Fly cutting cast pistions
#1
Fly cutting cast pistions
Excuse my ramblings,questions logic and sarcastic snide remarks.
Pulled the top end down thinking I had pistion slap. Upon pulling down found rear exuast rocker was some dam odd ball,leaving aprx 1/8 inch of clearance in the Rocker supports. There roller rockers that a pear could be ultimas. 1.695s. But who really knows as they have some wacky numbers stamped in them. With 3 diffrent part numbers all together.
Pulled top end rest the way down,as to be honest I didn't notice the rocker arm issue till later.
Pistions look in good shape no scuffs on them or the bores.
.045 heads gasket, .005 deck height.
Pistions are domed,appear to be a older set of s/e pistions from what I can find with the part numbers. Harley and their dam part number changes has made finding solid info has been like getting kicked in the *****.
Heads have been worked on, back when bike was buit bored to 95 in the 05 era. 1.9 intake, stock 1.5?? Exuast. And milled to 79cc chambers. S&s 5.85 cams on gears.
In a rude attempt to figure out what rocker ratio was I came up with 1.7 using a pair of calipers and a .100 washer. Egyptian brain surgery at its best.
Wanting to bring down the quench to .035,head gasket change is in order.
Since I have luck of a curious cat,figured better clay it up and make sure before I end up getting declared awake and aware.
Looked up specs for the 585, TDC .186 intake & .179 on exuast. Multiple that by rocker ratio,
1.695 rockers .314 I & .303 e
Broke out my Egyptian brain surgery tool the calipers.
Measured from valentine tip, to guide with valve seated, zerod out then backed off .314 &.303. Made a mark with felt pen and a oring.
Bolted heads up, with the old .045 hg, tq to 42lbs and pushed the valve down with the pistion at tdc.
Intake left aprx .010 and exuast right to metal.
Looking at the ware marks not really marks but friction zone, on the valve steams it looks as my math was right....
Bikes be running 20,000 miles like this pretty dam hard with me, and aprx 10,000 with previous owner.
so I'm THIKING I'm ETHIER Doing Some Math wrong, OR IGNORANCE Is Bliss As THEY say.
From my math if I put stock ratio rocker 1.625 on that could give me .012 on the exuast and and .022 intake,don't think enuff clearance, even with the .045 hg let along a .030.
Trying not to buy pistions and reboring,I'm going with the assssumption these pistions are cast, can they be fly cut for reliefs, or am I just better to sack up and new pistions .
Feel a snowball coming in the summer when I should be out blowing around like a tumble weed.
Pulled the top end down thinking I had pistion slap. Upon pulling down found rear exuast rocker was some dam odd ball,leaving aprx 1/8 inch of clearance in the Rocker supports. There roller rockers that a pear could be ultimas. 1.695s. But who really knows as they have some wacky numbers stamped in them. With 3 diffrent part numbers all together.
Pulled top end rest the way down,as to be honest I didn't notice the rocker arm issue till later.
Pistions look in good shape no scuffs on them or the bores.
.045 heads gasket, .005 deck height.
Pistions are domed,appear to be a older set of s/e pistions from what I can find with the part numbers. Harley and their dam part number changes has made finding solid info has been like getting kicked in the *****.
Heads have been worked on, back when bike was buit bored to 95 in the 05 era. 1.9 intake, stock 1.5?? Exuast. And milled to 79cc chambers. S&s 5.85 cams on gears.
In a rude attempt to figure out what rocker ratio was I came up with 1.7 using a pair of calipers and a .100 washer. Egyptian brain surgery at its best.
Wanting to bring down the quench to .035,head gasket change is in order.
Since I have luck of a curious cat,figured better clay it up and make sure before I end up getting declared awake and aware.
Looked up specs for the 585, TDC .186 intake & .179 on exuast. Multiple that by rocker ratio,
1.695 rockers .314 I & .303 e
Broke out my Egyptian brain surgery tool the calipers.
Measured from valentine tip, to guide with valve seated, zerod out then backed off .314 &.303. Made a mark with felt pen and a oring.
Bolted heads up, with the old .045 hg, tq to 42lbs and pushed the valve down with the pistion at tdc.
Intake left aprx .010 and exuast right to metal.
Looking at the ware marks not really marks but friction zone, on the valve steams it looks as my math was right....
Bikes be running 20,000 miles like this pretty dam hard with me, and aprx 10,000 with previous owner.
so I'm THIKING I'm ETHIER Doing Some Math wrong, OR IGNORANCE Is Bliss As THEY say.
From my math if I put stock ratio rocker 1.625 on that could give me .012 on the exuast and and .022 intake,don't think enuff clearance, even with the .045 hg let along a .030.
Trying not to buy pistions and reboring,I'm going with the assssumption these pistions are cast, can they be fly cut for reliefs, or am I just better to sack up and new pistions .
Feel a snowball coming in the summer when I should be out blowing around like a tumble weed.
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