BMW M3 Forum
BMW M3 Forum BMW M3 Gallery BMW M3 Reviews BMW M3 Social Groups BMW M3 Chat M3Forum Sponsors >>
Loading


Mobile M3forum
Go Back   BMW M3 Forum.com (E30 M3 | E36 M3 | E46 M3 | E92 M3 | F80/X) > BMW M3 Discussions > E46 M3 (2001-2006)
Tire Rack Buy Winter Tires Now!
Not a member? Register Now!
Register Gallery All Albums Garage Search Today's Posts Mark Forums Read Calendar FAQ

E46 M3 (2001-2006) Engine: S54 - Max Hp: 333 hp at 7,900 rpm / 262 lb/ft at 4,900 rpm
Total Produced: 45,000+ - Years Produced: 2001 to 2006.


Reply
 
Thread Tools Display Modes
Old Tue, Nov-03-2015, 01:58:14 PM   #41
SliM3
Registered User
 
SliM3's Avatar
 
Join Date: May 2012
Posts: 2,620
In the garage:
Reputation: 0 SliM3 is on a distinguished road
Location: Atlanta

United States




Default Re: REM (ISF) Microfinished S54 Crankshaft

Quote:
Originally Posted by Drewster View Post
First off, kudos on the shop wanting every component on there for balancing! I'd think that's a good sign.

Personally, I would wait until you have everything on there. As I said in another thread (to much debate), an inline 6 is a very balanced configuration. *However* the problem comes in when you've got a crank that's reaaally long, and you put a varying load on both ends.. and you run it up to 8,000 rpm

Unlike other engines that aren't balanced internally, there's nothing you need to bolt onto the crank to *balance* it externally, but you do need a damper to keep those oscillations in check. Looking at the graph here, you want to avoid the big, scary sine wave https://en.wikipedia.org/wiki/Fileamping_1.svg from this article https://en.wikipedia.org/wiki/Damping. Since the crankshaft is a constantly moving object under constant stress and strain, you really want to avoid those oscillations. Hence, the thing bolted on the accessory side is a *damper*, not a harmonic *balancer*.. although multiple people vehemently disagreed with that last bit, so I'll leave that grain of salt there. You don't read about snapped cranks too much with an OEM damper in good condition, but I've read about/ heard people who "upgraded" the damper and lost a crankshaft/ engine... I guess that's my really verbose way of saying to make sure the stock damper is used and to not to screw with the damper as long as its in good shape.

Even though the engine is an ideally balanced configuration... you still have the issue of some stuff going up and down while other stuff goes round and round. A normal part of balancing is using precise bob weights for rotating weight and reciprocating weight.. which would be thrown off by going back and reducing the rotating weight later. Something I'm curious about and you might ask them is "overbalancing". Essentially you use a little more than the normal 50% reciprocating weight to make sure the engine is balanced at high RPM.. but not necessarily outside of the desired operating range. If you're going to be racing it and spending the vast majority of the time at 7900 RPM rather than 900, it's supposed to help reduce the higher RPM oscillation/ vibration and save wear on components.

Point being - using a lightweight assembly at one end rather than what the engine was set up for could theoretically make things behave very differently than the stock mass. If you're spending the money to do it right, wait until you can let them do everything right.
Great response, thank you. Steve (machinist) says he balances up to 10,000 rpm, and I want to say 55% of the recip weight. Don't quote me on that figure though.

But yeah you're right, I need to have everything ready to go and not piece-meal later on. Guess I'll start looking at some of the Southbend disc/pressure plate offerings and roll with a new LUK DMF.

Damper is in great shape, BTW.
Jump to top SliM3 is offline   Reply With Quote
Sponsored Links
Register now and remove these ads
Old Tue, Nov-03-2015, 02:08:35 PM   #42
paffy
Registered User
 
Join Date: Jun 2010
Posts: 1,214
Reputation: 0 paffy is on a distinguished road
Location: Queens

Czech_Republic




Default Re: REM (ISF) Microfinished S54 Crankshaft

Awesome info !!

To what level does the dual-mass flywheel effect the damping compared to the rubber damper up front ?

Is it a "system" ?

Do they work independently ?

Do the flywheel springs have more of a detrimental effect on axial vibration?

