M42club.com - Home of the BMW E30/E36 318i/iS
DISCUSSION => Swaps, Turbos, Buildups => Topic started by: IlovM42 on January 08, 2013, 02:33:27 AM
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Hi everyone
As i said in an another post, i'm looking to build a little N/A M42 for my 318is e30
I have been thinking on 2 different simple setup
First setup is to use M42 crank with 86mm bore S50b30 pistons (but haven't find them yet) to make a 1881cc M42 with higher compression ratio.
this avoid a lot of work, only things to do is bore the block, change rod bearing and M44 head gasket as I know.
Second setup is to go with M44 crank and 86,5mm bore S50b32 pistons (already find them) to make a 1957cc M42 as I'm keeping the M42 head, but i don't know if the M44 head gasket can be use, also i didn't find a lot of information about M44 crankshaft. Engine is not going to revs past 7200rpm so there will no problem with the M44 crank right? the fact that is cast and not forged like the M42 one is really a problem on such a little N/A engine? I guess problem come with boost.
So if you have some ideas/answers/remarks about this two setup feel free to post :D
I also have an M47 crank but this involve much more manufacturing and i want to keep the engine a square one (bore > stroke) and don't go long stroke (bore < stroke)
All this will be going to power my stripped out 318is e30, with E36 gearbox and 3,45 LSD :D
Thanks in advance!
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Sounds good!
Im keeping mine real simple... Just going to swap in m50tub25 pistons.
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what is the benefit of using M50b25TU pistons than M44 pistons if both of them are 84mm diameter?
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Piston design.. Higher compression.
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do you use those pistons on a M42 or M44?
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do you use those pistons on a m42 or m44?
m42
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Here are some helpful links if you didnt come across them yet..
http://www.motortraders.net/groups/attachments/1_35_m42.pdf
http://www.e30zone.net/e30zonewiki/index.php/M42
M50 piston chart..
http://www.e30zone.net/e30zonewiki/index.php/M5x#Pistons
Enjoy
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Here are some helpful links if you didnt come across them yet..
http://www.motortraders.net/groups/attachments/1_35_m42.pdf
http://www.e30zone.net/e30zonewiki/index.php/M42
M50 piston chart..
http://www.e30zone.net/e30zonewiki/index.php/M5x#Pistons
Enjoy
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Sorry about the double post
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thanks for the links ;)
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Excellent links. I havent seen the M50 piston chart.
I would go with the M44 crank. Might as well add some stroke to the equation. I dont think forged versus cast really matters here! I don't think it matters for most FI builds either.
Not sure which pistons to use. Personally I would just use custom ones to make sure I get the bore and CR correct.
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Sounds good!
Im keeping mine real simple... Just going to swap in m50tub25 pistons.
Have you already done this?
Doesnt the piston slap the valves? Because the M50TUB25 piston with lowest compression height has cr: 32.55
This gives a piston that sits (32.55-31.65)=0.9mm higher. Standard deck height is 0.15 above. This makes about 1.05mm above deck hight.
The head gasket is 1.75mm compressed, giving you only 0.7mm to spare.
The valve pockets from the M50TUB25 are 0.87 and 2.24. If u subtract 0.9mm from these pockets. U get 0(+.03) and 1.34mm. Comparing this to the standard m42 pockets of 1.65 and 1.85. So thats seems like a recipe for disaster. If you want higher CR, that asks for higher duration, higher lift cam...
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Working on it and yes i have taken all that in consideration. I will have the pistons decked and have new slots to make up for the valve clearance.
As for the cams.. I will go with a longer duration intake and leave the exhaust cam stock. Im already running itbs from a gsxr 750 tuning with tunerpro rt/ ostrich 2.0
With most of my time and funds going to my new born this build will be a long one... I hope to have most of it if not all of it done fall 2013.
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You could find urself some s50b30us pistons, also wrist pin 22m.
CR 32.8
VT 0.52 and 3.11
s50b32us is 86.4mm but CR 31, so never high enough.
If you go through the hassle of pocketing and decking pistons w new rings, why not bore to 86mm? Its an extra cost of about €300, the rings are also more expensive. That would make a great short stroke high revving, with your itbs and assymetric cam profiles. A dream come true :p
Also the M3 pistons are forged, so lighter, designed for the job and less weakened by pocketing and decking. That makes for all forged internals (drool)
Your next limitation must be the hydraulic lifters.
