M47 crank + custom pistons, rods, etc.

[Febi Guibo]

we're getting there...

At present, I don't have a lot of information, but the bottom end of my long-awaited 2.1L M42 is coming together.

As you may have figured out by now, I don't know so much about cars, but I am at least getting better at posting pictures:

http://m42club.com/fotomat/febi/crank_woodruff.jpg
http://m42club.com/fotomat/febi/bottom_end.jpg


Last little tidbit... for you european guys, it turns out that BMWs M47 diesel engine was used on some 'Rover' brand cars... so if you're cruising the pick-n-pulls, it might be a source for a stroker crank.

[asubimmer]

wow I can't wait to see it man, if you don't mind me asking what kinda ball park is this gonna cost?

[Febi Guibo]

well charlie... let's just say "the pioneers take the arrows..."

seriously, I'm not like... proud of modding via checkbook, but my expertise building up an engine is really limited (having completed 75% of a rebuild doesn't really cut it), plus with my current capabilities (time, space, tools, + equipment) are... also limited.

Anyway, hopefully we'll learn a little something as a group, even if I wind up with the mother of all white elephant projects.

--

Actually... this is sort of interesting re: your turbo project. I decided to go N/A because I have like, no experience working with turbos, and the one car I've had with a turbo (saab) was less than, um, super 'exciting'. But it may turn out that it's more cost-effective/better to do a very buttoned-up lower compression M42 build, and then turbo it, then to do a very fault-intolerant, high compression, high rev N/A build.

[asubimmer]

well what about a 2.1L turbo m42!! haha well when i get this done we can talk about it. I would be more than happy to help you out w/ it.

[e9nine]

Giggitty giggity...is the mechanic working on this your buddy or are you paying *full pricing*? Is it safe to assume you're going all out with this or you're gonna do it in stages?

[Febi Guibo]

I'm having an engine builder do it all at once...

initially, I was going to buy the parts, have the crank machined and porting work done on the head, and then assemble it... but good sense got the better of me. even still, this is only a start... ugh!

[e9nine]

A few more questions:You gonna do any headwork, any intake/breathing mods, will you do the m20 flywheel mod, what are you doing for engine management and exhaust work (i.e. high flow cat and dia. piping)

You do know we all have our eyes on you and will be eagerly reading your updates :D

Hopefully you pull through all of this at a rapid pace and will be rolling around with m42 power that no one else has :cool:

[Febi Guibo]

har...

The major stuff at this point is all the internals, so in a way, it will be done in stages. Stroked to 2130cc, diesel crank, custom pistons, carillo rods, smaller valves, beehive springs, everything is getting balanced, flow work for the head, lightweight flywheel... and cams... and bigger injectors.

I haven't come to a conclusion re: the cams yet, but they might be around 254 degrees or so.

A lot of the bolt-on stuff: exhaust, intake, MAF, computer will have to come later, although I'm having a chip burned to get me by until I can really feel the engine out and learn more about megasquirt or other systems (eg: help!!)

anyway, mechanically / god willing, this will be a great platform to carry through the life of the car (or multiple cars... haha). My car is running fine now, but a rebuild is going to happen sooner than later and, after all... I love the M42!!

[1991318is]

Wow, I'm jealous of u getting to do that build. I wanna build another motor so bad, but need to slow down as my wallet is still messed up from the last build i did. Those rods look awesome, those H beam ones are so freaking strong, I love those style. Good luck w/ the build, I'm definately watchin to see how it turns out for u and possibly I will follow w/ the idea.

Brendan

[nickmpower]

what all needed to modified on the crank?

[StreetSpec_iS]

awesome mate!!!! good to see this come through from someone 'closer to home' than the gizmo guy. keep us posted man.

i'm assuming the 'rover' connection is the Land Rover Freelander like we got over here. if so, awesome.

[dude8383]

:eek:

JEALOUS.

that is all

[Febi Guibo]

well... denis... ain't nuthin' to be jealous of...

- you've got your youth...

- I have a crank from a 4-cyl diesel engine
(that hasn't been in a new car for like, over 10 years)...

[shellback]

Any one of these M47 equiped cars can be used?

http://www.bmwinfo.com/23480.html

I have to ask, and please forgive me, but how much is one of those cranks?
Pistons?

Thanks,
Chris

[kowalski]

well what about a 2.1L turbo m42!! haha well when i get this done we can talk about it. I would be more than happy to help you out w/ it.

thats what iv been thinking.. im heading to europe on the 24th and if i can find a crank, well then :) the fun will begin.

[christophbmw]

I have to ask, and please forgive me, but how much is one of those cranks?
Pistons?

Thanks,
Chris
new they cost $990 check it out:
http://www.realoem.com/bmw/showparts.do?model=AT72&mospid=47655&btnr=11_3314&hg=11&fg=20
....thats all i could find.

