M42club.com - Home of the BMW E30/E36 318i/iS
DISCUSSION => Engine + Driveline => Topic started by: peerless on May 22, 2008, 10:31:42 PM
-
I keep hearing about this M20 conversion so I decided to do some research into what the real advantage was.
Flywheel weights
------------------
5/90 US 318is M42 5sp. A/C. Originally Twin Mass 21 21 1 223 550 (http://bmwfans.info/part-21211223550/) 12.250kg / 27lbs
-----------
3/89 European 318is M42 5sp. NON-A/C. Single Mass 11 22 1 739 315 (http://bmwfans.info/part-11221739315/) 9.9kg / 22lbs
-----------
3/90 US 325is M20 5sp. A/C. Single Mass 11 22 1 706 573 (http://bmwfans.info/part-11221706573/) 8.5kg / 19lbs
__________________________________________________ ______________
Clutch Kit weights (Includes Clutch Cover, Disk, Throw-out bearing)
-------------------
5/90 US 318is M42 Dual Mass 21 21 1 223 571 (http://bmwfans.info/part-21211223571/) 5kg/11lbs
3/89 European 318is M42 Single Mass, 21 21 1 223 570 (http://bmwfans.info/part-21211223570/) 5.6kg / 12lbs
3/90 US 325is M20 Single Mass, 21 21 1 223 102 (http://bmwfans.info/part-21211223102/) 6.98kg / 15lbs
__________________________________________________ _______
Combined weights as rotating assembly
-------------------------------------------
5/90 US M42 Dual Mass. 17.25kg / 38lbs
3/89 Euro M42 Single Mass. 15.5kg / 34lbs
3/90 US 325is M20 Single Mass 15.48kg / 34lbs
____________________________________________
Total weight savings of M20 single mass to M42 single mass 0 lbs.
__________________________________________________ _______
With the M42 specific flywheel you can use a M42 starter. No need to change the starter pinion gear as required with the M20 conversion. This can be a problem if your starter shits the bed at the track or some parking lot. You can go to a parts store and buy a starter and throw it in the car. What if the car changes ownership and the new owner takes it to a shop and the tech is scratching his head why the new M42 starter doesn't work.
In regards to cost I have broken that down as well. Here the M20 conversion does have and advantage. M20 single mass flywheels are plentifully available in the US. These can be found used in mostly good condition for $50-100. The Euro M42 single mass flywheel is not a common item here in the states so they most likely would be purchased new. Pelican has them for $323. We purchased ours through a private party for $200 shipped, new in the factory BMW box. I haven't checked my dealer pricing yet.
Price Comparison (new parts, pelican parts for pricing)
______________________________________________
5/90 US M42 Dual Mass, Flywheel $685 Clutch Kit $209 ($894)
3/89 Euro M42 Single Mass, Flywheel $323 Clutch Kit $230 ($553)
3/90 US M20 Single Mass, Flywheel $367 Clutch Kit $216 ($583)
Total Cost saving of M20 vs M42 flywheel conversion using new parts, none, it would cost $30 more. But again that using new flywheels and as mentioned before the US single mass flywheels are fairly plentiful in good used form.
Also as one last note of interest, the M42 single mass because of its design leaves a LOT of meat that can be milled off for a very good weight savings, maybe more so then the M20?.
A nice trait of the M20 is it has more surface area. M42 215mm/8.46" to M20 228mm/8.97" diameters. Thats 13mm/.500" (1/2") difference. For the forced induction guys, thats a good thing.
Well that about wraps up my research on the subject. I hope you find it useful and informative.
If you see an error in what I researched please point it out and provide references to included information. Something of this nature needs to be correct.
Part numbers and weights where provided by bmwfans.info
M42 single mass advantages:
Lighter weight over the dual mass unit and just as light as the M20 conversion.
Use factory M42 starter with no modifications
Use factory clutch kit complete
Uses factory length flywheel bolts
All parts readily available.
Disadvantage:
Cost involved in acquiring single mass flywheel
====================================
M20 single mass conversion advantages:
Lighter then M42 dual mass, but same weight as M42 single mass.
1/2" more clutch surface diameter for improved load capacity on high HP M42's.
Less cost for flywheel as they are plentiful used in good condition.
All parts readily available.
Disadvantages:
Must purchases additional throw out bearing as the M20 bearing is too short. (323i)
Must use modified flywheel bolts
Must use spacer in back of flywheel for proper spacing
Must modify existing starter and install M20 pinion gear
For complete M20 conversion instructions and modifications read here, http://www.blackforestindustries.com/m20flywheel.htm
Comments?
-
Excellent info. Thanks for doing all the research. This deserves a permanent place in refference. Did the later m42/m44 engines in the e36 chassis also use the same dual mass flywheel?
-
Great info. The way people write about the conversions you'd think it'd be at least 10lb difference... not so.
What about cost and weight of aftermarket flywheels? Would it be worth it to get the flywheel if the clutch is still relatively new?
good question about E36 clutches, although, didn't they get a different transmission? Somewhere I thought it said those newer trannys were better?
So how much weight can be milled off the M20 flywheel?
If I have to do a clutch job i'll convert but for 4lb it's not a huge deal now.
-
We purchased a 93' E36 M42 as a core engine and it had a dual mass flywheel.
It turns out that the single mass flywheel was also used in early US E30 318is models, from 11/89-3/90. Hell most catalogs don't even show a US M42 until 91'.
http://bmwfans.info/part-11221739315/&detail_usage=E30|2-T|318is-M42|USA|L|M
http://bmwfans.info/part-11221739315/
-
You can mill a M20 flywheel down to about 13 lbs. A M42 down to 17 lbs. I have one of each. The M20 is prefered if you have a modified engine as it can handle more power. Otherwise the M42 is just fine. There is an e-bay vendor that has a BMW junkyard in GA that sells the M42 single mass flywheel every once and awhile. Goes by the name of VINES. I got mine for $50
-
I'm aware of the rattling that occurs with BMWs and dual mass FW setups changed to lighter FWs. I read a lot of complaint on bf.c about the E36s.
Does it 'chatter' at idle? Can you hear it from outside the car?
