engine query
12-28-2001 | 01:32 AM
#1
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From: GA
engine query
my wife and son bought me a yellow aircraft a-4 for xmas, problem is the ramtec fan is set up for os-91. i was thinking of a k&b 1.0 but was told it will cavitate once airbornnothing against os, just too pricey!any advice would be appreciated.---henry
12-28-2001 | 02:14 AM
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From: Star,
ID
os91
The only enginge you should be thinking about putting in the Yellow A-4 is the OS 91..
Rossi, maybe , but for all round no hassle , no tinkering performance get the Os91....you WILL be money ahead----period.
My opinion from experience.......
Rod Springer
Rossi, maybe , but for all round no hassle , no tinkering performance get the Os91....you WILL be money ahead----period.
My opinion from experience.......
Rod Springer
12-28-2001 | 02:58 AM
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From: Spokane,
WA
Engine for A-4
I would only consider a OS 77 or 91 for your A-4 project.The 91 is a stong running and dependable engine.Finding a tuned pipe that will work with the K&B 100 , is a problem.
Good Luck
Charlie Hissom
Good Luck
Charlie Hissom
12-28-2001 | 01:37 PM
#5
engine query
Stay away from the K&B 1.0! You will have nothing but problems ( Broken Rods) A friend here had one in his Yellow F16 and broke several rods in it ( Including a RPM Rod!) It was never reliable!
Get the OS91 for it. Much better engine and you can get parts....
Get the OS91 for it. Much better engine and you can get parts....
12-29-2001 | 02:18 AM
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From: Apple Valley,
CA
Ducted Fan Engine
Nun45,
you can use the OS.91 and it is a very good engine-but if you want max.power and performance-get a Rossi .90 or 1.05-heres what you can do-use 3 head shims-if you don't like the Rossi carb,(although it is a good carb)-a OS.91 carb can be used-Break the engine in just like the directions say-use 5% nitro fuel with 8 ozs. of extra castor oil added to it- a OS.91 will turn a Byron fan rotor at around 19,500-20,000 rpm. The Rossi .90 will spin it at 22,000-a lot more power.
Jackjet
you can use the OS.91 and it is a very good engine-but if you want max.power and performance-get a Rossi .90 or 1.05-heres what you can do-use 3 head shims-if you don't like the Rossi carb,(although it is a good carb)-a OS.91 carb can be used-Break the engine in just like the directions say-use 5% nitro fuel with 8 ozs. of extra castor oil added to it- a OS.91 will turn a Byron fan rotor at around 19,500-20,000 rpm. The Rossi .90 will spin it at 22,000-a lot more power.
Jackjet
12-29-2001 | 04:22 AM
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Re: engine query
Originally posted by nun45
my wife and son bought me a yellow aircraft a-4 for xmas, problem is the ramtec fan is set up for os-91. i was thinking of a k&b 1.0 but was told it will cavitate once airbornnothing against os, just too pricey!any advice would be appreciated.---henry
my wife and son bought me a yellow aircraft a-4 for xmas, problem is the ramtec fan is set up for os-91. i was thinking of a k&b 1.0 but was told it will cavitate once airbornnothing against os, just too pricey!any advice would be appreciated.---henry
Nice plane...you have a good family to buy you such a great toy!
I'm a little jealous 
12-30-2001 | 12:54 AM
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From: Mill Creek, IN
O. S. .91
Have you checked with National Hobbies in GA? A few months ago I picked up an O. S. .91 there for around $255, which puts it in roughly the same price ballpark as the K&B. I agree with the rest of the guys... You can't beat the small-head O. S. .91 for ducted fan reliability. It's worth the wait. Good luck! (BTW, it sounds like you have a GREAT family.)
b/r,
Earl
b/r,
Earl