What happens when you replace the flywheel ?
__________________
http://www.msstuning.com/ - serving your MSS5x flashing needs
2014 BMWCCA NY autox E class champion
My GTS4 build journal - http://www.m3forum.net/m3forum/showthread.php?t=551613
Jump to top paffy is offline   Reply With Quote
Old Tue, Nov-03-2015, 02:32:32 PM   #43
Flow
Registered User
 
Flow's Avatar
 
Join Date: Mar 2011
Posts: 2,850
In the garage:
Reputation: 0 Flow is on a distinguished road
Location: France

France




Default Re: REM (ISF) Microfinished S54 Crankshaft

I understand maybe 10% of all that you are saying, but it is awesome !

Thank you for sharing and keep us updated on your build.
__________________
- Florian E46 M3 tightening torques PDF
2004 M3 TiAg / LSB SMG
Jump to top Flow is offline   Reply With Quote
Old Tue, Nov-03-2015, 02:38:16 PM   #44
Drewster
Registered User
 
Drewster's Avatar
 
Join Date: Aug 2014
Posts: 2,678
In the garage:
Reputation: 0 Drewster is on a distinguished road

United States




Default Re: REM (ISF) Microfinished S54 Crankshaft

Quote:
Originally Posted by paffy View Post
Awesome info !!

To what level does the dual-mass flywheel effect the damping compared to the rubber damper up front ?

Is it a "system" ?

Do they work independently ?

Do the flywheel springs have more of a detrimental effect on axial vibration?

What happens when you replace the flywheel ?
I'd argue that anything directly attached to the crank makes it behave as part of that mechanical system. Just like a suspension component with specific mass, spring, damping, and torsional characteristics, you can't bolt something on without changing that equation.

I'm honestly not sure what the dynamic response of a dual-mass flywheel would be. Although having the engine balanced for that mass (flywheel springs fully compressed and the whole assembly under constant load) would probably give me enough of a warm/ fuzzy, I would think modeling the dynamic loading is a job for very expensive software.

I read one article online saying that balancing the engine as a whole was "not ideal for race cars" since a change in one component would alter the balance... but my personal argument to that is that replacing a like-for-like component will have less of an effect than adding a whole bunch of mass and damping to an otherwise "known" system. Ideally I would think you would balance the crank, then check everything with the full weight/ assembly for the final desired balance. If you're racing and you lose chunks of your flywheel, engine balance is probably going to be the least of your concerns, anyway. If the engine isn't balanced when fully assembled, what's the point?

Last edited by Drewster; Tue, Nov-03-2015 at 02:49:30 PM.
Jump to top Drewster is online now   Reply With Quote
Old Tue, Nov-03-2015, 02:52:45 PM   #45
bimmerdriver
Registered User
 
Join Date: Jul 2013
Posts: 3,299
In the garage:
Reputation: 0 bimmerdriver is on a distinguished road
Location: Metro Vancouver

Canada




Default Re: REM (ISF) Microfinished S54 Crankshaft

Quote:
Originally Posted by digger View Post
So lets take a stock S54 stock 139mm rod at 8000rpm vs no change other than 150mm rod. i chose 150mm so the differences can be seen

0* and 360* = TDC
180* = BDC

longer rod dwells more at TDC and less at BDC

longer rod has lower peak piston speed

longer rod has lower acceleration at TDC but slighty higher around BDC

longer rod reduces peak rod angularity from 18.1 to 16.9*

Peak piston speed is the same as the crankpin speed for very long rod.

moral of the story is a minor change in rod length doesn't produce vastly different piston motion.
Well done!
__________________
2002 (12/2001) M3 6MT Coupe Carbon Black on Black - ZCP/CSL Wheels, 245/35/19 Mich PS2 & 285/30/19 Conti ExtremeContact DW, H&R 15 mm Front Spacers, CSL F/R Brakes, EBC Redstuff, TMS SS F/R Brake Lines, PSS9, TMS F/R Sway Bars, TMS Rear Control Arms, TMS Underdrive Pulleys, TMS/Carbonio Intake, Eisenmann Exhaust, AutoSolutions 30% SSK, BMW Illuminated Shift Knob, BMW Performance Pedals, BMW Performance 4.10 R&P, CDV Delete, Flossmann GTR Carbon Fiber Hood/Trunk, Carbon Fiber Rear Diffuser, Euro Front Signal Lights, Euro Rear Tail Lights, Angel Eyes, Homelink