-
I have a ltw 323i flywheel that weighs roughly 11lbs.
I paid less for the whole deal that the M20 clutch kit.
This by far is the best option because the flywheel is lighter than ALL three you've mentioned. Not sure about cost or availability but I got lucky with my purchase.
323i Flywheel : $75
323i TOB: $63
M20 Clutch: $100
ZERO chatter with this setup.
-
I forgot about the 323 flywheel. I have one as well. I scored it for $40 at the local pick a part.
I will agree thats a light weight flywheel. As you mentioned its lighter then all 3 compared.
Interesting, might have to update my comparisons. I would assume that the starter still needs to be modified?
I have a ltw 323i flywheel that weighs roughly 11lbs.
I paid less for the whole deal that the M20 clutch kit.
This by far is the best option because the flywheel is lighter than ALL three you've mentioned. Not sure about cost or availability but I got lucky with my purchase.
323i Flywheel : $75
323i TOB: $63
M20 Clutch: $100
ZERO chatter with this setup.
-
I forgot about the 323 flywheel. I have one as well. I scored it for $40 at the local pick a part.
I will agree thats a light weight flywheel. As you mentioned its lighter then all 3 compared.
Interesting, might have to update my comparisons. I would assume that the starter still needs to be modified?
Yeh I had to swap pinion gears from the m20 starter and throw it in the m42 starter...pretty easy to do though, just gotta heat it up like crazy.
-
I have a ltw 323i flywheel that weighs roughly 11lbs.
I paid less for the whole deal that the M20 clutch kit.
This by far is the best option because the flywheel is lighter than ALL three you've mentioned. Not sure about cost or availability but I got lucky with my purchase.
323i Flywheel : $75
323i TOB: $63
M20 Clutch: $100
ZERO chatter with this setup.
I'll have to keep my eye open for 323i parts! Where did you score yours?
-
I'll have to keep my eye open for 323i parts! Where did you score yours?
I scored the flywheel on bimmerforums, but it was pure luck because someone PM'ed me asking if I wanted one.
The TOB I ordered brand spankin new from Patrick @ BMA Parts.
:)
-
Can you use the dual mass clutch with a single mass flywheel?
-
No, will not fit.
-
Euro 323i throw out bearing: 21517521471
US 325i throw out bearing: 21517521471
US 318is throw out bearing: 21517521471
so, unless realoem is wrong, you dont need to change the bearing, right?
just wanted to mention how much of an idiot i am, as about a month ago there was a 323i at pick n pull, and i didnt even think to pull the flywheel. just throwing that out there.
-
You can just use an m20 starter
I bought a m20 jb racing 8lb flywheel and m20 clutch disk and m3 pressure plate. Should be able to give feedback on the setup soon
-
What about the e21 323i flywheel?
-
are you saying that if you use a single mass m42 flywheel you can use the stock m42 starter and clutch kit. what if you have a/c can you use the single mass fw?
-
yall just jelous of my "euro" canadian non ac single mass :)... it came as a shock to me when i dropped the trans and has a look at a funny little flywheel
(http://i100.photobucket.com/albums/m24/sha1234/DSC02852.jpg)
-
The single mass flywheel works with the twin mass starter. The single mass flywheel uses a different clutch kit and flywheel bolts, however.
-
very different clutch
(http://i100.photobucket.com/albums/m24/sha1234/DSC02849.jpg)
twin mass
(http://i100.photobucket.com/albums/m24/sha1234/DSC02848.jpg)
single mass
(http://i100.photobucket.com/albums/m24/sha1234/DSC02846.jpg)
disks
-
Lmfao that clutch was toast, hope you at least sanded the flywheel down, if not you might as well pull it apart to remove the glaze, and that pilot bearing is clearly dry.
-
ahhaha... the flywheel was machined... and most parts replaced for new
-
so i just picked up my single mass flywheel and clutch.
except mine is off of a 86 325es
the flywheel weighs 24lbs and the clutch kit weighs 14lbs
but after i lighten it it should be good.
now i just need to get the 323i throw out bearing and ill be set
oh yeah and i got it for the best price FREE!!!
-
Sorry for bringing back an old thread but i am trying to find a sprung clutch disk that will fit between an Alum M42 flywheel and M42 dual mass pressure plate.Can someone explain to me why the M42 single mass clutch disk wil not work with an M42 aluminum flywheel and M42 dual mass PP? Is there not enough room for it to spin? If they have the same spline and same dia. then as long as it fits and spins with reasonable clearance then it should work.No?
Thanks
Glen
-
Just for the record, a late model M20 starter will bolt right up... no need to change pinion gears.
-
Just for the record, a late model M20 starter will bolt right up... no need to change pinion gears.
Which year M20 starter is considered a late model? Would you happen to have a part number for the above? Thx!
-
Readily available M20 single-mass flywheels can easily, cheaply, and safely be taken down to 11 pounds. The starter and TOB options are easy!
Of course, there are always other flywheels that have been used with great results. It's up to you if you want to piece the assembly together.
-
So can you use a e30 325i TOB with the m20 flywheel with acceptable results?
-
So can you use a e30 325i TOB with the m20 flywheel with acceptable results?
Yes, but my is with e36 gearbox.
-
Is this worth stickying btw?
-
Is this worth stickying btw?
i can easily do that but would have to get approval from ALL of the mods.
-
I always read through these flywheel/clutch threads but dont know what parts to get, you guys seem to all be 30's and I have an e36 M42, I dont konw what applies and what doesnt. Plus I have A/C and I see that mentioned as well.
I would like to just get a M42 flywheel and grind it down, I would like to keep the starter stock. With the M42 single mass flywheel ground down you can still use the M42 clutch? Or could I upgrade to another pressure plate? I was wondering how the M42 clutch fork function was affected by grinding a good part of the flywheel away.
Or, if I were to actually shell out $600 for a M42 LW FW and I could use M42 stock clutch, which one would I use, the Dual mass clutch or single mass clutch? Im all disoriented now.
-
dual mass flywheel needs a dual mass clutch, ditto with the single mass. They are not interchangeable.
-
Just for the record, a late model M20 starter will bolt right up... no need to change pinion gears.
