home made 5 cylinder radial engine automatic timing advance

[@johnparrish9215]

It's great to see what is possible but I wish to God you had made long videos on how it was made. It's a brilliant engine and you should be very proud of it.

[@ThatMattaTatta]

Now you just need to build the rest of the plane

[@raffaellobottoni871]

Right!😂

[@GICK117]

Sounds like a low revving, torque-y Porsche 911 air cooled engine. Nice. Whats your rev limit?

[@prvt8pyle]

How did you make the crankshaft?

[@tim777jet]

Crankshaft started life from a Honda XR 400. Cut it in half and pressed the crank pin out. After making the master rod and the main crank pin we pressed it all together. I made it a .004 interference fit and it took just over 12 tons to press together. Runout is .0015 thou at each end. The crank pin and master rod clearance I made 0.0015 but think 0.002 would have been better. No problems though. We balanced it same method as the very early radial engines using all the rotating masses plus just over half the reciprocating masses (0.509). Due to the unusual geometry created by the master rod the other 4 cylinders are not exactly equal in their movement and so a compromise in the engine balance has to be made. Due to the differences in geometry you can not set the cam timing and ignition timing at 72 degree increments. There is a difference of 3 or 4 degrees when the pistons reach TDC which is a quirk of the radial. On production engines for example magneto cams may not be machined at exactly 360 degrees divided by the number of cylinders, a couple or few degrees difference is ground in. Building the engine was a huge learning curve, many differences to a standard engine design. Biggest worries were the balancing and the oil system but both came out ok. I made aluminium conrods and the biggest worry is the loads imposed on the exhaust stroke with no buffer. Compression stroke is no issue it is the tensile loads which are huge and a worry. Crankcase was machined from 11 inch billet ally bar. It holds a lot of heat when the engine runs. The 5 carbs are from a 400 cc snowmobile, cheap as chips new.

[@richhardchoppers7869]

​@@tim777jetowesome build sir. You should made the video or just slideahow pics of the progres ypu made it. Would love to watch it. 👍👍👍

[@timcoppinger3373]

Sweet!

[@jameskirk4652]

still sonds like a vw engine!!

[@phoschnizzle826]

It seems to work well, but I wouldn't call it robust. Not something I'd care to depend on in flight.

[@Tenkai917]

It's probably more reliable than most of the engines taking to the skies in the early 1900s. In those days you didn't even wear a parachute: if your plane fell apart around you, you just died like a man.

[@phoschnizzle826]

@@Tenkai917 I was referencing the timing advance portion. That belt drive mechanism, while functioning adequately on a test stand, doesn't look like it'll pass a safety inspection. I have no concerns about the radial engine portion, that's reasonably robust technology.

[@connor1642]

Badass

[@MrRedeyedJedi]

You have to be single to create things like this lmao

[@tim777jet]

My wife machined some parts of this engine and heavily involved throughout all of the design and build.

[@MrRedeyedJedi]

@@tim777jet well if that's true, god knows where you found her,but if she puts up with it keep her.