pparaska Posted May 6, 2006 Share Posted May 6, 2006 I've got the Dart Sportsman block back from the machine shop (now zero decked and bored/honed to my pistons from the old 406). Had to have the crank polished (dirt got in the bearings somehow, and they were showing copper). So I need new bearings for the mains at least. I usually use Clevite 77 H or P bearings, but I've heard people say the King Alecular bearings are good also. http://www.kingbearings.com/advantages.html I found the ones I need pretty cheap - $25 for main bearings. These are the silicon Alecular bearings. I know, silicon is sand. Not sure it's something I want in a bearing. They make them without the silicon also. http://www.kingbearings.com/SI.htm Any experience or advice appreciated. Quote Link to comment Share on other sites More sharing options...
Sam280Z Posted May 6, 2006 Share Posted May 6, 2006 Silicon dioxide (silica) is sand. http://en.wikipedia.org/wiki/Silica Silicon is a common constituant of metal alloys, esp aluminum. Compare to the difference between carbon and carbon dioxide. Carbon mixed with iron is steel. I don't have any experience or advice with this issue, sorry. Quote Link to comment Share on other sites More sharing options...
pparaska Posted May 6, 2006 Author Share Posted May 6, 2006 I understand what you're saying, but the fact that they talk about the "silicon" knocking off the high spots on the crank journal, I came away thinking it was more like silica. Quote Link to comment Share on other sites More sharing options...
mark Posted May 6, 2006 Share Posted May 6, 2006 Pete!! Go do your pt or something. Get well first. No, really, good to see you feel like getting after the car. Quote Link to comment Share on other sites More sharing options...
pparaska Posted May 6, 2006 Author Share Posted May 6, 2006 This is like mental therapy! Laying around for a week and a half will drive ya nuts! I'll be in the garage a bit now, filing piston rings, mic'ing journals, etc. The wife will have to put the crank on the bench though . Quote Link to comment Share on other sites More sharing options...
jbk240z Posted May 6, 2006 Share Posted May 6, 2006 I'm glad to hear the surgery went well and you seem to be getting around okay. Definitely let the wife help with any lifting. Take care. Quote Link to comment Share on other sites More sharing options...
jakeshoe Posted May 6, 2006 Share Posted May 6, 2006 King bearings are excellent quality. Some builders prefer them over the Clevite... I've had excellent luck with them. Quote Link to comment Share on other sites More sharing options...
DaleMX Posted May 6, 2006 Share Posted May 6, 2006 I'd never seen those bearings before. Sounds like the added material thickness might be a true crank saver. Quote Link to comment Share on other sites More sharing options...
A. G. Olphart Posted May 6, 2006 Share Posted May 6, 2006 I like the obvious disparity in 'good' bearing characteristics as described in the two flack sheets. Their soft bearings tout the material's thickness because embedability is a good thing; their rock hard bearings brag on how foreign materials are flushed right through. IIRC from classes long ago, embedability is/was a good thing. The old cast babbit bearing material from the early 20th century had it in spades, but was too soft/ deformable for extended lifespans. Really hard bearings (like Aluminum) had extreme load carrying capabilities, but zero tolerance for dirty oil. I've no personal experience with racing, but have read that dragsters use soft bearings to minimize crank damage from any metal to metal contact that occurs. They also expect to check and change bearings regularly. (Real Racers, please stand up and correct me if I'm wrong). King's SI bearings would probably last forever as long as the oil remained good and clean. (But, personally, I don't see crank polishing as a bearing function). I like trimetal bearings: a bit of embedability, yet hard enough to go the distance. (Again, just personal opinion). . Quote Link to comment Share on other sites More sharing options...
jakeshoe Posted May 6, 2006 Share Posted May 6, 2006 I know of one guy who was running King bearings, had an issue with an oil pump or shaft during staging on a 10 second SBC powered car (383, Chevy II). He made the pass anyway, loaded the car. tore engine down to find he did in fact have an issue, the crank polished after making a pass with no oil pressure. Bearings were toast but they did what they advertise. King bearings are Israeli manufactured and are a good quality part. IMO bearings are not used to "polish" a crank, nor should you be running dirty oil. Type of bearing material depends on application, some specific applications will need more embedability, others may need a very hard bearing due to the very high oil pressures needed to keep the engine together. Quote Link to comment Share on other sites More sharing options...
