CM/CB 400 Twins plus Athena Head Gaskets

[LongDistance]

I'm not thrilled with this gasket set. Yes, everything is there and it all fits correctly. The problem is the head gasket. It's clearly marked on the surface as being 1.5mm, actually measures at 1.6mm. The OEM Honda gasket is 1.1mm. Doesn't sound like much but that roughly .020" thicker which lowers the compression a little, I thought. I've gone ahead and installed it and while waiting for a pinched shoulder muscle to heal I decided to run the numbers using this calculator http://www.csgnetwork.com/compcalc.html
Sadly the numbers don't lie and the compression ratio has been changed from 9.25 to 8.61 . A fairly significant drop. Add to that the cam timing will be advanced @3* if my calculations are correct. This is fine if you want to increase the low end power and be able to run less than 86 octane fuel.
Needless to say I've ordered a OEM gasket from Honda and the engine will be coming apart again before I break in the new rings.
Lesson learned about using aftermarket parts.
If anyone has a Vesrah head gasket around I'd be curious to know the thickness of it. I've contacted several places that sell them but no one has any in stock to measure.
I have sent an email to Athena asking about the gasket thickness, waiting to hear back.
I've also emailed Vesrah and no response yet. David Silver Spares has responded and say they'll be asking their supplier NE Brand

 

[cxman]

the real question will be what is the final thickness of the gasket compressed?

the gasket may be in spec once compressed by proper torque

 

[LongDistance]

Compressed thickness is .062" or 1.57mm :'(

 

[NvgtrWiggles]

Where did you order your OEM head gasket from and how much did it cost?? I remember having trouble getting it from Honda last time I tried, but I could be wrong.

 

[LongDistance]

I order them from my local dealer. They even honor the online Honda parts pricing from sites like this one http://www.servicehondapsn.com/fiche_select1.asp?cat=Motorcycles&mfg=Honda