My Hodgson 9 Radial Final Assembly

[dmac]

Terry,

Most impressive build you have there.

Why not stretch yourself and go for a triple row radial.

Dave

 

[gbritnell]

First off a very hearty congratulations on the completion and running of your engine. The sound is incredible! Although I've seen a number of the Hodgson radials built I've never talked at length to many of the builders. Here is something I found on my little radial, as the crankcase gets hot it conveys the heat to the carb which in turn starts to vapor lock or at least cause erratic running. I ended up making an insulator bushing to go between the carb and crankcase and it's seems to have helped immeasurably.
Once again, outstanding work.
gbritnell

 

[Septic]

I would honestly like to say that I really don't like it.....

But as that would be a grossly unfair and untrue statement, based purely upon my own limited attention span and lack of patience, I can only express my admiration at your dedication and attention to detail... A beautifully crafted rendition of the type and a truly praiseworthy winner of the award in every respect...

 

[capin]

Beautiful !Terry, everything you've built has been first rate but you have outdone yourself. Brian

 

[Blue_Rock]

What a beautiful work of art Terry! Congrats

 

[mayhugh1]

I was surfing YouTube recently and stumbled across some videos by an Australian company called Rotec. This is a relatively small company that builds and sells full-size radial engines to homebuilt aircraft enthusiasts. I had previously been only vaguely familiar with Rotec, having seen a video of one of their engines running in a custom-buit motorcycle. The video that I stumbled across was probably made early in the company's history. It's a video of a quarter scale nine cylinder engine that, if you don't look carefully, you will swear is another Hodgson model with the optional rocker boxes.
[ame]https://m.youtube.com/watch?v=bP3-WSvnGIY[/ame]
The heads are essentially identical to stock Hodgsons with the main visual difference between the engines being the location of the distributor which, in the Rotec design, is on the crankshaft axis. The video of the 350 (cc) is evidently an early run of the small scale prototype built to test their design before starting the full scale build. If you listen carefully at the end of this video you'll hear someone in their group watching the test say "OK, but it will never work in a real plane."
There are several other videos including this one showing some highlights of their manufacturing process:
[ame]https://m.youtube.com/watch?v=CVu6vjPvxkg[/ame]
that was probably made sometime later. Those who have built a Hodgson-9 will see some steps eerily similar to those performed during their own builds. You'll also notice the familiar intake/exhaust flange milled into the rear of the heads. A change in the head design to note, though, is a modification they made to support two spark plugs per head. As it turns out, the full-size Rotec design includes redundant ignition systems - spark and magneto.
This video will bring a smile to the faces of all who have actually built a Hodgson or similar model radial:
[ame]https://m.youtube.com/watch?v=jwpnucBidGQ[/ame]
where the technician, who looks a lot like the guy in the 350 video, is explaining how to troubleshoot failures in the spark ignition system. If you watch carefully you'll see him holding a familiar red, white, and black three wire cable while explaining how to ohmmeter test the Hall sensor inside the distributor. - Terry

 

[Stieglitz]

Hi Mayhugh1,
Thanks for sharing your project,a real work of art.
Cheers.

 

[DickInOhio]

Where did you get your propeller? Nearly finished with my 9. Beautiful build. I followed along as I built mine.

 

[mayhugh1]

Dick,
You can find them here:
http://www.aircraftinternational.com/Products/Propellers/BielaCarbonProps.aspx

Terry

 

[Bentwings]

These are photos of the two completed carb assemblies I plan to try with my H9. The first is a Walbro 345 carb that I salvaged from an old yard tool, cleaned up, and rebuilt. I designed a simple bolt-on linkage adapter to work with my throttle control on the firewall. The carb bowl contains a ball-and-spring pressure requlator to supply 5 psi fuel to the carb and return the excess to the fuel tank. I wish it had a choke or primer, but I drilled a small hole in the top cover so I can press down on the diaphragm with a small tool which I think will prime it while under fuel pressure.
The second carb is a Super Tiger RC helio engine. This bowl simply regulates the level of fuel with a drain hose back to the fuel tank. Again the linkage is compatible with my throttle control and the adapter at the rear matches the back of my engine - Terry

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View attachment 60995

Nice work and thanks fir the tips. I’m just getting started on modeling parts for review. I’ll have to read this over several times to take it all in. .i especially like the metallurgical comments.i still don’t really follow the cylinder head work. I guess I’ll just have to work on it myself. I’ll save this and review it later. I may even have some to add myself as I progress.

byron nelson

byron