Rod bearing crush too much?
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Rod bearing crush too much?
While sizing rod bearings I was checking crush and I think it's a bit much.
Big end is 2.086" bearing is a steel backed shell.
I torque both bolts to 18 ft/lbs then release one.
I am measuring with a feeler on the loosened side .008" with 2 rods at .010".
Clearances are all where I want them.
Big end is 2.086" bearing is a steel backed shell.
I torque both bolts to 18 ft/lbs then release one.
I am measuring with a feeler on the loosened side .008" with 2 rods at .010".
Clearances are all where I want them.
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Re: Rod bearing crush too much?
What engine is this?
You can cut a man's tongue from his mouth, but that does not mean he’s a liar, it just shows that you fear the truth he might speak about you!
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Re: Rod bearing crush too much?
Never heard of measuring bearing crush like that... is that an actual thing somewhere?
DON'T PANIC
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Re: Rod bearing crush too much?
In what manner did you determine that your clearances are where you want them ? Mark H .
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Re: Rod bearing crush too much?
Shoe,
I have never heard of the method you are describing. How are you measuring the big end bore ? It should be between 2.0866 and 2.0871 with the bolts torqued.
Also like Mark said . . . how are you measuring your clearances ?
I have never heard of the method you are describing. How are you measuring the big end bore ? It should be between 2.0866 and 2.0871 with the bolts torqued.
Also like Mark said . . . how are you measuring your clearances ?
Bill Koustenis
Advanced Automotive Machine
Waldorf Md
www.enginerepairshop.com
Advanced Automotive Machine
Waldorf Md
www.enginerepairshop.com
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Re: Rod bearing crush too much?
Measuring bearing crush is done in the manner the op described, although checking torque varies.turbo camino wrote: ↑Wed Jan 31, 2024 5:09 am Never heard of measuring bearing crush like that... is that an actual thing somewhere?
Re: Rod bearing crush too much?
All clearances are being verified with a mititoyo dial bore gage and Mititoyo micrometer.
Big end of the rod is in fact 2.0866". I dropped the last digit in my original post.
That is the dia listed on the card and verified via mic and dial bore gage.
That method of checking crush was recommended to me by a manufacture of rods a number of years ago.
Some years ago I assembled an engine using like components that had a rub at the base of the locating tang.
The post mortem discovery came to excessive crush. In that case the crush was .012" via the above method.
I believe it's a stackup of the rod BE at the low end of the tolerance and the race bearing adding crush.
It seems like this is an area of engine building that there isn't a lot of discussion about.
I may see about having the BE hone .0003" to bring the tight ones in line with the rest.
Big end of the rod is in fact 2.0866". I dropped the last digit in my original post.
That is the dia listed on the card and verified via mic and dial bore gage.
That method of checking crush was recommended to me by a manufacture of rods a number of years ago.
Some years ago I assembled an engine using like components that had a rub at the base of the locating tang.
The post mortem discovery came to excessive crush. In that case the crush was .012" via the above method.
I believe it's a stackup of the rod BE at the low end of the tolerance and the race bearing adding crush.
It seems like this is an area of engine building that there isn't a lot of discussion about.
I may see about having the BE hone .0003" to bring the tight ones in line with the rest.
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Re: Rod bearing crush too much?
does the steel backside of the bearing have some type of flash coating rust preventative measure applied, or is it bare metal?
a lot of times they are processed with something or other.
who is the bearing manufacturer?
a lot of times they are processed with something or other.
who is the bearing manufacturer?
Re: Rod bearing crush too much?
Sounds like too much crush imo.
We have discussed this a few times before. I can search for you later if you are not finding it.
We have discussed this a few times before. I can search for you later if you are not finding it.
Re: Rod bearing crush too much?
I had done a fairly broad search prior to posting this.
But any additional information is greatly appreciated.
I've reached out to the bearing manufacturer and am waiting a response from engineering.
For many years I had always just done a thumbnail check to make sure the shell was proud, until I got bit.
But any additional information is greatly appreciated.
I've reached out to the bearing manufacturer and am waiting a response from engineering.
For many years I had always just done a thumbnail check to make sure the shell was proud, until I got bit.
Re: Rod bearing crush too much?
My comment about it being discussed in the past was mostly aimed at the other posters, but in any case here is what I found googling myself briefly.
hmmm, that sounds wrong LOL
viewtopic.php?t=49678
viewtopic.php?t=53428
viewtopic.php?t=52916
hmmm, that sounds wrong LOL
viewtopic.php?t=49678
viewtopic.php?t=53428
viewtopic.php?t=52916