I'm doing my condition inspection and want to check the torque of the 4 allen head engine mounts. The KAI refers to Rotax IPC Sect. 28 Engine suspension Frame Assy. Torque Value, couldn't find section 28 of IPC, instead I looked at the Rotax Engine Installation guide, it said to refer to air frame instructions. Does anybody know what the torque is or where to find it? Thanks.
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Engine mount allen head torque
- Thread starter bobg56
- Start date
NinerBikes
Well Known Member
Is there a way to paint witness marks on these Allen bolts, to inspect, instead?
RFSchaller
Well Known Member
It?s really not a big deal to do. You just have to unbolt and lift the intake manifolds to get to a couple of the bolts. Ten minutes max using an Allen head socket an extension and a universal joint or a good Wobble head on the Allen wrench head. I just finished my 8th annual and have never found one under torqued.
Torque stripe (torque seal) should never be relied on as an indicator that a fastener is still at full spec torque.
It should be used for only two purposes.
1. As an indicator during the build that a fastener has been final torqued.
2. As an inspection indicator that a fastener has rotated.
It is important to understand that a fastener not having rotated is not a reliable indication that it is still at specified torque.
Example - The RV-12 PAP specifies that after the first 5 hrs of flight, the landing gear bolts be re-torqued. The reason is that in situation where a highly loaded fastener is located where there is a stack up of numerous parts, during initial torquing, those parts don't always fully nest/seat on each other. A bunch of load cycles or vibration can cause them to nest together better which relieves the tension preload on the fastener. Once that occurs, it is no longer properly torqued.
This can occur with something like the engine attach bolts as well. That is why the Rotax inspection check list specifies checking for proper torque.... not inspecting to see if the fastener has rotated.
If someone is serious about checking/confirming the torque of any given fastener, the only way to really do it is to put a torque wrench on it.
It should be used for only two purposes.
1. As an indicator during the build that a fastener has been final torqued.
2. As an inspection indicator that a fastener has rotated.
It is important to understand that a fastener not having rotated is not a reliable indication that it is still at specified torque.
Example - The RV-12 PAP specifies that after the first 5 hrs of flight, the landing gear bolts be re-torqued. The reason is that in situation where a highly loaded fastener is located where there is a stack up of numerous parts, during initial torquing, those parts don't always fully nest/seat on each other. A bunch of load cycles or vibration can cause them to nest together better which relieves the tension preload on the fastener. Once that occurs, it is no longer properly torqued.
This can occur with something like the engine attach bolts as well. That is why the Rotax inspection check list specifies checking for proper torque.... not inspecting to see if the fastener has rotated.
If someone is serious about checking/confirming the torque of any given fastener, the only way to really do it is to put a torque wrench on it.
