New generation of
01-28-2010, 04:19 PM
#1
Member
Thread Starter
New generation of
I am just starting a Wing mfg. P-5 build and have not settled on the optimum power plant. At 640 squares, this is not a large pattern airplane by any means. I do want an SPA legal airplane and will not pipe the motor (Probably a tongue muffler that weighs less than an ounce and it will have retracts, just left down at contests). Otherwise, I want to wind up with as light of a model as possible but yet have good power to weight. (The airframe should come out pretty light as I have ample amounts of 5-6 lb balsa for sheeting, control surfaces, etc. from my C/L stunt days)
I was perusing one of the Milwaukee hobby shops Greenfield News and Hobby and came across one of the new Evolution 60NXs in his display case. I had read what Mike had to say about this motor in the thread on the Horizon Hobby P-7. Needless to say, I was so impressed with the small size I brought it home. In comparing with the OS 55AX and the benchmark OS 61 SF, some interesting numbers become evident:
First, the Evolution is amazingly small? Side by side with the 55 AX the Evo is actually a touch shorter! Mounting lugs are the exact same dimension as an OS 46 case size! With minimal relief to the inner inside of the mount, both the 55AX and Evo 60 will bolt into a 46 mount pad. One difference worth noting: The Evo lugs are drilled for 8-32 mounting bolts while the 55AX is drilled for 6-32s. Funny Evolution would choose the larger lug holes and then market it as a bolt in replacement for a 46. I will wind up shimming mine with an aluminum tube if I use it.
Second: The carb opening on the SF is way bigger! If air going in is any indication of power (we know it is), the 61 SF is going to out muscle both the Evo and OS 55.
Third: Weights. Not advertisements, but actual measured weights (Ohaus triple beam balance) without muffler: OS 61 SF - 558.0 grams or 19.6 OZ. Evo 60 - 406.2 grams or 14.3 OZ. OS 55AX - 400.0 grams or 14.05 OZ. Now the OS 55 was missing its glow plug and the Evo is stock with the rear needle. I am going to remove the bracket that holds the rear needle and tube which should shave another 10-15 grams. All-in-all I bet the Evo and OS 55AX come out nearly identical in weight when I finish with them.
As much as I love the SF, I am wondering if the Evo or 55AX would be a better balance for the P-5s 640 squares. I am still stunned by the nearly 6 OZ weight difference between the new gen "light cases" and the tried and true SF. Pretty amazing! That delta can go a long way towards any power deficit!
Any thoughts? I know Crank mentioned the 55Ax as a good choice for the P-5. Other opinions?
Sean
pics are are side-by-sides with the Evo and SF and then the Evo and 55AX. Last is a size comparision between the Evo, 55AX, and a standard 46!
I was perusing one of the Milwaukee hobby shops Greenfield News and Hobby and came across one of the new Evolution 60NXs in his display case. I had read what Mike had to say about this motor in the thread on the Horizon Hobby P-7. Needless to say, I was so impressed with the small size I brought it home. In comparing with the OS 55AX and the benchmark OS 61 SF, some interesting numbers become evident:
First, the Evolution is amazingly small? Side by side with the 55 AX the Evo is actually a touch shorter! Mounting lugs are the exact same dimension as an OS 46 case size! With minimal relief to the inner inside of the mount, both the 55AX and Evo 60 will bolt into a 46 mount pad. One difference worth noting: The Evo lugs are drilled for 8-32 mounting bolts while the 55AX is drilled for 6-32s. Funny Evolution would choose the larger lug holes and then market it as a bolt in replacement for a 46. I will wind up shimming mine with an aluminum tube if I use it.
Second: The carb opening on the SF is way bigger! If air going in is any indication of power (we know it is), the 61 SF is going to out muscle both the Evo and OS 55.
Third: Weights. Not advertisements, but actual measured weights (Ohaus triple beam balance) without muffler: OS 61 SF - 558.0 grams or 19.6 OZ. Evo 60 - 406.2 grams or 14.3 OZ. OS 55AX - 400.0 grams or 14.05 OZ. Now the OS 55 was missing its glow plug and the Evo is stock with the rear needle. I am going to remove the bracket that holds the rear needle and tube which should shave another 10-15 grams. All-in-all I bet the Evo and OS 55AX come out nearly identical in weight when I finish with them.
