Clerget 9B Rotary Engine. 1/8th. Hasagawa.

Hello guys, I'm not building an airplane but I am building an engine from one. I've been interested in radial engines for a while now and have been enjoying all the Sopwith Camel builds on here. After a long time hesitating, I finally gave in and bought the Clerget 9B 1/8th scale engine kit from Hasagawa, the one that comes with the Sopwith Camel kit.

There's not a lot of parts in the kit and all are very well molded with almost no flashing, in particular the cooling fins on all the cylinder halves are perfect and I didn't have to do any cleaning up at all (except for the sprue attachments), just glue them together.

Being a very basic engine, it doesn't require heaps of super detailing as with modern car and bike engines, but there is the opportunity to add extra detail by using real nuts and bolts (and this one is really going to clean out my stocks), and some hand made valve springs.

I started with the easy bit first. Assemble all the cylinders and a few other smaller sub assemblies. Once this was done I thought I had better remove the molded nuts and bolts and drill out the holes for the new ones before I spray the primer on.

Out comes all the little nuts, bolts and washers to be sorted, counted and put with the appropriate parts. I'll do the crank case later, for now I'll just start with a few bits.

A couple of coats of primer can dry in the sun while I go to the hobby shop for more paints.

At last I can get back to doing a bit more on the Clerget. The last 2 weeks has been so busy at work, driving 1000 Klm's a day.

I airbrushed Tamiya chrome silver enamel on the cylinders and put them in the sun to dry while I got to work on the crankcase. There's an awful lot of holes to drill out here but I got it done and then had to rest my eyes, all I could see was circles1what1

On the rear of the crankcase are some molded lines and pins to which the spark plug wires attach. I'm guessing these lines are a continuation of the wires down into the crankcase so I removed the lines and pins so I can replace them with real wire.

Once all this was done, the primer was sprayed on.

When the primer on the crankcase had dried enough I mixed up some Mr.MetalColor Alminume (that's what it says on the jar) and airbrushed it on. It came up quite nice, but then I put a cylinder against it to see how it looked only to find there was no difference between the two colors. This is not what I wanted. I'm looking for bunch of slightly varying shades of bare metal and also a few contrasting colors so it's not just all silver.

I thought maybe a light misting of something else over the top might make that subtle difference visible. Tamiya titanium gold acrylic looked like it might do the job, but would the acrylic and the enamel react with each other? Only one way to find out, so I mixed some and sprayed a very light mist on one cylinder to see if anything was going to happen. Nothing happened, but I couldn't see any change in shade or color. On with another coat, and just the slightest change, maybe. Another coat just to be sure and that's what I wanted. Some of the reference photos I've scraped up show the cylinders have a faint yellowing to them and it appealed to my eye. The 3rd photo here shows the gold a lot darker than it actually is next to the silver. It might blend in better when more parts are added.

The main shaft has had a couple of color changes also. The two castings were too dark done in Tamiya gunmetal acrylic so I added a drop of Tamiya chrome silver acrylic to the gunmetal and now it’s a strange dark silver. The shaft itself received a coat of Alclad stainless steel but again I wasn’t happy. Boy, am I fussy or what? Then I remembered I had a piece of adhesive vinyl film I picked up from a sign writer ages ago. It looks like brushed stainless, so I cut out a piece to fit around the shaft, and look at that, what a beauty.

The Clerget has 2 magnetos’ to supply current for the spark and they are attached to the main shaft behind the engine. My references show a variety of colors for the magneto’s so I’m just going with my own color scheme on this one. The main bodies were airbrushed with Tamiya gloss black enamel with highlights of Alclad polished brass airbrushed next, and then Mr.MetalColor copper was brushed by hand, finishing with another coat of gloss black brushed by hand for a different texture.

Then I added the nuts, bolts, washers and screws. Wow, doesn’t that bring it to life.

I've taken a big leap forward here to do something different to fiddly little nuts & bolts. I felt like doing the display base for the engine to sit on so set to work cutting out a piece of craft board to fit into an 8"x10" picture frame. I've removed the glass but kept the backing board to support the piece I've just cut.

While at the hardware shop looking for something totally unrelated I just happened to notice this iron-on veneer edging for cupboards. It's just the thing for the job.It's real Jarrah from Western Australia in a 5mtr roll, 22mm wide.

I cut pieces to fit diagonally and then cut each one down the centre to make them 11mm wide. I then sanded all the edges so the joins between the planks would be noticeable and proceeded to iron them all into place one at a time. The joins were mostly pretty tight with only a few grooves so I opened up the grooves a bit more by carefully drawing a razor saw through the joins between each plank. The planks were all trimmed and sanded around the edge of the board and then a light sanding over the entire surface has it ready for a couple of coats of gloss varnish, which I haven't done yet.

While the gloss varnish is drying on the timber floor boards I've had an attempt at bending up an exhaust valve spring. Not too bad for the first one, and looks much better than the plastic molded one. Only 8 more to go, and then 9 intake valve springs, which will be easier as they are just small coils.

Here is a very simple little coil spring for the intake valve made by winding some soft wire around the 1mm stainless wire I'm using for the valve stems, and cutting it off at the right length. I hope the final outcome will be worth all the effort I'm putting in now.

I've started adding some nuts & bolts to the crank case and it's looking better now, but it sure is using up the hardware supplies pretty quick when everything is in multiples of 9. On the air intake tubes alone there will be 36 x .8mm bolts & washers and 18 x .8mm nuts. In a few areas I'm a couple of bolts short so they will have to wait till the new stocks arrive from ScaleHardware, which may take a while as the post office tells me the volcanic ash cloud has upset the flow of international mail.

The first cylinder has received its new valve springs, and compared to the molded springs in the kit, I think it will be well worth the effort of all that wire bending, don't you?

Thanks Dan for fixing things up so I can finish this tread.

After all the valve springs were fitted to the cylinders it was spark plug time. They are all molded in pairs, 2 plugs per cylinder. I thought about making spark plugs but opted out in the end and just painted the plastic ones in the kit.

The instructions say to use silk thread for spark plug leads but that wouldn't look right, also, in some of my reference photos it looks like the leads are bare wire. I tried a few different ways of doing the leads. First I was going to do full insulated with just the ends bared but it wasn't working right, so then I tried removing the insulation and putting on a piece of heat shrink but it wouldn't shrink enough before it started to melt. It seemed the bare wire was the way to go, so I cut 18 pieces, stripped the insulation off and twisted each one nice and tight, then put a loop in one end of each one to go on the spark plugs.

To attach them I put the loop over the spark plug and using tweezers, gave the wire a little twist to tighten the loop around the plug. Then I glued the wire to the post and pushed the end into the hole near the main shaft. I cut small pieces of black vinyl tubing and put one on each wire to be the crimps that hold the wire on the plug.

WOW! That looks great! 1nworthy1

Thanks Mike. I've been having a ball doing this one. I keep telling myself I'm going to build an easy one straight from the box, but so far I haven't been able to break the addiction to adding extra stuff and changing things around.

Here I have attached the part that holds the main shaft, (to me it's kinda like a bell housing so that's what I've been calling it), to the stand that supports the engine. I used no glue for this, the nuts & bolts hold it together.
I didn't bother removing the ejector pin marks as the flywheel and crank case cover the whole thing. Those little lumps in there keep the fly wheel away from the bell housing so the engine can rotate freely.

On the back of the bell housing is this tube that I think may be an oil line or fuel line, I'm not really sure what it's for. Anyway, whatever it is I've chopped it up and replaced some of it with vinyl tube and some copper wire for strength and support, and 2 stainless nuts.