Technical Engine builders Which Rod Bearings?

syn909

Specialist
Jun 27, 2018
64
22
0
Ride
'07 335i
I got about 102K on my motor and need to do the oil pan gasket, while I am in there I figure its a good time to do the rod bearings.

Using the stock crank and rods whats the best rod bearings to go with? I see people using King, Kolbenschmidt, ACL, OEM? I have searched high and low and found nothing really concise. Vehicular DIY used the King bearings and totally effed over his motor and I read that they were also putting in the wrong size bearings in the boxes. I realize they are labeled but that kind of quality control points me to no for king.
 

Illsic_Design

Specialist
Feb 2, 2018
59
27
0
Sac, Nor-Cal
Ride
09 335i
King GPC coated here. Bearings had some wear at 200k

Sizes are stamped on the bearing, so also up to installer to make sure they are putting in the correct parts. Mistakes do happen no matter how good QC is, believe me I work at a huge manufacturing facility as an inspector/QA.
 

Threetirtyfive

Corporal
Jan 9, 2019
135
68
0
Ride
335i
Mine were like new at about 150k miles, no wear, but as part of my engine build I now run King SV - no issue. Having looked up GPC as above- those seem to have an additional coating to help when there's oil starvation.

Personally, I wouldn't change them if you're not doing an engine build and don't have any knock. It's not a weak point in the N54.
 

mikeseli

Corporal
May 23, 2017
138
77
0
Ride
2009 BMW 335i
Any rod bearing you select from your list is better than keeping the old rod bearings. There is no "best" they are pretty much equal. I would go with King due to the lower price, this is what I did.

If you do regular oil changes and the engine warms up before you push it to its limits the rod bearings will last 120-150K miles.
 
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colo_evo

Corporal
Jun 6, 2017
159
111
0
Ride
E90 335i MT
Any rod bearing you select from your list is better than keeping the old rod bearings. There is no "best" they are pretty much equal. I would go with King due to the lower price, this is what I did.

If you do regular oil changes and the engine warms up before you push it to its limits the rod bearings will last 120-150K miles.
Are you suggesting OP replace his rod bearings?
 
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Reformatt

Specialist
Oct 28, 2019
81
41
0
53
Houston
Ride
2010 335i E92
I used the king standard size rod bearings through summit, they were surprisingly inexpensive.
After sitting passenger in my car an watching someone money shift from 3rd to 2nd thankfully they held up. But in the future I will not be so easy to hand someone my keys I died a little in that moment 🤦🏻
 

syn909

Specialist
Jun 27, 2018
64
22
0
Ride
'07 335i
Sure, if your doing the oil pan gasket, do the rod bearings as well, it 2.5-3hrs of labor once you’re there.
Precisely if you are at 110K and I am going to do all that work to get the pan off might as well do the rod bearings.
 
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syn909

Specialist
Jun 27, 2018
64
22
0
Ride
'07 335i
I used the king standard size rod bearings through summit, they were surprisingly inexpensive.
After sitting passenger in my car an watching someone money shift from 3rd to 2nd thankfully they held up. But in the future I will not be so easy to hand someone my keys I died a little in that moment 🤦🏻
Is your crank completely stock? Did you polish it prior to new bearing installation?
 

Reformatt

Specialist
Oct 28, 2019
81
41
0
53
Houston
Ride
2010 335i E92
Is your crank completely stock? Did you polish it prior to new bearing installation?
To be honest it’s my “3rd” engine lol First 2 are a complete different story.

1st engine: I bought the car cleanish title from IAA “one accident” had front end damage. This was before I knew these engines ate belts. That engine ran great till it starved itself of oil. It’s all torn down for a future rebuild.
2nd engine: The parts car I bought from IAA had rear end damage never intended to use the engine...it didn’t last long
3rd engine: LKQ purchased changed all the leaky bits and “while I was at it” did the rod bearings crank and the original bearings looked fine didn’t polish. Engine has been strong no complaints.
You could say I have taken the crash course into the N54 world lol.
 

roccos

New Member
Oct 23, 2020
3
3
0
im using standard King rod bearing. motor was apart i checked all clearances using dial-bore gauge. the Kings were all off, final measurement was .0033" over max allowable as per clearances sheet. Which is .002-.0027". what i ended up doing to sending bearings out to be coated, which gave me back a half thou .0005. coating was $40. ive just torn the motor down, as ive converted the 9mm to 11mm. just checked all conrod bearings, they look fine after about 8k miles. was pushing 500hp area. always let the oil temp get to op temp before i pounced it

i would highly recommend unless you are able to check with a dial-bore which you cant do while motor is together you use stock bearings. using aftermarket and plastigauge may not work out well for you. Like Vehicular DIY guy. total crap shoot. with stock you are almost guarantee to meet clearances

pastigauage is a ballpark guesstimate

the mains Kings came in within spec between .0015-.002"

hope this help some of you
 
Last edited:

Reformatt

Specialist
Oct 28, 2019
81
41
0
53
Houston
Ride
2010 335i E92
im using standard King rod bearing. motor was apart i checked all clearances using dial-bore gauge. the Kings were all off, final measurement was .0033" over max allowable as per clearances sheet. Which is .002-.0027". what i ended up doing to sending bearings out to be coated, which gave me back a half thou .0005. coating was $40. ive just torn the motor down, as ive converted the 9mm to 11mm. just checked all conrod bearings, they look fine after about 8k miles. was pushing 500hp area. always let the oil temp get to op temp before i pounced it

i would highly recommend unless you are able to check with a dial-bore which you cant do while motor is together you use stock bearings. using aftermarket and plastigauge may not work out well for you. Like Vehicular DIY guy. total crap shoot. with stock you are almost guarantee to meet clearances

pastigauage is a ballpark guesstimate

the mains Kings came in within spec between .0015-.002"

hope this help some of you
A rather late response to this post but will add a little insight.

I was the person that gave the cams an cam shells to Vehicular DIY at the time we didn't live all that far apart... anyway long story short I do believe the root cause of the engine eating itself whole was a damaged oil pump.

I am still running std King bearings without issue..same bearings VDIY used..knock on wood I haven't jinxed myself...because I'm for certain running beyond what a stock open block should be doing...I'm am on borrowed time..

But I do agree use caution with any bearings mistakes can happen an remember "Racecar" or BMW ...It can an will break at any moment ;)
 

roccos

New Member
Oct 23, 2020
3
3
0
A rather late response to this post but will add a little insight.

I was the person that gave the cams an cam shells to Vehicular DIY at the time we didn't live all that far apart... anyway long story short I do believe the root cause of the engine eating itself whole was a damaged oil pump.

I am still running std King bearings without issue..same bearings VDIY used..knock on wood I haven't jinxed myself...because I'm for certain running beyond what a stock open block should be doing...I'm am on borrowed time..

But I do agree use caution with any bearings mistakes can happen an remember "Racecar" or BMW ...It can an will break at any moment ;)
when he put the motor back together after the timing chain guide and gears went into motor. i had said in comments on YT that was very iffy. wasnt too long there after, knock knock
 

Keltalon135i

Lurker
Sep 3, 2020
20
12
0
Atlanta
Ride
135i
King GPC coated here. Bearings had some wear at 200k

Sizes are stamped on the bearing, so also up to installer to make sure they are putting in the correct parts. Mistakes do happen no matter how good QC is, believe me I work at a huge manufacturing facility as an inspector/QA.
Concur 100%!