M42T 2.1 Build Thread

[HipMF]

Hola,

I don't check this forum very often anymore, but it's good to see that you're still active with this build. Do you still need an oil pan? I don't have any urgent need to visit my storage unit, but I have a couple things I need to drop off/pick up, so I could look for one.

Anyway, I wanted to weigh in on the squish discussion. I was first exposed to squish through David Vizard's small block chevy books. He emphasized the need to get the squish right for all of the reason you already stated; better mixing of the combustion chamber reduces hot-spots that cause detonation, results in cleaner, more complete combustion, lower octane requirements, etc. However, I wonder how effective this is on a pent-roof combustion chamber like the m42. The squish area is tiny compared to and SBC:



I'm not trying to say it's not worth pursuing, it certainly can't hurt. Just thinking out loud here...

[HipMF]

Also, while I'm here...

I thought long and hard about doing an N/A m42 before deciding to go turbo. The biggest factor that swayed me was the fact that I'm new to tuning. I've seen what other people around me have done, and I figured that I was almost certain to pop a motor or two as part of my learning curve. Stock bottom ends are cheaper to replace than built ones. Still, the siren song of ITBs still lingers in my memory as a possible opportunity missed...



M20s though... that's a glorious sound... but I digress...

[autox320]

Hola,

I don't check this forum very often anymore, but it's good to see that you're still active with this build. Do you still need an oil pan? I don't have any urgent need to visit my storage unit, but I have a couple things I need to drop off/pick up, so I could look for one.

Anyway, I wanted to weigh in on the squish discussion. I was first exposed to squish through David Vizard's small block chevy books. He emphasized the need to get the squish right for all of the reason you already stated; better mixing of the combustion chamber reduces hot-spots that cause detonation, results in cleaner, more complete combustion, lower octane requirements, etc. However, I wonder how effective this is on a pent-roof combustion chamber like the m42. The squish area is tiny compared to and SBC:

I'm not trying to say it's not worth pursuing, it certainly can't hurt. Just thinking out loud here...

It's overlooked IMO, but significantly important in all builds even pent roof. Common on just about every twin cam engine. The space between piston and head dictates the limit but if could would also keep the area within limits of the valves close. Limit of PV clearance is cam selection otherwise could use more dome. I remember the optimal M10 being done by skidmark racing. Welded up and machine out a perfect dome then using exact mirror'd piston shape dome with only exception of the valve pockets to use a large camshaft. Maximizing the entire chamber as you reach compression height. Last I remember they were making over 220whp from a 2L M10.

[Retoropak]

I am mainly looking for compression numbers.

I will be primarily running on e85 hence the 9:5 or maybe 10.0 compression. However i still want to be able to run 93 octanes at low boost (7-12 psi depending on wg spring).

So i will get the pistons to get me the higher compression with 0.04” gasket and approximately 0.035-0.04” squish and if i will have a hard time controlling ping with 93 then i will swap 0.08” or thicker gasket to drop the compression 3/4 of a point.

[Retoropak]

Do you still need an oil pan?

Nah i change my plans a bit
I decided to go with e36 subframe and rear sump. Thank You tho

Another question is related to the vert mounted motor.
I more or less know what to do with the oil pan oil pickup etc. Also it seems that head is symmetrical and will drain pretty good when vert mounted.
How about the transmission. What could possibly go wrong if i rotate the tranny 30 degrees?
Should i anticipate some heavy lubrication problems? how about adjusting tranny fluid levels?
Ideally i would like to avoid chopping and re-welding bellhousings

[Retoropak]

I picked up some spindles and control arm for my front.

I am going to test fit e36 spindles and see what i can do about front coilovers and if i would be able to use my koni strut inserts.


While junkyard shopping i checked some e90 spindles and think that they might be a better option than e36.

They are aluminum. The accept 51mm id /53mm od strut tube ( clamp). They have bolted hub/bearing assemblies.

The ony problem is the control arm they use two arms that have quite unique ball joints. Ball joint shafts are straight and there is a ball seat that holds the ball joint to the spindle.

I am just not sure how i would mount the spherical bearing there. Maybe a custom half sphere shaped spacer?




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[autox320]

I picked up some spindles and control arm for my front.

I am going to test fit e36 spindles and see what i can do about front coilovers and if i would be able to use my koni strut inserts.


While junkyard shopping i checked some e90 spindles and think that they might be a better option than e36.

They are aluminum. The accept 51mm id /53mm od strut tube ( clamp). They have bolted hub/bearing assemblies.

The ony problem is the control arm they use two arms that have quite unique ball joints. Ball joint shafts are straight and there is a ball seat that holds the ball joint to the spindle.

