Bob Riding Posted January 19, 2023 Report Share Posted January 19, 2023 I've finally got to the main bearing install on my rebuild of the '56 230ci motor. The machine shop didn't need to do anything to the main journals or con rod journals except polish them. They were ground .020 on the previous rebuild and my Bernbaum bearing set was also 0.20 over. I followed @keithb7's video and plastigaged the mains and they all came out .002 clearance. Spec is .0005-.0015. Should I worry? Quote Link to comment Share on other sites More sharing options...
keithb7 Posted January 19, 2023 Report Share Posted January 19, 2023 (edited) I wouldn't sweat being out a ½ thou. That's finer than frog's hair. Me? I'd be inclined to resume with reassembly. Some books I have here show .0005 to .002 specs. The Chrysler Industrial engine book I have here states .0005 to .0015, maximum allowable .002 I look forward to what others have to say! Edited January 19, 2023 by keithb7 Quote Link to comment Share on other sites More sharing options...
allbizz49 Posted January 19, 2023 Report Share Posted January 19, 2023 Might be the angle of the picture, but looks closer to 003. Quote Link to comment Share on other sites More sharing options...
Dodgeb4ya Posted January 19, 2023 Report Share Posted January 19, 2023 (edited) .001" per 1" of shaft diameter. You're way fine @.002" on the mains.........lotsa correct info at bearing/ engine parts manufacturers.. https://www.mahle-aftermarket.com/na/en/support/installation-tips/engine-bearing-fitting-tips.jsp Edited January 19, 2023 by Dodgeb4ya 1 Quote Link to comment Share on other sites More sharing options...
Bob Riding Posted January 19, 2023 Author Report Share Posted January 19, 2023 12 hours ago, allbizz49 said: Might be the angle of the picture, but looks closer to 003. Yes, bad photographer! Quote Link to comment Share on other sites More sharing options...
kencombs Posted January 19, 2023 Report Share Posted January 19, 2023 I'm in the 'you're OK' camp too. Added clearance used to be a common setup on competition engines. As long as the pump can maintain adequate flow to build pressure it's a good thing. 1 Quote Link to comment Share on other sites More sharing options...
Adam H P15 D30 Posted January 19, 2023 Report Share Posted January 19, 2023 Maybe it's the picture but those journals don't look great, I know you said they were polished... But they will probably be ok. What are the rod clearances? Quote Link to comment Share on other sites More sharing options...
47 dodge 1.5 ton Posted January 19, 2023 Report Share Posted January 19, 2023 (edited) I would be far more concerned about the surface finish if as rough that picture shows. Should have been ground to size. Appears to have been turned(with the tool seat after the insert failed)and then emory polished. They knew they were running out of material to hold tolerance and quit polishing. The surface finish will eventually seat if it doesn’t gawd, adding a much undesired bearing clearance. I know you said they only polished- what did it look like prior? Edited January 19, 2023 by 47 dodge 1.5 ton 1 Quote Link to comment Share on other sites More sharing options...
Bob Riding Posted January 19, 2023 Author Report Share Posted January 19, 2023 43 minutes ago, Adam H P15 D30 said: Maybe it's the picture but those journals don't look great, I know you said they were polished... But they will probably be ok. What are the rod clearances? They were actually polished and looked great back from the machine shop. I think what you are seeing is remains of WD-40 once I pulled the caps back off. 1 Quote Link to comment Share on other sites More sharing options...
Los_Control Posted January 19, 2023 Report Share Posted January 19, 2023 I do wonder about the surface of the crank ... the bubbles or pits do not look correct. Is it like cross hatching on a cylinder wall? I have a used crank & A poor photo .... The surface on the crank is smooth & polished right out of the engine. Is buried away now for future use .... but it is smoother then the crank pictured above. The bearings on this engine does leave the center line on the crank. Is normal. I dunno??? I have never rebuilt engines before. I would almost venture to say, the crank on this engine I pulled out of a junk pile, looks better then the new crank from the machine shop. Just asking if that is a acceptable surface from a machine shop. Quote Link to comment Share on other sites More sharing options...
