Substitute Engines

willows5050 · 10 September 2009, 05:56 PM

I'm interested in finding out what engines are being used when one can't afford or find an old radial engine. I've looked at the HCI and Rotec. It's never to early to start planning.
Don

snj5 · 10 September 2009, 06:14 PM

Quote:

Originally Posted by willows5050

I'm interested in finding out what engines are being used when one can't afford or find an old radial engine. I've looked at the HCI and Rotec. It's never to early to start planning.
Don

Be advised that HCI is no longer delivering complete engines - only plans and castings. That said, it does look really cool and was a neat idea.

I did a similar search and have just purchased a Rotec based on they have a lot out there, have continually developed the engine and folks report a good service record. That said, there is an anti-Rotec web site, but it seems to concern an early engine.

There is talk of folks that have made new Oberursels and a French rotary, but I believe these are quite expensive and very limited in production and support.

Good luck and let us know!

Maxim08 · 11 September 2009, 05:52 AM

Willows5050,
What type of engine are you searching for? What aircraft are they for and are they to be full size? Do you have some idea of weight etc?
A search of the 'Replica' threads will uncover a lot of discusion re replacement engines. Depending on your intended use, I suggest that you balance the theories with what have been used in completed, flying aircraft.
You are bang-on regarding it never being too early for the engine. You don't want to end up with a static display due to lack of engine availability!
Regards,
John

willows5050 · 11 September 2009, 05:40 PM

I'm looking at building either a Tommy, Pup or 1 1/2 Strutter, full size like the original. Rotec would be nice subsitute but the cost might break the bank at the end of the project. The problem with the Tommy is there aren't a lot of replicas around, same with the strutter. I will search the old threads when I get more time.
Don

snj5 · 11 September 2009, 05:56 PM

Quote:

Originally Posted by willows5050

I'm looking at building either a Tommy, Pup or 1 1/2 Strutter, full size like the original. Rotec would be nice subsitute but the cost might break the bank at the end of the project. The problem with the Tommy is there aren't a lot of replicas around, same with the strutter. I will search the old threads when I get more time.
Don

Excellent choices.
I have heard that if you are going full size, the 1/2 strutter is quite an imposing airplane. I seem to remember one Strutter replica using a 220 hp Continental Radial with good performance. While the originals were powered by 110 - 130 hp Clerget, as we've seen before they were torque monsters making the power at a low rpm enabling large props for adequate thrust. Modern engines have to turn faster (limiting prop size) and while making more hp, are sometimes limited in torque and thrust, neccesitating a larger engine.

Both the Tommy and the Pup are smaller (Airdrome has a Pup kit as you know and a prototype with the 110 hp rotec, engine cost @ $10K) and the smaller engines, even the Valley VW will produce enough torque to pull them fine.

Good luck - looking forward to your progress!

Maxim08 · 11 September 2009, 06:23 PM

On the GWFM's 1-1/2 Strutter we are using a converted Continental tank engine which is actually 240 hp. Downside is that you need a special hub for a prop due to the shortened sae20 spline area.
The Strutter is definetly a crowd pleaser and would be a good choice. Not alot more work than any other fullsize a/c although the wing span can be hard to hangar. To my (limited) knowledge, the only other flying Strutter replica is Ken Kellet's in Florida.
Regards,
John

D.A. · 12 September 2009, 01:44 AM

Quote:

Originally Posted by snj5

There is talk of folks that have made new Oberursels and a French rotary, but I believe these are quite expensive and very limited in production and support.

Do you have any info/links to these reproductions?

Thanks in advance.

karrart · 12 September 2009, 10:44 AM

Quote:

Originally Posted by Maxim08

....To my (limited) knowledge, the only other flying Strutter replica is Ken Kellet's in Florida.
Regards,
John

There's Javier Arango's Appleby-built repro, originally with a 145 Warner, later re-engined with a Gnome.
Robert Karr
Bits of Strutter scattered around:
RK’s Pfalzhood - Pfalz, Halberstadt, Nieuport, CAMEL!!!

RAF56_Ball · 12 September 2009, 01:12 PM

I too have a Rotec, R-2800 (the 110 hp). If you go with anthing smaller than the 1-1/2 strutter, you would be fine with it.
If you go with a full-sized Strutter built according to original designs, you would do well to consider the R-3600 (150 hp) to get adequate thrust. The 2800 can swing an 80-84", but that is it's limit. The 3600 might swing a 100-104", but would use a lower pitch than original. If you use a 104" 62" pitch, cruise speed of 106 mph (~ 90 kts), so the Rotec could turn at 2700 RPM, for a prop speed of ~817'/sec (73% mach) it would still be only 81-82% at full power.
If you were to build a Strutter using Airdrome Airplanes or Graham Lee-like construction techniques and materials, the structure of the plane should be about 60-70% of the weight of the real Strutter, and you could get away with the smaller engine. You would still be better off with the R-3600, but I think it would be do-able.

willows5050 · 12 September 2009, 10:13 PM

I know that I could get away with less hp with a Lee or Baslee Kit. I'm currently working on a Lee N11 that is getting a VW and an Airdrome DVII kit. This palne is going to probably be my last project. I want it to be as close to the original as I can. I think I'll have to save twenty-five cents of every dollar I spend on parts to ease the sticker shock of the engine.

Don