Author Topic: Conrod bolt NUTS  (Read 3621 times)

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Offline fantino

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Conrod bolt NUTS
« on: July 21, 2010, 12:41:00 PM »
Quick question... I bought a new set of conrod bolts for my 500, the old nuts are kind of rounded on a few corners and should probably be replaced anyways. Do I have to use the recommended honda nuts, or can I go down to Fastenal and get an appropriate grade metric nut?

I'm guessing the Honda nuts are work hardened with some fancy proprietary method or something and I'll have to shell out the ~$4 a piece, but it never hurts to ask :-p

Also, what do you guys use to torque these nuts down? I can't find any sockets thin enough to get past the shape of the conrod and can't measure torque with a hand wrench... Any advice is appreciated!

Evan

Offline wrenchmuch

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Re: Conrod bolt NUTS
« Reply #1 on: July 21, 2010, 03:24:22 PM »
Rod bolts are generally replaced . When they are installed and torqued they will strech . When you re torque them they will be more prone to breakage . Having said that a lot of people re-use the bolts with no problems . If you plan on being aggressive with your machine change them .  I took a 6 point socket and ground the end diameter down till it fit . If you replace your bolts , buy nuts at the same time .
Good luck
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Offline MCRider

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Re: Conrod bolt NUTS
« Reply #2 on: July 22, 2010, 08:21:27 AM »
Rod bolts are generally replaced . When they are installed and torqued they will strech . When you re torque them they will be more prone to breakage . Having said that a lot of people re-use the bolts with no problems . If you plan on being aggressive with your machine change them .  I took a 6 point socket and ground the end diameter down till it fit . If you replace your bolts , buy nuts at the same time .
Good luck
Mike
He has new bolts, nuts were the question. But I agree, gotta have new nuts too. There proably is an adequate aftermarket supplier, but by the time you chase them down, maybe just buy OEMs.

Good suggestion on grinding the socket. Probably what has to be done.
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Offline fantino

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Re: Conrod bolt NUTS
« Reply #3 on: July 22, 2010, 11:38:35 AM »
OEM it is then, I guess! And yeah, good tip for the socket, I bought a sacrificial one today to grind down. I thought about buying a crows foot attachment, but then I realized it would change the leverage of my wrench and throw off torque readings...

Thanks!

Offline wrenchmuch

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Re: Conrod bolt NUTS
« Reply #4 on: July 22, 2010, 05:17:54 PM »
Oops I missed that .
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Offline fantino

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Re: Conrod bolt NUTS
« Reply #5 on: July 23, 2010, 04:35:51 PM »
One other question: when assembling the conrods, what is the verdict on using threadlocker?

Offline Gaither

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Re: Conrod bolt NUTS
« Reply #6 on: July 24, 2010, 10:28:33 AM »
FWIW

I proffess to know nothing. However, this I learned from a successful NASCAR engine builder.

ALWAYS lube threads to be torqued - to prevent measuring ANY amount of friction in your torque readings. The larger the bolt, the more potential friction. Oil or "thread locker" will suffice as lube.
Gaither ('77 CB550F)

Offline MCRider

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Re: Conrod bolt NUTS
« Reply #7 on: July 24, 2010, 01:13:13 PM »
FWIW

I proffess to know nothing. However, this I learned from a successful NASCAR engine builder.

ALWAYS lube threads to be torqued - to prevent measuring ANY amount of friction in your torque readings. The larger the bolt, the more potential friction. Oil or "thread locker" will suffice as lube.
I was taught, absorbed this technique also. However, in a past thread here on the issue, an expert (BobbyR?) in the field of torquing, let us know that some torque values (most?) take into account clean DRY hardware. So that threw a wrench into my belief system.

Since most of our torque amounts are in pretty wide ranges, I'm not too concerned. Will likely do head nuts and such dry from now on. or until I learn better, again.
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Offline fantino

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Re: Conrod bolt NUTS
« Reply #8 on: July 25, 2010, 11:39:43 PM »
So, it appears OEM Honda part suppliers don't stock connecting rod nuts. Bolts, for sure, but no nuts! CMNSL is the only place I've been able to find, but they want €8 per nut. I'm sure there must be another solution that doesn't require spending $80 on a small handful of nuts (they're just nuts, after all).

Any suggestions?


Offline bwaller

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Re: Conrod bolt NUTS
« Reply #9 on: July 26, 2010, 05:02:46 AM »
Honda part #13214-410-003 con-rod nuts for $2.37 ea.

Offline MRieck

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Re: Conrod bolt NUTS
« Reply #10 on: July 26, 2010, 05:07:29 AM »
I recently bought them. The 750 nuts work to.
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Offline 754

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Re: Conrod bolt NUTS
« Reply #11 on: July 26, 2010, 07:36:03 AM »
Those bolts/nuts are a finer class of fit than standard hardware.

