engineboy

I am a professional engine rebuilder and I need help. I am working on a gray marine 327 AMC engine. It is a reverse rotation engine. Normally on reverse rotation engines the pistons go into the cylinders backwards. At the time that it was taking it apart, I did not know it was a reverse rotation so I did not notice the orientation of the pistons. Does anyone know? Also, are the rear main seal and the timing cover seal different? Thanks

engineboy said:

I am a professional engine rebuilder and I need help. I am working on a gray marine 327 AMC engine. It is a reverse rotation engine. Normally on reverse rotation engines the pistons go into the cylinders backwards. At the time that it was taking it apart, I did not know it was a reverse rotation so I did not notice the orientation of the pistons. Does anyone know? Also, are the rear main seal and the timing cover seal different? Thanks

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I am not an expert on this 327 AMC engine as I've actually never laid a tool on one, so I can't help you with any specifics on this.
However, I will share this with you.

The AMC 327 appears to have an open combustion chamber. IOW, no wedge area that may require a piston that mirrors the wedge.
You would know this more so than I would.




On a typical RH Reverse Rotation engine, the piston wrist pin offset is the concern.
With an piston that is double valve relief (or no vavle reliefs) and is either a flat top or a full dished, the piston is ambidextrous, and can simply be re-orientated (turned around) on the connecting rod to accommodate the RH Rotation wrist pin offset.

For examples:

These pistons (SBC) are ambidrextrous, meaning that one p/n fits all 8 cylinders, and that they could be re-orientated on the connecting rod for a RH Reverse engine.




Obviously a single valve relief, L/C Quench, or D-dish pistons like these would not be ambidrextrous, and would require 2 p/n's for all 8 cylinders.
You may be able to turn these around in sets of 4.



If your pistons appear to be ambidrextrsous, you may be able to simply re-orientate them.
I'd contact the piston manufacturer and ask them.

Next would the camshaft. I don't know what the industry did for the cam drive on this AMC engine.
IOW, did they double gear drive it? (cam rotates standard direction), or did they chain drive the camshaft? (cam rotates RH Rev)
None-the-less, and as you know, the cam profile must be correct for the RH Reverse Rotation.

Front and rear crankshaft seals are definitely different for the RH Reverse engines.
If you were to look closely at the tiny serrations just prior to the lip seal, you'll see that the serrations are reversed. This sweeps the oil correctly for this rotation.

Good luck.