Congrats with the family expension, a future m42 enthousiast :)
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Thanks for the added info! Im going to look into it. If im going to upgrade the valve-train i might as well get the crank balanced and harmonic balancer to match so i can rev past 7200rpm without any crank walk
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well euro S50b30 pistons bought, so project will be to build a M42 with 140mm rods ans 86mm S50 pistons :D
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Whats the difference between s50b30 euro and us pistons?
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Whats the difference between s50b30 euro and us pistons?
They're just different, ch, wrist pin, dome, ..., same diameter. Im not home so cant acces the info.
Enjoy the mahle online catalog:
http://catalog.mahle-aftermarket.com/product_catalog/modules/motorComponent/specs/index.xhtml?subId=4 (http://catalog.mahle-aftermarket.com/product_catalog/modules/motorComponent/specs/index.xhtml?subId=4)
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you can find th eanswer here on another post
http://www.m42club.com/forums/showthread.php?t=17052
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you can find the infos here
http://www.m42club.com/forums/showthread.php?t=17052
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you can find the infos here
http://www.m42club.com/forums/showthread.php?t=17052
oups sorry for triple post, network problem
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well euro S50b30 pistons bought, so project will be to build a M42 with 140mm rods ans 86mm S50 pistons :D
how are you going to fit 21mm diam wrist pin into 22mm rod small end?
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I think the con rods he's using will have the right wrist pin and crank diameters
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I think the con rods he's using will have the right wrist pin and crank diameters
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Your next limitation must be the hydraulic lifters.
Not per se, you can rev the engine to 10K with hydraulic lifters... but not with the stock ones ;-)
The problem with our lifters is that the oil can't go out fast enough, buy them/modify them with a larger exit hole and you are in honda rev zone :P
I'd love to have a high revving short stroke 2lt M42.. it would beat the honda b16/B18 engines for sure.
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The solution for cam lifters
http://www.youtube.com/watch?v=ynVBlDMow3k
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The solution for cam lifters
http://www.youtube.com/watch?v=ynVBlDMow3k
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Not per se, you can rev the engine to 10K with hydraulic lifters... but not with the stock ones ;-)
The problem with our lifters is that the oil can't go out fast enough, buy them/modify them with a larger exit hole and you are in honda rev zone :P
I'd love to have a high revving short stroke 2lt M42.. it would beat the honda b16/B18 engines for sure.
Hydraulic lifters to 10k? I wouldn't go over 7500 with the latem42/vw ones, which is already high.
Idk about drilling the lifters. if u starve the oil feed its a bigger mess.
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Hydraulic lifters to 10k? I wouldn't go over 7500 with the latem42/vw ones, which is already high.
Idk about drilling the lifters. if u starve the oil feed its a bigger mess.
I think the metric mechanic hydraulic lifter upgrade will allow for higher rpm. Not sure of their limit but for sure not 10k rpm.
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how are you going to fit 21mm diam wrist pin into 22mm rod small end?
you can change the bearing on the rod to suit the 21mm wrist pin
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That cam tray conversion does work. There is some work involved as you saw in the video, but there is more. You have to clearance 2 points on the ex. cam tray to fit it in the head properly and you also have to drill (1 or 2) new hole(s) in the #1 bearing cap for the cam so the chain rail guide will fit. I did this conversion years ago. Glad to see someone is trying new avenues as well.
Someone needs to do a bit more research on this subject I think before we can say what does and doesn't really work with beehive and dual spring set ups and to what rpm is safe. Sure you can rev 10K on a hyd lifter, but what happens to the valve in all this? It also depends on the cams you run as to where your power will be.
Solid lifters are always an option and safer for higher revs due to their stability, but who wants to take their valve train apart to do a valve adjustment on a street car? Some may....I prefer the, set it and forget it mode, on the street car. My track car however does have shim under bucket and has to come apart for a valve adjustment only because of the high lift of the cam which is over 12mm. That means re-timing the cams again which is no fun.
