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piston Rings

2015VXR

Member
I have a mercury 90 HP 4 stroke that i just installed new rings and honed the cylinders. I have about an hour run time on the motor. I building a mercury 115 4 stroke that uses the same piston rings. Can I hone the cylinders on the 115 and reuse the piston rings from the 90hp. I not going to use the 90Hp anymore.

Thanks
 
Do you think they are seated into the other cylinders already? I know it only a $160 for the new set of ring. But I'm trying to understand why they can't be used. Any insight to help understand, would be great.

Thanks
 
.. From the 'Book of Jim'..,The piston rings perform a critical function during all four phases of intake, compression, power, and exhaust. The rings keep oil and air from being drawn past the piston on the intake stroke. The rings keep all of the air/fuel in the cylinder during the compression stroke. during the power stroke the rings keep all of the expanding gases from blowing past the piston as the pressure pushes the piston down. On the exhaust stroke, the rings make sure that all of the spent gases are pushed out the exhaust port. Rings that do not seal well can leave 10, 20, 30, or more horsepower on the table depending on the size, compression ratio, and speed of the engine. Leaks during compression will cause loss of velocity and volumetric efficiency. Leaks on power stroke will let bad stuff into the crankcase to wreak havoc with the cleanliness of said oil (here comes loss of lubricative qualities of the oil and resultant engine damage). Rings that leak on the exhaust stroke will lower scaveging and allow some residual exhaust to dilute the incoming charge on the upcoming next intake event, again, lost power. How are we doing so far?
 
Helpful and informative, but did you notice how I ran intake and compression together there just to see if Sim would notice.
 
OK let's hijack. I call this one Bearscat. We must step back in the past a ways, before cell phones and video games and similar stuff. Old Jim was just young Jim back then but deep into reading and studying and performing actual applications from the "Boys Book of Aggravations". I was fortunate to have an "old man" of my very own. Something that youngsters of today are keenly missing. Old men are nowadays somehow very underrated. I think every kid should have an old man of his own to hang out with and be taught the finer points in life. The wisdom, knowledge, experience, and including the mastery of some of the finer elements of language, learned and earned throughout a lifetime, cannot just be picked up by osmosis. Most old men have this to spare, time too.
 
Having time to spare can be invaluable to a youngster. Your old man wouldn't have just a pinched off minute here and there to offer, but would have whole days, nights, and even weeks at a time to spend with you, often outdoors, nearly always away from the womenfolk, who generally were concerned that the male portion of the group kept there 'nose to the grindstone' as it were. This 'grubbing for money' can make one rather unpleasant and can cause one to fritter away their life in pursuit of it if one is not careful. Phrases like 'Stay out of trouble' (really, what's the point?), and 'Staying on the high road' (I never found nothing good on the high road, but on the low road, it was guns, tools, Ford roadsters, vessels of all sizes, bikes, aircraft, parts of all kinds and various equipment, some of which is still unidentified to this day) hung in the air around the female portion of the group. They would also endeavour to keep you under their ever watchful gaze. Their preoccupation with keeping sharp objects, tools, guns, matches, bad language and dirt away from the inquisitive hands of the young male population of the group had reached a fever pitch one summer. I had been sent immediately upon being ejected from the front door of the schoolhouse to the confines of a ranch owned and operated by a retired uncle for the summer. The women folk had committed a major miscalculation on this one.
 
I'm not knocking Fathers here at all, being one myself, but they tend to be busy when one feels the urge to fish or hunt or maybe just spend the day poking about the woods hiking, following game trails or maybe just studying crows. Adults loose that 110 percent concentration that a youngster applies to stuff that they do, that and the boundless energy that many a youngster posses. On a side note, I have been trying to syphon this energy up from the youngfolk, and bottle it up for some of the older (there's that word again) elements. Anyways, My old man happened to be my Grandfather. I don't ever remember seeing him mad. He always had a good word concerning everybody. My heart leaps up whenever someone recognizes some small beneficial side of my character and might blurt out something to the effect of "You're a lot like Grandpa in that respect" Up at the ranch, there really weren't any confines at all. Having been in the logging, building, earthmoving, farming, and occasional bank robbing business (well, just kidding about that one), the ranch was home to all kinds of fantastical remnants of equipment, some of which defied identification. Some of it was still in one piece even. My Aunt and Uncle, through some sleight of nature, had been left childless, a shame in light of the fact that they absolutely loved kids. There was a large, really tall massive barn that sat some ways from the ranch house. the barn overlooked a pasture that slowly dropped down to a meadow and then to the woods. There was a wonderful workshop attached to a lower end of the barn. There was an old but lovingly maintained stationary gas engine that powered, by way of a leather looking belt, a shaft that ran the length of the ceiling of the shop. Smaller belts that ran off of this shaft powered a lathe, drill press, buzz saw, generator, table saw, planer, band saw, and other stuff too. The lower level of the barn housed trucks,tractors, tools, barn cats, lumber, the occasional livestock, ect. The upper level had a room on the end that overlooked the pasture and meadow. You might imagine that that room became my room for that glorious summer. In the very top of the barn,at the roof, on that second level, was attached a track that extended the full length of the barn. There was a trolley that ran on this track. You could move the trolley out to either end of the barn, through big doors that opened outward, and by use of ropes and pulleys, you could hoist hay and pretty much anything else that you wanted, up to the second floor. Normally, the second floor was chock full of hay bales, winter food of a lot of the critters that wandered around the ranch would need later. One could while away their spare time swinging from the rope that hung down from the trolley and jumping into piles of hay. I might make small mention that the young ladies found some keen interest romping about in the hay, a development that did not go unnoticed.
 