Not to bring it up from the dead, but will it bolt up to the E36 gearbox? And what year are you considering a "late" model 325? My M20 starter is out of an 88.
-
Not to bring it up from the dead, but will it bolt up to the E36 gearbox? And what year are you considering a "late" model 325? My M20 starter is out of an 88.
I don't know if it will bolt up to the e36 gearbox. Is it different than the e30 one? My starter came off of a 1990 M20.
-
I'm leaning toward the single mass M42 option, but have a couple questions.
If I go the single mass non-ac M42 flywheel, and single mass non-ac clutch M42 kit, will I need different bolts for the flywheel?
-
I decided to Sticky this, lots of good info here.
-
I'm wondering about this myself. I was figuring the non-A/C setup would be the perfect solution. I'll be waiting until my clutch gives up the ghost though.
-
If I go the single mass non-ac M42 flywheel, and single mass non-ac clutch M42 kit, will I need different bolts for the flywheel?
Yes.
-
Is this in reference to a E30 323i or E21 & I'm guessing either way its still the same 323i TOB? As for the clutch does it have to be for a 323 or could a 325 clutch be used as im guessing the 323i has single mass where as the 325 has dual so clutchs would not be interchangeable?
I have a ltw 323i flywheel that weighs roughly 11lbs.
I paid less for the whole deal that the M20 clutch kit.
This by far is the best option because the flywheel is lighter than ALL three you've mentioned. Not sure about cost or availability but I got lucky with my purchase.
323i Flywheel : $75
323i TOB: $63
M20 Clutch: $100
ZERO chatter with this setup.
-
I wasn't sure about that. The e30 323i never came stateside, we got the 325i instead. I assumed that it was the e21 323i or the similar e21 320i/6.
-
I believe the reference is to the same parts I'm using. I've got the parts here in my hands right now:
SM Flywheel from 1979 euro 323i E21 (M20) 11 22 1 264 517
clutch disk for 1990 325i; 21 21 1 223 174 (BavAuto)
pressure plate for 1990 325i; 21 21 1 223 026 (BavAuto)
T.O. B. to fit 'E21 323i; 21 51 1 204 525 (BavAuto)
The pressure plate, disk and flywheel fit together perfectly. As for fit into the car, a few days will tell. The only open question is the need for a flywheel-to-crank spacer. We will measure and see but I believe I can leave it out. I think the TOB was used for several years and spans E21 and some E30. BMWFans shows this TOB being used up to March '84 in the Euro E30 323i.
Here are the other parts I'm using for my 1991 318is flywheel conversion:
flywheel bolt 28mmlong 11 22 1 717 840
pressure plate bolt 07 11 9 901 023
slave cylinder 21 52 1 116 300
alignment tool BavAuto CA83 (see note below, yours may vary)
pilot bearing 11 21 1 720 310 (BavAuto) (see note below, yours may vary)
rear engine seal 11 14 1 706 785 (BavAuto)
locating dowel 11 11 1 743 118 (Pelican)
exhaust gasket 18 30 1 711 969 (Pelican)
exhaust nuts 18 30 1 737 774 (Pelican)
Starter from 1989 325iX (Bosch), rebuilt
I'm not sure why the previous poster claimed his flywheel was 11 lbs. Perhaps this was an estimate, or perhaps it has been lightened, but I weighed my flywheel and it came in at 13.6 lbs not including any bolts or spacers. After resurfacing I weighed it again and it is now 13.4 lbs.
There is a metal spacer that came with the flywheel ((pn 11 22 1 262 827). On the E21 it was between the bolt heads and the flywheel (also shown on realOEM/BMWfans diagrams). I note that many photos of M20 flywheel conversions into 318s show that installers don't include this spacer. I'm not sure why not, since it is a standard part used with all M20 SM flywheels as far as I can tell. I will re-use that spacer as well in my installation. It affects the depth to which the flywheel bolts penetrate, so is worth a mention.
Update: it turns out that the pilot bearing listed above (plus alignment tool) was wrong for my car. Further study of BMWfans shows that the Getrag 240 transmission input shaft diameter changed in Sept '90 production from small (12mm) to large (15mm). I bought the 15mm one (above) but in fact should have got the 12 mm one: 11-21-1-709-681 Your requirement will depend on production date.
update: the rear engine seal mentioned in the parts list above did not get used for two reasons. The mechanic did not trust the part delivered as he was not familiar with the brand, plus it turns out my rear main seal was not leaking after all. It was transmission oil that was splashed all over the place and dripping onto my garage floor. What a mess, on the clutch too. Transmission sent out for repair.
-
Keep us posted...I'm unsure what I have going on in there, but I'll be sure to check this out when mine taps out.
-
Kl its nice to know im not on my own with this I've PM'd "dude8383" to see if he can shed some light. Even 13.4lbs is still alot lighter than the m20 unit and should make for a good revvy base in an e30 as I done the M20 conversion to an E36 about a year ago and even on the much larger car it was very noticeable.
Also some people have been saying that the later 325i starter will fit without modification which i did not find to work last time, I think it was from a 1990/91 so does anyone have any more info on this or part numbers??
-
Kl its nice to know im not on my own with this I've PM'd "dude8383" to see if he can shed some light. Even 13.4lbs is still alot lighter than the m20 unit and should make for a good revvy base in an e30 as I done the M20 conversion to an E36 about a year ago and even on the much larger car it was very noticeable.
Also some people have been saying that the later 325i starter will fit without modification which i did not find to work last time, I think it was from a 1990/91 so does anyone have any more info on this or part numbers??
I've been told that without question the M20 starter just bolts right in, however with all things the devil may be in the details. I have found one poster who claimed it must be a Bosch brand starter. It seems that in the US we mostly see the Bosch starter but there have been other brands used so fitment may vary. I was also told the starter had to be from a late model 325 (experience quoted was from 90 or 91). The BMW pn for the starter hasn't changed from 87 to 91 (per BMWFans), but who knows if this is dead accurate.
I thought previously that the difference in starters had to do with electrical hookup, not mechanical fit. Yours is the first comment I've seen that mechanical fit was an issue.
