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Rod bearing orientation

General engine tech -- Drag Racing to Circle Track

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ptuomov
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Rod bearing orientation

Post by ptuomov » Sun Jan 05, 2020 12:12 pm

Working on some custom rods with new (to me) bearings. Does the orientation of the bearing matter?

The bearing has two identical halves with an oil hole (that will not lead anywhere in these rods):
DE23CEB9-E202-48BB-874F-82E61CD6CFEC.jpeg
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Kevin Johnson
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Re: Rod bearing orientation

Post by Kevin Johnson » Sun Jan 05, 2020 2:03 pm

You could try moving the locating tab orientation and prove that Audi and Porsche are mere slaves to convention. An empirical study.
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Re: Rod bearing orientation

Post by PackardV8 » Sun Jan 05, 2020 2:12 pm

ptuomov wrote:
Sun Jan 05, 2020 12:12 pm
Working on some custom rods with new (to me) bearings. Does the orientation of the bearing matter?

The bearing has two identical halves with an oil hole (that will not lead anywhere in these rods):

DE23CEB9-E202-48BB-874F-82E61CD6CFEC.jpeg
FWIW, I had a long conversation about this with a Clevite engineer. The condensed version is no, the tangs are just there for blind engine assemblers. If they're in your way, just grind them off. Many recent design engine bearings have no tangs.
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ptuomov
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Re: Rod bearing orientation

Post by ptuomov » Sun Jan 05, 2020 2:41 pm

PackardV8 wrote:
Sun Jan 05, 2020 2:12 pm
ptuomov wrote:
Sun Jan 05, 2020 12:12 pm
Working on some custom rods with new (to me) bearings. Does the orientation of the bearing matter?

The bearing has two identical halves with an oil hole (that will not lead anywhere in these rods):

DE23CEB9-E202-48BB-874F-82E61CD6CFEC.jpeg
FWIW, I had a long conversation about this with a Clevite engineer. The condensed version is no, the tangs are just there for blind engine assemblers. If they're in your way, just grind them off. Many recent design engine bearings have no tangs.
Any thoughts on the (dead) oil hole location? For example, in relation to the crank oil feed holes?

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Re: Rod bearing orientation

Post by Kevin Johnson » Sun Jan 05, 2020 3:52 pm

2JZ.jpg
Here you go, Toyota performed that experiment for you.

http://www.2jzgarage.com/wp-content/upl ... Engine.pdf

Per the oiling hole, the Turbo 924 engine from Audi had an oil squirter in about that location.
Kevin Johnson wrote:
Sun Jan 05, 2020 2:03 pm
You could try moving the locating tab orientation and prove that Audi and Porsche are mere slaves to convention. An empirical study.
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Re: Rod bearing orientation

Post by ptuomov » Sun Jan 05, 2020 4:34 pm

I don’t think the orientation can matter at all for any bearings that are used in V8 engines with asymmetrical big end cheeks. One rod rotates in a different direction as the other. I think this settles it, any if the four possible orientations will work.

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Re: Rod bearing orientation

Post by modok » Wed Jan 08, 2020 1:39 am

Although it barely matters, putting both locating tangs on the same side has three advantages I have noted.

-Assuming all shells are identical, but not perfect, if some are thicker on one side than the other.....(as if the wall excentricity was slightly off center)
Then tangs on the same side gives a truer ID than the other way.

-The side with the tangs is weaker at the parting surface, so tighten the side with no tangs last to get best seating.

ahhh -if the split of the bearing housing is off center, it still works fine.

Dang it took me a long time to remember the third one. I knew there was three #-o

I would prefer to be rid of the tangs entirely, really not needed, but if you've got em, make the most of it.

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