Arlan McKee · Oct 16, 2006 09:59 AM
#0 sourceHaving read and been involved in discussions about the differences in handling between the LA 40 and 46, I wanted to offer my observations from the past month or so of trying to get good consistent stunt runs with good pull from an LA 40.
I think that the bottom line with the 40 is that it will not pull an 11 inch prop unless the model is small enough to make the 40 exessively powerful enough to run in almost a full 4 stroke. On my 50 oz model, a good setting on one flight may run away on the next with an 11 inch prop. Furthermore, I just don't think that ANY APC prop works worth a darn on the 40. I have been cutting Zinger 12 x 4's down to 10 3/8 x 4-5 1/2 and 10 1/2 x 4-5 1/2 with the 5 1/2 pitch only in the last 2 stations. These are then thinned and reshaped with a better airfoil. The 12 inch prop body is much thicker than the 10 and 11 inch props. When cut down, they make a very chunky, wide blade prop. I do re-proportion the tips and thin them.
These props run in a wet 2 cycle for the entire flight without the slightest urge to run away, and pull like a bear. They also weigh an ounce less than the APC.
I have 2 different 40's and have tried them both. Neither have a boost port. Both have run stock mufflers with the stinger drilled out and clunk tanks with muffler pressure.
I think that the bottom line with the 40 is that it will not pull an 11 inch prop unless the model is small enough to make the 40 exessively powerful enough to run in almost a full 4 stroke. On my 50 oz model, a good setting on one flight may run away on the next with an 11 inch prop. Furthermore, I just don't think that ANY APC prop works worth a darn on the 40. I have been cutting Zinger 12 x 4's down to 10 3/8 x 4-5 1/2 and 10 1/2 x 4-5 1/2 with the 5 1/2 pitch only in the last 2 stations. These are then thinned and reshaped with a better airfoil. The 12 inch prop body is much thicker than the 10 and 11 inch props. When cut down, they make a very chunky, wide blade prop. I do re-proportion the tips and thin them.
These props run in a wet 2 cycle for the entire flight without the slightest urge to run away, and pull like a bear. They also weigh an ounce less than the APC.
I have 2 different 40's and have tried them both. Neither have a boost port. Both have run stock mufflers with the stinger drilled out and clunk tanks with muffler pressure.
I think that alot of folks that dislike the LA 40 should break away from the 11 x 4 APC and put a prop on there that the engine can handle without getting hot enough to run away. I don't think much of the APC 101/2 x 4 1/2. I think that it has a very narrow window of success and it just sounds like #####.
Does anyone else have any success with the 40 or observations that differ?