 This is one are of your motor you dont want to cut corners.
 Broken cases, are not fun...neither are broken sleeves or barrels..
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Offline fantino

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Re: Conrod bolt NUTS
« Reply #12 on: July 26, 2010, 10:47:36 AM »
Honda part #13214-410-003 con-rod nuts for $2.37 ea.

Well there's the problem, I've been looking all around for p/n 13214-300-000. It'd be nice if they'd actually update the fiche with the superseded part  :-/ Thanks guys!

Offline Gaither

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Re: Conrod bolt NUTS
« Reply #13 on: July 26, 2010, 06:11:08 PM »

[/quote]
I was taught, absorbed this technique also. However, in a past thread here on the issue, an expert (BobbyR?) in the field of torquing, let us know that some torque values (most?) take into account clean DRY hardware. So that threw a wrench into my belief system.

Since most of our torque amounts are in pretty wide ranges, I'm not too concerned. Will likely do head nuts and such dry from now on. or until I learn better, again.
[/quote]

MCRider

Thank for the update. I didn't know that. 'Wonder which torque wrench accounts for "dry" and which don't. Also, when did the tool mfg's start this?

I can't disagree with your info. However, since my tools are getting old, like me, I'm gonna stick to the "lube the threads" rule. It worked for the engine builder I mentioned over TOO MANY years.

Thanks much
Gaither ('77 CB550F)

Offline MCRider

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Re: Conrod bolt NUTS
« Reply #14 on: July 26, 2010, 06:44:13 PM »

I was taught, absorbed this technique also. However, in a past thread here on the issue, an expert (BobbyR?) in the field of torquing, let us know that some torque values (most?) take into account clean DRY hardware. So that threw a wrench into my belief system.

Since most of our torque amounts are in pretty wide ranges, I'm not too concerned. Will likely do head nuts and such dry from now on. or until I learn better, again.
[/quote]

MCRider

Thank for the update. I didn't know that. 'Wonder which torque wrench accounts for "dry" and which don't. Also, when did the tool mfg's start this?

I can't disagree with your info. However, since my tools are getting old, like me, I'm gonna stick to the "lube the threads" rule. It worked for the engine builder I mentioned over TOO MANY years.

Thanks much
[/quote]
If memory serves, it wasn't the tool mfgs but the shop manual printers. All quoted values are assumed dry, is what I gathered from the discussion.

Still I also prefer the logic of lubing the threads first, it seems more elegant, and as you say evidence is it mustn't matter.

I did a search and found lots of perspective

http://www.dansmc.com/bolts2.htm

And amazing in my Google search I turned up this:
http://forums.sohc4.net/index.php?action=printpage;topic=63819.0

And this one has good comments
http://www.thumpertalk.com/forum/archive/index.php/t-200128.html

If you accept the premise that a lubed bolt should have 20% less torque, then looking at the head nuts for example:
http://www.salocal.com/sohc/tech/torquetable.htm
The upper range is 18.1 and 80% of that is the lower range of 14.48.

So I'd probably lube it or anti seize it and go to 16.
« Last Edit: July 26, 2010, 06:47:43 PM by MCRider »
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Offline MCRider

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Re: Conrod bolt NUTS
« Reply #15 on: July 26, 2010, 07:04:12 PM »
Like so many things in life more than one way to skin a cat. Find what works and apply it consistently.

Its probably more important or as important that with head nuts for example, you follow the squish pattern, tighten down in stages, and that they all end at the same place than whether there is a drop of oil on them.
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Offline kos

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Re: Conrod bolt NUTS
« Reply #16 on: July 26, 2010, 08:18:43 PM »
From a factory trained Honda Mechanic and SR service Rep for 10 years with American Honda Motor Company.... Always lube bolts. you can't get a proper torque reading while galling the threads tightening the nuts to the bolt or stud thread.

Enough of this banter...just do it and get'r done and go riding!

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Offline scunny

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Re: Conrod bolt NUTS
« Reply #17 on: July 26, 2010, 11:22:14 PM »
you will notice in the workshop manuals that they stipulate some bolts to have the threads lubed with engine assembly grease and some with engine oil. they also mention torque values for these bolts as opposed to the generic 6mm 8mm 10mm values. me I lube
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Offline purf_man

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Re: Conrod bolt NUTS
« Reply #18 on: April 13, 2013, 01:46:04 PM »
hate to dig up an old one but....

I just got done wrestling off nuts on my 550 crank (need to do the 650 crank next)

Is there a lower profile option for the nut on the conrods?  I was wondering if I could just order the proper grade 12point nuts from mcmaster ARP or whoever??

$2.50 a nut seems a little steep.

BTW looks like I am donating a new socket to the shop at work to get ground down to fit.  Going to get the end squared up on it too
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