1997 328is 5MT Coupe Madeira Violet on Black - Staggered M Forged Double Spoke Wheels, Bilstein Sport, H&R Sport, M Tech Rear Spoiler (Sold)
Jump to top bimmerdriver is offline   Reply With Quote
Old Tue, Nov-03-2015, 02:56:25 PM   #46
bimmerdriver
Registered User
 
Join Date: Jul 2013
Posts: 3,299
In the garage:
Reputation: 0 bimmerdriver is on a distinguished road
Location: Metro Vancouver

Canada




Default Re: REM (ISF) Microfinished S54 Crankshaft

Quote:
Originally Posted by SliM3 View Post
Alright, well since you guys are in physics mode maybe you can answer this question for me:

The machine shop wants every last component that bolts to crankshaft to complete dynamic balancing. I'd like to go with the twin plate clutch from Max PSI, though I really can't squeeze it out of the budget until spring. That being said, if the shop is balancing the crank using the stock DM flywheel, clutch & bolt weights, how severely will I throw off the final balance when I eventually go with the new clutch?
They should be basing their balancing on the assumption the flywheel and pressure plate are already balanced so there won't be any changes if/when you replace them in the future.
__________________
2002 (12/2001) M3 6MT Coupe Carbon Black on Black - ZCP/CSL Wheels, 245/35/19 Mich PS2 & 285/30/19 Conti ExtremeContact DW, H&R 15 mm Front Spacers, CSL F/R Brakes, EBC Redstuff, TMS SS F/R Brake Lines, PSS9, TMS F/R Sway Bars, TMS Rear Control Arms, TMS Underdrive Pulleys, TMS/Carbonio Intake, Eisenmann Exhaust, AutoSolutions 30% SSK, BMW Illuminated Shift Knob, BMW Performance Pedals, BMW Performance 4.10 R&P, CDV Delete, Flossmann GTR Carbon Fiber Hood/Trunk, Carbon Fiber Rear Diffuser, Euro Front Signal Lights, Euro Rear Tail Lights, Angel Eyes, Homelink

1997 328is 5MT Coupe Madeira Violet on Black - Staggered M Forged Double Spoke Wheels, Bilstein Sport, H&R Sport, M Tech Rear Spoiler (Sold)
Jump to top bimmerdriver is offline   Reply With Quote
Old Tue, Nov-03-2015, 03:02:09 PM   #47
bimmerdriver
Registered User
 
Join Date: Jul 2013
Posts: 3,299
In the garage:
Reputation: 0 bimmerdriver is on a distinguished road
Location: Metro Vancouver

Canada




Default Re: REM (ISF) Microfinished S54 Crankshaft

Quote:
Originally Posted by Drewster View Post
First off, kudos on the shop wanting every component on there for balancing! I'd think that's a good sign.

Personally, I would wait until you have everything on there. As I said in another thread (to much debate), an inline 6 is a very balanced configuration. *However* the problem comes in when you've got a crank that's reaaally long, and you put a varying load on both ends.. and you run it up to 8,000 rpm

Unlike other engines that aren't balanced internally, there shouldn't be anything you need to bolt onto the crank to *balance* it externally, but you do need a damper to keep those oscillations in check. Looking at the graph here, you want to avoid the big, scary sine wave https://en.wikipedia.org/wiki/Fileamping_1.svg from this article https://en.wikipedia.org/wiki/Damping. Since the crankshaft is a constantly moving object under constant stress and strain, you really want to avoid those oscillations. Hence, the thing bolted on the accessory side is a *damper*, not a harmonic *balancer*.. although multiple people vehemently disagreed with that last bit, so I'll leave that grain of salt there. You don't read about snapped cranks too much with an OEM damper in good condition, but I've read about/ heard people who "upgraded" the damper and lost a crankshaft/ engine... I guess that's my really verbose way of saying to make sure the stock damper is used and to not to screw with the damper as long as its in good shape.