Los_Control Posted January 19, 2023 Report Share Posted January 19, 2023 Just now, Bob Riding said: I think what you are seeing is remains of WD-40 once I pulled the caps back off. Ahh! Quote Link to comment Share on other sites More sharing options...
Los_Control Posted January 19, 2023 Report Share Posted January 19, 2023 Bob just likes pulling tricks on us to see if we are paying attention 1 Quote Link to comment Share on other sites More sharing options...
Adam H P15 D30 Posted January 19, 2023 Report Share Posted January 19, 2023 1 hour ago, Bob Riding said: They were actually polished and looked great back from the machine shop. I think what you are seeing is remains of WD-40 once I pulled the caps back off. Did you apply WD40 when you were plastigaging? Been a while but I think the surface is supposed to be dry to get an accurate reading.... Quote Link to comment Share on other sites More sharing options...
47 dodge 1.5 ton Posted January 19, 2023 Report Share Posted January 19, 2023 Should have been dry and measurement taken at near 90% of full torque. They don’t do 100% due to stretching bolts. If oil spots— maybe ok, but you have more clearance than measured. Quote Link to comment Share on other sites More sharing options...
Bob Riding Posted January 20, 2023 Author Report Share Posted January 20, 2023 I appreciate all of the viewpoints. I used WD-40 and 85 ftlbs. Lots of info out there on what to do and what not to do. Newbee engine reassemblers (like me) enjoy the process and go with what we think is the best advice. Sometimes we fall short, but as long as I don't blow up the motor, I'll be happy. 1 Quote Link to comment Share on other sites More sharing options...
Adam H P15 D30 Posted January 20, 2023 Report Share Posted January 20, 2023 Redo it dry and see where you end up.... 1 Quote Link to comment Share on other sites More sharing options...
47 dodge 1.5 ton Posted January 21, 2023 Report Share Posted January 21, 2023 (edited) I wanted to apologize after looking back over my replies for being brash. This is an educational forum for those working through projects. I have a fair amount of experience machining and building engines(apprentice in my younger days becoming a machinist). We built a lot of hi-preformace, diesel, & stock rebuilds. I have almost no experience with flat head Chryslers but the machining practices are the same in most cases. When it comes to actually building, many have their own techniques, some better than others. Fortunately, now we have the internet to enhance the communication among folks and learn from others mistakes. One of those is the use of thread adhesive such as “locktite”. I personally swear by it as this allows better torque when drawing down fasteners (it provides lubricant). At the same time I would not recommend the use of Wd-40 on main or rod bearings because it actually has cleaner qualities (again, personal preference). In any case, you are making great progress during your build and better doing as much yourself. Most places are suffering from experience or trying to make as much as possible causing a lot of corner cutting! Best of luck, Kevin Edited January 21, 2023 by 47 dodge 1.5 ton 2 Quote Link to comment Share on other sites More sharing options...
Bob Riding Posted January 21, 2023 Author Report Share Posted January 21, 2023 Thanks Kevin, no offense taken. Like @keithb7I'm having fun and learning as I go. My brother-in-law also used to build and restore engines and vintage iron, and I remember him saying never to mate dry bearings and journals, hence the WD-40. I had't heard about the taking measurements at 90% torque. Interesting. Are their fasteners that you wouldn't use Loctite on? Mains and conrod bolts maybe? Quote Link to comment Share on other sites More sharing options...
47 dodge 1.5 ton Posted January 21, 2023 Report Share Posted January 21, 2023 (edited) So I use loctite on rod bolts and have used it on mains as well although have also used a very light coating of the orange copper gasket sealer on the main bolt threads threads lately. Both provide lubricant during assembly (the bolts draw down tighter with the same torque setting on your wrench when compared to dry putting less stress on the bolts themselves). This was our practice on engines that turned high rpm’s and bolts were torqued well above standard recommended ranges in service manuals. I personally like the idea so have continued to do so on all engines and have had good success. Don’t think it’s necessary on a 4K rpm engine though. So on the bolt torque subject. My training provided by fastener suppliers only recommend bolts to be used at full torque(which is based on shear point design) 1 time! There has been many discussions on the subject from our vendor’s & engineering that provide theory’s supporting this as each time a bolt it torqued, it is weekend and loss of thread life. This is why we recommend to stay under that threshold until final assembly. Again— I have seen bolts reused without an issue many times. I would recommend to do a very thorough inspection and confirm there are no pits from rust at a minimum. Myself— cost of bolts, replace. Hope this may be useful down the road!! Kevin Edited January 21, 2023 by 47 dodge 1.5 ton Quote Link to comment Share on other sites More sharing options...
