Robin conversion
09-09-2004 | 11:34 AM
#1
Robin conversion
Here's a Robin, about 25cc...Haven't run it yet...2 lbs, 4 oz..Easy conversion, cut off the extra casting, a G23 hub fits the crank..The rear case has three holes to mount to the firewall..This hub is a custom for my ignition..The sensor is in the ring behind the hub, on the front of the case..
Harold, if you're out there, this is yours...[8D]
Harold, if you're out there, this is yours...[8D]
09-09-2004 | 12:59 PM
#2
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From: Ottawa,
ON, CANADA
RE: Robin conversion
Howdy RCIGN1.
This particular engine is the Robin NB-26.I was discussing this with Harold a while back and he mentioned that he was sending his engine out to you to be converted.I have two of these myself that I bought years ago with the intention of using the stock ignition system.Like some of the Poulan engines,I found out that the coil is not mounted to the engine but rather to the cover instead.Many of these were converted over to stock ignition anyways with the addition of a coil bracket that was designed by a local machinist who was at that time involved in the hobby.They worked extremely well and seemed to be very low in vibration at all speeds.
I haven't finished my two as the gentlemen who was making the parts for these engines has since left the hobby unfortunately.The engine seems to be very similiar to the Zenoah G-23 in crankshaft design and was very interested to read that a G-23 hub fits the Robin 26 also.Same taper and everything.I have all of the machining of the engine cases completed so all I'm really missing to get them going is prop hubs and some type of ignition system.I was wondering if you could expand on the equipment side of things and tell me what is involved in converting the Robin 26 to electronic ignition?Would like to get an estimate of cost of parts if possible also.Any input,most gladly appreciated.
P.S-Was wondering why the cylinder is rotated 180 degrees from its stock configuration.Both of mine have the spark plug facing forward.Was this done intentionally?Just curious.
This particular engine is the Robin NB-26.I was discussing this with Harold a while back and he mentioned that he was sending his engine out to you to be converted.I have two of these myself that I bought years ago with the intention of using the stock ignition system.Like some of the Poulan engines,I found out that the coil is not mounted to the engine but rather to the cover instead.Many of these were converted over to stock ignition anyways with the addition of a coil bracket that was designed by a local machinist who was at that time involved in the hobby.They worked extremely well and seemed to be very low in vibration at all speeds.
I haven't finished my two as the gentlemen who was making the parts for these engines has since left the hobby unfortunately.The engine seems to be very similiar to the Zenoah G-23 in crankshaft design and was very interested to read that a G-23 hub fits the Robin 26 also.Same taper and everything.I have all of the machining of the engine cases completed so all I'm really missing to get them going is prop hubs and some type of ignition system.I was wondering if you could expand on the equipment side of things and tell me what is involved in converting the Robin 26 to electronic ignition?Would like to get an estimate of cost of parts if possible also.Any input,most gladly appreciated.
P.S-Was wondering why the cylinder is rotated 180 degrees from its stock configuration.Both of mine have the spark plug facing forward.Was this done intentionally?Just curious.
09-09-2004 | 01:36 PM
#4
RE: Robin conversion
Looks like a great little gasser...Didn't want the spark plug so close to the prop....All the internals are symmetrical so you just turn the crank and cylinder around in the case...The front of the case casting is round, with some 45 degree angle pieces..I milled these off and made a ring to press fit around the casting and will put the sensor in that ring...The G26 hub has the same taper and could have a matching ring pressed onto it for the small magnet to trigger the sensor...He sent a C&H syncro spark along with the engine...The carb needs to be rotated 90 degrees so the throttle servo can be connected without a bell crank...A 3.8 thick G10 block will do that, and make the carb closer to the cylinder...He sent a WA197 carb, which should be perfect...There's a new Walbro, same size, that has a choke plate..I'm getting some of these for other small gasser conversions in the future..The G23 has 2 bearings on the front of the crank, with the outer one being the seal for the case..The Robin has only 1, and the case can't be bored enough for another...I should have some rpm numbers today with 18-6, 18-8, 17-8, and 16-8 props...
10-05-2004 | 11:05 PM
#9
My Feedback: (1)
RE: Robin conversion
Hi all,
I have a couple of robin's - 1 25cc converted and 1 30cc waiting. My 30cc looks like the 25 posted by Ralph but the 25 is different. Notice the plug orientation. This is a great conversion and I was pleased with the # on the bench (g23 range right off the bat. -stock exhaust- no tweeking yet). As it was a year ago I can't remember the exact # but it likes a 17-8 apc.
Both engines were surplus concrete tamper/vibrator motors but my source ran out before I could get more. (They were $45 Canadian/$35 US) I am still kicking myself.
The first two pics are the 25 (on a dynaflite chipmunk project) and the last two are the 30.
Chris
I have a couple of robin's - 1 25cc converted and 1 30cc waiting. My 30cc looks like the 25 posted by Ralph but the 25 is different. Notice the plug orientation. This is a great conversion and I was pleased with the # on the bench (g23 range right off the bat. -stock exhaust- no tweeking yet). As it was a year ago I can't remember the exact # but it likes a 17-8 apc.
Both engines were surplus concrete tamper/vibrator motors but my source ran out before I could get more. (They were $45 Canadian/$35 US) I am still kicking myself.
The first two pics are the 25 (on a dynaflite chipmunk project) and the last two are the 30.
Chris