I received assistance from KenCopperwheat and dude8383 in sourcing the right parts.
-
I have a late model 325i downstairs, and an earlier 325. When I do my swap I'll verify fit and part numbers. Just waiting on a cheap lift to appear on Pittsburgh CL...
-
I have a lightweight M20 single mass in my car and I weighed it at 10.75-11 lbs. It is possible. I will also have 2 or 3 lightweight single mass M20 flywheels for sale shortly just like mine. These bolt right in with no problem. I'll post when I'm ready. If 2 or 3 people are interested let me know now. I still need to figure out a price.
I think that mine was a '87 or '88 325i clutch kit and new flywheel bolts. You retain the M42 starter.
-
I have a lightweight M20 single mass in my car and I weighed it at 10.75-11 lbs. It is possible. I will also have 2 or 3 lightweight single mass M20 flywheels for sale shortly just like mine. These bolt right in with no problem. I'll post when I'm ready. If 2 or 3 people are interested let me know now. I still need to figure out a price.
I think that mine was a '87 or '88 325i clutch kit and new flywheel bolts. You retain the M42 starter.
id be interested. hell id even drive to pick it up. gives me a excuse to come with in range of AC. plus i have some friends in the belmarw/neptune area i havnt seen in years :(
-
Could a 325e clutch and pressure plate work or does it have to be a 325i??
-
.
-
Could a 325e clutch and pressure plate work or does it have to be a 325i??
I tried to figure this one out just by looking at part numbers and found it confusing. Pelican Parts (whose website makes browsing quite easy) shows 3 different clutch disk part numbers depending on production dates, with changes occurring on Aug/Sept 85 and April/May 86. BMWfans shows 4 disk part numbers, with changes on Sept '85 and May '86 which agrees with Pelican. But they also show an additional part number with the designation For Vehicles with: 325 (V002A) = Yes. I don't understand this note at all.
It is this last part number that matches what Pelican is actually offering for the 325i, which implies that later 325e with SM flywheel could indeed use the 325i disk.
Now, looking at the pressure plate part numbers on BMWfans, there is a change at May 1986, with different pns before and after. Pelican shows the same pressure plate for 325e up to April '86 as is used in the 325i. I get the impression that this date, April '86/May '86 is when the 325e changed from single mass to dual mass flywheel.
Not sure if any of this helps, but bottom line is to find someone who has hands-on experience with your year of car for the final word.
-
This is an update on my flywheel conversion project. Previous info is in post#42 of this thread.
The car is back on the road and working smoothly. The clutch pedal feels exactly right, engagement and disengagement is perfectly smooth with no issues. There is zero noise, like chatter for example, during idle or any other time. The starter works perfectly with no issues. My idle is very smooth, perhaps slightly better than it used to be, but that may be my imagination. So there seems to be no drama and no issues after installation.
To be clear, I did not do the install, my favorite BMW independent shop handled it. If there were issues, I would have heard about them.
Now, as far as improvement to the car is concerned, I was not blown away, but it was better, no question. It is safe to say that my expectations, after many months of preparation and reading other's comments, got a bit too high. I was expecting a major difference in the speed at which the engine changes revs between shifts, and I was expecting a big change in the feel of acceleration in first and second. These expectations were wrong.
On my first drive with the new setup, there is no question the car feels lighter and livelier accelerating from a stop. So the improvement is obvious, just not as big as I was hoping. I expected to have to relearn how to drive due to the light flywheel spinning down much faster between shifts, but its not like that. Sure, it spins down noticeably faster, but not dramatically so, and adapting to it was so easy that it happened subconsciously with no effort at all. Some posters have described the change as "waking up" the car. Yes, that is a good description. But it doesn't "transform" the car.
I notice that I can re-engage the clutch on up-shifts just a bit quicker as the rev-matching happens just a bit quicker. That is a definite grin generator.
So, my advice to those E30-M42/318is owners who want to go to a lighter flywheel...don't be afraid of using a 13.5 lb M20 flywheel (along with the M20 clutch plate and disk) as this weight is clearly fine for street use. So much so that I wonder why they didn't fit this sort of thing in the factory those many years ago.
-
So I found the easy way for me. They have a thread in this forum. here, dynotech motorsports (http://m42club.com/forums/showthread.php?t=7731&highlight=dynotech+flywheel)
emailed
http://www.dynotechonline.com
complete kit ran me $535
12 lb lightened M20 flywheel (with M42 starter ring gear)
325 clutch kit
shorter flywheel bolts
longer slave cylinder push rod
They have the all in one solution and cost wasn't bad in my book.
(http://img339.imageshack.us/img339/7352/dsc05768s.jpg)
(http://img179.imageshack.us/img179/1415/dsc05767v.jpg)
:D
-
This is an update on my flywheel conversion project. Previous info is in post#42 of this thread.
The car is back on the road and working smoothly. The clutch pedal feels exactly right, engagement and disengagement is perfectly smooth with no issues. There is zero noise, like chatter for example, during idle or any other time. The starter works perfectly with no issues. My idle is very smooth, perhaps slightly better than it used to be, but that may be my imagination. So there seems to be no drama and no issues after installation.
To be clear, I did not do the install, my favorite BMW independent shop handled it. If there were issues, I would have heard about them.
Now, as far as improvement to the car is concerned, I was not blown away, but it was better, no question. It is safe to say that my expectations, after many months of preparation and reading other's comments, got a bit too high. I was expecting a major difference in the speed at which the engine changes revs between shifts, and I was expecting a big change in the feel of acceleration in first and second. These expectations were wrong.
On my first drive with the new setup, there is no question the car feels lighter and livelier accelerating from a stop. So the improvement is obvious, just not as big as I was hoping. I expected to have to relearn how to drive due to the light flywheel spinning down much faster between shifts, but its not like that. Sure, it spins down noticeably faster, but not dramatically so, and adapting to it was so easy that it happened subconsciously with no effort at all. Some posters have described the change as "waking up" the car. Yes, that is a good description. But it doesn't "transform" the car.
I notice that I can re-engage the clutch on up-shifts just a bit quicker as the rev-matching happens just a bit quicker. That is a definite grin generator.
