My experience of DIY Rod bearings (WPC and OEM bolts)

Move Over · 08-28-2016, 10:55 PM

Quote:

Originally Posted by Brian_Fantana

So if you had to do it again would you do it yourself or pay someone?

Funny you ask...I just did it all over again last weekend.

The oil separators started leaking a few months back, and so did my valve covers again. Now that I have spent a year with this motor, I am getting to know it pretty well and quickly.

So, i just did both gaskets again, all 24 bolts, and my oil separators last weekend.

I am happy to report there are no leaks. About 100 miles in and still bone dry. We'll see if I can keep that up.

MFL · 08-29-2016, 08:34 AM

I'm 2,500 miles into my BE Bearing swap. Glad I did it!

Move Over · 08-29-2016, 09:00 AM

Quote:

Originally Posted by MFL

I'm 2,500 miles into my BE Bearing swap. Glad I did it!

Either those or VAC's newer bearings will be my next set. I've been following Doc Oc's thread and his VAC bearings came out great.

reece146 · 08-29-2016, 03:00 PM

That OEM torquing requirement is something else...

Are these torque to yield bolts?

Ridiculous torquing sequence leading to ridiculous bearing issues... just a thought. New guy on the assembly line gets the first dozen or so wrong till his supervisor notices...

Move Over · 08-29-2016, 03:09 PM

Quote:

Originally Posted by reece146

That OEM torquing requirement is something else...

Are these torque to yield bolts?

Ridiculous torquuing sequence leading to ridiculous bearing issues... just a thought. New guy on the assembly line gets the first dozen or so wrong till his supervisor notices...

I believe they are stretch bolts. (Not sure if the same thing). But yes incredibly ridiculous regardless lol.

reece146 · 08-29-2016, 03:13 PM

Yep, same thing. Stretch (plastic deformation) raises the strength of the bolt when the metal yields.

Doc Oc · 08-29-2016, 04:05 PM

Quote:

Originally Posted by Move Over

Either those or VAC's newer bearings will be my next set. I've been following Doc Oc's thread and his VAC bearings came out great.

I was even shocked at how good they looked. After all the talk of bore distortion and sanding/not sanding the parting lines, to see them come out so clean they could be resold was a very pleasant surprise. Props to vac.

Green-Eggs · 08-29-2016, 09:02 PM

Quote:

Originally Posted by Move Over

Either those or VAC's newer bearings will be my next set. I've been following Doc Oc's thread and his VAC bearings came out great.

Quote:

Originally Posted by Doc Oc

I was even shocked at how good they looked. After all the talk of bore distortion and sanding/not sanding the parting lines, to see them come out so clean they could be resold was a very pleasant surprise. Props to vac.

Doc I think you might be thinking that "even with these problems" of bore distortion and not sanding the partings lines, your bearings came out looking fine. Those errors might be exactly why they looked so good, not in spite of them.

The bore distortion is real. When the VAC/ARP bolts were installed to VAC specs, the bore distortion gives EXTRA clearance in the right spot. The extra clearance has been measured to be up to 1.2 thousandths. With this much extra clearance, when the bearings come out, they look perfect. But they did it at the expense of distorting the bearing bore from what it was supposed to be; it changed the bore from being slightly oval to more rounded.

Not sanding the parting lines is going to add a few ten-thousandths extra clearance on top of that. This adds extra clearance on top of the extra clearance added by the bore distortion. These two factors combined may be the cause of the perfect looking bearings, not in spite of them.

It's impossible to tell what yours would have looked like if you didn't have the extra clearance of the bore distortion and I'm guessing without sanding the parting lines too. Most likely the would have looked good as well, but we can't hold up your case as any type of example of relief when the bore distortion may have been a significant contributing factor to how the bearings looked when they came out.

I hope that makes sense.

Move Over · 08-29-2016, 09:09 PM

Quote:

Originally Posted by Green-Eggs

Doc I think you might be thinking that "even with these problems" of bore distortion and not sanding the partings lines, your bearings came out looking fine. Those errors might be exactly why they looked so good, not in spite of them.