[nickmpower]

thats what iv been thinking.. im heading to europe on the 24th and if i can find a crank, well then :) the fun will begin.

hook a brotha up!!!!!!!

[kowalski]

hook a brotha up!!!!!!!

ill be buying as many things as i can afford/find/carry
smoked elips
m47 cranks:)
whatever else i can stumble upon.

pm me if your lookin for anything particular (nothing unreasonably, i can't bring body kits back)

[Eurospec]

I have big plans for the carYou weren't kiddin' :)

Best of luck!

[1991318is]

I have a crank from a 4-cyl diesel engine
(that hasn't been in a new car for like, over 10 years)...

Atleast it didn't have spun bearings, that'll create a nightmare on the wallet with that grind, if they could even salvage the crank.

new they cost $990 check it out

Ouch, a custom crank for my v8 is like 400 new for a custom forged one. Mine was liek 100 I thnk to have it ground down, but that was after I had the crank. I htink it was 400 total for crank and regrind since I went with a stock forged one. Only difference as this was a v8 which would take much longer to grind down and clean it all up.

[e9nine]

new they cost $990 check it out:
http://www.realoem.com/bmw/showparts.do?model=AT72&mospid=47655&btnr=11_3314&hg=11&fg=20
....thats all i could find.


FYI RealOEM pricing is NOT accurate. Call your vendors/dealers of choice and find out anytime you want accurate pricing.

[tim_s]

wow, that's beautiful! great photos too! what CR you going for? looks high! (flatish top pistons despite the big valve pockets)! 2130cc, thats some absolutely huuuge pistons you've got in there! what dia. have you gone for? are you not a bit worried about the wall thickness!?
man, you've taken this to extremes! what length rods are those? they look very nice!
is that a cast crank? what length?

[tim_s]

oh an just to pick up on the rover thing, no no no! the crank nose is wrong on rover engines, well at least the ones i've seen!

[2002maniac]

NICE! Strokers love wild cams. I would reccommend something aggressive. The added displacement offsets the low end torque loss common to aggressive cams but your top end will SCREAM!

[1991318is]

Only issue is the compression. Trying to keep it decent will be super hard w/ a huge cam and a stroker.

[tim_s]

NICE! Strokers love wild cams. I would reccommend something aggressive. The added displacement offsets the low end torque loss common to aggressive cams but your top end will SCREAM!

lol, should read

2002Maniac loves wild cams


actually sod it


tim_s loves wild cams *

* but only on track cars or cars with ITBs as they're a pita to live with on a daily driver

[kowalski]

Febi, if you don't mind, i'm trying to price out my project... how much were the custom pistons and rods? you can PM the price to me if you want to keep it confidential... thanks
Mike

[2002maniac]

* but only on track cars or cars with ITBs as they're a pita to live with on a daily driver

Displacement is the cure.

[thumper3ld]

Once again i say, someone start mass producing this stuff so that the price drops down and we can all have fun.

[1991318is]

Displacement is the cure.
Talk about displacement, you should see the DART Ford big block. It's well into the 700 cubic inch range. Off the top of my head, I think the pistons are either 5 or 6 inches wide, its huge, but runs like a bat out of hell on the dragstrip.

[kowalski]

you guys seen the chevy 904? that thing is MASIVE!

[tim_s]

Displacement is the cure.

too true. bit of a problem on an m42 though!

anyway febi, how did you get to 2130cc? i'm impressed at that! what CR you running?

[Febi Guibo]

Hey, sorry the details on all this are still coming together... I'm still about a month or so away, so here's hoping!

the target compression ratio is about 11.5:1

my figure on the displacement was an estimate, but the crank takes the stroke out to 88mm or so.

re: to fit the M47 crank --needs to be shortened by about .5mm, and a woodruff was cut for the timing gear (in the pic)

[tim_s]

Hey, sorry the details on all this are still coming together... I'm still about a month or so away, so here's hoping!

the target compression ratio is about 11.5:1

my figure on the displacement was an estimate, but the crank takes the stroke out to 88mm or so.

re: to fit the M47 crank --needs to be shortened by about .5mm, and a woodruff was cut for the timing gear (in the pic)

sure, reason i asked was because to get 2130cc with your crank you'd need pistons that would leave very little meat indeed between bores. did you have a regrind on the crank too? the tolerences on mine weren't very good, be intrigued to see how yours is as mine had done very few miles.
what crank bolt did you use btw?

[sheepdog]

Very nice!

[Antrieb]

Looks like it's going to be great Febi!

[Eurospec]

Looks like it's going to be great Febi!A non m42 owner... anyone in favor of a ban??






jkin dude :p Welcome!

[Febi Guibo]

he can stay...

...as long as he participates in each and every group buy... :D

[kowalski]

he can stay...