A. G. Olphart Posted May 8, 2006 Share Posted May 8, 2006 Valid point Jake; soft bearing materials will wash out, given high oil pressures and tight clearances. IIRC, they also tend to pit/crater when overloaded for a long time. (Sorry; can't check this at the moment as my old Federal Mogul bearing book is in one of a zillion boxes waiting to be unpacked). I don't think anyone intentionally runs dirty oil, but as Pete could probably confirm, **** happens. A chunk of grit too large to 'flush right through' can make a mess. Did your buddy's crank polish up round, or were the rod journals a bit flat on one side? . Quote Link to comment Share on other sites More sharing options...
pparaska Posted May 8, 2006 Author Share Posted May 8, 2006 The laryer of the King bearings that are the bearing surface is a good bit thicker than the babbit layer of the Tri-metal bearings, so imbeddability is actually better. I have no idea where the dirt got into the oil. I'm not sure that it was actually debris. It was right in the center of the bearing, in line with the oil hole. It MIGHT have been a raised area around the oil hole chamfer. The bearing was dug out pretty deep all across that area, deepest in the center. But it MIGHT have been dirt. I know I was REALLY careful about taking the oil pump apart, blueprinting it and cleaning it, as well as cleaning the pump pickup. I even took the pickup apart. I cleaned the oilpan many times too, but there's a slight chance that there was dirt, etc. trapped under the area where the internal baffling meets the pan. I tried very hard to get that clean though. You can believe that when I put the 406 back together (starting this week) I will be even more careful about dirt, etc. Anyway, I've asked around and no one had anything bad to say about the King bearings, only good things. This includes people that build lots of engines for customers and themselves for street and racing. I mic'd the crank last night and ordered (STD) King Alecular bearings for it. carshopinc.com had them in stock, supposedly. I've never bought from them before, but they listed all of them and the different sizes on their web store and made it easy to order exactly what I wanted. Quote Link to comment Share on other sites More sharing options...
jakeshoe Posted May 8, 2006 Share Posted May 8, 2006 Valid point Jake; soft bearing materials will wash out' date=' given high oil pressures and tight clearances. IIRC, they also tend to pit/crater when overloaded for a long time. (Sorry; can't check this at the moment as my old Federal Mogul bearing book is in one of a zillion boxes waiting to be unpacked). I don't think anyone intentionally runs dirty oil, but as Pete could probably confirm, **** happens. A chunk of grit too large to 'flush right through' can make a mess. Did your buddy's crank polish up round, or were the rod journals a bit flat on one side? .[/quote'] I didn't measure the crank so can only go from what I was told, but it apparently was still perfect. It was in a fairly high dollar build and having it done "RIGHT" wouldn't be a problem, so I'm sure it was G2G. Any SBC should use a bearing with decent embeddability IMO. The oiling system is excellent. I've used King in SBC and BBC builds and will select them over a Clevite if it's an option fo about the same cost. That said, there is nothing wrong with a Clevite, Vandervell, Federal Mogul, etc.. They all work well. Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted May 8, 2006 Share Posted May 8, 2006 I mic'd the crank last night and ordered (STD) King Alecular bearings for it. carshopinc.com had them in stock, supposedly. I've never bought from them before, but they listed all of them and the different sizes on their web store and made it easy to order exactly what I wanted. So, what did the crank mic at, was it round, and what bearing clearance are you planning on running? Quote Link to comment Share on other sites More sharing options...
pparaska Posted May 8, 2006 Author Share Posted May 8, 2006 So, what did the crank mic at, was it round, and what bearing clearance are you planning on running? After using the standard to calibrate the 0.0001" mic, each journals had no more than 0.0002" of variation in diameter as I went around them 90 from one measurement to the next. Main journals, measured at half distance between cheeks, were: #1 2.4479 vs 2.4480 90 degrees apart #2 2.4479 vs 2.4480 #3 2.4480 vs 2.4481 #4 2.4481 vs 2.4481 #5 (in line with forward oil hole for/aft location) 2.4482 vs 2.4482 #5 (in line with rear oil hole for/aft location) 2.4483 vs 2.4483 I remeasured and got very similar results the 2nd time Rod journals, measured in for/aft location of oil hole for each rod: #1 2.0990 vs 2.0990 #2 2.0990 vs 2.0990 #3 2.0990 vs 2.0988 #4 2.0991 vs 2.0990 #5 2.0991 vs 2.0991 #6 2.0992 vs 2.0990 #7 2.0990 vs 2.0991 #8 2.0988 vs 2.0989 Again, when I measured the second time I got very similar results, only a .0001" difference from the time before on just a few locations. OF course, you can split hairs even on a vernier scale, and sometimes that was the reason - a measurement would come in as either a bit more than 2.0991 or a bit less than 2.0992, But I was taught not to try to read those split hairs and try to decide which vernier mark looked closer. As far as bearing clearances, I'd like to see no less that 0.0025" and no more than 0.0030" on the mains, no less than 0.0020" and no more than 0.0025" on the rods. But I'm all ears. Any suggestions? I can get 0.001" undersize bearings to mix and match with the STD ones to try to hit those numbers. Quote Link to comment Share on other sites More sharing options...
jakeshoe Posted May 8, 2006 Share Posted May 8, 2006 One thing to watch put for when measuring crank journals is taper from the center to the sides or across the journal. You can end up right on in one area and too big or too small just across the journal if it wasn't set up properly on the crank grinder. Quote Link to comment Share on other sites More sharing options...
pparaska Posted May 8, 2006 Author Share Posted May 8, 2006 Good point - I'll do a more thorough survey. Quote Link to comment Share on other sites More sharing options...
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