BMW (finally) publishes S65 Rod Bearing Clearance Specs

[DrFerry]

Green-Eggs The Honda S2000 5W30 oil viscosity spec - which has almost the same bearing clearances as the S65 and revs to 8K RPM - makes me think about switching back to 5W50 might be actually worth doing in cold weather even with my B.E. Bearings? Any thoughts based on the recent information we now have? Just wondering.

[Assimilator1]

Earlier S2000s revved to 9k!

[charliev68]

Is it possible, 10w60 is needed for the VANOS? Piston Ring to cylinder wall lubricant?

[DrFerry]

Originally Posted by charliev68

Is it possible, 10w60 is needed for the VANOS? Piston Ring to cylinder wall lubricant?

Quite possibly, but it's also needed by the rod bearings. Haha. Imagine owning an E9X M3 and living in Alaska, Northern Canada or the Nordic regions of Europe where a 10W60 oil's cold flow pump-ability into the rod bearing in sub zero temperatures might be challenging. Reims have been written on BMW's choice of oil for the S65 but perhaps Honda knew something BMW didn't given the S2000s similar rod bearing clearances and 5W30 OEM oil viscosity spec.

[DrFerry]

Originally Posted by Assimilator1

Earlier S2000s revved to 9k!

And I'm guessing those earlier S2000s did that (9K RPM) using the 5W30 viscosity oil and all done with similar rod bearing clearances to the S65?

[Assimilator1]

Not sure TBH.

[UPSROD]

You guys seem to forget the 10 part of the 10-60! Viscosity of 10 W when cold!

[DrFerry]

Originally Posted by UPSROD

You guys seem to forget the 10 part of the 10-60! Viscosity of 10 W when cold!

Exactly. 10W is twice as thick as 5W in a cold winter climate. Hence, the concern for the S65 with tight rod bearing clearances in the winter when using a 10W oil.

[Helmsman]

Originally Posted by DrFerry

Exactly. 10W is twice as thick as 5W in a cold winter climate. Hence, the concern for the S65 with tight rod bearing clearances in the winter when using a 10W oil.

10W gives a thick and nice grease lube during Winter time, worked nicely for my car during its first 13y of life time....
Not passing 2k rpm until oil temps are 70C or so though, where after 3k rpm till "full temp" is reached.

[DrFerry]

10W gives a thick and nice grease lube during Winter time, worked nicely for my car during its first 13y of life time.... Not passing 2k rpm until oil temps are 70C or so though, where after 3k rpm till "full temp" is reached.
Haha. Grease lube is probably the right description for a 10W viscosity with OEM rod bearings, and given the tight OEM S65 rod bearing clearances. Perhaps BMW chose 10W60 due to piston ring clearsnces and or emissions.

Meanwhile, no such dynamic red line, or warm procedure required by Honda I'm aware of with the 5W30 and similar tight bearing clearances. The below image is from the S2000 manual and a post on the warm-up topic from the S2000 forums.
.

.
https://www.s2ki.com/forums/s2000-ta...ur-car-914811/
.

[Reddevils7]

Originally Posted by Helmsman

10W gives a thick and nice grease lube during Winter time, worked nicely for my car during its first 13y of life time....
Not passing 2k rpm until oil temps are 70C or so though, where after 3k rpm till "full temp" is reached.

I do about the same as you. I picked up a single owner low milage E92 recently and did the bearings for peace of mind. I ty to keep it below 2k until it's fully warmed which is about 92-94°C, just shy of the 210°F marker on the dash.

What is the lowest operating temp for OEM 10w60? On the coldest days here, I've checked the temp before starting the car with bimmer link and it's about 5°C

[DrFerry]

5 Centigrade = 41 Fahrenheit

[Helmsman]

Originally Posted by Reddevils7

I do about the same as you. I picked up a single owner low milage E92 recently and did the bearings for peace of mind. I ty to keep it below 2k until it's fully warmed which is about 92-94°C, just shy of the 210°F marker on the dash.