So, my advice to those E30-M42/318is owners who want to go to a lighter flywheel...don't be afraid of using a 13.5 lb M20 flywheel (along with the M20 clutch plate and disk) as this weight is clearly fine for street use. So much so that I wonder why they didn't fit this sort of thing in the factory those many years ago.
You should really consider pairing this up with a chip. I have to admit when I did this swap for a friend of mine (achtungE30) I noticed that it didn't feel like my car did.
So I found the easy way for me. They have a thread in this forum. here, dynotech motorsports (http://m42club.com/forums/showthread.php?t=7731&highlight=dynotech+flywheel)
emailed
http://www.dynotechonline.com
complete kit ran me $535
lightened M20 flywheel (with M42 starter ring gear)
325 clutch kit
shorter flywheel bolts
longer slave cylinder push rod
They have the all in one solution and cost wasn't bad in my book.
http://img339.imageshack.us/img339/7352/dsc05768s.jpg
http://img179.imageshack.us/img179/1415/dsc05767v.jpg
:D
That sir is AWESOME. I'm glad someone is offering a whole kit now. What does the flywheel weigh?
-
You should really consider pairing this up with a chip. I have to admit when I did this swap for a friend of mine (achtungE30) I noticed that it didn't feel like my car did.
Do you mean that your car feels better or his does? What are the important differences between the two?
I wonder how yours and mine would compare? I already had the DySylva EAT chip for 93 octane installed, so my car was already pretty lively before the swap. One other thing I did at the same time as the FW swap was to replace a 4.10 open diff with a 4.27 LSD. I wonder if the limited slip diff is slightly more lossy. Wanna race?
I did a dyno run before the swap, and we measured 125HP and 115 ft-lbs at the wheels, so it was healthy. Now it is noticeably livelier again.
-
Well the car in my signature doesn't have an m42 but my old red car did.
The main difference between my old car and his old car was that he didn't have a chip and mine did. It just didn't feel as sluggish anymore. It's hard to describe the feeling b/c it's been nearly 3yrs since I took the red one apart.
I drove the car with a stock flywheel for 2yrs and to me it was a big improvement when I installed the lighter flywheel and chip.
A 4.27 lsd will definitely make things a bit more interesting but you'll probably experience some discomfort when driving on the highway b/c of the higher rpm's. If the car is mostly a toy and see's the track more often, then this is an excellent upgrade.
Those are pretty strong numbers for a little m42b18 :D Even though I've long since moved over to the 2.5l 24v engine, I still have a soft spot for m42's. In fact when I have more time than I know what to do with, I will build myself a little stroker!
Do you mean that your car feels better or his does? What are the important differences between the two?
I wonder how yours and mine would compare? I already had the DySylva EAT chip for 93 octane installed, so my car was already pretty lively before the swap. One other thing I did at the same time as the FW swap was to replace a 4.10 open diff with a 4.27 LSD. I wonder if the limited slip diff is slightly more lossy. Wanna race?
I did a dyno run before the swap, and we measured 125HP and 115 ft-lbs at the wheels, so it was healthy. Now it is noticeably livelier again.
-
That sir is AWESOME. I'm glad someone is offering a whole kit now. What does the flywheel weigh?
Edited post, 12 lbs
-
I tried to figure this one out just by looking at part numbers and found it confusing. Pelican Parts (whose website makes browsing quite easy) shows 3 different clutch disk part numbers depending on production dates, with changes occurring on Aug/Sept 85 and April/May 86. BMWfans shows 4 disk part numbers, with changes on Sept '85 and May '86 which agrees with Pelican. But they also show an additional part number with the designation For Vehicles with: 325 (V002A) = Yes. I don't understand this note at all.
It is this last part number that matches what Pelican is actually offering for the 325i, which implies that later 325e with SM flywheel could indeed use the 325i disk.
Now, looking at the pressure plate part numbers on BMWfans, there is a change at May 1986, with different pns before and after. Pelican shows the same pressure plate for 325e up to April '86 as is used in the 325i. I get the impression that this date, April '86/May '86 is when the 325e changed from single mass to dual mass flywheel.
Not sure if any of this helps, but bottom line is to find someone who has hands-on experience with your year of car for the final word.
Yeh too confusing but cheers anyway
Does anyone know the difference between the 325 clutch and the 320/323 part as i've found this but unsure if there is a difference in fitment or would I be correct in assuming the pressure plate is weaker/softer??
its listed as:
FITS BMW E30 320i 323i 1983 TO 1991
228mm DIA PLATE
Any help would be appreciated and my apologies for keep asking random questions about the clutch but the cheepest i can find a 325 cluch near me is nearly £200!!!! as i already have a barely worn in stage 1 cluch i dont want to throw nearly £600 down the drain for a mod that I've done before and have had good results but not worth that sort of cash and also cant afford trial and error approach.
-
I just bought the used single mass m42 flywheel off of the classifieds here and I was wondering if anyone knows the lowest weight I can have it machined down to. Going through this thread I saw 13 pounds, is that what I should do?
-
Easiest way:
M20 flywheel, mill down the engine side of the flywheel a bit to get clearence
M20 starter
M20 flywheel bolts (dont forget the big spacer between the flywheel and bolts!)
M20 clutch
Done!
-
M42 single mass advantages:
Lighter weight over the dual mass unit and just as light as the M20 conversion.
Use factory M42 starter with no modifications
Use factory clutch kit complete
Uses factory length flywheel bolts
All parts readily available.
Disadvantage:
Cost involved in acquiring single mass flywheel
====================================
Are you sure that the M42 single mass uses the same length flywheel bolts?
http://www.realoem.com/bmw/showparts.do?model=BE51&mospid=47425&btnr=11_1151&hg=11&fg=20
realoem shows 2 lengths 25 and 50mm
In other words: are the M42 single mass flywheel and clutch kit the only needed parts for the swap?
I am interested in this setup because in europe it is not a problem finding the M42 single mass at junk yards.
-
The single mass flywheel uses shorter flywheel bolts.
