OK .074 recommendation
11-21-2011, 07:56 PM
#1
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OK .074 recommendation
What prop for an OK .074? Seems like the 6X4 might be a bit small but Idont know if this engine is supposed to be a stump puller or a revver.
11-21-2011, 08:10 PM
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RE: OK .074 recommendation
APC makes a special prop for .15 size combat that is 6.5X4.5. You might give that one a try. The OK isnt a stump puller... more like a Cox reed engine that can turn larger props.
11-21-2011, 08:42 PM
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RE: OK .074 recommendation
Hello Jeffies, Just prop the thing for the plane, & don't worry 'bout the engine. These things breath so poorly, that regardless of prop, you're not likely to reach "destruct" speed (the rod & crank don't like 18K) unless you really get serious with the mods. ........... Some RPM readings for a stock .074 Cub ; MAS 7x3 = 11,500, ........... APC 4.75x4.75 = 13,400, ........... APC 4.75x4 = 14,700 .......... APC 5.7x3 = 14,000 ............... APC 5x3= 15,900 , .............. TD 5.5x4 = 12,600, ........... MAS 5.5x4 = 14,000
MAS 5.5x4 cut to 5" diameter = 15,000 .............................. I've had one of these mounted on a EPP mustang (street fighter?) for the last 2 or 3 yrs.. The AUW is 'bout 8+ OZs. Have tried a load of props, & have settled on the APC 5.7x3 or MAS 5.5x4. Slight difference in verticle & speed. Either way, quite a blast .!!!!!!!!!! ................ George K.
MAS 5.5x4 cut to 5" diameter = 15,000 .............................. I've had one of these mounted on a EPP mustang (street fighter?) for the last 2 or 3 yrs.. The AUW is 'bout 8+ OZs. Have tried a load of props, & have settled on the APC 5.7x3 or MAS 5.5x4. Slight difference in verticle & speed. Either way, quite a blast .!!!!!!!!!! ................ George K.
11-30-2011, 05:41 PM
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RE: OK .074 recommendation
as a lot younger person I used Cub 074's on 1/2A flite streaks and musciano hollow logs and really didn't do any better then a baby bee or cub 049.
The Cubs were mostly anemic but to their credit you could slap almost any of the recommended props within reason and it would turn them enough to get you airborne. Powerhouses they are not but I surely did have my share of fun with them 50 years ago.
Dennis
The Cubs were mostly anemic but to their credit you could slap almost any of the recommended props within reason and it would turn them enough to get you airborne. Powerhouses they are not but I surely did have my share of fun with them 50 years ago.
Dennis
12-01-2011, 04:52 AM
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RE: OK .074 recommendation
ORIGINAL: dennis
as a lot younger person I used Cub 074's on 1/2A flite streaks and musciano hollow logs and really didn't do any better then a baby bee or cub 049.
The Cubs were mostly anemic but to their credit you could slap almost any of the recommended props within reason and it would turn them enough to get you airborne. Powerhouses they are not but I surely did have my share of fun with them 50 years ago.
Dennis
as a lot younger person I used Cub 074's on 1/2A flite streaks and musciano hollow logs and really didn't do any better then a baby bee or cub 049.
The Cubs were mostly anemic but to their credit you could slap almost any of the recommended props within reason and it would turn them enough to get you airborne. Powerhouses they are not but I surely did have my share of fun with them 50 years ago.
Dennis
