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OS .40 LA Operation

Old 10-06-2017, 09:30 AM
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Join Date: Dec 2005
Location: Milan, IN
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Default OS .40 LA Operation

Bought this engine recently NIB and I have been running it to break in. Using 10% nitro with a castor/synth oil mix. I have a new toy in a Harbor Freight infrared thermometer that I used to take some readings during the runs. Here are my questions:

1) At an ambient air temp of about 75F, I am seeing temps of 200-215F at the cylinder head on the exhaust side, 135-150F on the intake side. Is there a maximum temp I should stay below?

2) I am getting 11,400 on Master Airscrew 10x6 composite. This is after running 3 tanks of fuel and running it slightly rich of peak so it still passes the pinch test. Is this a typical RPM for this engine/prop?


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