Even though the engine is an ideally balanced configuration... you still have the issue of some stuff going up and down while other stuff goes round and round. A normal part of balancing is using precise bob weights for rotating weight and reciprocating weight.. which would be thrown off by going back and reducing the rotating weight later. Something I'm curious about and you might ask them is "overbalancing". Essentially you use a little more than the normal 50% reciprocating weight to make sure the engine is balanced at high RPM.. but not necessarily outside of the desired operating range. If you're going to be racing it and spending the vast majority of the time at 7900 RPM rather than 900, it's supposed to help reduce the higher RPM oscillation/ vibration and save wear on components.

Point being - using a lightweight assembly at one end rather than what the engine was set up for could theoretically make things behave very differently than the stock mass. If you're spending the money to do it right, wait until you can let them do everything right.
Unless there is a very good reason to overbalance, it's much more important to minimize the differences in the balance. It significantly reduces bearing loading at high rpm if the balance is done more precisely.
__________________
2002 (12/2001) M3 6MT Coupe Carbon Black on Black - ZCP/CSL Wheels, 245/35/19 Mich PS2 & 285/30/19 Conti ExtremeContact DW, H&R 15 mm Front Spacers, CSL F/R Brakes, EBC Redstuff, TMS SS F/R Brake Lines, PSS9, TMS F/R Sway Bars, TMS Rear Control Arms, TMS Underdrive Pulleys, TMS/Carbonio Intake, Eisenmann Exhaust, AutoSolutions 30% SSK, BMW Illuminated Shift Knob, BMW Performance Pedals, BMW Performance 4.10 R&P, CDV Delete, Flossmann GTR Carbon Fiber Hood/Trunk, Carbon Fiber Rear Diffuser, Euro Front Signal Lights, Euro Rear Tail Lights, Angel Eyes, Homelink

1997 328is 5MT Coupe Madeira Violet on Black - Staggered M Forged Double Spoke Wheels, Bilstein Sport, H&R Sport, M Tech Rear Spoiler (Sold)
Jump to top bimmerdriver is offline   Reply With Quote
Old Tue, Nov-03-2015, 03:05:36 PM   #48
bimmerdriver
Registered User
 
Join Date: Jul 2013
Posts: 3,299
In the garage:
Reputation: 0 bimmerdriver is on a distinguished road
Location: Metro Vancouver

Canada




Default Re: REM (ISF) Microfinished S54 Crankshaft

Quote:
Originally Posted by SliM3 View Post
Great response, thank you. Steve (machinist) says he balances up to 10,000 rpm, and I want to say 55% of the recip weight. Don't quote me on that figure though.

But yeah you're right, I need to have everything ready to go and not piece-meal later on. Guess I'll start looking at some of the Southbend disc/pressure plate offerings and roll with a new LUK DMF.

Damper is in great shape, BTW.
Great that he balances up to 10000 RPM, but unless you have it on good authority (i.e., someone with experience building 9000 RPM S54 engines) that using 55% of the reciprocating mass instead of the normal 50% is preferable, I'd tread carefully.
__________________
2002 (12/2001) M3 6MT Coupe Carbon Black on Black - ZCP/CSL Wheels, 245/35/19 Mich PS2 & 285/30/19 Conti ExtremeContact DW, H&R 15 mm Front Spacers, CSL F/R Brakes, EBC Redstuff, TMS SS F/R Brake Lines, PSS9, TMS F/R Sway Bars, TMS Rear Control Arms, TMS Underdrive Pulleys, TMS/Carbonio Intake, Eisenmann Exhaust, AutoSolutions 30% SSK, BMW Illuminated Shift Knob, BMW Performance Pedals, BMW Performance 4.10 R&P, CDV Delete, Flossmann GTR Carbon Fiber Hood/Trunk, Carbon Fiber Rear Diffuser, Euro Front Signal Lights, Euro Rear Tail Lights, Angel Eyes, Homelink

1997 328is 5MT Coupe Madeira Violet on Black - Staggered M Forged Double Spoke Wheels, Bilstein Sport, H&R Sport, M Tech Rear Spoiler (Sold)
Jump to top bimmerdriver is offline   Reply With Quote
Old Tue, Nov-03-2015, 03:27:31 PM   #49
SliM3
Registered User
 
SliM3's Avatar
 
Join Date: May 2012
Posts: 2,620
In the garage:
Reputation: 0 SliM3 is on a distinguished road
Location: Atlanta

United States




Default Re: REM (ISF) Microfinished S54 Crankshaft

Quote:
Originally Posted by bimmerdriver View Post
Great that he balances up to 10000 RPM, but unless you have it on good authority (i.e., someone with experience building 9000 RPM S54 engines) that using 55% of the reciprocating mass instead of the normal 50% is preferable, I'd tread carefully.
Don't quote me on that 55%. I could be totally off-base with that one.

