Monday, March 25, 2019

Defroster/Heater Switch

I’m restoring an early Heinkel with the air vents in the door and I was missing the heater/de-mister switching piece.  This is a hard to get item, and I’d been looking for a few years to find one. Since I’d been doing all sorts of metal work to fix my car, I thought I had the skills to reproduce my own piece. It took a while but it wasn’t that hard, and the materials were basically free. An enthusiast with a little bit of skill and perseverance could do it, so I’ve made up the instructions below in case anyone else wants to make their own.

Pictures and Drawings:
I didn’t have the piece and didn’t know anyone with one (in the USA there aren’t many Heinkels), so I posted a question on the Facebook Heinkel Trojan Club page. Mark Fisher came up with some pictures for me:

Heinkel Kabines and Scooters
Heinkel De-Mister Photos
It was time to put my 7th grade mechanical drawing skills to work! Based on the one measurement I knew (the pipe opening of 45mm), I could determine the other measurements from the photos and produce a drawing of the most complicated parts. Here are my drawings of the main pieces for your reference (I’ve simplified a few things based on the materials and tools available):  
Heinkel Cars and Cabin Scooters
De-Mister Main Tube

Heinkel Cars and Cabin Scooters
De-Mister Backing Plate
Materials and Tools Required:
I scavenged most of the materials, and you probably can too. Here’s a list of the materials and tools you need to make the parts:

·         1 foot length of 1 ¾” (45mm) exhaust pipe
·         3” wide steel stock, 1/8” (3mm) thick and about 8” long
·         4” length of ¼” (6mm) smooth steel rod- zinc plated if available
·         2 rubber grommets that fit around the rod
·         3mm screw and washer

If you are restoring a car you probably have most of the tools you need:
·         Drill press or cordless drill with vise
·         1 ¾” (45mm) bi-metal hole saw
·         8mm drill bit
·         1/8” (3mm) drill bit
·         3mm tap
·         Angle grinder with cutoff wheel, grinding wheel, and 40, 80, and 120 grit flap disks
·         Pipe center finder
·         Welder

Once you have the parts and the tools you are ready to go. There are five metal pieces you will need to make:
  • Backing plate
  • Main Tube
  • Heater nozzle tube
  • Air deflector
  • Valve

Let’s walk through each one:

The Backing Plate:
This piece attaches to the car body and sits snug against the door when it’s closed. The original piece was stamped; since I don’t have a metal press I substituted 1/8” thick steel stock. The strength should be more than adequate for the purpose intended.  

This piece requires three different operations; drilling, cutting and bending. Here’s how I did it:
I transferred the drawing to the steel plate and then used a center punch to mark the hole locations. This piece has 3 holes. The largest hole is 45mm (1 ¾”) and can be cut with a bi-metal hole saw. 
Hole Saw

Layout of Backing Plate

After you cut the hole save the little blank, which will probably be stuck up inside the saw; you can use that for the switch piece! The other holes are 8mm (for the door hinge) and a 1/8” (3mm) hole.  
You can drill the big hole by making a small starting hole and then using either a drill press or a cordless drill, provided you can mount the bar stock securely. Use a low speed (I used 625 rpm on my drill press) and some sort of cutting oil or lubricant the keep the temperature down and prevent the heat dulling the tool.

Once I drilled the holes I cut the backing plate to size using a grinder and cutoff wheel. It’s crude but effective. Once I got the approximate shape I used a 40 grit flap disk to get close to final shape, followed by 80 and 120 flap disks to finish it up.

Bending a 3mm thick steel plate is not easy! I put it in my vise and used an 8 pound sledgehammer to get the angle to 45 degrees.

The Tubes:

You need to make 2 tubes; the main tube and the heater diverter. The diverter tube needs to be scribed to fit the main tube. Before the internet, determining how to do this was tricky; now all you have to do is go to a website, enter some calculations, and voila you have exactly what you need. I use the website to produce a graph that I then attached to the tube. Once you do that you can cut away the excess metal with a standard 36 grit grinding wheel attached to your grinder. 
Graph wrapped Around Tube

You can also cut the diverter tube to length with a hacksaw or cutoff wheel, then sand the cut smooth. I made mine about 5mm longer than my estimate because it looked a little short.

The main tube requires several operations. The first is to cut the tube at an angle for where it will be welded to the base plate. I eyeballed about a 12mm difference in length from the photos that Mark provided. I also knew (or hoped!) that if I was off I could just bend the base plate into a final adjustment. Then I drilled a 45 mm (1 ¾”) receiving hole into the tube using the hole saw. If you have a drill press you should use a center finder to make sure you have the exact middle. If you need a center finder they’re available on the internet for about $8 (6GBP).  They look like this:
A cheap center finder
The last operation on the main tube was to drill holes for the switch part. Once again use the center finder to find the center of the tube, then mark and drill the holes straight through the tube and come out the other side.

