ACl Rod bearing question

[krashdumie05]

nope 0.25mm = 0.010"

OP what is the P/N on the packet?

Pn i got is 6B1569HX-STD. The .025mm or .001. was recomended by a shop that deals primarily with e46 m3s (they are a shop that people have head on the forums). The extra clearance was recomended based on my usage

[digger]

Pn i got is 6B1569HX-STD. The .025mm or .001. was recomended by a shop that deals primarily with e46 m3s (they are a shop that people have head on the forums). The extra clearance was recomended based on my usage

OK so its not 0.25mm atleast that's been established.

With things like this always measure and go based on actual measurements with the stock size first off as with everything there is a range of values, and deal with what is in front of you.

0.001" extra is more than likely too much additional clearance unless yours are well and truly on the tight side

[krashdumie05]

Thanks for the help. Do you know where I can find the clearance specs?

[Syfon]

And, to head off your next question, ARP rod bolts are also a downgrade from stock. Less round bore and less clamping force.

Problem is, if OP has an lci variant with non-reusable rod bolts, and he wants to plastigauge each journal, he'll need 2 x sets of oe rod bolts as they're single use only.

I used ARP rod bolts in mine. Torqued to spec as per ARP's recommendations along with their fastener assembly lube (I don't have a stretch gaue). No problems on my end.

The whole thing about ARP rod bolts not providing adequate clamping force is nothing but a myth. Yes they may provide less than OE rod bolt clamping force, but it's clearly a negligible amount. Otherwise we'd have seen numerous S54 failures solely attributed to ARP rod bolts and their lesser clamping force.

ARP rod bolts are fine so long as their torqued to spec per ARP AND their fastener assembly lube is utilised.

Furthermore - for anyone wanting to use ARP rod bolts in their LCI S54 (i.e. M10 rod bolts), the correct part number is 201-6102. S50B30 M10 ARP rod bolts are correct for LCI S54's with M10 bolts.

https://arp-bolts.com/kits/arpkit-de...?RecordID=1108

[Syfon]

OP FYI - I have ARP main & rod bearings in mine.

Rod bearing P/N is 6B1569H - .25

My crank was machined so oversize were correctly chosen / installed.

[dutchhome]

I used the ARP bolts on my 2001 but used a stretch gauge rather than going based on torque. I did try the torque technique first and measured stretch afterwards and I found the stretch to be very inconsistent. Based on this experience and because ARP recommends using a stretch gauge I decided stretch alone was the better technique.

Regardless of what is chosen, oil analysis should detect early wear before it becomes a problem as long as everything was installed properly.

[digger]

Thanks for the help. Do you know where I can find the clearance specs?

i found this

http://www.adkusters.dsmynas.com/Web.../11_24_571.pdf

0.040mm to 0.070mm (0.0016" to 0.0028")

or as a second source

http://wiki.rcollins.org/core/index....4_Rod_Bearings

Bearing Clearance Variance

0.0361 - 0.0660 mm

0.00142 - 0.00260 inch

[Anri]

Yeah, extra clearance on the s54 is a reliability downgrade. Avoid.

Hi Ian,

Bellow are the reasons why we need extra clearance on our engines which are
pushed and beaten hard on track and road fun local canyon.

Let's look at the engineering/physics behind this.

Tablet of Contents:

- First, Second Order Harmonics.
- Oiling and low oil S54 pressure design.


When the second order Harmonics appear pass 7000+ the more RPMs
the more they will get pronounced, at 8000rpm things are nasty and at 8200rpm
S54 is shaking its own guts...everything start to vibrate, lose transmission mounts
bolts, Shredded vibration dampers etc. A crankshaft is a spring/torsion bar.
One of the major upgrade on engine management is "Soft-Cut" red line... BMW was
aware of the fact we will bounce the rev limiter and the rev bounce is not like
on the older engine. The Spark cut attracts resonances. For sure 1.52.7 rod ratio is not
helping as well.


Starting from S38 B36 / S14 B25 the crankshaft material used up to date by BMW Motorsport
is CrMo42 which is stronger material than CrM45 by little.

Understanding all of the Physical issues in the crankshaft which are caused
by other factors the crankshaft twist exactly in the bearing journal area Webs. If you study
those million s54 bearing show cases.....pay close attention it depends how much the particular
S54 has been driven but note there are 2 type of ware. Bearing shell is worn out in the
end area were the rod journal meets the fillet and the web.

Another area were bearing ware out we can see is in the center. This is related to when the
piston will travel towards BDC and make a full stop. I forgot the equation I have to dig into my
books but at 8000rpm the piston of say 500grams is turning into few thousand pounds....which
at speed it must make a full death stop which is very very hard on the bearings.


The next area to look over is a TDC that is the other area very hi load !!! when the dynamic CR
is at 8000rpm the combustion pressure is hi and when the spark occurs at TDC the forces are violent.

Rod BE are perfect round when installed form Brand New ones few thou miles its over...egg shape
say we will consider let say 0.002mm off round, add that to the package.