Quote:
Originally Posted by bimmerdriver View Post
A longer rod increases the peak force, although your rods aren't that much longer than stock. How does the mass of your piston / rod / bearings compare with stock? Did you consider the Lang Racing approach of going with a wider rod bearing?
Missed your questions from earlier

Stock weight, not including the bearings:
1150 grams

Aftermarket weights, not including bearings (the tool steel wrist pin upgrade added some additional weight as well):
1068 grams

I did consider the wider bearing option, but honestly the cost worked out better with the crank exchange from Lang, the components I have now, and microfinishing.

Plus, I wanted to concentrate more funds on the cylinder head, which is coming up very shortly. Waiting on a quote for the [custom] intake/exhaust multi-angle seat cutter blades from Goodson.


EDIT: Here is the con-rod bolt strengths.

ARP 2000: 190,000 psi yield/220,000 psi tensile
  • 0.006" stretch = 90% of yield = 19,000 lb. clamp-up preload
  • Using Drewster's force estimate of 25.4 kN @ 9000 rpm = 5710 lbs.
  • Safety Margin (cyclic tension load/clamp-up preload) = 166%


SPS-CARR: 260,000 psi yield/310,000 psi tensile
  • 0.006" stretch = 90% of yield = 26,000 lb. clamp-up preload
  • Using Drewster's force estimate of 25.4 kN @ 9000 rpm = 5710 lbs.
  • Safety Margin (cyclic tension load/clamp-up preload) = 227%
Jump to top SliM3 is offline   Reply With Quote
Old Tue, Nov-03-2015, 03:35:01 PM   #50
Drewster
Registered User
 
Drewster's Avatar
 
Join Date: Aug 2014
Posts: 2,678
In the garage:
Reputation: 0 Drewster is on a distinguished road

United States




Default Re: REM (ISF) Microfinished S54 Crankshaft

Quote:
Originally Posted by SliM3 View Post
ARP 2000: 190,000 psi yield/220,000 psi tensile
  • 0.006" stretch = 90% of yield = 19,000 lb. clamp-up preload
  • Using Drewster's force estimate of 25.4 kN @ 9000 rpm = 5710 lbs.
  • Safety Margin (cyclic tension load/clamp-up preload) = 166%


SPS-CARR: 260,000 psi yield/310,000 psi tensile
  • 0.006" stretch = 90% of yield = 26,000 lb. clamp-up preload
  • Using Drewster's force estimate of 25.4 kN @ 9000 rpm = 5710 lbs.
  • Safety Margin (cyclic tension load/clamp-up preload) = 227%

Cool. Now I know what rod bolts to use when I refresh my bearings

Just for good measure, I would run the numbers using the actual mass of your rod, pin, and piston using an acceleration of 55k m/s^2 (multiply weight in [kilo]grams to get Newtons).. all I did was use the mass of the stock piston itself to try and put the right amount of trepidation in 'ya

Last edited by Drewster; Tue, Nov-03-2015 at 03:55:29 PM.
Jump to top Drewster is online now   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump



All times are GMT. The time now is 11:49:01 PM.


Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
M3Forum.com and M3forum.net is in no way sponsored, endorsed or affiliated by or with BMW NA / BMW AG or any of it's subsidiaries or vendors.
BMW and M3 (E90 M3 | E92 M3 | E93 M3 | E46 M3 | E36 M3 | E30 M3) are registered trademarks of BMW AG.
M3Forum Terms of Service
Copyright 1999-2017 M3Forum.com
Discussing REM (ISF) Microfinished S54 Crankshaft in the E46 M3 (2001-2006) Forum - Engine: S54 - Max Hp: 333 hp at 7,900 rpm / 262 lb/ft at 4,900 rpm
Total Produced: 45,000+ - Years Produced: 2001 to 2006. at BMW M3 Forum.com (E30 M3 | E36 M3 | E46 M3 | E92 M3 | F80/X)