The bore distortion is real. When the VAC/ARP bolts were installed to VAC specs, the bore distortion gives EXTRA clearance in the right spot. The extra clearance has been measured to be up to 1.2 thousandths. With this much extra clearance, when the bearings come out, they look perfect. But they did it at the expense of distorting the bearing bore from what it was supposed to be; it changed the bore from being slightly oval to more rounded.

Not sanding the parting lines is going to add a few ten-thousandths extra clearance on top of that. This adds extra clearance on top of the extra clearance added by the bore distortion. These two factors combined may be the cause of the perfect looking bearings, not in spite of them.

It's impossible to tell what yours would have looked like if you didn't have the extra clearance of the bore distortion and I'm guessing without sanding the parting lines too. Most likely the would have looked good as well, but we can't hold up your case as any type of example of relief when the bore distortion may have been a significant contributing factor to how the bearings looked when they came out.

I hope that makes sense.

It does make sense, but can you elaborate on where the bore distortion is originated from? ARP bolts? VAC bearings?

Green-Eggs · 08-29-2016, 09:18 PM

Quote:

Originally Posted by Move Over

It does make sense, but can you elaborate on where the bore distortion is originated from? ARP bolts? VAC bearings?

It's the rod bolts. More specifically, it's the clamping force of the rod bolts. If the clamping force of the VAC/ARP bolts at 45 lbs equaled the clamping force of the OEM bolts at 20 Nm + 130 degrees, then there presumably wouldn't be any bore distortion. Undertorqued bolts tend to add extra clearance at 90-degrees because the bore isn't fully stretched into shape yet by the increased clamping force. Overtorqued bolts do the opposite; they reduce the clearance at 90-degrees.

Here's measurements and graphs that show the results of different rod bolt types and how they affect the shape of the bore.

http://wiki.rcollins.org/core/index..../S85_Rod_Bolts

Mdriv3r · 08-31-2016, 09:45 PM

Any pics of the install? Could you post them?

takrdown · 09-01-2016, 09:14 AM

Quote:

Originally Posted by Move Over

Funny you ask...I just did it all over again last weekend.

The oil separators started leaking a few months back, and so did my valve covers again. Now that I have spent a year with this motor, I am getting to know it pretty well and quickly.

So, i just did both gaskets again, all 24 bolts, and my oil separators last weekend.

I am happy to report there are no leaks. About 100 miles in and still bone dry. We'll see if I can keep that up.

You didn't by chance see how those WPC bearings were holding up did you? I went WPC with OEM bolts as well and I'm curious. Thanks!

Move Over · 09-01-2016, 09:44 AM

Quote:

Originally Posted by takrdown

Quote:

Originally Posted by Move Over

Funny you ask...I just did it all over again last weekend.

The oil separators started leaking a few months back, and so did my valve covers again. Now that I have spent a year with this motor, I am getting to know it pretty well and quickly.

So, i just did both gaskets again, all 24 bolts, and my oil separators last weekend.

I am happy to report there are no leaks. About 100 miles in and still bone dry. We'll see if I can keep that up.

You didn't by chance see how those WPC bearings were holding up did you? I went WPC with OEM bolts as well and I'm curious. Thanks!

No, that's the wrong end of the motor haha. I'd have to pull the bottom end open to see the condition of them.

Move Over · 09-01-2016, 10:06 AM

Quote:

Originally Posted by premo

Any pics of the install? Could you post them?

What pictures are you looking for?

pbonsalb · 09-01-2016, 10:57 AM

There are some DIY threads if you search for them, but none are a perfectly photographed step by step DIY. If you need that, you will have to wait until someone does one.

Move Over · 09-01-2016, 11:02 AM

Quote:

Originally Posted by pbonsalb

There are some DIY threads if you search for them, but none are a perfectly photographed step by step DIY. If you need that, you will have to wait until someone does one.

