Kohnke Rebabbitting
Well-known member
*Text below quote
V
*Mr Kohnke... I stand by my findings exactly as stated. Purchasing fresh soft plastigage did indeed give an accurate read on my 1" mike or I wouldn't print it here. As well, the fresh plastigage worked perfectly on my bearings ... while the old hard stuff had failed to flatten.
5 minutes of google searching has just turned up numerous warnings about the shelf life of plastigage.
...I invite you to look.
As well, I've posted here Clevite's (the manufacturers) full data sheet cautioning one to clean all oil from the shaft. The picture is small, so you'll have to transfer & enlarge it if you want to read the instructions.
*Also I've added a link.
I should add...it's doubtfull that instructions for something this critical would leave ANY steps to assumption as you imply.
Mr Kohnke I'm not bothered so much with your suggestion that I'm making this up as I go along....not as much as I'm alarmed by your missinformation being further missunderstood & leading to the potential failure of a student's engine.
I mean what if someone reads your posting & oils the ENTIRE bearing surface before placing the gauge down & ends up with far too much clearance?
Or shall we assume every student should know that?
I think if you purchase some fresh plastigage you'll indeed find it works dry as the manufacturer's data instructs...and you can stop adding oil to soften it.
While you're at it, check the FRESH plastigage with a good micrometer & I think you'll find it reads exact.
LINK to instructions http://www.3sx.com/store/faq/plastigage/index.asp
Well Craig, I hope I didn't ruffle your feathers to bad, to the point of having them fall out around your tail area. I keep mine numbered for just such an occasion. In the first place, checking Plastigauge with a Mic. for size will be .003, on a .001 to .003 piece, with out oil, if you tried to compress it, as you said, you turned your Mic. to .001, and you got a reading of .002-50, you made my point exactly. With out oil, the plastigauge hangs on to the dry surface, an won't let it spread to its full potential under any given pressure. As far as what it is made of, you think it is wax, I don't know, but it seams to me seems to me if it was wax, that they would have called it Waxygauage!! When Plastigauge came out in our area years ago, I bought a box, and it had the same instructions with the box that I see posted here, they were not in the box, but a set came with the box when you bought some, they had them on the counter, so you could read them. Well I took the Plastigauge home, and I had just got done with an Air Cooled Franklin, 1914, I knew what I had for clearance in the Tobin-Arp, align Bore, by using a Post Mic., and an out side mike, and that was right to the 1/10th of a thousands, well I laid a piece on each main bearing, 9 in all, WITH OUT OIL, CLEAN, DRY, AND SHINY, I torque wrenched each main cap, and then removed the caps, WOW my first thought, THIS S. DON'T WORK, so i called Vern, an engine rebuilder in Fort Dodge, and he had had the same trouble, the first time, Arnold Motors, they have about 77 machine shops, so he called the head office machine shop, and they said simply, use 30W oil. What I got, as many have said on the Barn, that the Plastigauge goes into the babbitt, I don"t think it spread out at all, that is when I found out that lacquer thinner works for removal of Plastigauge. Well now I had brand new oil wells in the caps, with out trying, wouldn't hurt anything, but not what I was after. So I got my oil can, which always has 30W oil in them, oiled the cap, and shaft, put the plastigauge in off to the other side, and this time it came out where it should have been. Craig, common sense will kick in on you some day. I have looked at my original post, I don't seem to be able to find where I was suggesting you make stuff up as you go along??? As far as my missinformation about how much oil to put on a cap, and oil the whole cap, the only harm that does is wast oil, and makes a mess, to drip in your eyes, I guess that is why that when Star-Bucks sells you a hot cup of coffie,, they have to worn the public in general, that you might get burnt. Like I said, do not read the cap, read the shaft, as there is still a chance of it sinking in to the babbitt. As far as checking some new Plastigauge, we always have new stuff, as we use it many times a week, and for many years, how often do you use it Craig?? I will say, I don't care at all what anybody does, Guy's, I am not trying to convince anybody, of anything, as it does not butter my bread, It works for me, as we don't have room or time for a bad bearings, and have never had one in 42 years, but we will always fight to keep the first time away. thanks Herm.