Imagine if you will, getting up at 3 and devouring a breakfast of farm fresh eggs, ham, sausage, cheese, breads and and bacon by the pound while in the company of men with names like Fingers, Lefty, The Swede, Dude, and Uptown. Oh the stories. Oh the language (when the ladies were out of range). Laughter that would shake the stove pipe at the roof. Then rattling off in an old truck into the forest. Chainsaws, tractors, cables, axes, clean air, wildlife, a kid in heaven. Now at the end of the day, you rattled back to the ranch, showered up, had another feast, attended to farm stuff and about the time that the stars were beginning to peak out, I would be climbing the ladder to the barn loft. You could sit on the edge of the floor at the big open door and look out South at the pasture and meadow and listen to the sweet hum of summer. The cool air would just be beginning to come down the mountain. You could lie on the floor and view the stars and there were a lot of them back then with no smog or city lights to hide them from sight. There were other tenants residing in that great barn, one of which was a great huge barn owl. He was a very light tan color that looked kind of whitish in the dark so he had been named 'Ghost'. They had built a nest box up under at the peak of the roof for the owl. While you were lying there staring at the stars, your eyelids beginning to draw down over your glassy eyes, the owl would silently glide right past on his way out for an evening snack at dusk. Later as it cooled and you were getting up to crawl into bed or maybe just get a blanket and cover up right there on the floor, the owl would silently swoop right up to the edge of the door and sit there looking out onto the pasture and meadow. Every once in a while he might give you a passing glance. On a moonlit evenings, he would glide back and forth over the fields and pick off mice and snakes and then he would swoop back to the doorway. It was while watching this that I came down with a bad case of wanting to fly.
 
Back in the day, one could build balsa wood models of aircraft and boats (gratuitous boating reference here) either from kits or plans or one's own design. I had built a few models and had in fact progressed to my own designs after following plans for a nifty little high wing tail dragger and ending up with a single masted sailboat which promptly sank in the lake on launch day. Hindsight reveals that this may have been an omen. The Navy had been flying around some low wing monster radial engined speedsters. I drew up a plan and built one up. The fighter planes had names like Wildcat or Hellcat, and even Bearcat. I liked that name, and I liked that plane. Low wing, retractable landing gear, 18, that's right, 18 cylinder 2500 hp engine, speeds above 400 mph ( sleight salivation here). The initial model had a two foot wingspan or so. With a loose grasp of the theory of lift, drag, center of gravity and stuff, the experimental craft flew well out into the barnyard when launched from the roof of the outhouse. Later, after some elevator adjustments and center of gravity tweaks, the craft glided like an arrow out across the barnyard, the pasture, caught an updraft, and just cleared the barbed wire fence at the edge of the meadow. It was most exhilarating. I immediately set about drawing a full scale one out on the floor of the loft.
 
Once the outline of the craft was drawn out on the floor of the loft it was time for construction. An old oak barrel became the main fuselage. 1x2 became stringers that led back to the tail. Ribs were cut out for the wings. There were a bunch of cardboard feed barrels that donated their bodies for skin for the body and wings. Now it had grown very hot and dry that time of year, so hot and dry that the woods had been closed down to logging. With not much else to do, Grandpa and Uncle and even some of the guys became interested in the project and donated time and skills for a few days. Before you could say 'Keep yo feet on da ground', a trim little craft was sitting on two main landing gear and a little castor wheel at the back under the rudder. From the oak barrel back to the tail were covered with the thick hard cardboard like material from the old feed barrels, roofing nails looked just like rivets in the skin. Wheels from a hand truck were the main wheels. An opening in the barrel contained the pilots seat. Rods went out to ailerons and elevator, likewise to a rudder. The ailerons and elevator and rudder was covered with old canvas that spent the winter covering haystacks. She was painted light blue on the bottom and dark blue on the top. Right near the tail, It said 'Bearcat'. Much to my chagrin, some comedian later added an s in between the r and the c with a little hyphen. The fellas were called away for a few days to help with the hay crop on a relatives spread in Eastern Washington. I didn't mind. Work forged ahead at a feverish pace. My childhood friend and cohort in mayhem, a guy some of you know as 'The Flame' arrived just in time to figure out how to power the machine. Radial engines being rather hard to come by at that juncture, we pored over the derelict equipment out behind the chicken coops.
 