...as long as he participates in each and every group buy... :D

i say we charge him, how about he has to pay for half of my project:D how does that sound?

[D. Clay]

I think diesels have like 20:1 compression. That should be bullet proof @11.5:1. I gather the increase in displacement is coming from the stroke. Just curious what the bore and stroke are for a stock 318 and for the build you are doing.

[shellback]

Just FYI - I called eurodepot a few days ago. They can get a M47 crank for about $800. Is this the amount we are expecting it will cost?

Chris

[kowalski]

thats at the stealer ya it will cost that. europe should be cheaper, iv got a part number so i'm gona buy every crank i can with that pn, which will probably be just one..:( but if i find more ill bring'm back

[shellback]

So, any new updates?

[Febi Guibo]

nothing much yet... the head is out being worked, and once that's done, I guess it will be torqued on without the crank in place, and then the cylinders and block will be checked for any signs of warping etc. Thats kind of the last major hurdle for the bottom end.

they had to go to a slightly shorter, lighter I-beam rod instead of the h-beam to get the compression ration down a little... with the h-beam rods, the CR was coming out to around 12.8, which the engine builder wasn't comfortable with; he's kind of using his S50-related experience to figure it out.

On my end, I've been gathering up all the other various parts... stuff that I can deal with when the motor is out... the starter, power steering pump, belts, plug wires, coils, etc. My coolant and vacuum lines are pretty new and I did the alternator in january...

I'll try to post some more pics shortly...

[nickmpower]

hey, what are the specs on the pistons and how much did they run you?

[Febi Guibo]

I will have final specs on the pistons shortly;

forged, custom from wiseco, and, um, they cost a lot... ugh!

The engine will be installed, hopefully around this time next week... so everybody cross your fingers...

[thumper3ld]

On my end, I've been gathering up all the other various parts... stuff that I can deal with when the motor is out... the starter, power steering pump, belts, plug wires, coils, etc. My coolant and vacuum lines are pretty new and I did the alternator in january...

I'll try to post some more pics shortly...

Power steering pump???? Dont be a wuss, eliminate that ishh.

[shellback]

I will have final specs on the pistons shortly;

forged, custom from wiseco, and, um, they cost a lot... ugh!



I thought S50 pistons were being used:confused:
Can they be used?

Chris

[Febi Guibo]

s50 pistons can be used, but the overbore is 'only' around 86mm...

more deets soon!

:D

[thumper3ld]

s50 pistons can be used, but the overbore is 'only' around 86mm...

more deets soon!

:D

Off Topic,

I'm assuming since u were able to post this u and dennis got home ok. :D

[dude8383]

lol you doubted our ability?!

[thumper3ld]

lol you doubted our ability?!

Lol, nah I doubt jonas' ability to read the correct torque specs from the manual and superman's ability to sheer off shock bolts in a single twist.

[Febi Guibo]

...hey, I've been working out, what can I say... I tore up the swaybar mount bolt too... I'm a monstrrrrrrrgh!

[dude8383]

jay next time you'll be reading the torque specs, and doing the torquing!

[thumper3ld]

jay next time you'll be reading the torque specs, and doing the torquing!

Lol, I'll over torque on purpose. Febi is not the only one that can sheer off a nut.

[Zoso]

Febi is not the only one that can sheer off a nut.

Is that the same as busting a nut? SICK! :D

[dude8383]

Is that the same as busting a nut? SICK! :D

haha good call!

[mrjezza]

Sorry to semi-hijack...

I'm now super eager to do a stroker kit myself, but I think im going to keep stock pistons so I don't have to bore and do a budget stroke.

The m47 crank is 88mm stroke and that with the 84mm bore = 1950cc.

m42 crank is 81mm stroke. I'm guessing that a simple crank swap would push the stock pistons too far up and make compression too high?

Would the answer be to get conrods that are 3.5mm shorter (7mm extra stroke /2)? This would place the piston back in the same place at TDC and 7mm lower at BDC right? Thus the stock compression ratio (10.5:1 or 10:1) is maintained?

What would I need to do to increase compression ratio to by 0.5:1?

[sheepdog]

Sorry to semi-hijack...

I'm now super eager to do a stroker kit myself, but I think im going to keep stock pistons so I don't have to bore and do a budget stroke.

The m47 crank is 88mm stroke and that with the 84mm bore = 1950cc.

m42 crank is 81mm stroke. I'm guessing that a simple crank swap would push the stock pistons too far up and make compression too high?

Would the answer be to get conrods that are 3.5mm shorter (7mm extra stroke /2)? This would place the piston back in the same place at TDC and 7mm lower at BDC right? Thus the stock compression ratio (10.5:1 or 10:1) is maintained?

What would I need to do to increase compression ratio to by 0.5:1?

