|
|
Any thoughts on why this may have happened?1965 SA-200Also where is the best place to get a piston and set of rings?ExcaliburLincoln Electric:Ranger GXT 250SA-200LN-25Pro MiG 256Pro Mig 180Esab CV 251Invertec 160Victor Torches
Reply:probably too tight in the bore when engine was rebuilt prior, or extremely loose in the bore from wear.. This happens a lot when a new piston is placed into a cylinder which has taper. If that is an engine with liners, the cylinder liner will need replaced also.SlobPurveyor of intimate unparalleled knowledge of nothing about everything.Oh yeah, also an unabashed internet "Troll" too.....
Reply:No liners.ExcaliburLincoln Electric:Ranger GXT 250SA-200LN-25Pro MiG 256Pro Mig 180Esab CV 251Invertec 160Victor Torches
Reply:Actually it is my guess that this is original equipment. The machine was in a barn since 1985 until I bought it 2 years ago. I did some valve work to get it running and check out the welder. It ran good and did for months until it started smoking one day.ExcaliburLincoln Electric:Ranger GXT 250SA-200LN-25Pro MiG 256Pro Mig 180Esab CV 251Invertec 160Victor Torches
Reply:If OEM and never rebuilt probably piston slap got to it over the years from wear. When you had the head off did you notice any marks in the piston crown, (std., ,010, ,020, etc.)?SlobPurveyor of intimate unparalleled knowledge of nothing about everything.Oh yeah, also an unabashed internet "Troll" too.....
Reply:Have to measure the bore at top and bottom and compare to original motor specs and wear limits.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:Damn, Ex ... hate to see that happened to your beautiful rig! Here are my sources in order by my experience ... check their prices as i have not bought pistons specifically from all of them.Rick Grindstaff @Grindstaff Engines, Inc.1041 S Vista AveIndependence, MO 64056 800-896-7676 816-796-6053 fax www.grindstaffengines.comRick went above and beyond what i consider good customer service. Answered every email and every stupid question, Even called me back after his computer and phone system went down to let me know that he would call me back when the system was back up and running. Most places would just sit there and wait for you to call back.oragkits.com (import stuffs)orBWParts.comLast edited by AFFENDE; 07-14-2015 at 10:08 PM.AWS CWI xxxx21711968 SA200 Originally Posted by WelderMike I hate being bipolar, It's awesome.
Reply:I made a visit to my local NAPA store today and Keith hooked me up with some $35 pistons. I'm going to get out cheaper than I expected @$200 for pistons, rings, bearings, head gasket as well as oil pan gaskets. Should have her bellowing by the weekend.I would love an explanation for such a problem thoughExcaliburLincoln Electric:Ranger GXT 250SA-200LN-25Pro MiG 256Pro Mig 180Esab CV 251Invertec 160Victor Torches
Reply:just curious, can you kinda describe when it happened, when you knew, etc. was it on start up, welding on warm eng at time, noise made, how long etc. ?? I'm not trying to be funny, but would like to hear the order of sequence
Reply:Originally Posted by ExcaliburI made a visit to my local NAPA store today and Keith hooked me up with some $35 pistons. I'm going to get out cheaper than I expected @$200 for pistons, rings, bearings, head gasket as well as oil pan gaskets. Should have her bellowing by the weekend.I would love an explanation for such a problem thoughExcalibur
Reply:How do you know that it needs machining slob?ExcaliburLincoln Electric:Ranger GXT 250SA-200LN-25Pro MiG 256Pro Mig 180Esab CV 251Invertec 160Victor Torches
Reply:Hi there;All engines wear as they are used. Although an upright inline engine tends to wear less through use rather than a "Vee" type design, they still wear. You have a broken piston skirt. This is usually a result of wear of parts through use, or improper sizing/assembly procedures. Look at it this way, there is a piston which is a certain diameter 90 degrees to the axis of the piston pin which the piston rocks upon. The skirt of this piston is usually slightly larger than the top ring land area of the sime piston but a couple thousandths. The cylinder diameter is yet a couple of thousandths larger yet than the largest diameter of the piston skirt. This is to allow the piston to expand in diameter from heat of compression and friction of the sliding piston rings. That being said, the scraping action against the cylinder walls by the piston rings slowly causes this cylinder to grow in size. Since the piston rings do not travel the full length of the cylinder the cylinder grows larger at the top that the bottom of the cylinder. This is called "taper". Now a new piston placed into an old and out of "true" cylinder will have more skirt clearance at the top causing piston "slap" as the piston transverses from it's upward to downward momentum through rocking upon it's piston pin axis. which imparts unusual and undesigned stress on the new piston. In cases this causes new parts to fail prematurely. The original piston failed and I'd doubt it didn't scratch the cylinder wall prior to letting go catastophically and winding up in the pan. This would not be a good thing to cover up with new parts.You need to measure the cylinder bores with a spring gauge and micrometer, or have a machine shop measure it up for corrective measures to be taken. You may have the "luck of the irish" and not need anything but cylinder honing prior to reassembly but an engine with the age it has is probably going to need a few other operations more than just new parts. I can't tell you exactly what it needs as far as labor and/or parts without physically seeing and measuring it up, nor am I suggesting you throw wheelbarrows of money at it which may be unneeded but it does need evaluated further.SlobPurveyor of intimate unparalleled knowledge of nothing about everything.Oh yeah, also an unabashed internet "Troll" too.....