The men had at one time, taken a chainsaw (Sim saw this coming) engine and mounted a propeller to it. This we called a brush burning fan. You would set the brush burning fan up on its three legs by a big pile of brush that you wanted to go away. It would supply a stream of air to invigorate the flames. It also had a small diaphragm pump attached to it to spray kerosene onto the pile of brush in inclement weather to help facilitate the flamage. We cannibalized the fan nearly as fast as you could say 'Motive Power'. We set the now engined craft up on saw horses and ran some center of gravity tests. We spent some time lengthening the rear part of the fuselage to cure some nose heavy tendency. The Bear's'cat was ready for flight tests but there was no way one kid was going to be able to launch that baby from the roof of the outhouse. The roof of the barn, maybe. It rolled around all right on the ground but wouldn't accelerate to take off speed. I figured that with the landing gear up, she'd climb like a homesick angel. The Flame suggested that he pull me down the country road behind the old farm truck. He figured that once he got to about 70 mph, I could haul back on the stick, and be on my way.
 
This was you were young when bones and punctures healed fast, this has disaster written all over it,.................... BUT, you ARE tellin the tale, so you must have survived it, you do have use of ten toes and ten fingers, see out of both eyes?????????????
 
There were a couple of problems with the country road idea. First and foremost was the fact that the road ran right in front of the farmhouse and thus, we would be in full view of the female population that had an unreasonable fixation on trying to keep me out of a huge category of stuff that they termed 'trouble'. The second problem, as I saw it, was how would I keep the tow rope out of the propeller. After all, once I was up to speed, I would have to let go of the rope before or maybe just after lift off. Some of the pictures of Navy craft showed them being propelled off of aircraft carriers. This idea of a catapult began to take root along with the idea of covert operations to take place South of the big barn, and therefore out of view of ever prying adult eyes. Sad to say, there wasn't any steam catapult in the various bits and pieces of derelict equipment parked behind the chicken coops. There was, behind the coops, the ever present snarl of cable and rope upon which I sat down on and elbows on knees and chin on hands, began to ponder. Gazing out toward the barn, you could plainly see the Bear's'cat in the upper doorway, suspended from the trolley that ran the length of the roof of the barn, sunlight reflecting off of the propeller. It looked as if it was ready to just float out across the barnyard. I had little doubt that if one were to hang a bunch of weight from one end of a rope hung from the trolley track and run said rope through a set of pulleys to the Bear's'cat, and then drop the heavy stuff off the other end of the barn, that the Bear's'cat would be propelled out into free flight. What little doubt I did have had caused me to offer up pilotage duty to the Flame. He politely refused, owning to the fact that he had on what he called, his 'good' pants, and had been instructed to not harm them in any way by his mother. He would later refer to these pants as his lucky pants.
 
Right before the woods had closed down due to the heat and record dryness, the guys had been involved in some 'high lead' logging. In a nutshell, you strung a cable between a couple of tall trees located on different mountains and then passed the felled trees from one area to the other to get across deep valleys and gorges and rivers and stuff. The idea light bulb in my head began to flicker like a dying ember. We could string a cable across the two big pines in the meadow. We could attach a cable mid span to that cable and run it all the way up to the barn trolley track. We could hook a pulley up at the junction of this cable across the trees and attach it to the old farm truck. The Flame could drive the farm truck toward the barn as fast as it would go and pull the Bear's'cat down this cable in the opposite direction. When I reached the end of the line, I mean cable, I would hit the latch and float free. "I'll climb out at full power to the West to take advantage of the prevailing wind to help with lift" I instructed the Flame. "I'll bank North and then East and come right down the road". "When I get up to the lake, I'll start my down wind and drop the gear and bring the power down". "Make sure you don't get in the way when I bring her in 'cause I'll be coming in hot". We chuckled at the sheer genius of our little plan. Took us two days to string the cables even with the use of the farm truck and an old John Deere tractor (Grampa:"You get it started, you can drive it") (on a side note, I figured that went for the motorcycle in the garage too, but that's another story). Day three found the Bear's'cat hanging from the trolley in the loft of the barn, gear up, flaps up, tank full, warmed up. I had Gramps's leather coat on ("probably cold up there at altitude") and his leather aviator motorcycle headgear as I scrunched down at the controls. The Flame sat idling at the end of the pasture. At a prearranged signal, the Flame would accelerate as hard as possible. I brought the power up. Dust and debris and hay blew out the back of the upper door of the loft. The Bear'scat tugged forward, hanging from the trolley. I gave the signal. The engine responded with a healthy roar at full power.
 
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