Steve Sampson
Well Known Member
I have an 160hp O-320 with a 10-5217 carb in an RV4 and c/s prop.
At full power, on initial climb out EGT and CHT head up quite quickly. Because I pull power back early to control temps, and climbing is not a problem in a -4, I can control CHT to 400, and the combined cht+egt to 1825. Both rules of thumb for engine longevity I understand.
It has been suggested to me however that I might want to have the main carb nozzle increased in size from .096" to .104". (Because the VANS airbox is very efficient.)
My questions are these:
1. Is this commonly done?
2. Is this the 'normal' amount of increase? Those numbers are tiny, but its a 17% increase!
3. Am I correct in assuming it only controls the amount of fuel at full power, after that it is controlled by the mixture control, provided I lean appropriately.
4. I need to get hold of a diagram of th carb. Is it easy to change the nozzle?
5. Is there any downside?
Anything else I ought to know?
Cheers!
At full power, on initial climb out EGT and CHT head up quite quickly. Because I pull power back early to control temps, and climbing is not a problem in a -4, I can control CHT to 400, and the combined cht+egt to 1825. Both rules of thumb for engine longevity I understand.
It has been suggested to me however that I might want to have the main carb nozzle increased in size from .096" to .104". (Because the VANS airbox is very efficient.)
My questions are these:
1. Is this commonly done?
2. Is this the 'normal' amount of increase? Those numbers are tiny, but its a 17% increase!
3. Am I correct in assuming it only controls the amount of fuel at full power, after that it is controlled by the mixture control, provided I lean appropriately.
4. I need to get hold of a diagram of th carb. Is it easy to change the nozzle?
5. Is there any downside?
Anything else I ought to know?
Cheers!