Holey onan block batman!!

admin

A friend from work (Dan) has a small 'fleet' of four cylinder 'J' series Onan generators for stand-by power and bought a blown unit (thrown rod) for parts last September.  After seeing it he decided he wanted to attempt repairing it and I sent a couple photos to member castweld (Peter) to look at  and give his opinion.  Based on what he could see in them he gave some suggestions for a 'field repair' and stated what he would do if he had it and offered and very reasonable estimate as to what it would cost to do the repair - again, based on what he could see in the photos.Long story short, Dan decided - as long as I was willing - he wanted to give it a go on our own and good, bad or ugly here are the results following some of what Peter recommended and improvising elsewhere as needed.  It remains to be seen if the crank still fits properly and turns free which is the next step in determining whether Dan proceeds with reassembly.  If it does, the entire repair area will be treated to a coat of JB Weld for - as Peter puts it - any "oops" which I suspect there are more than one.Mandatory thread posting stats:Hobart 1/8" Normacast rod from TSC (70-120amp recommended)Syncrowave 180 SD set to DCEP (recommended by the rod)Set at 100ampsDig initially set to '3' then to '7' then to max. (seemed to work better than higher amp setting)XM32 'The Message' on the radioSoaked to the bone with sweatThe 'patient' and the cause of the injury.  Crank throw actually contacted the rod on the beam and pushed it thru the block.  Block was pressure washed and sprayed down with Brake-Kleen in the affected areas in an attempt to clean any remains of oil but . . .. . .after a while once heat compliments of my 50,000btu John-Deere space heater (red arrow upper photo) was applied the 'S' crack (yellow arrow upper photo, red arrow lower photo) showed signs of oil contamination that still remained.  This same evidence also lead to the discovery of several other cracks as I had no way to magniflux.  Donor pieces from a trashed Generac/GM block were used as fillers for the pieces that were missing from the Onan.  Top donor piece proved to be the only post weld crack victim that I believe to be the result of the left half (crack area) being thinner than the right half and original block.  Should have used a better donor piece.Heat was reapplied several times throughout the entire process.Thought we were finished when we discovered another crack that followed the cast parting line along the base of the rear two cylinders.  Drilled the ends, ground out, more heat and 'short stitched' welded it up.I didn't expect 'castweld' Peter results but I was disappointed with my performance with the Hobart Normacast rod and the poor donor piece selection but Dan says if the crank still fits properly and spins free he'll be ecstactic.  So, time will tell.Thanks for looking.Last edited by duaneb55; 07-04-2010 at 01:54 PM.MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Reply:looks like pretty fair results to me without the use of a furnace. Sometimes a lotta black magic in making a good cast iron repair. And a lotta patience.
Reply:I think you did pretty good. You learn to swim the easy way or the hard way, you chose the hard way ..That one empty mounting bolt looks all rusted out like nothing was bolted up there. That would be my only concern if something generating some substantial torque needed to mount up there. Finding all the cracks and then getting them stopped is real important. Looks like you did that."The things that will destroy America are prosperity at any price, peace at any price, safety first instead of duty first, the love of soft living and the get rich quick theory of life." -Theodore Roosevelt
Reply:Good morning Happy Fourth of July.....you say if the crank bolts back in, would it have been possible or feasable to have welded the block with the cranck bolted and torqued in to help keep the block from any warping?..just askin..
Reply:Good job Duane, no matter how well you clean you will usually have some engine oil show up when welding.PETER
Reply:Originally Posted by CarlHAnd a lotta patience.
Reply:Looks good, Duane!! I agree w/ Carl in that there's sometimes a lotta black magic in cast repair. The base for my floor drill press got broke when we moved here. I bought some nickel rod, heated it up well and stick welded it. It's held together well so far. 'Course I didn't have engine oil and things like that to deal w/ either, plus it was circular which I guess would make things a little easier.    If the crank still fits well you're a winner!!!                                                    MikeOl' Stonebreaker  "Experience is the name everyone gives to their mistakes"Hobart G-213 portableMiller 175 migMiller thunderbolt ac/dc stick Victor O/A setupMakita chop saw
Reply:Good job there. I did that one time to a Kohler block. I did have to use the epoxy to finish the job on that one as well. Cast iron takes a lot more time and energy than the average person thinks.Millermatic 252XMT 304'sDynasty 280DXHypertherm PowerMax 1250Miller Trailblazer 302 EFIOptima PulserXR feeder and XR Edge gun and more athttp://members.dslextreme.com/users/waynecook/index.htm
Reply:Hey Duane   Been busy trying to beat the rain on the hay, turned out okThere has to be some distortion going on there.  Lot of weld, and a lot of heat.  Lacking a furnace, I would have rosebuded (is that a word?) the Bee Jeesus out of the thing around the weld, and kept the heat to it as it cooled, and beyond.  And probably left the crankshaft and bearings in it while I welded it.  (sort of to keep some sort of stabilizing thingy going as it heated and cooled)I'd guess it might have banana'd the block towards the weld, and maybe messed with the piston bore relationship to the crank.BUT WHO CARES, IT WAS TOAST TO BEGIN WITH  I always figure it isn't any "broker" than when I started (shrug).The high nickel rods run very "soft" for a reason.  They're designed, so I've heard, to limit heat input.  It's why they are supposed to run at relatively low amps.  It fools guys used to working with regular rods on mild steel.  You can have a tendancy to turn the amps up to achieve the "dig" you're used to on mild steel.  You don't hear the "snap!" when running these rods, and it can fool you.  As a matter of fact, Lincoln brand rods are labeled "Softweld"I don't see how you could have done any different on a field repair.I would have maybe used a one piece mild steel patch, but it would probably be the wrong thing to do, dunno  I really don't know the forces that are present in that part of an engine block, and the ridgitity required."Any day above ground is a good day"http://www.farmersamm.com/
Reply:hi nickel rod runs like crap too, so it's not you..........it's the nature of the beast"Any day above ground is a good day"http://www.farmersamm.com/
Reply:Duane If the cranks tight or loose (end play) pm me. A little machining can correct it. I would look for rollers making contact on one side of race.Peter
Reply:I am impressed!(Retired) Professional firefighter, amateur everything else I try to do...Oh yeah:  Go Big Red!   (You know: one of the 12 members of the Big 10 cuz we left the 10 members of the Big 12...)
