Thursday, July 22, 2021

Misselwood Concours 2021

Sunday , July 18 started as a rainy day but eventually cleared enough to become a great day to attend the Concours d' Elegance. Misselwood is one of three juried Concours in New England. I entered my Heinkel Kabine in the microcar class. They also had a "woodie" class (wooden-bodied cars) for the first time so I was encouraged to bring along the Campi-style trailer that I tow behind my Heinkel Tourist 103-A2.

Heinkel Tourist with Trailer and Heinkel Kabine

Here's another angle of the trailer and scooter:

I found out my trailer was waterproof!

And I took second place in the Microcar category:

Getting the prize and handshake

The "roll-by"

And a video of me exiting the Concours with my scooter / trailer rig, courtesy of Matthew Nutter:

Sunday, June 14, 2020

Camping and Picnic Trailer

Here's something I finished during the Covid pandemic for my Heinkel Scooter: a single-wheeled trailer to tow my stuff. I had to cancel two big trips because of Covid. I'm not going anywhere this summer because of the pandemic, so I can take little picnicking, camping beer/food pickup or beach trips.  It's based very loosely on an East German "Campi" design that my friend Werner in Germany built. Since I'm also a woodworker I chose to make the storage area out of wood, reminiscent of a "woody" station wagon or wooden boat.
Travel Trailer and Heinkel Tourist Scooter
13 Feet of Scooter and Trailer!

Trailer with access hatch

This was a very challenging project- almost every piece is curved, bent or angled. From now on right-angled woodworking will be boring!

The trailer weighs about 80 lbs and runs on a single 4.80x8 tire. I've added some pictures below and a description of how I made it.

My friend Werner gave me some detailed measurements of his trailer and I used them as a place to start. I started scouring the internet for design ideas and found a lot of videos, but this one in particular was really helpful: Single Wheeled Trailer.  This gentleman provided good sources for the wheel and design for the U-joint.
Prototyping the metal frame of the Heinkel trailer
I learned some new and improved metal and woodworking skills. My welding is much better. Here's the trailer hitch I built for the scooter, which lets me keep the rack and spare tire:
Trailer Hitch with U-Joint
It bolts directly into the frame of the scooter using the existing holes. I raised the rack by topping the existing spare tire mount bolts with coupling nuts, and covered that assembly with 7/8" black water supply tube, which I left slightly long to act like a lock washer when I bolted down the rack:

I also learned to better cut and rout channels in complex shapes. I had to build several helper jigs to get the curves and channels correct:
Various routed and curved custom shapes
I added a kickstand so the trailer could stand on it's own and not have the woodwork damaged, since a one wheel trailer is not stable:
Kickstand, based on the Heinkel Scooter Kickstand

Kickstand in the Up position with return spring and toe grab
The trailer is made of Ash and Okume, Ash was the first choice of car body makers in the US for wooden station wagons. It is light in color and very strong. I used Okume for the rest since it looks like mahogany, is waterproof and can bend. Okume's natural color is boring so I used a Walnut stain to darken it:
Staining the pieces

Example of the color contrast on the hatch
I finished it with 8 coats of spar urethane. Spar urethane is flexible and contains UV protection. I could have achieved a glass-like finish with a few more coats, but I was afraid the wood would end up looking like the cheap plastic imitations you see in car interiors. This level of finish highlights the woodgrain nicely.

Next Steps:
I just got my license plate. It is registered as a "homemade" trailer, costs $20 per year and is covered under my homeowner's insurance. The total length is over 13 feet so it is not as nimble as a regular scooter. I've gone up to 35 miles per hour in my test rides to determine how it reacts at faster speed.  I'm learning how to load it to avoid swaying, and checking the welded joints to make sure they don't crack under stress.

I hope you like it. I've attached some other pictures of the build in progress below:
Figuring out the shape using a cardboard template
Using the cardboard template to do all subsequent measuring

Building the case supports and kickstand
Jigs to cut and rout channels in the front of the trailer

Checking the height of the rack. Hitch size is 1.25" (US "class 1" hitch" standard)

LED Taillight/brake light / turn signal

Underneath view showing frame and kickstand

Inside. it's quite large. I'm using a dog leash as a strap because of Covid-induced supply shortages
Big enough for a cooler, sleeping bags, tent 

Another inside shot
Door access to shock load adjustment

In the US you need front and rear side lights. These are LED too.

Here's a video!

Monday, August 12, 2019

The Best Carburetor Option Yet?

If you’ve read my blog over the years you know how fickle carburetors can be. I’ve tried several options; rebuilding existing ones, buying lightly used ones, buying a new Bing, using a Jetex- you name it I have tried it. In the spirit of trying to get my car to be the best it can be I have tried another option, and I’m happy to report results that are worth passing on.

Here's the carburetor: a 30mm Tiawanese OKO carb made for 250cc quads. I’ve put several hundred miles on one in a variety of conditions and I’ve been pleased with it. This carb solves several issues for me. Installation is not too hard (but not necessarily easy) but well within the reach of anyone who tinkers with their car on a regular basis (and who doesn’t; It’s a Heinkel!)