As much as I love the SF, I am wondering if the Evo or 55AX would be a better balance for the P-5s 640 squares. I am still stunned by the nearly 6 OZ weight difference between the new gen "light cases" and the tried and true SF. Pretty amazing! That delta can go a long way towards any power deficit!
Any thoughts? I know Crank mentioned the 55Ax as a good choice for the P-5. Other opinions?
Sean
pics are are side-by-sides with the Evo and SF and then the Evo and 55AX. Last is a size comparision between the Evo, 55AX, and a standard 46!
01-28-2010, 05:48 PM
#2
RE: New generation of
You have it right. I have a bit of experience with the 55AX. I have found that I can count on it to deliver 12k with an 11-7 prop using 15% nitro with the stock muffler. Using a Mac's 8.5 muffled pipe, I can squeeze about 13,800 rpm, although with that pipe, the needle is out about 3-1/2 turns. That pipes is too small, even though it is supposed to be the "right size" pipe for that engine. Is is pipey, overly rich in the mid range, and sucks a huge amount of fuel.
However, with a Mac's 10cc Quiet pipe, the results are far more pleasing. I got 13,500 average with an 11-7, and the needle was only out about 1 turn from the muffler setting. Consequently, the mid-range performance is linear, and the fuel consumption is reasonable. Having to open the needle on a piped engine is normal, as the engine uses more fuel when it is on the pipe. Common sense.
I find that the .55AX is not a real replacement for a brute .61 (Rossi, Webra, etc) but is equivalent in power to many .61 engines from the old days. It is ideal for aircraft like the Mach 1, or your P-5, where the extra weight (higher wing loading) is not worth the power trade off.
The deciding factor between the AX and the Evo would be power output, being that they weigh the same.
-Robert
However, with a Mac's 10cc Quiet pipe, the results are far more pleasing. I got 13,500 average with an 11-7, and the needle was only out about 1 turn from the muffler setting. Consequently, the mid-range performance is linear, and the fuel consumption is reasonable. Having to open the needle on a piped engine is normal, as the engine uses more fuel when it is on the pipe. Common sense.
I find that the .55AX is not a real replacement for a brute .61 (Rossi, Webra, etc) but is equivalent in power to many .61 engines from the old days. It is ideal for aircraft like the Mach 1, or your P-5, where the extra weight (higher wing loading) is not worth the power trade off.
The deciding factor between the AX and the Evo would be power output, being that they weigh the same.
-Robert
01-29-2010, 08:02 AM
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RE: New generation of
According to what I've read, the size of an early '70s 60 engine would have been like your 55AX or Evo 60. Sometime around 1975, the engine manufacturers all increased the physical size of their 60s. That's why your OS 61 SF is bigger.
Tom
Tom
01-29-2010, 11:20 AM
#6
RE: New generation of
This is the successor of the Gold Head, the 60-FSR brought out 1974 (first Schnuerle OS 60). Weight is 470 g / 16.6 oz w/o muffler and 590 g / 20.8 oz with. Power as specified 1.7 hp (maybe without muffler) but realistic (with muffler) is 1.27 hp at 13800 rpm. It may be propped to lower rpm giving good torque.
An interesting point is a hint in the original instruction leaflet: If no muffler pressure is used one should use a carburetor inlet (smaller diameter, more suction) for the 7B carb or use a Perry carb. Might explain the big carb opening?
An interesting point is a hint in the original instruction leaflet: If no muffler pressure is used one should use a carburetor inlet (smaller diameter, more suction) for the 7B carb or use a Perry carb. Might explain the big carb opening?
01-29-2010, 08:56 PM
#7
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Thread Starter
RE: New generation of
Thanks, Crank. Those pics are actually what sold me on pursueing the P-5. Tom is quite the craftsman!
Tom, I have a lightly used Enya 60 III. I will weigh it and snap some pics side-by-side with the Evo 60/OS 55 over the weekend. Will be interesting to see the size difference. Had not thought of that comparision.
Evo Remote needle. They got smart guys and the remote needle can be unscrewed, a cap on the carb removed, and the needle threads right into the carb. Total eliminatation of the remote and about 12 grams of wieght. Thanks Horizon!
Sean
Tom, I have a lightly used Enya 60 III. I will weigh it and snap some pics side-by-side with the Evo 60/OS 55 over the weekend. Will be interesting to see the size difference. Had not thought of that comparision.
Evo Remote needle. They got smart guys and the remote needle can be unscrewed, a cap on the carb removed, and the needle threads right into the carb. Total eliminatation of the remote and about 12 grams of wieght. Thanks Horizon!