Just my .02
Cheers,
~Ralph
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On another note...getting back to the original question, You can use those in combination with each other as long as your math is correct. It should all fit just fine. Your main items that are not going to change are your crank and rod length correct? So you have to make adjustments to your small end in the rod to accept the piston, and shave the piston to fit the block height for your compression, and cut reliefs and dish the piston top as well. You should be able to make it work with no issues.
Good Luck.
Cheers,
~Ralph
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The solution for cam lifters
http://www.youtube.com/watch?v=ynVBlDMow3k
Thats pretty slick. I think lightweight hydraulic units or shim under bucket at the M42 diameter are fine though.
How much lighter are the M50 style lifters?
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A guy (ForcedFirebird) on E30tech.com has hydraulic lifters that weight 48grams that he uses in M50 engines. Supposedly they are rated to 7900 rpms.
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does anybody know the dish volume of s50B32's pistons, please?
trying to figure out Cr with the set up we're talking about...
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how are you going to fit 21mm diam wrist pin into 22mm rod small end?
You can swap con rod small end bushings from 22 mm to 21 mm. I did this with mine with M42 rods to fit Wössner E36 M3 forged pistons. Cost about 170€ so it was not cheap but it works.
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ok. good to know. will stick to honda conrods anyway...
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Not per se, you can rev the engine to 10K with hydraulic lifters... but not with the stock ones ;-)
The problem with our lifters is that the oil can't go out fast enough, buy them/modify them with a larger exit hole and you are in honda rev zone :P
I'd love to have a high revving short stroke 2lt M42.. it would beat the honda b16/B18 engines for sure.
Stock oil pump starts to cavitate at ~9000 rpm, so for higher rpm you need modified pump or dry sump system. Problem is not the hydraulic lifters it self but also the weight of the lifters. Anyway I bought supertech solid lifters, springs and valves to use with catcams 300deg cams ;) Only god knows when I will prepare my engine because have no time for my car already 2,5 years after marriage! :D
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well, i reuse this tread as i'm about to purchase a M44b19, as I can't find a M42b18 from E36 at a decent price, and this M44 is a really good deal. so i wanted to know if there is person here using the M44 crankshaft and if there is anu issues with it.
Lot of people say it's worse than the M42 one for being cast and having only 4 counterweight instead of being forged with 8 counterweight for the M42 one, but i don't think there will be problem with an mid build engine running with a rev limit set at 7200 rpm.
Going to look if i find more info about M44 crank but i will go for the second setup i think, M44 crank with stock 140mm rod and S50b32 pistons, for a total displacement of 1950cc instead of 1881cc for M42 crank with S50b30 pistons.
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You wont have any issues with the M44 crank at those revs or power level.
Internet speculation just scares people into believing nonsense.
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yeah it's what I think too.
I will put M41 bearing on it, it appear they are stronger/better. does someone know about that? havent find info at the moment
just need to find out what pistons I will use and if I need to get them machined to fit the engine and have a decent CR
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So M44 is in my garage, but I can't use S50B30 euro pistons as they will be too high.
best bet will be the S50b32 US pistons (or better say S52B32) as they have a KH of 31mm which will be perfect, putting the pistons only 0,6mm higher that stock ones, and they already have 22mm wrist pin so no need to change the bearing on the rod.
Now I need to find more info and 4 of them or use the S50b30 euro piston I have and machine them down to make them fit and change rod bearing from 22mm to 21mm
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No matter what you decide to do you will have to "give" somewhere. Whether it be in the piston, rod, crank, head, block or even the head gasket. You really need to look at all of those as ONE and not separate. They all work together and have to be exact in height for the engine to work. I say this all the time to people that want to just mix and match and whatever with parts.......Do your MATH first and see where you end up. You can't just go by what the specs say on a piece of paper because they may not work for you. Sure you can shave a piston and block and a head but what about rod length and crank throw and H/G thickness and dished piston and valve reliefs for cams and and and...:D
What compression is that? Now is that standalone ECU or chipped M42 or flashed M44? No matter how the engine turns out it is definitely a custom tune.
It can and will all work, and work really well as long as you do your math and plan out the entire engine before you start buying parts. That includes cams and intake and exhaust as well. Air in needs to get out just the same.
You can use any part you want as long as you know the other parts can work with it as well. There is a lot of info on this forum and experience from members that have gone this route. Why not plan out a complete engine and post it to the group and then get some feedback? I plan on posting my complete stroker build shortly. This way everyone can see what I did and then possibly expand from there.