Here’s the carb as I bought it off of EBay:
Carb purchased from e-bay

Here are the issues with my existing setup that I hoped to solve, and how this carb stacks up:
Poor idling
Flat spot on acceleration
Running rich (black spark plug)
No bodywork modifications
Accelerator pump?
Easy to get parts
Easy to tune
Easy access to make adjustments
Mostly (use stubby screwdriver for idle)

General overview of the carb:
This is a 30 mm CVK Carb. It has a 30mm orifice with a 36mm (exterior) manifold mount.

Air intake view
Manifold side

Accelerator pump is cylindrical piece on left bottom

Electronic choke is in upper right hand section in this picture
It has an accelerator pump like the original equipment Pallas 22mm. It also has an electric choke, which means you don’t have to pump the gas to start it. It has a 46 mm intake opening for an air filter.  Don’t be embarrassed if none of these stats are familiar; not one of them is a standard Heinkel measurement.


Installation is a 5 step process: I've gone through each one below with plenty of photos.
The steps are:
1. Make a new throttle cable
2. Run a wire to power the electric choke
3. Make an airtight seal from the carb to the existing Heinkel intake manifold
4. Make a supporting bracket for the carb
5. Install an air filter

You may also need to re-jet the carb, but I'll talk about that at the end of the post.

Making a new throttle cable: The Oko carburetor has different ends than a Pallas. Not to fear, you can make your own cable quite easily. I used a Venhill U01-4-101-BK Universal Motorcycle Throttle Cable Kit - 5mm OD, made in the UK. Cost was $16.99 delivered to my house. The only trick is here is to determine the proper length of the inner cable. Loop the outer cable up and over the engine and then down into where the carb will sit. Then measure the distance from the top of the adjuster to one of the cable holding holes on the carb. That’s your distance.

Running a wire for the electric choke: The electric choke replaces pumping the throttle when you are starting the engine cold. The electric choke is temperature activated by an electric current that comes from the ignition circuit. The other end of the wire runs to ground. The easiest place to pick up the ignition circuit is where all of the black wires meet up under the dash, so you need to run a wire all the way back to the dash. I setup my carb with electrical disconnects so I could easily take it apart if necessary (and it has been necessary a few times).
Disconnects for electronic choke

You can see the black wire under the tube. It would be a tight
 fit in the tube but you could do it if you had time
Making airtight seals: The Heinkel carb intake manifold has a 28mm outside diameter. The new carb has a 30mm opening. There are two ways to bridge this gap- make a custom manifold adapter or find some off the shelf component. Luckily there is an off-the-shelf solution (sort of). I poked around my local motorcycle salvage yard and came up with a “spigot manifold”. The manifold solves the carb side of the problem. Here's an example of one I purchased from Amazon that is an exact fit:
Perfectly sized spigot manifold

Installed on carb
The other end I solved using 3 o-rings slid over the end the Heinkel intake manifold. I used 1 1 1/8” inside diameter 1 3/8” OD O-rings, which are a common size in the US and cost 50 cents each. I assemble everything with screw clamps and got a great fit.

1 3/8" OD O-rings - 3 required

Put one on the manifold
Put two more inside the spigot manifold

Installed - a really nice fit
Supporting the Carb: While the airtight fit was great, it was so flexible it would fall off quickly from vibration. The solution was to make a carb “exoskeleton” to support it and prevent if from falling off. I made a bracket. You can weld up one like I did or assemble one with nuts or rivets. Here’s a picture of mine. This is version 2.0: the first one allowed the carb to fall backwards off of the manifold, so I made an extra support piece that sits atop the speedo housing to prevent this from occurring again.

Welded L-shaped bracket 

Top of bracket attached to convenient throttle spring mounting holes
Extra support keeps it from tipping backwards
Installing the air filter: This is easy! Just buy a standard Chinese 46mm ID air filter from eBay and mount it on to the end of the carb. In an ideal world you would actually run the air intake up to the original spot, but I tried to make an adaptor for this and the air cleaner kept falling off. They are only $5.00 each but that adds up after a while!

The air cleaner- 2 for $8.99 on Amazon
Air cleaner from back- I safety wired the air cleaner to keep it from falling off

My abortive attempt to connect the air cleaner to the original housing; it kept falling off!

Jetting the carb: I spent time jetting the carb to avoid flat spots and hesitation. Jetting is a bit time consuming, Paul Spakov has a great series on YouTube on how to tune GY6 carbs(a reference to the ubiquitous Chinese engines that use this type of carb); here's a link to one:  that explains the process.
I think I'm running one size of jets down from the stock. Chinese carb jets are standard and super cheap (at least compared to a Heinkel Bing jets); I think a whole set was $12.

Get this Jet Set along with the Carb

Performance: I've been running the carb since April and it has met all my objectives. I have yet to do a top speed test yet, although I have run it up to 45mph and felt there was still more power available if I needed it. I've been getting about 50mpg (US) which might be a little less than I used to get, though when I check the plug the color is good.
Plug color is light brown- a good sign

 On the whole I'm happy and would recommend this improvement to anyone.