Sean
02-01-2010, 10:38 AM
#8
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Thread Starter
RE: New generation of
OK, I dug out an Enya 60 III. THis engine is a ringed, loop scavenged motor that should be fairly representative of a typical late 60s choice for power. Should be on par size and weight to the Tigre and Gold Head OS.
Measured weight is 420 grams or 14.75 oz. This is certainly light, but still 3/4 oz heavier than the Evo and OS 55AX. Lugs are drilled (from the factory) for 8-32s. Interesting to note that the crankshaft is a size in between the 46 diameter crank in the Evo/OS 55 and the large crank in the 61SF. Also interesting is the carb venturi on the Enya is even smaller than the Evo/OS 55. Case size shows the Enya is overall much closer to the Evo and OS 55 but still a bit larger. You can see what I am talking about with the pics.
I still stand pretty amazed at these new large displacement/small case motors coming from the manufactures. I have to believe that they make good power for thier size and weight. Can't wait to run them this Spring!
Sean
pics are a side-by-side of the Enya 60 vs Evo 60, #2 pic is a comparison from the back, #3 is the Enya 60 in the middle of the Evo and OS 55
Measured weight is 420 grams or 14.75 oz. This is certainly light, but still 3/4 oz heavier than the Evo and OS 55AX. Lugs are drilled (from the factory) for 8-32s. Interesting to note that the crankshaft is a size in between the 46 diameter crank in the Evo/OS 55 and the large crank in the 61SF. Also interesting is the carb venturi on the Enya is even smaller than the Evo/OS 55. Case size shows the Enya is overall much closer to the Evo and OS 55 but still a bit larger. You can see what I am talking about with the pics.
I still stand pretty amazed at these new large displacement/small case motors coming from the manufactures. I have to believe that they make good power for thier size and weight. Can't wait to run them this Spring!
Sean
pics are a side-by-side of the Enya 60 vs Evo 60, #2 pic is a comparison from the back, #3 is the Enya 60 in the middle of the Evo and OS 55
02-01-2010, 12:39 PM
#9
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RE: New generation of
ORIGINAL: UStik
This is the successor of the Gold Head, the 60-FSR brought out 1974 (first Schnuerle OS 60). Weight is 470 g / 16.6 oz w/o muffler and 590 g / 20.8 oz with. Power as specified 1.7 hp (maybe without muffler) but realistic (with muffler) is 1.27 hp at 13800 rpm. It may be propped to lower rpm giving good torque.
An interesting point is a hint in the original instruction leaflet: If no muffler pressure is used one should use a carburetor inlet (smaller diameter, more suction) for the 7B carb or use a Perry carb. Might explain the big carb opening?
This is the successor of the Gold Head, the 60-FSR brought out 1974 (first Schnuerle OS 60). Weight is 470 g / 16.6 oz w/o muffler and 590 g / 20.8 oz with. Power as specified 1.7 hp (maybe without muffler) but realistic (with muffler) is 1.27 hp at 13800 rpm. It may be propped to lower rpm giving good torque.
An interesting point is a hint in the original instruction leaflet: If no muffler pressure is used one should use a carburetor inlet (smaller diameter, more suction) for the 7B carb or use a Perry carb. Might explain the big carb opening?
There was a blackhead model in between the goldhead and the OS .60F SR schneurle ported engine. It was very similar to the goldhead.
My first OS was a .15, but my second OS, the one that I learned to fly "multi" with, was an OS Max .58 R/C. I have managed to collect several of them over the years. The .58 was built in the .50 crankcase version of this engine. Dual ball bearings, a baffled piston and a single piston ring, IIRC. A great running and throttling engine that was equipped with an easy to adjust air bleed carb. Only problem with it was that I couldn't keep the engine running during an outside loop. It could have been a fuel tank problem. I was new in the hobby (1969).
Ed Cregger
02-01-2010, 02:39 PM
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RE: New generation of
The new "short stroke"...
A picture is worth a thousand words...seeing them in action is well, 10,000 words! The photo below (posted a zillion times) from left to right is the Mark Radcliff 1981 WC Phoenix 8 powered by the "big block" OS and pipe, my WM Intruder powered by the OS .61 AX APC 12 x 9 and Mike McConville's Hangar 9 Phoenix 7 prototype powered by the Evo .61 and Macs pipe APC 11 x 7.
