peeled off, and every sliding surface was locked solid.
 I dragged it home and, with the help of some friends, began tearing it down to its individual components.

Electric Motor during Rebuild
Amazingly, after a summer's worth of grinding, chipping, repainting, and reassembly, the only parts that could not be reused were a few dozen fasteners and the threaded rod for locking the Z-axis. Despite its limited size and lack of dials, its provided me with years of reliable service since then.

Thursday, September 19, 2013

Carburetor Modification Part 2

Once the carburetor diameters were modified on the lathe, I boiled them for half an hour to leach out any remaining salt from the various passages. I bought a cheap pot from Wally World, filled it with water, and let it sit at a rolling boil:

Someday, I may actually cook FOOD on this stove...
I then blew the passages out with compressed air, and a bit of carb cleaner to purge any moisture.

A few years ago I bought a pair of grimy velocity stacks at a swap meet for a fiver, but never really knew what to do with them. I tried them out on my gutted mikunis, and found that they just happened to fit nearly perfectly. I just needed to file off some burrs and smooth out the casting, give the bellmouths a thorough scrubbing, and clamp them on.

Taking Shape
After that, it was relatively straightforward to clean and reassemble the rest of the carbs. I have no clue which jets to use, so I'll just keep using the ones that the carbs came with to get started. They were previously installed on a Triumph Trident 750, so they should be relatively close to the correct tuning for a 250cc piston each.

Clean and ready for installation
The only other major modification I made was to the float bowl screws. It is difficult to remove the bowl with a screwdriver when the carbs are installed, so I replaced them with a combination of spacers and thumbscrews:

Now the bowl can be easily dropped by hand, in order to adjust the jetting while in place.

Sunday, September 15, 2013

KZ400 Diesel Fuel Economy Test

Last fall, after installing the supercharger on the biofuel bike, we wanted to measure its fuel economy in real-world conditions. Upstate New York offers a lot of roads with radically-changing terrain, so we chose a route near Troy to perform the test. We filled the bike to the brim at a gas station on Route 2, east of Troy in Brunswick, and marked the fuel's height with a dipstick.

Our destination was Petersburgh Pass, a mountain pass approximately 18.7 miles away. The total route, upon return to the gas station, would be 37.5 miles with a total elevation change of 1579 feet.

Our Route

Resting at the Top

Parking Lot View

The bike performed flawlessly, although I was unable to shift into second gear on the steeper parts due to lack of power (as expected). The last 2 miles were a slow 20mph crawl to the top, but there were zero mechanical troubles. After returning to the same pump and filling up to the dipstick a second time, we measured a fuel consumption of 0.4 gallons, which calculates to an economy of roughly 95 miles per gallon, at top speed over variable terrain.

Tuesday, September 10, 2013

BSA Bantam - Testing the 12 Volt Ignition System

I was finally able to take some video of the BSA running with the new ignition system. Enjoy!

BSA Bantam Ignition Test

BSA Bantam - Repairing the Engine Cases

Backtracking on the BSA project a bit, the biggest obstacle to repairing the engine was the enormous crack that had developed in the crankcase.


No one I spoke to had ever seen a crack in that position before, and our best guess was that, over the years of sitting without a piston or cylinder head, the case had filled with water, froze, and split at the seam. Regardless, The case could certainly not be used like that, especially since 2-strokes rely on a pressure-tight bottom end to function correctly. I brought the case to a local welder to have the crack patched up, but the results were not...encouraging.

 Either there was still oil contamination in the crack, or the welder wasn't familiar with the material, but the results were extremely sloppy and porous. I ground down the inner weld only to find numerous blow-holes and voids. It was only a lack of available donor cases that kept me from scrapping this part entirely. I spent a week hand grinding and filing the weak welds down:

 ...and then was able to find a different welder who specialized in cast aluminum repair. His results were a huge improvement, and wiped away most of the irregularities left by the previous guy. I fixtured the case into my ancient milling machine to clearance the inside of the case for the crankshaft:

and decided to leave the outer weld bead alone. The case is so thin at this point that I decided the extra strength and material was more important.

Friday, September 6, 2013

BSA Bantam - Homemade 12V Ignition System

When I bought my Bantam Trail Bronc it was, lets say, a bit rough:

50 bucks, but the tetanus was free!
At that point, maintaining originality wasn't my concern. Just getting it running again would be a big enough hassle, so I left it mostly as is, and gave it a full engine rebuild and some new tires.

I won't get into the details on the engine build today, because that could take up several posts. I could write for pages about that job, so instead, I'm gonna focus on the modernized electrical system that I installed.