What is the lowest operating temp for OEM 10w60? On the coldest days here, I've checked the temp before starting the car with bimmer link and it's about 5°C

5C over zero? Since I got the M3 I finally hired a garage (prior that many Winters out in the cold) but even day time at work -10C (14F) is pretty normal. Nema problema for the M3. And yes, I only use 10W60. I don't idle for more than cold start to finish and off we go.

Btw this is "down south" in Stockholm, up north they reported -48C (-54F) in January... Up there Volvo counts...

[Reddevils7]

Originally Posted by Helmsman

5C over zero? Since I got the M3 I finally hired a garage (prior that many Winters out in the cold) but even day time at work -10C (14F) is pretty normal. Nema problema for the M3. And yes, I only use 10W60. I don't idle for more than cold start to finish and off we go.

Btw this is "down south" in Stockholm, up north they reported -48C (-54F) in January... Up there Volvo counts...

Ya that's what the app reports. I'll check again tomorrow at both home and work parking garages before I start the car. The garages are partially open. The ambient temp these days is about 20s F (48°F today). Last month it was single digits F for a little bit with wind chill hitting -7F.

[Assimilator1]

Originally Posted by DrFerry

And I'm guessing those earlier S2000s did that (9K RPM) using the 5W30 viscosity oil and all done with similar rod bearing clearances to the S65?

Btw I discovered in my thread that I'd posted the wrong Honda for that engine, the K20A2 is fitted to Civics, Integras and Accords Type R JDMs.
The F20C (2 ltr, 9k RPM limit) and F22C1 (2.2 ltr, 8.2k RPM limit) are the ones fitted to the S2000.
I'm going to see if I can find the oil and rod bearings specs for that, unless you already have?

Btw, according to wiki the K20A2 has a redline of 7.8 or 7.9k, with a cut off of 8.1k or 8.25k RPM.

[DrFerry]

Originally Posted by Assimilator1

Btw I discovered in my thread that I'd posted the wrong Honda for that engine, the K20A2 is fitted to Civics, Integras and Accords Type R JDMs.
The F20C (2 ltr, 9k RPM limit) and F22C1 (2.2 ltr, 8.2k RPM limit) are the ones fitted to the S2000.
I'm going to see if I can find the oil and rod bearings specs for that, unless you already have?

Btw, according to wiki the K20A2 has a redline of 7.8 or 7.9k, with a cut off of 8.1k or 8.25k RPM.

Great info. Can’t wait to hear what you find. I don’t want this to become an “oil thread”, we know how those go. But remember years ago on this forum all the 5W50 and 0W40 threads about protecting rod bearings from start up wear and cold climates ? Anyway, as I like to say, “keep us a breast”….

[Assimilator1]

Looks like Nutterbutter at a Honda S2000 forum has posted screenshots of the Honda manual rod bearing clearances and measurements (and Honda are fine using plastigauge too!), screenshots show the clearance spec new is 0.03mm to 0.054mm.
Oil spec seems to be 10w/30!

[2226cc]

Originally Posted by charliev68

Is it possible, 10w60 is needed for the VANOS? Piston Ring to cylinder wall lubricant?

The vanos on S65 is the same all other car makers use, there’s nothing special about it, it definitely doesn’t need 10w60 to operate

[M3SQRD]

Originally Posted by DrFerry

And I'm guessing those earlier S2000s did that (9K RPM) using the 5W30 viscosity oil and all done with similar rod bearing clearances to the S65?

The F20C 2.0 L in the AP1 went to 9k rpm

The F22C1 2.2 L in the AP2 went to 8.2k rpm

I’ve owned two AP1 and one AP2, and combined mileage in the s2000s was ~225k marvelous miles! IIRC, there were no changes in oil viscosity requirements between the F20C and F22C1 - 5W30 for both engines.

[Sneaky Pete]

The S65 mean clearance was 0.046mm and the grading scheme allowed a total range of 0.029/0.062mm

Given that the RB clearance for the S65 taken from the drawing held at Mahle is completely in line with the clearances given in the Wiki for nearly the whole range of BMW engines listed.
Doesn't that give anyone pause for thought?
Why is it only the S65 that is suffering such high (sometimes catastrophic) RB wear.
Is there no significant difference between the S65 and all the other BMW engines with the same clearance, built in the same BMW factories for the same USA market that could account for it?