The Switch:
Since I didn’t have any information or picture of the switch I had to make it up (of course I found one later!). I decided to put the switch in place past the heater outlet, since most of the time I thought I’d need heat rather than defrost in cold New England.

Remember the blank from the base plate? That is the perfect size for the switch valve. You need to attach the blank to some sort of lever so you can operate the switch. I decided to use a piece of bent ¼” tubing and attach it to the switch as shown below. I drilled a 1/8” hole and tapped it for a 3mm screw.

You need to do a little shaping of the switch as shown in the picture. 
The switch parts

I used rubber grommets to seat the metal lever. I thought they would keep the lever taut but still easy enough to move with a finger:
Zinc rod with grommets

When you’re done with these steps you should have a set of parts that look like this:

The parts ready for assembly

Once the parts have been made and test fit it’s time for welding. Weld the heater tube to the main tube first, then clean up the weld:

The first weld

After that weld the tube assembly onto the base plate:
Using magnets and a block of wood to position the weld
When you’re done it will look like this:
The completed piece, except for foam gasket
The next step is to find a foam or rubber gasket to use between the door and the switch. That will have to wait for the car to come back from the shop.

That’s all there is to it. I spent about 8 hours over a couple of days making this start to finish, but I got the satisfaction of making my own part. You can too!

If you have any questions feel free to drop me a line at

Monday, August 20, 2018

The Heinkel Engine "Hall of Shame"

Over 13 years of Heinkel ownership I've accumulated a number of engines; people have given then to me, I've found them in various places, or people have told me about them and I purchased them.  There are a surprising number of engines out there in the USA, especially considering that maybe only a few hundred total vehicles (almost all scooters) were “officially” sold here by dealers.

One thing almost every engine has had in common was some type of major mechanical fault or abuse. Scooter engines tend the have the least damage; with car engines, each one has a hard luck story.

I present to you a “Heinkel Engine Hall of Shame”.  These are some of the best surprises I’ve come across working on engines, what I suspect happened to them, and what I’ve done (or will do) to fix them.

We'll start off slow and work our way up:

Example #1

Engine type: 175cc Scooter
Diagnosis: This is your basic "hole in the piston". The scooter still ran with an obliterated top ring, and no barrel scarring. I guess that’s why they have multiple rings!

Heinkel Cars and Cabin Scooters
Heinkel Piston Hole
Fix: Simple (but not cheap): buy a new oversize cylinder, rings, and barrel. 
It was from my first Heinkel scooter:

Heinkel 103-A2, originally sold in Chicopee Falls, MA

Example #2:

Engine Type: 200cc car engine:
Diagnosis: Everybody like corn flakes, and in addition to being a breakfast staple the box can be used as a gasket:
Heinkel Cars and Cabin Scooters
Brought to you by Kelloggs

Fix: This was easy. Use a proper gasket! That weird yellow green mold was a new one on me but came off easily.

Example #3:

Engine Type: 200cc car engine:
Diagnosis: Someone overheated this head, probably with a torch, until it started to melt. Aluminum starts losing it’s strength at 600 degrees and distorts at around 800 degrees so my guess is someone went at this with a torch for some reason (maybe to anneal it and soften the head for profiling? Who knows) 
This engine also came with two heads:
Fix: If this was the only cylinder head left in the world you could machine it flat and remove the low spots. I left it as is and put it away.

Example #4:

Engine Type: 200cc car engine:
Diagnosis: Ether someone tried to run a bigger plug or this is the result of a botched helicoil insert.
that hole is way too big for a regular plug
Fix: For as bad as this head looked the fix was pretty easy; I used one of these, and a regular length spark plug:
The adaptor cost less than the postage to the USA!. Here's a link to the product:

Example #5:

Engine Type: 175cc Car Engine
Diagnosis: Mice!
Heinkel Cars and Cabin Scooters
Fix: This really could be any old engine case. If it’s outside in a New England winter something will try to nest in it. But this engine case was harboring something else even more surprising that we’ll see in a minute.

Example #6:

Engine Type: 175 or 200cc car engine
Diagnosis: An engine builder’s bodge. I could see how this happened, but before doing this kind of work you think they would have asked “maybe I’m doing something wrong?” But no, they went at these pushrods with a grinder.  The problem here was that they probably trying to use 175cc engine rocker arms on a 200cc engine, or vice versa. They  look the same but are different.  his person though they would make it “work” by grinding away at the pushrods. 
Heinkel Cars and Cabin Scooters
What beautiful grinding
Heinkel Cars and Cabin Scooters
I'm not sure I can fix them
Fix: I'd probably try a metal epoxy and reshape them. I'm filing them away for now.

Example #7:

Engine Type: 200cc car engine:
Diagnosis: Snowflake shards of metal and oil that looks like silver nail polish are sure signs of a blown bottom end crankshaft bearing.
Heinkel Cars and Cabin Scooters
those snowflakes are busted metal!