You are asking for SERIOUS trouble doing this.
You will have to bore and hone the block, the reason is you increased the stroke, at the bottom and top of the cylinder wall will be a ledge that your rings will catch on. You will not be able to stroke it without doing basically a complete rebuild.

[tim_s]

You are asking for SERIOUS trouble doing this.
You will have to bore and hone the block, the reason is you increased the stroke, at the bottom and top of the cylinder wall will be a ledge that your rings will catch on. You will not be able to stroke it without doing basically a complete rebuild.

i agree. however depending on how many miles you've done you might get away with a re-hone and some new rings. my bores were in surprisingly good condition for a 100k+ mile engine, you could still see the honing marks. the engine i used to make the 2.1 however was too far gone for that.
anyway to me its a bit redundant as imo this wouldnt be the best way to get some bigger capacity on a budget. just throw some massively oversized high CR lightweight pistons in there with the standard crank, put in a lightened flywheel, rebuild the rest of the block and you'd be away. would be much more in character with the m42's revvy nature, you dont want to make it that much of a long stroke imo, and buying a crank, modding it, getting new rods etc is more work than just an overbore. just my $0.02

[sheepdog]

i agree. however depending on how many miles you've done you might get away with a re-hone and some new rings. my bores were in surprisingly good condition for a 100k+ mile engine, you could still see the honing marks. the engine i used to make the 2.1 however was too far gone for that.
anyway to me its a bit redundant as imo this wouldnt be the best way to get some bigger capacity on a budget. just throw some massively oversized high CR lightweight pistons in there with the standard crank, put in a lightened flywheel, rebuild the rest of the block and you'd be away. would be much more in character with the m42's revvy nature, you dont want to make it that much of a long stroke imo, and buying a crank, modding it, getting new rods etc is more work than just an overbore. just my $0.02

True.
You bring up a good point though.

Stroking costs money. Boring is relatively cheap.
Bore the block add custom pistions to raise the cr and bore size and call it done. This would be more than likely be cheaper than going to a stroker crank setup and you would get a rebuild out of it.

This also does not increase piston speed (meaning more heat and wear), and will be a simpler setup.

[mrjezza]

Hmm okay. How much can the block be bored safely?

Also, even though the specific example I gave above wont work, is the maths for shortening the conrods correct... IE you need to shorten the conrod by (stroke/2)mm to maintain stock compression? Also, would a head gasket that is (stroke/2)mm oversize have the same effect?

[sheepdog]

Hmm okay. How much can the block be bored safely?

Also, even though the specific example I gave above wont work, is the maths for shortening the conrods correct... IE you need to shorten the conrod by (stroke/2)mm to maintain stock compression? Also, would a head gasket that is (stroke/2)mm oversize have the same effect?

If I remember correctly 87.5 was the max. Jim from Metric recommends 87. Unless you really want to push it.

[tim_s]

Hmm okay. How much can the block be bored safely?

Also, even though the specific example I gave above wont work, is the maths for shortening the conrods correct... IE you need to shorten the conrod by (stroke/2)mm to maintain stock compression? Also, would a head gasket that is (stroke/2)mm oversize have the same effect?

87mm is the max i'd go to being sensible. if you stroke the engine but keep the same pistons unchanged you will increase the CR, as CR is the ratio of vol at BDC:TDC.

[koyota]

87mm is the max i'd go to being sensible. if you stroke the engine but keep the same pistons unchanged you will increase the CR, as CR is the ratio of vol at BDC:TDC.

Hi Tim, would shaving the stock pistons of M42 E36 be very dangerous. I mean the stock pistons are good for boost up to 1.xx BAR. As I posted here http://m42club.com/forums/showthread.php?t=4656 I can get the M47 crank cheap in Bulgaria( 400$ ) and I'd really love the bottom end torque this stroke will give me. The trouble comes with the pistons. I have been told that ordering custom pistons is way too risky, since you can not be sure what will come in the box.

[hesgone2fast]

Hi Tim, would shaving the stock pistons of M42 E36 be very dangerous. I mean the stock pistons are good for boost up to 1.xx BAR. As I posted here http://m42club.com/forums/showthread.php?t=4656 I can get the M47 crank cheap in Bulgaria( 400$ ) and I'd really love the bottom end torque this stroke will give me. The trouble comes with the pistons. I have been told that ordering custom pistons is way too risky, since you can not be sure what will come in the box.

$400??
Can you get a M47 crank for me and ship it to me for $500 plus shipping(that means you win $100)?

[RouteZeroDesign]

Can i just add that tim's last post in this thread was june 2006.....i doubt he will be checking back here.

Your probably better off pm-ing him or sending him an email.

Koyota- Ordering custom pistons isnt a problem as long as you get them through a reputable source...and even then, if they show up on your door step and they are wrong, send them back.