Sniper Posted January 21, 2023 Report Share Posted January 21, 2023 Pretty sure I would not take any of that advice. Torque to yield bolts are one time use, the ones we use are neither torque to yield nor one time use bolts. Lock Tite makes no recommendation on using it's products for rods or mains. As for it being a lubricant, the service manual torque specifications are with SAE 30 oil as the lubricant. Deviation from that lubricant can change the required torque specification. If you were torquing your rods and mains dry you were doing it wrong to begin with. Not sure why you think using RTV on the main bolts is needed. Shear strength has nothing to do with torque specifications, other than you don't want to meet or exceed it. The purpose of torquing a bolt is to properly stretch it in use in order to provide the correct clamping force for the connection.. To much and you shear, too little and it comes loose. A properly torqued bolt does not require locktite to hold. 2 Quote Link to comment Share on other sites More sharing options...
LeRoy Posted January 23, 2023 Report Share Posted January 23, 2023 On 1/21/2023 at 2:40 PM, Sniper said: Pretty sure I would not take any of that advice. Torque to yield bolts are one time use, the ones we use are neither torque to yield nor one time use bolts. Lock Tite makes no recommendation on using it's products for rods or mains. As for it being a lubricant, the service manual torque specifications are with SAE 30 oil as the lubricant. Deviation from that lubricant can change the required torque specification. If you were torquing your rods and mains dry you were doing it wrong to begin with. Not sure why you think using RTV on the main bolts is needed. Shear strength has nothing to do with torque specifications, other than you don't want to meet or exceed it. The purpose of torquing a bolt is to properly stretch it in use in order to provide the correct clamping force for the connection.. To much and you shear, too little and it comes loose. A properly torqued bolt does not require locktite to hold. Where does "farm tight" fall into the torque spec? It was a commonly used term where I grew up (central Illinois) and I think it meant as tight as you can get it. Quote Link to comment Share on other sites More sharing options...
Sniper Posted January 23, 2023 Report Share Posted January 23, 2023 27 minutes ago, LeRoy said: Where does "farm tight" fall into the torque spec? It was a commonly used term where I grew up (central Illinois) and I think it meant as tight as you can get it. Well, as tight as I can get it usually means I broke it. Not interested in dealing with that. 1 Quote Link to comment Share on other sites More sharing options...
Sam Buchanan Posted January 23, 2023 Report Share Posted January 23, 2023 (edited) Maybe use the German method of torqueing? "Guttintigtt" ? Edited January 23, 2023 by Sam Buchanan Quote Link to comment Share on other sites More sharing options...
Sniper Posted January 23, 2023 Report Share Posted January 23, 2023 (edited) having worked on plenty of German stuff, both in and out of the automotive field, all I have to say is that German engineering is overly complicated and not maintenance friendly. Edited January 23, 2023 by Sniper Quote Link to comment Share on other sites More sharing options...
kencombs Posted January 23, 2023 Report Share Posted January 23, 2023 44 minutes ago, Sniper said: having worked on plenty of German stuff, both in and out of the automotive field, all I have to say is that German engineering is overly complicated and not maintenance friendly. Way back in '82 I was finally comfortable with spending the money for my first new car. Actually, wife's first new car, I had my toy vechicles. So, my boss was big on Mercedes and I took a look. Wound up buying a Toyota Cressida, their top of the line at the time. Because, the 3-4 year cost of dealer recommended maintenance on the Merc was more than the payments on the Toy! Never regretted that decision. Even though I traded it in on an 83 when they put the Supra engine and independent rear suspension into the Cressida line. Great cars! 100K + miles and not one cent in unscheduled maintenance. Oil, filters , tires and just drive it. OTOH, my bosses Merc made several trips for fix little stuff. Turbo diesel was bulletproof, but power accessories were another matter. Quote Link to comment Share on other sites More sharing options...
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