In building a replica WWI aircraaft, I would presume that it would be well high impossible to obtain original engines. I suppose modern radials could substitute for rotaries, but which are favored for this usage? Which are used as in-line substitutes?

Rotary engined replica birds are commonly powered by 145hp Warner or 220hp Continental radials. Types that were powered by V-8 engines (SPAD, SE5A) are usually powered by a common horizontally opposed aircraft engine in the 200hp range, typically a Lycoming or Continental. In-line birds like the Fokker D.VII and Albatros will usually substitute a 200hp Ranger in-line 6 converted to run upright.

Hi all,

Just came accross a photo of Nieuport 24C with a Hisso. Does anyone remember Carl swanson's "knock about" (sport) Spad with the Buick Invicta V-8? Was it successfull? This might be the answer to Hisso availability. The 24C?... just a strange engine /aircraft association.
Charles

I've never seen the SPAD you speak of. Clifford Aeroworks offers an 80% SPAD for a Geo Tracker engine though.
www.cliffordaeroworks.com

Just remember that when one uses a modern engine to replace those of yesteryear a problem soon becomes apparent. The old engines usually had a max rpm in the 1400-1700 range while more modern engines are usually up in the 2600-3000 range. Hence the old engines produced a lot more torque per rpm. What it boils down to is that when one uses more modern engines you can't use a scale propellor. Newer propellors have smaller diameters to efficiently use the power available for the lower-torque, higher-rpm modern engines. However, this said, plenty of people use modern engines because they have no choice......certainly understandable. The aircraft sound different from the originals but that's a pretty small price to pay to be able to get up into the air.

Slightly Modified VW engines with a REDRIVE of about 2.2:1 would be good. This would give you a Prop RPM of about 1363 RPM at engine RPM of 3000. This would allow a 85-90" prop or more. Remember a redrive is a torque multiplier, not just a rpm adjuster. There are a couple of new small scale radial engines out there but haven't been proven as of yet. If you build a heavy duty full scale you can use a modified M14P Russian Radial. Steve Culp of Culp Aviation is building Sopwith Pup kits to use this engine . Normally, the M14 is of 280-360 HP at 2900+ RPM. It uses a redrive. Steve Culp is removing the redrive and putting on a cover from another Russian engine and Running direct drive at 1800 rpm and getting 160 hp.
Should run forever at this speed.
Cher'o,
Lt. Dwight Rudder, RFC
Great War Aeroplanes Asso.

Dwight,

Where would one get a reduction drive like the one you mention? Great Plains has three ratios listed on their web site: Available in 3 ratios: 1.29 to 1, 1.6 to 1, and 2.0 to 1. Are there other companies making redrives for VW engines?

Regards,

There is currently a book in publication that covers this topic. *It is titled: Converting Auto Engines for Experimental Aircraft.

I got a copy a few years ago, and it contained a lot of good information. *I was casting about for an engine for a replica of an Albatross B-II (two-seater)

Bill

Thanks, Bill, I'll see if I can get a copy!

Regards,

This company carries that title, along with many others useful to homebuilders:

http://www.buildersbooks.com/index.html