ORIGINAL: Bill Adair
Earl,
You are correct, the plug flange is what spaces the standard head away from the unthreaded part of the cylinder, but the NV diesel heads must be modified to provide that same clearance.
Alex did say that the factory has been notified of the defect, and will hopefully correct future production.
Bill
It was Gkamysz and I that discovered the problem and I reported it to Alex-Frankly I'm surprised that these are being sold without being corrected. I know he's on this side of the world and Russia is a long way away but any machine shop could fix the initial run of these for a few cents a piece, or, they could be sent back to Russia for touch-up. We're talking about just kissing the threads and making a 2mm land, they could probably do all of them without making a fixture and have a relatively unskilled shop hand do the work without supervision.