HTH,
Cheers,
~Ralph
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Warsteiner I'm 200% agree with you, thisis why i try to go little by little.
First step was to find an engine, I was planning on using an M42 and just put S50b30 pistons in it as I know peoples who already done it but it happens that I had this great deal with an M44, so need to start thinking again.
I know all need to work together as one, and that i will not find part that i can put in and just crank the engine, there will need machining and other things to work together but It's possible to reduce the amont of work involve and for sure the cost.
For example S52B32 pistons looks to be the more economic choice, as they have a 22mm wrist pin like M44 rods and they have lower KH, so there will be less work to make them fit, but will they give the better results etc...I still don't know
this is my very first build, so I have a lot to learn and it wil take time, I'm not very kind of doing a dedicated post for my build as I know it will take long time to have something made and the result is people being annoying :(
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well I bump this post a little as i have to make a choice.
Do I use the S50b30 pistons I already have or do I buy the S52 pistons I have found...
good point for S50b30 pistons
-already have them
-they need to be decked and maybe pocketed for the valves but this will be good to have the desire CR (don't know the price to do it yet)
- M44 headgasket can be used
bad points for S50b30
-need to change rod bearing as wrost pin is 21mm on pistons (22mm on rods)
good point for S52 pistons
- will be add a little more displacement
-they sit 0,6mm lower than S50b30 pistons (0,6mm higher than M44 ones) so less to take off no need to cut new valve groove
- wrist pin diameter is 22mm so no need to change rod bearing
bad points for S52
- don't have them yet but know where to find them
- don't know the volume of the piston so, can't estimate the CR with them, if it's too low, I can take out some volume on the combustion chamber by surfasing the head, but how much is needed?
- need a custom/performance gasket (with lower thickness to augment CR? will this be enough?)
So if people on here know the volume of S52 pistons, this will help me a lot
thx
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You are referring to Euro pistons correct?
M3 pistons are all S50 in the Mahle catalog. But you need to refer to them as US or Euro.
So, which are you trying to use? Euro wrist pins are 21mm. US are 22mm.
86.0mm S50B30 US compression height 32.8mm
86.4mm S52B32 US compression height 31.0mm
S52 is based off the M52
86.0mm S50B30 Euro compression height 31.6mm
86.4mm S50B32 Euro compression height 32.3mm
No matter what, all need to be decked and pocketed for the valves as well as dished for desired compression.
I think the M44 head gasket will allow for the 86.4mm piston.
Desired Compression Height = Block height - (Stroke/2) - rod length -piston protrusion out of block
Using stock rods and M44 crank:
DCH= 212-(83.5/2) - 140 -.15
DCH= 212-(41.75)-140-.15
DCH=30.1mm
So you can use any piston of your choice as long as you make the CH 30.1mm So if you go with the US 3.2L 31mm/CH 86.4mm piston you only need to shave off .9mm, then dish it and cut the pockets for the valves. Simple!
Just to give you an idea....for my stroker I used 3.0L US pistons and 138mm rods. I spoke with TEP racing when I was considering going with JE pistons and they said that even a 28.15mm CH was ok. NOW that is with a custom piston and stock rods at 140mm on a M47 crank. It all depends on how much meat you have at the top of the piston.
Compression Height of Stock S50 Piston is 32.8mm with Honda 1.8L VTEC B18C (GSR) 138mm rod
Desired Compression Height = Block height - (Stroke/2) - rod length
Desired Compression Height =212mm - (88mm/2) - ((138mm[Honda rod] - .15mm{protruding out of block}))
Desired Compression Height =212mm - 44mm - 137.85mm
Desired Compression Height =*30.15mm
The DCH is a desirable height.
30.15mm = 212mm - (88mm/2) - 138mm -.15mm*
This tells you that your target compression height is 30.15mm and we have enough meat to shave off 2.65mm from the 32.8mm :-P
Rod needs small end bushing to be drilled to fit 22mm S50 pin.
Again.....do all your math first and then buy your parts. Or use what you have and make it work. BUT I would never deck the head to make up any kind of distance when you have so many other variables such as the HG and pistons and rods. Just my .02
Cheers,
~Ralph