[e46e92love]

Originally Posted by Sneaky Pete

Too funny....green eggs is such an inveterate liar.
My 2009 E92 M3 oil test results from Blackstone were posted in the Oil analysis thread (post#136) on 10-24-2013 where I inferred that it was one of the highest copper content recorded to date.
I kept my 2009 M3 for another year and then traded it in with ~60k miles for a 2013 E92 M3 with 3k miles.
I traded the 2013 E92 M3 in 2017 for an F82 M4 (a very disappointing car).

So now we finally have the official original BMW E9x M3 OEM RB mean clearance taken from the original drawings held by Mahle of 0.046 mm.
Not to be confused with side clearance obviously...as some clown did above. Lol.
An RB clearance that looks remarkably similar to the clearance quoted for a large number of other BMW engine in the wiki.
AFAIK none of which have suffered the same catastrophic RB wear.
What now for the tight bearing house of cards?...much obfuscation and deflection I would imagine.

On UK engine failures:
There continue to be very few UK engine failures as a function of productions numbers..not per capita as that would just be stupid.
What is the total number of USA engine failures at the moment...must be in the many hundreds by now.

On usernames...
You:
Pencil geek..banned
Regular guy...banned
OM VT3...shill username used to discredit other bearing suppliers
Green Eggs...hilariously pretending not to be part of BE bearings.

I can't believe I've been sucked back into this nonsense.

Yeah, I’m not sure why you did either.

I make it simple, and I know everyone will flame me for this, and this is not a shot at your questions or anyone else’s: take total production numbers, then take total engine failures from STOCK vehicles (meaning never tuned or SC) and I bet the MTF is better than most cars and undefeated against any other engine that revs to 8300 rpm’s while being more than capable of running past 100k miles without being rebuilt.

Sorry, BMW gave us a gem, some found ways to piss all over it for mythical rod bearing and low torque arguments and here we are: with boring, automatic driven turbo engines with as much personality as a dead donkey.

Just my .02. Don’t miss the drama from these forums that seemed to rule this place from 2007-2018.

Cheers,
e46e92

[e46e92love]

Originally Posted by DrFerry

Why would Honda spec a 5W30 oil viscosity for their S2000 and BMW spec a 10W60 oil viscosity for the S65 E9X M3 when the rod bearing clearances are similar?

>>>
The Honda S2000
Honda S2000 (F22C1)
Engine capacity - 2 ltr
Engine power - 237 hp
Hp/ltr - 118.5
Redline - 8000 RPM
Preferred oil spec - 5w30
Rod bearing clearance variance - 0.02-0.06mm
Crankshaft pin/rod journal diameter - 49.988mm
Clearance to Journal Size Ratio - 0.008mm

S65 specs
Engine capacity - 4 lts
Engine power - 414 bhp
Bhp/ltr - 103.5
Redline - 8300 RPM
Spec'd oil - 10w60
Nominal rod bearing clearance - 0.0381mm (0.00150")
Rod bearing clearance variance - 0.0292 - 0.0508 mm (from BE's S65 wiki for the later Alu/tin shells, which apparently have a slightly higher minimum)
Crankshaft pin/rod journal diameter - 51.9786-51.9887 mm (official specs posted in the S65 wiki)
Clearance to Journal Size Ratio - 0.0007mm

Source Assimilator1 's thread:
https://www.m3post.com/forums/showthread.php?t=1827360

I would venture to guess it’s because the majority of the wear and tear on the engine comes from cold startup / first start of the day. 10w60 I bet remains on the parts longer after shut down, hence leaving more lubrication on parts leading to lower cold start wear. I think it’s also why the higher mileage cars seem to have LESS problems. Ask the boys with cars from Maranello the bills they get when they first turn them over after winter storage

Again, this is what I’d like to call my opinion and not fact based statement backed by a multi-million dollar research project to confirm

Cheers,
e46e92