Reply:I would guess the piston had some sort of stress riser. Just a guess tho. I had the same thing happen in a dirt bike motor. Single cylinder with a nickle Si sleeve. No damage to the cylinder. Washed the case out with soap and water just in case piston debris got into the case. Installed new piston and all was good for a couple more years. The engine seized up after a couple years later because it ran on its side after that for a minute (wipe out). I would drop the pan and inspect then replace all four pistons IMO.
Reply:that is a textbook skirt failure. Could be several things that cause it.Overheat causing the piston to deform and subsequent piston slapworn out skirt or bore causing piston slapjust plain old metal fatigueThe skirt inline with the connecting rod receives a lot of thrust load on a loaded motor, I've seen a lot of small engines with this failure. Make sure to check the bore for wear and concentricity, if it's oval shaped it's due for a full rebuild.
Reply:Originally Posted by SlobHi there;All engines wear as they are used. Although an upright inline engine tends to wear less through use rather than a "Vee" type design, they still wear. You have a broken piston skirt. This is usually a result of wear of parts through use, or improper sizing/assembly procedures. Look at it this way, there is a piston which is a certain diameter 90 degrees to the axis of the piston pin which the piston rocks upon. The skirt of this piston is usually slightly larger than the top ring land area of the sime piston but a couple thousandths. The cylinder diameter is yet a couple of thousandths larger yet than the largest diameter of the piston skirt. This is to allow the piston to expand in diameter from heat of compression and friction of the sliding piston rings. That being said, the scraping action against the cylinder walls by the piston rings slowly causes this cylinder to grow in size. Since the piston rings do not travel the full length of the cylinder the cylinder grows larger at the top that the bottom of the cylinder. This is called "taper". Now a new piston placed into an old and out of "true" cylinder will have more skirt clearance at the top causing piston "slap" as the piston transverses from it's upward to downward momentum through rocking upon it's piston pin axis. which imparts unusual and undesigned stress on the new piston. In cases this causes new parts to fail prematurely. The original piston failed and I'd doubt it didn't scratch the cylinder wall prior to letting go catastophically and winding up in the pan. This would not be a good thing to cover up with new parts.You need to measure the cylinder bores with a spring gauge and micrometer, or have a machine shop measure it up for corrective measures to be taken. You may have the "luck of the irish" and not need anything but cylinder honing prior to reassembly but an engine with the age it has is probably going to need a few other operations more than just new parts. I can't tell you exactly what it needs as far as labor and/or parts without physically seeing and measuring it up, nor am I suggesting you throw wheelbarrows of money at it which may be unneeded but it does need evaluated further.
Reply:Originally Posted by ironmangqthat is a textbook skirt failure. Could be several things that cause it.Overheat causing the piston to deform and subsequent piston slapworn out skirt or bore causing piston slapjust plain old metal fatigueThe skirt inline with the connecting rod receives a lot of thrust load on a loaded motor, I've seen a lot of small engines with this failure. Make sure to check the bore for wear and concentricity, if it's oval shaped it's due for a full rebuild.
Reply:Originally Posted by ExcaliburSlob thanks for your concern! There is no way in hell I would have taken the time to sit down and write out an explanation as detailed as this without being paid.When I first dropped the pan and discovered the piece of piston skirt laying in the bottom I assumed as did you that the cylinder bore is scarred from top to bottom. However, upon removal of the head and then pushing the piston out across an unidentifiable rim ring a smile came back to my face. I gazed into the cylinder looking for that big vertical scratch but it wasn't there! I rubbed and rubbed but couldn't feel what I thought I should be seeing either! I held a vertical straight edge against the cylinder wall with my flash light behind it just knowing I could slide a dime under. "What the hell" I said to myself. "This old thing has been sitting its whole life.". Maybe just maybe it's just like you said it's the luck of the Irish.Now that you know the rest of the story would you complete the in-frame for @ $200-$300 or would you take it to the motor shop and have that $1500 overhaul?Thanks again for your concern.Excalibur
Reply:Do you have one overhauled and ready to go? I'll just buy from you?ExcaliburLincoln Electric:Ranger GXT 250SA-200LN-25Pro MiG 256Pro Mig 180Esab CV 251Invertec 160Victor Torches
Reply:If you can't find a replacement, then yes, clean it it and weld it. You have to realize when it was new, the piston was not round, I don't know how they do it, but the pistons are are elliptical, once it's hard again, So when it gets hot it's round again.
Reply:Originally Posted by ExcaliburDo you have one overhauled and ready to go? I'll just buy from you?Excalibur
Reply:Well there goes the luck of the Irish. I was going to offer you $1200. For one.ExcaliburLincoln Electric:Ranger GXT 250SA-200LN-25Pro MiG 256Pro Mig 180Esab CV 251Invertec 160Victor Torches
Reply:Originally Posted by ExcaliburWell there goes the luck of the Irish. I was going to offer you $1200. For one.Excalibur
Reply:Originally Posted by ExcaliburDo you have one overhauled and ready to go? I'll just buy from you?Excalibur
Reply:Originally Posted by AFFENDEFWIW ... i had a shop deck the head, deck the block, grind the valve seats, bore the cylinders, R&R valve guides, R&R cam bearings, R&R & size rod bearings, and hot tank it ... $250.Worth it ... especially since a full rebuild kit ran me less than $500 (add in another $50 for freeze plugs, rod bolts and nuts, head bolts, etc) |
|
发表于 2021-8-31 22:32:44