Reply:Originally Posted by duaneb55Yeah, the "two hour job" (what I told Dan I estimated it to be) turned into just over six by the time we were done.  Did a lot of heating and perhaps more than prep and welding combined.Thanks Sandy but time will tell as the jury is still out on this one.  Nothing attached to that rusty bolt boss.  Battery ground cable goes to the one to the left of it and the one to the far left is for starter support.I wouldn't have tried it with the crank in BUT, these have a large, two piece center bearing support (required by design) that could and probably should have been torqued in place for the project.  Where were you yesterday?Thanks Peter but I'll be honest, being better equipped and far more experienced, I would have rather seen Dan and I make the trip to your place and let you do it.
Reply:Nice repair.. It gets pretty depressing when your welding away to find more cracks showing up, adding time to the bid.. Next thing you know, you giving the job away for free.Common sense in an uncommon degree is what the world calls wisdom.
Reply:I dont care what anybody sez, that is some real art work Duanne.  Looks like you found it all and got it all stitched up, so if the crank goes in and turns ya done good!!!  If not, you didnt lose anything but a little time, and you learned a ton doing it so even that wasnt really a waste. I'm like you I like to save it from the scrap pile if possible whenever possible.  Sometimes I waste too much time on a project like that, but it sure is fun while I am "wasting" the time.  Job well done!!!!!BobI'm spending my Kids inheritance, I dont like him that much anyway!!!!!!Enuff tools to do the job, enough sense to use em.Anybody got a spare set of kidneys?  Trade?
Reply:Originally Posted by duaneb55A Mandatory thread posting stats:Hobart 1/8" Normacast rod from TSC (70-120amp recommended)Syncrowave 180 SD set to DCEP (recommended by the rod)Set at 100ampsI didn't expect 'castweld' Peter results but I was disappointed with my performance with the Hobart Normacast rod and the poor donor piece selection but Dan says if the crank still fits properly and spins free he'll be ecstactic.  So, time will tell.Thanks for looking.
Reply:I'm with matt , I say it works also. If the block can take the stress of running under full power the little welding shouldnt change anything.
Reply:Thanks to everyone for all the compliments.Dan called tonight and said the crank slipped right in and spins free as a breeze.Matt - I was aware of the Normacast stats and even have some Hobart N55 but the ". . .pre-heat to 700-800 degrees mandatory. . ." for the nickel rod concerned me seeing as I knew the little JD heater couldn't get it there.  Had used the Normacast on a much less critical application (milling vise) with success and figured . . . MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Reply:Hi duaneb, I suspect if you or I either one sold that rod we would put the 700-800 on it too. Iron is just an "iffy" thing, I'm glad it worked out for you.Matt
Reply:Duaneb55,I just noticed that the expression on this little guy (  ) in your last post (post #18) is the same as the expression in your avatar.  Kinda funny.Nice repair.Last edited by joedirt1966; 07-06-2010 at 10:12 PM.
Reply:Nice repair. I love to see people do what they can with what they got. And it works!
Reply:Out of curiosity, is it recommended to drill the ends of cracks in cast or not?(My apologies for this mild theft of topic)Tom.Lincoln SA 200Esab Caddy 160Thermal Arc 201TSMiller Dialarc HFI don't like making plans for the day because then the word "premeditated" gets thrown around the courtroom....
Reply:Originally Posted by dubl_tOut of curiosity, is it recommended to drill the ends of cracks in cast or not?
Reply:Originally Posted by joedirt1966Duaneb55,I just noticed that the expression on this little guy (  ) in your last post (post #18) is the same as the expression in your avatar.  Kinda funny.Nice repair.
Reply:Originally Posted by duaneb55I do.yea, looking back I can see nowYou're joking right?  You've posted to the 'Hijack King's' thread!:laughWell, in that case.....naw, I won't go thereYes, brazing was an option considered and is a common method but . . .MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Reply:When ya gonna fire it up?"Any day above ground is a good day"http://www.farmersamm.com/
Reply:He'll be putting it back together over the next week or so and then we'll see.MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Reply:Originally Posted by duaneb55He'll be putting it back together over the next week or so and then we'll see.
Reply:Dang that looks like a pain, nice job.HH187Hobart 500i plasma cutterClark 4.5" GrinderDewalt 14" chop saw30 gallom 1.6 hp compressor10 gallon pressure pot sand blasterlots of hand tools
Reply:nice job
Reply:just wanna check my avatar