Fix: Send the crankshaft to the Heinkel Club of Germany ( and get them to rebuild it. The cost is around 300 Euros. I tried to have this fixed in the USA but could not find anyone willing to undertake the task.

The same engine had a different (but related) issue. Take a look at this clutch bell. Notice anything missing? If you guessed a whole section of the clutch side itself, violently separated from the main clutch bell, then you are correct:

Heinkel Cars and Cabin Scooters
There's something missing...

Example #8:

Engine Type: 200cc car engine:
Diagnosis: Attempting to push start a car that couldn’t possibly go anywhere because the crankshaft was locked up.  When you push start a car you are basically attempting to start the car by spinning the tire, which is not how the car was designed.  Depending on the gear you use and the age/ mileage of the engine you are putting tremendous strain on internal components. In this case the clutch plates took the first hit, in declining order from the main clutch spring. You can see how the tabs are more progressively worn the closer you get to the outside of the clutch (where the diaphragm spring is located).

When I took it apart I found the missing piece at the bottom of the crankcase. 
Heinkel Cars and Cabin Scooters
Clutch bell with missing part

Heinkel Cars and Cabin Scooters
The busted piece

Heinkel Cars and Cabin Scooters

Fix:  It was serendipity that this piece broke away - I was going to weld it back on, but when I saw the stress cracks throughout the clutch I abandoned that idea. I’ll store this with the abused cylinder head and fix it only if I’m desperate.

Example #9:

Engine Type: 200cc car engine:
Diagnosis: Stupidity on my part! I can give you the diagnosis because I’m the one that caused the problem by overreving an engine into a freewheeling state on my test rig. According to my machinist, in an overrev situation the valves usually collide with the piston and trash the top end. In my case the rod bent. I also toasted the bottom bearing. At first glance nothing looks amiss, until you realize that the connecting rod is supposed to be straight! This connecting rod bent in two dimensions.
Heinkel Cars and Cabin Scooters
It doesn't look so bad...

Heinkel Cars and Cabin Scooters
A bend to the back (or front)

A bend to the left
This is an example of a bottom end when the bearing has been destroyed:

Heinkel Cars and Cabin Scooters
Fried bottom end bearing
Fix: There’s no economically viable fix. Thank goodness for parts engines! I’m going to use a spare crank. 

Example #10:

Remember that mousy engine from example 5? It had a mystery that I could only solve after having my bent connecting rod:
Engine Type: 175cc car engine:
Diagnosis: Broken connecting rod smashing through an engine case.  I never understood the hole in this engine case:
Heinkel Cars and Cabin Scooters
Mystery Heinkel Engine Hole
 Take a closer look- the force came from within and made the hole:
Heinkel Cars and Cabin Scooters
It came from the inside!
 Which was also a convenient second entrance for the mice.
Heinkel Cars and Cabin Scooters
Heinkel Engine Hole
Fix: None. just a mystery solved. I've been using the engine to mock up the alignment of the new floor I put in my second car. 

Well that's enough problems for a lifetime? Do you have any Hall of Shame Candidates? If you do please send them over and I'll post them. 

Saturday, June 16, 2018

I’ve been busy!

I haven’t posted for some time but that doesn’t mean I haven’t been doing Heinkel things. Far from it! I restored a Heinkel 103 A1 scooter and I made this:

I fabricated the entire side of this Kabine

Installed new roof parts too!

I never welded or did metal fab before this

Over 50% of the metal is new

From this:
One word to describe it- SAD!

The wood is a structural element

A lemon from which to make lemonade

At least the colors are bright

It’s taken me over three years, during which time I learned to weld, take a coach building / metal fabrication class, made my own bodywork tools, and hammered a lot of metal! Over half of the car is new metal that I either fabricated or got from Jim’s Microcars Parts.

The car is off to the body shop for plastic fill and paint! I’ll be posting some snippets along the way so stay tuned.

Sunday, May 29, 2016

Tax Evader

Tax Evader

I purchased a collection of Heinkel parts recently and found this gear selector indicator:
Heinkel Cars and Kabines
Heinkel Car Gear Shift Selector

Notice anything missing?

It turns out that in the UK you could register a three wheeled vehicle as a motorcycle and pay less road tax. It must have been significant (or the purchasers of the vehicles were stingy) because there was a catch- the vehicle could not have a reverse gear.

Microcar manufacturers appear to have removed the reverse option in several ways:
  1. Don’t install a reverse gear;
  2. Make the cable or shift linkage in a way that it was impossible to access reverse (or fourth gear, take your pick);
  3. Make a shift selector that precludes shifting into reverse.
I’ve experienced the latter two. My first car had either 4th or reverse (not both) until I installed a longer cable from the UK club. And now here’s an example of a no-reverse shifter gate.
Heinkel Cars and Kabines
Heinkel Gear Selectors

Does anyone need one for an “authentic” restoration?