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OS 91 RZ compression

Old 05-15-2015, 09:07 PM
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Default OS 91 RZ compression

Hallo Bax,

I have bought 3 OS 91 RZ rear exhaust engines and run them in fast RC1 classic pattern ships.

2 of them have normal/ low feeling compression when you turn over the top. 1 has a very high compression when you turn over the top.

Do you have a explanation for this ?

Regards Michael
Old 05-18-2015, 06:19 AM
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A higher-than-normal compression feel can be caused by a ring seal that's tighter than normal, tolerances all in the positive direction that create a bit more of a compression ratio.

You can get a high-compression "feel" if the connecting rod is bent. Then the engine will be difficult to turn over as the piston rises.

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