Jump to content
ptwizz

Radial engine build

Recommended Posts

Another photo added - Supercharger housing.

This one is guaranteed to raise accusations of having a CNC mill hidden away in the back of my garage. All the machining was carried out on my manual mill, using an improvised profile copying device. Kiwi dropped in during the process and has seen how it's done. I'll add some photos of the process in the coming days.

 

Share this post


Link to post
Share on other sites
On 05/06/2018 at 17:56, alan_k said:

Well done Pete on the GST, plus of course your continued work on the radial engine.

Thanks Alan. I've just completed the last couple of hours solo at the weekend, so I'll be sending off for my license this week and getting a permit on my Thruster, G-BZNP.

Share this post


Link to post
Share on other sites

More photos added to the album and more progress.

The supercharger housing has been bored to the profile to fit the impeller, using a fiendishly bodged copy technique which worked rather better than expected. I have not yet bored the holes for the inlet tracts to the cylinders. The inlet tracts will be fabricated from stainless steel and I have a better chance of boring the holes to match the geometry of the fabricated parts than the other way around.

In the meantime, the supercharger parts are assembled and the SU carb hung on the front, looking like it means business.

In other news, I am now the holder of a NPPL(M) and my aircraft passed inspection. I may be gone for some time...

Edited by ptwizz

Share this post


Link to post
Share on other sites

Superb work, and i admire your steadfast comittment to such a huge project, it`s all i can do to summon the enthusiasm to change my bikes` oil these days..

When do you think it`ll be ready to fire up?

 

Well done on the NPPL..

 

BTW, we have a mutual aquaintance - Bren (works in the builders merchants near you)?

Edited by Hann__

Share this post


Link to post
Share on other sites

Hi Hann,

I don't consider myself patient. The engine is a hobby, so I work on it when the mood takes me and step back from it as soon as it starts to feel like work. For that reason, there is no projected date for firing up.

I see Bren quite regularly on Tuesday evenings at the Old Buckenham bike night. Very nice chap!

 

  • Upvote 1

Share this post


Link to post
Share on other sites

Another couple of photos added, showing the mechanism for engaging the high supercharger speed. A cable will pull on the long end of the curved lever, pulling the ends of the brake band together. When assembled, the brake band sits around the ring gear carrier shown in the other photo.

I had a chap come to visit last week, who is also building a radial engine. I am not the only person in the world mad enough to embark on such a project!

Share this post


Link to post
Share on other sites

New photo - the first of the inlet tracts loosely assembled.

Now I need to practice Tig welding thin stainless tube a lot.

Edited by ptwizz
  • Like 2

Share this post


Link to post
Share on other sites

One last photo to round off the year.

A 'dry' assembly with all the 'front end' parts in place. This marks the completion of the induction side of the engine. Next will be the oil supply, scavenge, oil tank, primary drive and ignition systems.

  • Like 1

Share this post


Link to post
Share on other sites

A long overdue update:

Progress has been interrupted by the need to rebuild my microlight engine, following an in-flight failure and forced landing in a random crop field. No damage to man or machine (apart from the dropped valve, piston, rod and barrel!) and the landowner was more interested in taking photos of the aeroplane in his field than complaining about it. He even helped with the recovery.

The radial engine now has its auxiliary drives gearbox on the back of the crankcase, containing 2:1 reduction bevel gears driving a vertical shaft which drives the main oil pump.

In progress is the oil tank, which also acts as the engine mount. The tank design is a short cone, for which I had to make a set of versatile bending rolls. These will later be adapted to roll the exhaust collector ring from 38mm stainless tube.

Photos of the bending rolls and the oil tank in progress added to the album.

 

  • Like 2

Share this post


Link to post
Share on other sites

More pictures added to the album. The oil tank assembly was tack welded together and brazed. Both front an rear faces were machined and grooves cut for the large O rings which will seal the tank to the back face of the crankcase and the front face of the primary drive case.

Bosses are fitted at the top for the oil return from the cooler and for the oil filler cap. When the auxiliary drives assembly is fitted, the main oil pump has an external O ring which seals into the boss fitted at the bottom of the tank.
The upper end of the auxiliary drive shaft sit below a hole in the top of the tank. The distributor will be fitted and sealed to the top face of the tank at that location.
  • Thanks 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



×