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'86 VFR750 engine oddities

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posted  this @  http://vfrworld.com/threads/what-do-i-have-here.54567/#post-576927


 i hoped and expected to buy a stock, running 750 engine but instead got this shipped in, not runnable as-is and needing work.





 first, a  major disappointment, as right front cylinder compression means big trouble:



so i pulled the front head and found some surprises !


special (mystery) high compression domed pistons CNC machined vs.oem cast pistons, fancy stuff !


a spot where the top of the piston hits the plug electrode at TDC is visible, the next big disappointment.



stock piston for comparison: 

\8--1--17 040.JPG



hot reground cam at right, stock is left:




hot reground cam is marked "NFF" or "NFI".  anyone know him ?  .020" more lift than stock.


porting and polishing by "R.E.D."  he has a website and alot of rich-guy, big-boat, fast-lane endorsers :






nice work by a pro


i discovered  2 very leaky intake valves on the  right front cylinder, accounting for the low compression.  my current theory is that new rings aren't seated (cylinders were not honed or cross-hatched) so running  he engine for awhile might boost the compression up..........i hope.





^^^^^^^^^^^^^^  from what little i  think i know about building engines and some experience, my best guess is that this one would be a troublesome beast in a street bike, needing expensive race fuel and prone to bad idle and overheating.  my challenge now is just to get it running, to test it out on the road a bit, then maybe sell it at some profit to a younger he-man multi-tattooed  bloke who needs to go fasta than i dare, or maybe an AMA or ARHMA vintage racer with deep pockets and 70+,  enjoying life in the elite atmosphere of the pits.


if it don't blow apart, that is.

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