-
Was just quoted $600 for the DynoTech kit if anyone was still interested in that. Looks like a good kit, and the price seems to climb up every month. Still look like it's worth it to you guys? I'm hard-pressed for time these days, and as much as I'd enjoy the search to piece everything together on the cheap, it's near impossible, so I'm thinking of going for this kit. Opinions or suggestions?
-
I am interested in this setup because in europe it is not a problem finding the M42 single mass at junk yards.
How common are the M42 single mass flywheels? I'm thinking that this is the best option, even though it's smaller in diameter.
-
Was just quoted $600 for the DynoTech kit if anyone was still interested in that. Looks like a good kit, and the price seems to climb up every month. Still look like it's worth it to you guys? I'm hard-pressed for time these days, and as much as I'd enjoy the search to piece everything together on the cheap, it's near impossible, so I'm thinking of going for this kit. Opinions or suggestions?
What clutch are they quoting?
-
i badly need a clutch too!
a year or two ago i wanted to get (e21) 323i flywheel as someone else on here did. but what clutch kit do I need with that, 323 or m20 (325i)
and would a 325i starter still work with that. i'm confused as hell :confused:
pelican parts catalog is further confusing me. i won't shop there again but they had reliable info..
-
i badly need a clutch too!
a year or two ago i wanted to get (e21) 323i flywheel as someone else on here did. but what clutch kit do I need with that, 323 or m20 (325i)
and would a 325i starter still work with that. i'm confused as hell :confused:
pelican parts catalog is further confusing me. i won't shop there again but they had reliable info..
Yes indeed, it is very confusing. My experience is that for the E21 323i flywheel (which is what I used) the M20 clutch kit is a perfect fit. See my list of part numbers in post #42 of this thread for details.
I also used a starter from a 325i, in fact a 325ix, and it fit correctly.
-
What clutch are they quoting?
It's the OEM Sachs M20 clutch with the rest of the bits above.
-
It's the OEM Sachs M20 clutch with the rest of the bits above.
Thanks!
-
http://store.bimmerworld.com/e30-325i-lightweight-flywheelperformance-clutch-kit-p1071.aspx
Would the BimmerWorld E30 325i JB Lightweight flywheel and Clutchmasters clutch work? It's $750 for both. How much lighter is the JB lightweight flywheel?
-Scott
-
Is this in reference to a E30 323i or E21 & I'm guessing either way its still the same 323i TOB? As for the clutch does it have to be for a 323 or could a 325 clutch be used as im guessing the 323i has single mass where as the 325 has dual so clutchs would not be interchangeable?
I cannot find any reference to a E21 or E30 323i at Pelican or RockAuto. Does anyone have the part number for the lighter 323i flywheel? Is it available in the states?
-Scott
-
For some reason I cannot find any reference to a E21 or E30 323i. Does anyone know the part number is for the 323i flywheel? Or better yet, a link to one I can buy in the US.
-Scott
-
Hi,
I have a spare M40 single-mass flywheel & clutch set (from my previous broken-down engine). Currently I run a M42 and I don't know what type of flywheel is in. Since they differ by only 2kg I want to lighten it anyway. Following bmwfans.info M42 single-mass FW is the same as M40's. According to this topic, If I find dual-mass in my car I should be able to fit lightened M40's FW right away. Am I right? Is it safe to go ~40% lighter in BMW?
-
great info..
-
Here's a pair (http://shop.ebay.co.uk/i.html?rt=nc&Manufacturer=BMW&_nkw=m40%20flywheel&_dmpt=UK_CarsParts_Vehicles_CarParts_SM&_fln=1&_sc=1&_sop=1&_ssov=1&_trksid=p3286.c0.m282) of cheap M40 single mass used clutches for sale right now. Post might be expensive over the pond, the TOBs seem AWOL and I'm not too sure of condition.
-
For some reason I cannot find any reference to a E21 or E30 323i. Does anyone know the part number is for the 323i flywheel? Or better yet, a link to one I can buy in the US.
-Scott
Scott, you'd be okay with the stock 325i TOB as well. I'm running this exact setup on my white 318i and haven't had a single problem.
-
How common are the M42 single mass flywheels? I'm thinking that this is the best option, even though it's smaller in diameter.
It's very common. I estimate about 50% of the IS'es in europe do not have A/C and do have the single mass flywheel.
-
I'm about to try this conversion. But where does the spacer go? The one that is on the m42 dual-mass flywheel which you take off by drilling through the rivets.. and then using on the m20 single mass setup.
Also, what transmission oil does everyone recommend again? :-)
-
I'm about to try this conversion. But where does the spacer go? The one that is on the m42 dual-mass flywheel which you take off by drilling through the rivets.. and then using on the m20 single mass setup.
Also, what transmission oil does everyone recommend again? :-)
Easiest way:
M20 flywheel, mill down the engine side of the flywheel a bit to get clearence for oil pan
M20 starter
M20 flywheel bolts (dont forget the big spacer between the flywheel and bolts!)
M20 clutch
Done! (works 100% on single mass M42, not sure about dual mass)
-
so much work to convert to single mass,rather just keep my dual mass.
-
The flywheel x-ref at RealOEM only includes one USA model...the early 318is until 3/90. Here's the diagram. (http://www.realoem.com/bmw/showparts.do?model=AF93&mospid=47305&btnr=21_0020&hg=21&fg=05) Though it's likely a dealer-only item and smaller than the M20 unit, it's plug & play. I have no need for the larger 228mm clutch though.
So I've been thinking about doing it with the M40 parts myself. From what I've seen, the correct parts are:
21 21 1 223 569 (http://bmwfans.info/parts/catalog/E36/Touring/Europe/316i-M43/LHD/M/browse/?search=21211223569&date=true) (refurb clutch assembly - Pelican lists it for $138 before shipping & 20% BMW overseas order fees)
Here's a LUK kit for $104. (http://www.partsgeek.com/catalog/1991/bmw/318i/clutch/clutch_kit.html)
11 22 1 739 315 (http://bmwfans.info/parts/catalog/11221739315/) (single mass flywheel - Pelican lists that for $404. I'd get it used, definitely)
Looks like Valeo finally released their dual-->single mass conversion kit too. $739 is pretty steep, but it has all the goodies (http://www.partsgeek.com/catalog/1991/bmw/318is/clutch/flywheel_conversion.html). Google "DMF Conversion Kit" & you'll see if it's a good fit for you. I've seen it for less, apparently it's the same kit for the M44 & M52 in the e36 & Z3. Still, that's like what my car is worth...it's a tough decision. :rolleyes:
Needs short bolts too, and I'm not sure if the M43 fork, anti-rattle spring & TOB are the right ones though since they fit the e36 transmission. The M40/M42/M43 with a single-mass flywheel was installed in all kinds of cars. I'm thinking it should be pretty easy to come by.
