Mud
Diamond
- Joined
- May 20, 2002
- Location
- South Central PA
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Homebuilt radial engine w/ VW heads and cylinders
- Thread starter Mud
- Start date
- Replies 52
- Views 23,970
Winterfalke
Stainless
- Joined
- Mar 26, 2011
- Location
- Huron
I have wanted to build one of these for the longest time, too cool.
SLG
Cast Iron
- Joined
- Jun 4, 2014
- Location
- New Mexico
I'm as mechanically-inclined as anyone you'll ever meet - but I just never could picture in my mind how the crank worked on a radial engine. Until now. Thanks for the post!
JohnEvans
Titanium
- Joined
- Sep 23, 2009
- Location
- Phoenix,AZ
Most of the parts are fairly straight forward but I would have liked to see how he did the cam ring to work the valves . The cam ring rotates at a fraction of engine speed not 1/2 of crank speed like a automotive engine.
Tommy
Cast Iron
- Joined
- Mar 12, 2002
- Location
- Brandon, MS
johnoder
Diamond
- Joined
- Jul 16, 2004
- Location
- Houston, TX USA
1/8 crank speed on the nine cylinder. Totaly differing in concept - the lobes serving multiple cylinders in turn.
Added early Wright 1820 photos. This is the late thirties "G" Cyclone with 1000 HP - when they still had forged Aluminum crankcases - possibly the first engines used on the B17 - geared nose of course. The ring with the lumps is the cam
Added early Wright 1820 photos. This is the late thirties "G" Cyclone with 1000 HP - when they still had forged Aluminum crankcases - possibly the first engines used on the B17 - geared nose of course. The ring with the lumps is the cam
Attachments
johnoder
Diamond
- Joined
- Jul 16, 2004
- Location
- Houston, TX USA
Pressure pump and scavenge pump and small sump for the latter to draw from. At least on the real radials (P&WA and Wright). Photo shows the sump between lower cylinders. Not much could be done about at least some oil sitting in lower pistons and being thrashed about.
They were all notorious oil users. Wright's polite word was that their engines EVAPORATED so much oil per hour.
They were all notorious oil users. Wright's polite word was that their engines EVAPORATED so much oil per hour.
Attachments
KB3AHE
Stainless
- Joined
- Jul 17, 2012
- Location
- Baltimore, Md.
Way Kool! ! I bet it took a lot of head scratching to figger out how he was going to do it. Not to mention all of the time it took to machine and build it!
Frank
Frank
Tommy
Cast Iron
- Joined
- Mar 12, 2002
- Location
- Brandon, MS
John,
I'm familiar enough with the innards of radial engines to know that the cam ring is a comparatively sophisticated piece of work. I would be interested in seeing how the builder machined that particular component.
Which leads to a couple of questions: What equipment did P&WA or Wright use to manufacture the cam rings back in the day, and, having already arrived at suitable lobe profiles, how would you personally go about making one using manual equipment?
~TW~
johnoder
Diamond
- Joined
- Jul 16, 2004
- Location
- Houston, TX USA
Don't know. Possibly made-for-the-job machinery since it was a production effort. Example is the huge noisy custom machine P&WA was still running mid-sixties (when I was there) to mill fins on the forged 2800 cylinder heads.
Semi production possibly six spindle Hydrotel, which came with tracer attachments, and something similar with grinding spindles after they were heat treated. Since the "tracks" have some overlap, the cutting/grinding tools would be similar in appearance to a Woodruff keyseat cutter.
Me on manual today? Step it off in the jig bore, then come closer with the jig grinder attachment in same set up, then hand lap out the little bumps.
Semi production possibly six spindle Hydrotel, which came with tracer attachments, and something similar with grinding spindles after they were heat treated. Since the "tracks" have some overlap, the cutting/grinding tools would be similar in appearance to a Woodruff keyseat cutter.
Me on manual today? Step it off in the jig bore, then come closer with the jig grinder attachment in same set up, then hand lap out the little bumps.
Bill D
Diamond
- Joined
- Apr 1, 2004
- Location
- Modesto, CA USA
What happens to the valve train oil. Does it just fly away into the wind. I have seen old cars with exposed valve trains like that. They quickly designed covers to keep out rain and dirt and to keep the oil in. Is it legal to fly with a home made engine like this?
Bil lD.
Bil lD.
northeastconfederate
Cast Iron
- Joined
- Jan 25, 2005
- Location
- New Egypt, NJ
I dunno about this engine, but Top Fuel Harleys don't have any pressure fed top end lube. In the old days (by which I mean 70's, 80's) they used to drill holes in the rocker boxes in strategic locations and lube pre-run with an oil can. The perforated rocker boxes kept most of the oil (or at least some of it) in there. Nowadays the Top Fuel HD guy I know lubes the valvetrain up with Never-Sieze. Apparently some guys mix oil and Never-Sieze but he just uses Never-Sieze. The Top Fuelers still have the pushrods and tappets exposed even thought the rocker boxes are enclused (except for where the pushrods enter). I'm guessing since this engine looks like it was built for show, more or less (and what an impressive show!! WOW!!) it maybe uses some similar idea for valvetrain lube since it probably doesn't run for too long at a time.
I'm wondering what keeps the thing from dragging itself away. Suppose the prop isn't designed to create much... what do you call it? "Pull"?
Capp48
Aluminum
- Joined
- Dec 21, 2012
- Location
- Ohio, Cleveland
Greetings. According to the builder he manually oils the valve train before each start up. Built for demonstration. Local VW dealer near builder is interested in displaying it. Ciao.
The prop in this video is way too small to have any more use other than creating drag and cooling on this engine. The wash of the prop is mostly defused by the jugs.
Radial engines are way cool...
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In the U.S. it is legal to fly this engine, or any other engine, as long as the aircraft is built by "amateurs", and deemed capable of flying by the FAA. I've seen small block Chevy's, chainsaw motors (Mac 101s), Subaru's, and other IC engines flown in experimental aircraft. Typically, you cant just knock the engine off of a Cessna and install your 1.8l Honda, you have to build the entire plane by hand, or from a kit.
This engine is probably more of a candidate for air flight than the others that I have mentioned. IC aircraft engines usually run at a low RPM, in order to swing a longer propeller. If the RPM/Propeller is spinning too fast, the tip speed gets too close to the speed of sound, creating a noisy inefficient scenario. Car engines are designed for higher RPMs to achieve full horsepower, which is not a desired trait in IC aircraft engines. You can always add a gear box, but that complicates things, and it's one more thing that can turn you into a lawn dart.
Kevin
I belive that "thrust" is the word that is used to measure the forces of an airplane engine.
northeastconfederate
Cast Iron
- Joined
- Jan 25, 2005
- Location
- New Egypt, NJ
I think 'thrust' is used when talking about jet engines. These end up 'pushing'. A prop pulls the plane, I think. That's why I didn't use 'thrust'. I could be completely wrong about everything I just said.............