Ian, BMW uses the same bearing clearance from M10 45 years ago with 5800rpm red line thru S54
thru S14 thru S65 etc...which is ~0.038mm-0.039mm I have done a lot MS engines and have collected
massive data.

So Ian, knowing how things are twisting in the bottom end having static bearing clearance of 0.038mm
is not enough when this package occurs you are no longer consistent 0.038 but more likely under
~0.030 mm or even less..


ACL offers the extra clearance which gives you extra around 0.012mm in real test not the box advert,
when assemble and measured the clearance is exact at ~0.051mm which is not really that much far away
from the 0.038mm.


At 0.051mm with rod extra clearance will prevent the crankshaft journal to touch the bearing shell
okay let me say reduce the "tight" clearance.


S54 Oil pressure is shit from the factory....Starting from year 2000 Engineers are so fucking stubborn
on oil drag....and for 2hp-3hp gains the Longevity of the rocker arms, bearing is nothing but short

No one has ever arise the subject why the S54 Oil Squirters don't have a check valves...they bleed
so much oil from the Main oil galley that is not even funny is why on S54 after hard hot laps at idle
of 950rpm+/- 975rpm+/- oil pressure is at merely 0.5Bar I can almost hear the bearings grind....LOL.
and why on every S54 when tuned I request the idle to be raised by 50-70rpms so that at idle
pressure is raised at around 1Bar which is still funny but better than 0.5Bar. Single reason for the
Oil squirter to stay open is that if the S54 squirter had check valve the Harmonics which do travel
thru the block will destroy the "ball-spring" is why every M54 driven on track the oil squirters do have
broken "Ball-springs"...VW squirters on diesel engines have exact this issue as well.

At the track on a Hot day the S54 oil pressure on a Hot lap is shit sits at around 3.8-4Bars at 8250rpm
my Mercedes 240D OM616 which operates at 4000rpm sits at 4.5Bar....


On S38 oil pressure at idle around 100C-210F Oil temp is at ~3.2Bar so that way there is enough pressure
to create massive and solid film. At the track I am at 4.8-5.5Bar and target is close to 6Bar at 8600-9000rpm.
Will vary depending on oil temps.

On S54 when do work on bearings I started to convert hi volume oil pump gear so that to increase
oil volume and I much happier with that set up.


On NASCAR SB2 type of engines were they rev to 9000-9500rpm these engines do use 0W-30weight
and very very very tight tolerances but they are after every single HP...but on these engines the rods are
trash after 2 races so the bearings. I have purchased NASCAR used Pankl rods for project and ovality is
way off for only 2 races and also behind the rod shell the rod surface have massive over heated spots for
hard 500miles.


There is a joke. "If the bearing tolerances are lose only you know and no one else.....but if they are
tight everybody will know..." LOL....

https://www.youtube.com/watch?v=qWhO0muWcfE https://www.youtube.com/watch?v=s92oZHgdWQk
Pure example sitting at 8350rpm S65 has exact very issue on Oiling, period.


Ian, cushion via strong oil film is not a bad thing, trust me.




Regards,
Anri.

[S54B32]

Problem is, if OP has an lci variant with non-reusable rod bolts, and he wants to plastigauge each journal, he'll need 2 x sets of oe rod bolts as they're single use only.

I used ARP rod bolts in mine. Torqued to spec as per ARP's recommendations along with their fastener assembly lube (I don't have a stretch gaue). No problems on my end.

The whole thing about ARP rod bolts not providing adequate clamping force is nothing but a myth. Yes they may provide less than OE rod bolt clamping force, but it's clearly a negligible amount. Otherwise we'd have seen numerous S54 failures solely attributed to ARP rod bolts and their lesser clamping force.

ARP rod bolts are fine so long as their torqued to spec per ARP AND their fastener assembly lube is utilised.

Furthermore - for anyone wanting to use ARP rod bolts in their LCI S54 (i.e. M10 rod bolts), the correct part number is 201-6102. S50B30 M10 ARP rod bolts are correct for LCI S54's with M10 bolts.

https://arp-bolts.com/kits/arpkit-de...?RecordID=1108

Sorry but that is total wrong! Original bmw rodbolts (m10x1.25 for „Facelift“ s54) need to be tighten to spec at least 3 times to achieve full clamping force / max tensile strength. But not more than 5 times. You can read this in the official bmw manual for shops (newtis, Ista-D or BMW AiR)

correct way to tighten them down is:
application torque: 5nm
joining torque: 30nm
angle of rotation: 105°

then loosen and repeat this (all together 3 times at least)

@anri: My oilpressure NEVER get lower than 1.5bar at very hot idle. Even after some laps on track. I‘m on full std oilpump, crank and std ACL bearings.


Bmw documents say: clearance 0,030-0,070mm with plastigauge measuring method.

[krashdumie05]

FYI. After speaking with acl they gave me some good information. They typically run the hx std on a stock unmachined crank

They said that based on my usage (8 de events / year) , they would run the HX-std but I would need to be mindfull of oil starvation at higher rms.