-
Why would you get that Valeo junk kit for $739!? That's made for profiting off people about to buy a NEW OE dual-mass flywheel (http://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=21-21-1-223-550-M37&catalog_description=Dual-Mass%20Flywheel%2C%20E30%20318i%20M42%2C%20318iC%2C%20For%20cars%20with%20Dual%20Mass%20Flywheel) replacement, and figure this kit will save them some money.
Used e21 323i or e30 325i m20 flywheel = $10-100 used
87-91 325i starter used from junkyard = $30 ish or rebuilt for ~ $100
From 325i/is/ic (1987-91)
Pressure Plate, w/o dual-mass flywheel (http://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=21-21-1-223-026-M38&catalog_description=Pressure%20Plate%2C%20w%2Fo%20dual-mass%20flywheel%2C%20325%2Fe%2Fes%20%281984-04%2F86%29%2C%20325i%2Fis%2Fic%20%281987-91%29%2C%20Each) = $82
Clutch Disc, 228mm, w/o dual-mass flywheel (http://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=21-21-1-223-671-M38&catalog_description=Clutch%20Disc%2C%20228mm%2C%20w%2Fo%20dual-mass%20flywheel%2C%20325i%2Fis%2Fix%2Fic%20%281987-91%29) = $107
Throw-out bearing from a 318i (1984-85), 318i/is/iC (1991), 325/e/es/i/is/iC/iX (1984-91), M3 (1987-91)
http://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=21-51-7-521-471-M38&catalog_description=Throw%20Out-Bearing%2C%20318i%20%281984-85%29%2C%20318i%2Fis%2FiC%20%281991%29%2C%20325%2Fe%2Fes%2Fi%2Fis%2FiC%2FiX%20%281984-91%29%2C%20M3%20%281987-91%29 or a e21 323i (http://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=21-51-1-204-525-M38&catalog_description=Throw%20Out-Bearing%2C%20323i%20European%20Models%20Only%20%28through%202%2F84%29%2C) = $43 vs $71
or just get the clutch kit (http://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=21-21-1-223-102-M38&catalog_description=Clutch%20Kit%2C%20325i%2Fis%2FiC%20%281987-91%29) = $240
Plus the bolts (http://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=11-22-7-805-885-M9&catalog_description=Flywheel%20Bolt%2C%2012x28mm%20%288%20per%20car%2C%20sold%20individually%29%2C%20325%2Fe%2Fes%20Manual%20Trans.%20%28through%204%2F86%29%2C%20325i%2Fis%2FiC%2FiX%20%281984-91%29), etc..
By the way, http://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=11-22-1-739-315-BOE&catalog_description=Flywheel%2C%20E30%20318i%2Fis%2Fic%20%281990-91%20Only%29%20For%20cars%20without%20Dual%20Mass%20Flywheel
"Quantity in Stock: 1"
-
IDK if I'd call Valeo "junk." I've used they're stuff on occasion, seems well enough made. They're economical, though not up to the reputation of first class suppliers like Sachs/Bosch/Hella/etc. I'm sure that could be found for less $$$ too. I thought the dual-mass was a LuK-designed (http://www.luk.de/content.luk.de/en/products/clutch_systems_new/zms_new/zms_new.jsp) product? I don't trust them yet.
I'm thinking this is a really good choice if you'd prefer that your mechanic installs it. Clutch swaps aren't for everybody...It's a bolt-in kit, all new parts, with a warranty to boot. Any reputable mechanic or dealer will put it in right the first time & likely stand behind their work.
That link you sent made me start thinking though...(never a good thing)...if the e28's use the same TOB, I'll bet the whole clutch would be similar. Sure the e30's are more common, but if an e28 was a one-stop-shop for all the parts that might be even cheaper!
***edit*** remove that thought. A new e28 flywheel by itself at Pelican is $840. Ouch. Looks like it's mostly the same as an early e30 M20 eta setup.
-
i rather use Valeo "junk instead of conversion thing. gotta pay to play you know what im saying mannnnggg.
-
I didn't mean Valeo is junk, just that kit :-)
You can get a brand new aluminium flywheel from JBR, Ireland Racing, etc for the m42 or m20 for $400-650. Sachs clutch kit is $200-240. That's almost the same total price as Valeo but much lighter. Or you could order an OE single-mass m42 flywheel (http://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=11-22-1-739-315-BOE&catalog_description=Flywheel%2C%20E30%20318i%2Fis%2Fic%20%281990-91%20Only%29%20For%20cars%20without%20Dual%20Mass%20Flywheel) for $400 (special order from Germany).
-
Does one have to ballance the flewheel after lightning it? Do flywheels come ballanced from the factory?
-
Does one have to ballance the flewheel after lightning it? Do flywheels come ballanced from the factory?
Yes, they must be balaced and comes from factory balanced.
-
I regret using e21 323 throw-out bearing on this conversion. Should of used 318/325 e30, saved ~$30 and had longer engagement which I like. Now if I put my foot on the clutch pedal while driving I burn the clutch.
-
Why you would be riding the clutch pedal anyway? You're only really supposed to have your foot there for shifting...
-
i have done a similar thing, got an m40 flywheel and an m40 clutch kit, everything fitted fine. can you guys get an m40 flywheel over there? I think the non air con m42s in US came with a single mass flywheel
-
The M40 flywheel is the same as the M42 non-AC flywheel, which I fitted in my car. I was able to find a brand new one that somebody was selling, but as a rule they'd have to be special ordered.
