PT20J Posted March 15, 2021 Report Posted March 15, 2021 I am playing around with an engine simulation program. I need some specifications that I've been unable to find and wonder if anyone has found them somewhere: Connecting rod length (crankpin center to wrist pin center) Valve timing: EVO, EVC, ICO, IVC in crankshaft angle ATDC Skip Quote
N201MKTurbo Posted March 15, 2021 Report Posted March 15, 2021 5 hours ago, PT20J said: I am playing around with an engine simulation program. I need some specifications that I've been unable to find and wonder if anyone has found them somewhere: Connecting rod length (crankpin center to wrist pin center) Valve timing: EVO, EVC, ICO, IVC in crankshaft angle ATDC Skip I’m pretty sure the rod length is in the overhaul manual. Every time you rework the rods, they get a bit shorter. There is a limit on how short they can get. Not sure about the valve timing, did you look in the TCDS? Quote
EricJ Posted March 15, 2021 Report Posted March 15, 2021 14 hours ago, PT20J said: I am playing around with an engine simulation program. I need some specifications that I've been unable to find and wonder if anyone has found them somewhere: Connecting rod length (crankpin center to wrist pin center) Valve timing: EVO, EVC, ICO, IVC in crankshaft angle ATDC Skip +1 that some of that should be in the overhaul manual. The manual I have is the Lycoming "Overhaul Manual Direct Drive Engine". At the end is the Table of Limits, which includes the center-to-center rod length as item 601. For an IO-360-A- it shows mfr min and max as 6.7485 to 6.7515. There are no service limits listed, so I guess that's the only limits. Valve dimensions and tolerances are in there, but I don't see timing information after a quick scan. The engine TCDS might have it. Quote
PT20J Posted March 15, 2021 Author Report Posted March 15, 2021 9 hours ago, N201MKTurbo said: I’m pretty sure the rod length is in the overhaul manual. Every time you rework the rods, they get a bit shorter. There is a limit on how short they can get. Not sure about the valve timing, did you look in the TCDS? 50 minutes ago, EricJ said: +1 that some of that should be in the overhaul manual. The manual I have is the Lycoming "Overhaul Manual Direct Drive Engine". At the end is the Table of Limits, which includes the center-to-center rod length as item 601. For an IO-360-A- it shows mfr min and max as 6.7485 to 6.7515. There are no service limits listed, so I guess that's the only limits. Valve dimensions and tolerances are in there, but I don't see timing information after a quick scan. The engine TCDS might have it. Thanks!. I couldn't find anything in the TCDS and I guess I missed the conn rod length in the OH manual -- makes sense it would be there since you would want to check for rod stretch due to an overspeed. Guess I can put a protractor on the prop and figure out the valve timing. Skip 1 Quote
carusoam Posted March 16, 2021 Report Posted March 16, 2021 For this deep of detail... Lets see if @M20Doc is around... (technical question for tech gurus...) Best regards, -a- Quote
A64Pilot Posted March 16, 2021 Report Posted March 16, 2021 22 hours ago, PT20J said: Thanks!. I couldn't find anything in the TCDS and I guess I missed the conn rod length in the OH manual -- makes sense it would be there since you would want to check for rod stretch due to an overspeed. Guess I can put a protractor on the prop and figure out the valve timing. Skip Your going to need a dial indicator too of course. ‘If your not certain how, look up how to degree a camshaft.’ Post your numbers if you don’t mind, be interesting to see what they are. Quote
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