It was their recommendation that I either run the HX std and reduce my rpm limit or increase sump and or install higher volume pump

Their other option is to run the h-std and just check for clearance.

I have martyns tool so I can reduce rpm limit easily

Im leaning towards running HXStd and reducing the rpm to 7000 as I rarely go to the limit even at the track

oh and yes I'm using the arp bolts. I have installed them on another s54 with no problems after 1k track miles. I'll be using them on my build.

[Obioban]

FYI. After speaking with acl they gave me some good information. They typically run the hx std on a stock unmachined crank

They said that based on my usage (8 de events / year) , they would run the HX-std but I would need to be mindfull of oil starvation at higher rms.

It was their recommendation that I either run the HX std and reduce my rpm limit or increase sump and or install higher volume pump

Their other option is to run the h-std and just check for clearance.

I have martyns tool so I can reduce rpm limit easily

Im leaning towards running HXStd and reducing the rpm to 7000 as I rarely go to the limit even at the track

oh and yes I'm using the arp bolts. I have installed them on another s54 with no problems after 1k track miles. I'll be using them on my build.

I can't decide if this post is a parody or serious. S54 not going over 7000rpm on track?

Anyway, back to tracking my 160,000 mile M3 with 8300rpm redline, shifted at 8000+ RPM for every shift of it's 20,000+ track miles.
(second set of OE rod bearings/bolts).

[bigjae46]

Anyway, back to tracking my 160,000 mile M3 with 8300rpm redline, shifted at 8000+ RPM for every shift of it's 20,000+ track miles.
(second set of OE rod bearings/bolts).

I prefer this bearing issue vs seeing the issues other cars have on track.

Not sure I’d consider the bearings to be a problem. More of a maintenance item on a high performance motor. If you consider the maintenance requirements on the older S engines then rod bearings and valve adjustments don’t seem so bad.


Sent from my iPhone using Tapatalk

[krashdumie05]

Contacted a few places to see what they recomended.

Lang racing. H-STD
rogue engineering. HX-STD no concern with rpm
Morehead speed works H-STD
FCP. HX-STD
VAC H-std although they don't sell them

[Syfon]

Sorry but that is total wrong! Original bmw rodbolts (m10x1.25 for „Facelift“ s54) need to be tighten to spec at least 3 times to achieve full clamping force / max tensile strength. But not more than 5 times. You can read this in the official bmw manual for shops (newtis, Ista-D or BMW AiR)

correct way to tighten them down is:
application torque: 5nm
joining torque: 30nm
angle of rotation: 105°

then loosen and repeat this (all together 3 times at least)

@anri: My oilpressure NEVER get lower than 1.5bar at very hot idle. Even after some laps on track. I‘m on full std oilpump, crank and std ACL bearings.


Bmw documents say: clearance 0,030-0,070mm with plastigauge measuring method.

BMW state the M10 rod bolts must not be reused?

I've never read anywhere they can be reused albeit not more than 5 times?

Mine was never opened (to my knowledge), yet I didn't reuse the stock m10 rod bolts. I went with arp rod bolts.

My post stated that the whole thing regarding arp rod bolts not providing sufficient clamping force may be true, however the clamping force differential would be miniscule, otherwise by now, we would have seen many s54's with arp rod bolts having failed where the failure could be directly and solely attributed to the arp rod bolts and their insufficient clamping force. Many people I know have built s54's with arp rod bolts (installed by torqueing to spec, and not by stretching), and they haven't failed after many thousand km's of hard street and track driving.

[Obioban]

Problem is, if OP has an lci variant with non-reusable rod bolts, and he wants to plastigauge each journal, he'll need 2 x sets of oe rod bolts as they're single use only.

I used ARP rod bolts in mine. Torqued to spec as per ARP's recommendations along with their fastener assembly lube (I don't have a stretch gaue). No problems on my end.

The whole thing about ARP rod bolts not providing adequate clamping force is nothing but a myth. Yes they may provide less than OE rod bolt clamping force, but it's clearly a negligible amount. Otherwise we'd have seen numerous S54 failures solely attributed to ARP rod bolts and their lesser clamping force.

ARP rod bolts are fine so long as their torqued to spec per ARP AND their fastener assembly lube is utilised.

Furthermore - for anyone wanting to use ARP rod bolts in their LCI S54 (i.e. M10 rod bolts), the correct part number is 201-6102. S50B30 M10 ARP rod bolts are correct for LCI S54's with M10 bolts.

https://arp-bolts.com/kits/arpkit-de...?RecordID=1108

You can plastigauge with stock bolts.

I don’t think I’ve seen anyone say the ARPs provide insufficient clamping force— just that they provide less clamping force (and a less round bore than ARP bolts torqued to their spec with their lube). The Oe bolts are also cheaper.

AKA. The ARPs are fine. But, the OE’s are cheaper, stronger, and rounder result, at the cost of marginally more effort to the job. Seems like an easy enough choice to me.