08:42:34am, Thursday, April 25, 2024
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Crankshaft “fillet”
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Can someone tell me if the fillet is needed on billet rods, I had some made and the edge of the rod is flush with the bearing it is not chamfered, thoughts? 5500 rpm engine. |
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Re: Crankshaft “fillet”
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xxx
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rods need to be clearanced for the radius on the crank |
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Re: Crankshaft “fillet”
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Right now the rods bolt up fine but do not touch the radios or fillet at all, Expensive paper weights ? |
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Re: Crankshaft “fillet”
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Registered: 01/23/2011 Posts: 241 |
It depends on how the rod is constrained, is it made to use the crankshaft flanks to control the location or is it made to use the inside of the piston to control rod location? Most people expect the rod location to be controlled by the flanks of the crankshaft, but it doesn't have to be.
Rich |
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Re: Crankshaft “fillet”
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so if the piston and rod fit snug it should be alright ? I would have to have shims made to go between piston and rod on both sides to center it. work ok? or custom pistons to fit the rod ends. |
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Re: Crankshaft “fillet”
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Registered: 03/31/2008 Posts: 762 |
You might want to post some pictures. I think I know what you are asking about, but a fillet is a rounding of an interior or exterior corner, like the radius that is typical on both ends of the crankshaft journal.
Questions: 1. Is the big end of the billet rod the same width as the factory rod? If not, how much narrower? 2. Put the bearing in the rod and place it on the crank without the cap. Try to move the rod side to side on the crank journal. What stops it? From your description I think the edge of the bearing hitting the fillet on the crank will be what stops it & if so you will need for the piston to guide the rod as described above. I don't have personal experience but I don't see why shims couldn't be used. I have no idea how to determine how much clearance is proper though, you may need to consider the different expansion rates of aluminum vs the rods and the shim material. |
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Re: Crankshaft “fillet”
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Tribology
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Rod side clearance has zero effect on oil pressure. Bearing clearance is the controlling factor. |
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Re: Crankshaft “fillet”
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Registered: 10/30/2018 Posts: 749 |
you are full of crap if you think that to much side clearance won' affect it The oil wont stay in the bearings the side clearance makes it harder for the oil to escape been there and done that with. the biggest oil pump peterson makes and couldnt keep the bearings in .Ihave put deutz rods in Cummins hercules and perkins rods in internationals MM rods in farmal ms along with custom aluminum and steel rods and shimed rods inside the position to keep the rods centered over the hole and won't work with to much side clearance Whoever made your rods should have made them the same width as the stock ones call me 270 566 2901 Edited 3 time(s). Last edit at 08/16/2019 03:08PM by Lewis Conner. |
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Re: Crankshaft “fillet”
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Tribology
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So every high end crank mfg, bearing mfg, tribologist and nascar engine guy is wrong. Jon Kaase is wrong too..because Lewis cobbled together some parts and had the bearing clearance wrong, stuff not round or big bleed and couldnt get the too much oil pressure he thinks he needs. If you could sit and do the math you would understand the side clearance could not have been your problem. The are 10000 + rpm engines out there with .300+ side clearance. Thats not typo - 300+ thou side clearance. Call up King or FM and speak with thier bearing engineers..then come back and tell me im full of crap. Call Bryant or Callies..Call Crower or Pankl..Call up Jon k..go ahead. Correlation does not imply causation..dig deeper |
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Re: Crankshaft “fillet”
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Registered: 10/30/2018 Posts: 749 |
Your full of crap know really full of crap put 300 thousands side clearance on your crank if you believe that crap and come back and let us know how it went .Im like the Farmers insurance company commercial i know a thing or two because ive seen a thing or two if you don't know this from personal exsperiance you don't know @#$%& and .they don't know @#$%& how many pounds boost are those Nas car guys making Clevite which I'm a dealer with after going through several sets of there h series bearings and cranks discussing clearances and continued problems brought this to my attention also Peterson after sending the pump back a couple ttimes and discussing possible problems with there pump and clearance's with the crank also brought this to my attention Now as you requested Tribolagy you are really full of crap Edited 1 time(s). Last edit at 08/17/2019 08:55AM by Lewis Conner. |
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Re: Crankshaft “fillet”
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Tribology
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Go ahead and remain willfully ignorant, see where it gets you. Your ad hominem attack right out of the gate tells me that you're aware that you might not know as much as you profess to know and it makes you uncomfortable. Not everything is as it seems and your one instance does not negate the volumes of proof that is out there on racetracks all over the world. You had excessive radial clearance or were uncovering an oil hole. Your Clevite sales rep isnt who you should be getting tech from and Peterson was just parroting ideas because the pump was NTF. No bearing engineer at Mahle would tell you that excessive side clearance caused low oil pressure unless the rod was being allowed to move enough to uncover a hole. If you would take the time to do some critical thinking and calculate the area of the flow paths created by the bearing jounal clearance and then do the same for the flow area of the side clearance you would see side clearance isnt the controlling factor unless you have your radial clearance ridiculously too large.Its an old wives tale that has been proven wrong by many builders on many engines. There are plenty of high hp high boost PGR engines out there. All i'm trying to do is clear up the myth of side clearance. |
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Re: Crankshaft “fillet”
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Registered: 10/30/2018 Posts: 749 |
You just play like your on the tv show Myth Busters and build you one. Now its confirmed you are definitely full of crap |
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Re: Crankshaft “fillet”
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Registered: 01/23/2011 Posts: 241 |
The answer is it depends, you would have to do a dimensional stack up to make sure the rod is properly centered in the piston and that the crank cant move far enough to cause the rod to hit the radius on the crank. You might be able to put the engine together and move the rod back an forth and move the crank the opposite direction and make sure that you have clearance between the rod and the radius of the crankshaft. It is best to find someone who has an engine built using the parts you have and see what they did and how it worked.
Rich |
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Re: Crankshaft “fillet”
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Radius
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As long as the bearing can't make contact with the radius of the crank they will be fine. |
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Re: Crankshaft “fillet”
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Registered: 10/30/2018 Posts: 749 |
IF the rod is to narrow you won't have good oil pressure |
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Re: Crankshaft “fillet”
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I would not try to center rod using wrist pin. Too much clearance between rod and cheek you loose oil pressure. Not enough clearance and you heat oil at bearing. MACK |
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Re: Crankshaft “fillet”
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Registered: 10/30/2018 Posts: 749 |
Thank you pup |
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