Flight Observations:
Mark Radcliff flew in the pouring rain and had enough horse power to fly as tall and big as he wanted. Mark was using the same prop he flew in the 80's.
Rusty's WM Intruder was clearly slower, airplane needed to have the energy carefully managed to draw acceptably large stuff, pooped out in an absolute vertical line. The best prop of the (5) tested was the APC 12 x 9 which was somewhat surprising. Fuel was Cool Power 15%. I assume the Mac's pipe scheduled to be added for spring flying will make a significant difference.
The Evo .61 was as powerful and flew larger stuff in the Phoenix 7 as Mark's OS powered P8. I was pleasantly surprised. Of course it sounded very cool using the off the shelf Mac's OS .61 short pre-tuned header/pipe.
Conclusion: The Evo @ $140.00 or so street price is an excellent value.
Rusty Dose
Team Futaba (...that's Hobbico you know)
A picture is worth a thousand words...seeing them in action is well, 10,000 words! The photo below (posted a zillion times) from left to right is the Mark Radcliff 1981 WC Phoenix 8 powered by the "big block" OS and pipe, my WM Intruder powered by the OS .61 AX APC 12 x 9 and Mike McConville's Hangar 9 Phoenix 7 prototype powered by the Evo .61 and Macs pipe APC 11 x 7.
Flight Observations:
Mark Radcliff flew in the pouring rain and had enough horse power to fly as tall and big as he wanted. Mark was using the same prop he flew in the 80's.
Rusty's WM Intruder was clearly slower, airplane needed to have the energy carefully managed to draw acceptably large stuff, pooped out in an absolute vertical line. The best prop of the (5) tested was the APC 12 x 9 which was somewhat surprising. Fuel was Cool Power 15%. I assume the Mac's pipe scheduled to be added for spring flying will make a significant difference.
The Evo .61 was as powerful and flew larger stuff in the Phoenix 7 as Mark's OS powered P8. I was pleasantly surprised. Of course it sounded very cool using the off the shelf Mac's OS .61 short pre-tuned header/pipe.
Conclusion: The Evo @ $140.00 or so street price is an excellent value.
Rusty Dose
Team Futaba (...that's Hobbico you know)
02-01-2010, 03:35 PM
#12
RE: New generation of
ORIGINAL: flystunt
I am just starting a Wing mfg. P-5 build and have not settled on the optimum power plant. At 640 squares, this is not a large pattern airplane by any means. I do want an SPA legal airplane and will not pipe the motor (Probably a tongue muffler that weighs less than an ounce and it will have retracts, just left down at contests). Otherwise, I want to wind up with as light of a model as possible but yet have good power to weight. (The airframe should come out pretty light as I have ample amounts of 5-6 lb balsa for sheeting, control surfaces, etc. from my C/L stunt days)
I was perusing one of the Milwaukee hobby shops Greenfield News and Hobby and came across one of the new Evolution 60NXs in his display case. I had read what Mike had to say about this motor in the thread on the Horizon Hobby P-7. Needless to say, I was so impressed with the small size I brought it home. In comparing with the OS 55AX and the benchmark OS 61 SF, some interesting numbers become evident:
First, the Evolution is amazingly small? Side by side with the 55 AX the Evo is actually a touch shorter! Mounting lugs are the exact same dimension as an OS 46 case size! With minimal relief to the inner inside of the mount, both the 55AX and Evo 60 will bolt into a 46 mount pad. One difference worth noting: The Evo lugs are drilled for 8-32 mounting bolts while the 55AX is drilled for 6-32s. Funny Evolution would choose the larger lug holes and then market it as a bolt in replacement for a 46. I will wind up shimming mine with an aluminum tube if I use it.
Second: The carb opening on the SF is way bigger! If air going in is any indication of power (we know it is), the 61 SF is going to out muscle both the Evo and OS 55.
Third: Weights. Not advertisements, but actual measured weights (Ohaus triple beam balance) without muffler: OS 61 SF - 558.0 grams or 19.6 OZ. Evo 60 - 406.2 grams or 14.3 OZ. OS 55AX - 400.0 grams or 14.05 OZ. Now the OS 55 was missing its glow plug and the Evo is stock with the rear needle. I am going to remove the bracket that holds the rear needle and tube which should shave another 10-15 grams. All-in-all I bet the Evo and OS 55AX come out nearly identical in weight when I finish with them.