-
I swapped m20 flywheel on my E36 m44 engine and i have rattle on idle. It's annoying a little but I will try different gearbox before trying to ignore this sound. :) No any rattle I have with same setup on my E30 M42, but without power steering anf A/C. My E36 m44 gearbox seems is in good condition, but probably I will try to swap it to newer E46 gearbox, or probably before I will try to check oil level....
-
Okay since I'm doing the m42 single mass swap, and haven't really seen many pics/evidence of this swap, I figured I should post my experiences.
Here's just the flywheel for now, stock, full weight straight from Germany.
(http://i987.photobucket.com/albums/ae356/balleristic31/photo-11.jpg)
Note: m42club has the m42 single mas weighs in at 22lbs , notice the actual weight.. :)
-
Update: got my clutch in from partsgeek.com. It was 107 shipped to my door and the brand was Luc. Came with tob, clutch alignment tool, and pilot bearings. Along with the clutch and pp of course. this brings my total cost so far to $257
I weighed the assembly as a whole an it came out to 32.5 pounds :) 20% less weight compared to dual mass setup. Tomorrow I get the flywheel lightened and balanced with the clutch :D
(http://i987.photobucket.com/albums/ae356/balleristic31/photo-14.jpg)
-
I used a special scale which gave weight 9.6kg. I am currently doing a special wheel for Keith. We are going to get it about 8Kg. It needs to be done with special way; just milling it normal way will drop the weight about 500g. I had one wheel done with that way and got it balanced as well. Friend will re-program his CNC machine differently, so we can do it more radical way.
These wheels can be easily found here since it was used also with 316I & 318I with M40 engines. Btw, does dual mass flywheel starter work with M40/M42 singlemass flywheel ? If not, then i must put a euro M42 starter to Keith's package.
-
I think we're good as far as starters go. BMW used the same one in several cars and markets. Part number 12411735524 superceded 12411715238 and cross-references to these models respectively:
http://www.realoem.com/bmw/partxref.do?part=12411735524&showus=on&showeur=on&details=1
http://www.realoem.com/bmw/partxref.do?part=12411715238&showus=on&showeur=on&details=1
-
Yes, M42 dual-mass starter works with M42 single-mass flywheel.
-
bloody hell this is confusing!!! people saying you need the stock spacer, people saying you need a 3mm spacer, people saying just use the 325i TOB you will be fine....
Anyway my question.
325i single mass (assuming its not 323i as its heavy), spacer drilled off the m42 one, 325i single mass clutch kit, could i just use a longer slave? and do any m20 cars have a longer one? or will it work just fine like the nisse bloke said? theres about 6mm difference between the two throw out bearings.
and with the use of the spacer, wouldnt you worry about it not being perfectly flat and putting the flywheel on a slight angle?
**edit**
never mind, i did further research and now have a better understanding of the topic. i will measure the distance from crank face to the top of the pressure plate thingos to see how far out it will be and wether it needs a 323 TOB or not. will also try to avoid spacing the flywheel out.
-
Here is another comparison after further research on BMW ETK software
E30 318i M40 Euro 5speed Getrag 240 with A/C, manufactured June 1990
Single mass flywheel p/n 11211739315 – 9.900 kg weight
Set clutch kit (inc. clutch cover, clutch disc & release bearing) p/n 21211223569 – 5.580 kg weight
Clutch disc p/n 21211223566 – 1.262 kg weight
Clutch release bearing p/n 21517521471 – 0.220 kg weight
Clutch release fork lever p/n 21511204229 – 0.515 kg weight
Starter motor p/n 12411735524 – 3.600 kg weight
E30 318is M42 Euro 5speed Getrag 240 with A/C, manufactured June 1990
Twin mass flywheel p/n 21211233550 – 12.250 kg weight
Set clutch kit (inc. clutch cover, clutch disc & release bearing) p/n 21211223571 – 5.036 kg weight
Clutch disc p/n 21211223492 – 0.834 kg weight for twin mass flywheel
Clutch release bearing p/n 21517521471 – 0.220 kg weight
Clutch release fork lever p/n 21511204229 – 0.515 kg weight
Starter motor p/n 12411735524 – 3.600 kg weight
Twin mass flywheel + clutch kit for E30 318is M42 Euro = 12.250 + 5.036 = 17.286kg
Single mass flywheel for E30 318i M40 Euro = 9.900 + 5.580 = 14.580 kg
Weight savings = 2.706kg
It is also interesting to note that:
1) Clutch release bearing, clutch release fork & starter motor for E30 318i M40 Euro is similar with E30 318is M42 Euro
2) The heavier weight of twin mass flywheel in E30 318is M42 Euro is compensated with the lighter clutch disc of E30 318is M42 Euro
Thus, to simplify the idea of converting twin mass flywheel on E30 318is M42 Euro 5 speed Getrag 240 manual trans with A/C, just swap using single mass flywheel from E30 318i M40 Euro 5 speed Getrag 240 manual trans with A/C together with the clutch kit.
No need to change the clutch release bearing, clutch release fork lever and starter motor
-
That's the way I'd been thinking it should be, but it's a trade-off. Euro SM flywheels are expensive & difficult to locate secondhand. Late model M20 flywheels take a lot more torque with the additional benefit of being cheap & common.
I was curious, so I went down & weighed an old clutch. This one is the old-style M20, with a slightly used clutch disc. Including the flywheel, spacer, pressure plate, clutch plate & bolts it came to 35lb 3oz (16 kg). My weight includes bolts but not the release bearing, and your quoted weights might include packaging materials. So it's not apples-to-apples, but it's in the ballpark. The M20 is far stronger and still weighs 1.25kg (almost 3lb) less than the stock DM clutch.
I wonder how much metal can easily be removed from the M40 SM FW?
-
Here we go again..........I have used the M20 FW and stock 325 TOB with No issues whatsoever. I lightened the M20 to about 11lbs or 12lbs.
Just my .02
Cheers,
~Ralph
-
Has anyone used an m40 solid and how does it compare weight and durability wise?
-
The M40 single mass is the same as the M42 single mass.
No problems with it in 4 years. Though the idle drops a bit low when the AC is on and I'm traveling slow (like <5mph) and then take my foot off the gas. I just have to clutch in more quickly than before. That's all.