The original system was a low output flywheel ignition coil. I replaced all the bits with aftermarket parts, and was able to get the thing running:

BSA Bantam First Start

And then, after that? Nothing. The bike never started again. It sat in my garage for a year while I rechecked, modified, and adjusted every possible part. I never suspected the coil because, well, it was brand new, and the plug sparked whenever I held it against the case. Then, 3 weeks ago, I tried the same process yet again, holding the plug against the case and kicking it over. Amazingly, at that exact moment, the coil which had apparently been internally shorting all along completely died and produced no more spark. Eureka!

It turns out that if the output is too low, a plug that sparks freely when held in open air may not necessarily spark inside the engine, where the gasoline wets it down. Before rebuilding, I wanted to precisely set the spark timing, but do away with the need for a timing disc. I modified a used spark plug with an adjustable screw and a soft aluminum cap and then inserted into the plug hole.

I carefully turned the crank until the piston hit the plug, and drew a reference line on the flywheel aimed at tab on the case. I then repeated this in the other direction, and punched a reference line between the two pencil lines. This marks top dead center.

 Next, I marked the location of the proper firing position, about 16.5 degrees before TDC, and marked that, as well as labeling it.

Next up was the electrical bits. I stripped out the coil and magneto core, and reused the stock points and condenser with new wiring.

I used these to trigger an aftermarket 12V Yamaha ignition coil that I mounted next to an original Bantam battery tray. I wired it all up and used a miniature hobby 12V battery to power the whole system.

Now it will reliably start on the second or third kick. I will have to take some video as soon as possible.

Thursday, September 5, 2013

Carburetor Modification Part 1

The original CV carbs installed on my CB450 twin had developed a major air leak around the throttle plate shaft that I could not seal. It looks like years of use had increased the gap between the shaft and the carb body, allowing air to be sucked through. I tried several combinations of o-rings to try to minimize the leakage, and even installed extra cable return springs to deal with the extra friction, but nothing worked.

O-rings installed

Extra spring installed

While racing in July, the engine began heavily pinging from detonation. Investigation of the left plug found the insulator scorched and the electrode bright blue from a lean condition, so I decided to junk the original carbs before they caused any serious damage.

The VM-30 Mikuni carb kits are a bit too pricey and, I think, a bit overkill for a stock CB500T engine. Also, the stock gas tank on a 500T sits low, and can foul the carbs, so I bought a set of Mikunis taken from a flood damaged Trident. They had salt deposits internally but were otherwise fine, so I boiled the better 2 in distilled water to leach out any chunks that I missed. 

The original boots are way too big for the mikunis I wanted to used, so I bought a pair of intake boots from a Honda XL175, which nearly match the CB500T's bolt pattern and intake diameter, but are designed for a carburetor with a 34mm diameter. I then machined the carb intakes to get a better fit:

Spinnin round

Original vs Re-machined

Unfortunately, after cleaning them I discovered that the carbs, which were advertised as VM28-49's, are actually VM26-8074's. This may be a hair too small, but they're already half finished, so I might as well try them out anyway. 

Then and Now: KZ400 Diesel

Digging through my pictures, I found this one taken 4 years ago of my vegetable oil racer. It was just a rolling frame, and only had the forks, wheels, fenders, and lights.

On arrival

I got it from a friend who bought the motor for parts, and gave me the rest of the hulk. Now, taken yesterday in the exact same spot:

Current setup

Now (un)officially retired from racing, it holds 6 land speed records for alternate fuel (vegetable oil). The best it ever managed was 60.2mph with a supercharger making 5 pounds of boost and a disabled rev limiter. The engine was originally rated at 6.5hp at the crank. With all the modifications and the blower, it was tested to 6.5hp at the tire

The specs are:
Chassis - 1977 Kawasaki KZ400 (mostly stock)
Suspension - H-D Sportster shocks at rear, stock forks
Wheels - Honda CB360 front, stock rear
Engine - Yanmar (clone) L70, 300cc diesel. 6.5hp@3500rpm (stock) / 8.0hp@4200rpm (blown) 
Supercharger - Whispair 1701 Industrial Roots Blower, 5psi rated boost
Intercooler - Custom unit from Bell Intercoolers
Transmission - Homemade 2-speed automatic 

Dyno comparison with and without the blower

First Post

Welcome to Oil Burners and Old Iron. We build everything from alt-fuel bikes to ratty beaters, and sometimes take them land speed racing. We'll be posting project builds, trip photos, and other projects that catch our eye. Here's a few of our projects to get started!

'77 KZ400 with a 6hp diesel engine

1968 CL450 with a CB500T engine