I got about 4 pictures into a DIY then realized I simply couldn't keep up lol

takrdown · 09-01-2016, 12:21 PM

Quote:

Originally Posted by Move Over

No, that's the wrong end of the motor haha. I'd have to pull the bottom end open to see the condition of them.

I'm an idiot LOL. I didn't read carefully enough....stopped reading after....I did it again. Thanks!

Move Over · 09-02-2016, 05:07 AM

Quote:

Originally Posted by takrdown

Quote:

Originally Posted by Move Over

No, that's the wrong end of the motor haha. I'd have to pull the bottom end open to see the condition of them.

I'm an idiot LOL. I didn't read carefully enough....stopped reading after....I did it again. Thanks!

Haha all good man. I'll be sure to let you know next year!!

Billj747 · 09-03-2016, 01:02 PM

+1 on WPC.

Great process. Over the years I've WPC'd everything from rod bearings, pistons, piston pins, rings, trans gears, synchros, clutch plates, LSD plates, Cams, Ring & Pinions, etc... and have had nothing but great results from them. Highly recommended.

takrdown · 09-05-2016, 02:37 PM

Quote:

Originally Posted by Billj747

+1 on WPC.

Great process. Over the years I've WPC'd everything from rod bearings, pistons, piston pins, rings, trans gears, synchros, clutch plates, LSD plates, Cams, Ring & Pinions, etc... and have had nothing but great results from them. Highly recommended.

Great to here!! After seeing how well the VAC ones looked in that one case on the forum I'm wondering how the WPC compared. Thanks!!

08-29-2016, 08:34 AM	#24
MFL Major 182 Rep 1,246 Posts Drives: E92 M3 Join Date: Sep 2013 Location: Bellevue, WA iTrader: (3) Garage List 2010 BMW M3 [9.00]	I'm 2,500 miles into my BE Bearing swap. Glad I did it!
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08-29-2016, 03:00 PM	#26
reece146 New Member 3 Rep 8 Posts Drives: B8 A4, M3 shopping Join Date: Aug 2016 Location: ON, CA iTrader: (0)	That OEM torquing requirement is something else... Are these torque to yield bolts? Ridiculous torquing sequence leading to ridiculous bearing issues... just a thought. New guy on the assembly line gets the first dozen or so wrong till his supervisor notices... Last edited by reece146; 08-29-2016 at 03:11 PM..
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08-29-2016, 03:13 PM	#28
reece146 New Member 3 Rep 8 Posts Drives: B8 A4, M3 shopping Join Date: Aug 2016 Location: ON, CA iTrader: (0)	Yep, same thing. Stretch (plastic deformation) raises the strength of the bolt when the metal yields.
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08-31-2016, 09:45 PM	#33
Mdriv3r Lieutenant 234 Rep 502 Posts Drives: F13 M6 Join Date: Apr 2014 Location: Great Lakes iTrader: (0) Garage List 2008 E92 M3 ESS Sup ... [10.00] 2014 F13 M6 Competi ... [9.72] 2005 E46 330Ci [10.00]	Any pics of the install? Could you post them? __________________
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09-01-2016, 10:57 AM	#37
pbonsalb Lieutenant General 7679 Rep 13,759 Posts Drives: 18 F90 M5, 99 E36 M3 Turbo Join Date: Feb 2011 Location: New England iTrader: (4)	There are some DIY threads if you search for them, but none are a perfectly photographed step by step DIY. If you need that, you will have to wait until someone does one.
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09-03-2016, 01:02 PM	#41
Billj747 Captain 176 Rep 658 Posts Drives: Everything Join Date: Feb 2009 Location: SoFlo iTrader: (0)	+1 on WPC. Great process. Over the years I've WPC'd everything from rod bearings, pistons, piston pins, rings, trans gears, synchros, clutch plates, LSD plates, Cams, Ring & Pinions, etc... and have had nothing but great results from them. Highly recommended.
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