As much as I love the SF, I am wondering if the Evo or 55AX would be a better balance for the P-5s 640 squares. I am still stunned by the nearly 6 OZ weight difference between the new gen ''light cases'' and the tried and true SF. Pretty amazing! That delta can go a long way towards any power deficit!
Any thoughts? I know Crank mentioned the 55Ax as a good choice for the P-5. Other opinions?
Sean
pics are are side-by-sides with the Evo and SF and then the Evo and 55AX. Last is a size comparision between the Evo, 55AX, and a standard 46!
I am just starting a Wing mfg. P-5 build and have not settled on the optimum power plant. At 640 squares, this is not a large pattern airplane by any means. I do want an SPA legal airplane and will not pipe the motor (Probably a tongue muffler that weighs less than an ounce and it will have retracts, just left down at contests). Otherwise, I want to wind up with as light of a model as possible but yet have good power to weight. (The airframe should come out pretty light as I have ample amounts of 5-6 lb balsa for sheeting, control surfaces, etc. from my C/L stunt days)
I was perusing one of the Milwaukee hobby shops Greenfield News and Hobby and came across one of the new Evolution 60NXs in his display case. I had read what Mike had to say about this motor in the thread on the Horizon Hobby P-7. Needless to say, I was so impressed with the small size I brought it home. In comparing with the OS 55AX and the benchmark OS 61 SF, some interesting numbers become evident:
First, the Evolution is amazingly small? Side by side with the 55 AX the Evo is actually a touch shorter! Mounting lugs are the exact same dimension as an OS 46 case size! With minimal relief to the inner inside of the mount, both the 55AX and Evo 60 will bolt into a 46 mount pad. One difference worth noting: The Evo lugs are drilled for 8-32 mounting bolts while the 55AX is drilled for 6-32s. Funny Evolution would choose the larger lug holes and then market it as a bolt in replacement for a 46. I will wind up shimming mine with an aluminum tube if I use it.
Second: The carb opening on the SF is way bigger! If air going in is any indication of power (we know it is), the 61 SF is going to out muscle both the Evo and OS 55.
Third: Weights. Not advertisements, but actual measured weights (Ohaus triple beam balance) without muffler: OS 61 SF - 558.0 grams or 19.6 OZ. Evo 60 - 406.2 grams or 14.3 OZ. OS 55AX - 400.0 grams or 14.05 OZ. Now the OS 55 was missing its glow plug and the Evo is stock with the rear needle. I am going to remove the bracket that holds the rear needle and tube which should shave another 10-15 grams. All-in-all I bet the Evo and OS 55AX come out nearly identical in weight when I finish with them.
As much as I love the SF, I am wondering if the Evo or 55AX would be a better balance for the P-5s 640 squares. I am still stunned by the nearly 6 OZ weight difference between the new gen ''light cases'' and the tried and true SF. Pretty amazing! That delta can go a long way towards any power deficit!
Any thoughts? I know Crank mentioned the 55Ax as a good choice for the P-5. Other opinions?
Sean
pics are are side-by-sides with the Evo and SF and then the Evo and 55AX. Last is a size comparision between the Evo, 55AX, and a standard 46!
-Robert
02-01-2010, 04:02 PM
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RE: New generation of
I suspect Wisconsin to be just about buried in snow right now. Vancouver (or rather Whistler), has received 10m of snow since early November!! [X(] That's just about 33 ft of snow - holy smokes! [:-]
I guess engines can be run in the dead of winter for those brave enough. At -38C with wind a couple of days ago, I couldn't feel my cheeks after 20 minutes outside. Now we're just back to -8C though.
David.
I guess engines can be run in the dead of winter for those brave enough. At -38C with wind a couple of days ago, I couldn't feel my cheeks after 20 minutes outside. Now we're just back to -8C though.
David.
02-01-2010, 04:50 PM
#14
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Thread Starter
RE: New generation of
What we need is a head-to-head RPM check of the .55AX, and the EVO. That would yield very interesting and useful information. Since you have both engines on hand, is there a chance that you could do this, and post the results?
-Robert
-Robert
Great suggestion and I have the test stand/digital tach ready. The only thing I will have to wait on is the warmer weather of Spring. The last time I broke-in an engine within the hangar here at work, I fogged out the whole place. The maintenance techs were ribbing me for a week! Something about the odor of castor oil residing in their uniforms! I never did see the problem...
Sean