I am just not sure how i would mount the spherical bearing there. Maybe a custom half sphere shaped spacer?


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E36 is same as E30. Can either use the old style DTM kits (make own or purchase) like this
90332-1.jpg


Or something like SLR speeds custom curved modeled after the factory E30/36/46 arms (Could make your own with tubes and spherical cups), like this

https://slrspeed.com/collections/rac...e-kit-3-series
fyi can buy the subframe "pins" from SLR separate if using a E36 front subframe; but i'd think a custom setup may be easier to fit width wise. May cut and weld the subframe shorter I guess but at that point you know me

Once the hole is reamed out which would only take a few min with a ream i'd maybe just weld on a spacer avoiding the odd part surface or machine it out flat.

[Retoropak]

I think i am going to stay with e36 spindles. I have bunch of docol tubing and enough rod ends and sphericals to do a set of arms so most likely i will be building my own.

the reason i want to stay with e36 spindles is availability of smaller brakes which will allow me to temporarily run 15" wheels.
Also e90 front suspension is double pivot which i would have t convert to single pivot which might screw the geometry up.


I also picked up m44 timing cover and some pulleys to convert to serpentine belt setup.

[autox320]

Have a list of parts for the timing case swap?

I've started collecting a few myself and thinking of doing it with my daily driver m42 (early E30 M42). The timing chain bearing deflector wheel is getting noisy(main culprit to do this swap). If makes it long enough planning on spring.

Bought a used m44 timing case off ebay with oil pump.
Ordered new lower right deflector guide but may need the a new one under the crank gear (heard its different).
Also bought a M44 timing chain (different length I think). Have all new gears etc already.
Ordered updated metal timing case gasket (has matching oil channel), new upper gasket set with head bolts.

I hate this job cause with this motor if want to do anything seems have to remove the head due to configuration and "profile gasket". So having my valve seals replaced and skim the head a bit while at it. Probably do some bottom end maintenance ie bearings etc. This motor has lots of miles (mid 300k) and may get re-honed/re-ring. I like this little engine, just wish they made the front timing set unbolt right off the front like the M10/S14, not sandwiched under the head .

[Retoropak]

Have a list of parts for the timing case swap?

( .

Still deed to get the list together.
My cranks landed in the states. I will have one today and second one by the end of the week.

I started getting my garage ready for the project. I insulated whole thing. And started hanging drywall. I am done with the ceiling and i hope ill finish walls over this coming weekend.

In a mean time i hope to get the cranks machined for m42 sprocket and pulley/damper.

I still need to source the crank washer and bolts.

M47 uses m18x1.5x102 and different washer than m42.



M42 uses m16x1.5x120




I believe i will have to machine a m42 washer

I will know mire once i see both cranks side by side.


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[Retoropak]

I got the set of m18 crank bolts and washers.
I started getting the timing parts list and damn that driver side slider is expensive. ~$200 for a piece of plastic is crazy. With chain, sliders, bolts, gaskets and tensioner i am looking at $400-$500 for the timing components.


One of the cranks arrived yesterday. I need to go to my local post office to pick it up tho. Ill try to drop it off at my machinist on Saturday. He will need to shave the nose by 0.5-0.6mm (0.023") and cut the keyway.

[autox320]

I got the set of m18 crank bolts and washers.
I started getting the timing parts list and damn that driver side slider is expensive. ~$200 for a piece of plastic is crazy. With chain, sliders, bolts, gaskets and tensioner i am looking at $400-$500 for the timing components.


One of the cranks arrived yesterday. I need to go to my local post office to pick it up tho. Ill try to drop it off at my machinist on Saturday. He will need to shave the nose by 0.5-0.6mm (0.023") and cut the keyway.

I spent $700 a year or so ago on just timing parts for the other M42 when rebuilding it. In there was new tensioner, and new gears (crank, cams) cause they get pointy and wear after 250-350k miles. Want crazy try S14 timing parts they exceed $1100 last I bought.

[Retoropak]

I spent $700 a year or so ago on just timing parts for the other M42 when rebuilding it. In there was new tensioner, and new gears (crank, cams) cause they get pointy and wear after 250-350k miles. Want crazy try S14 timing parts they exceed $1100 last I bought.

I didn't count sprockets. Mine are in decent condition but might replace em as well to have everything brand new.

[Retoropak]

I picked up my diesel crank

M47 diesel crank by w grync


And this is why you need to cut a longer keyway and use a second key

M47 diesel crank by w grync, on Flickr

[autox320]

I picked up my diesel crank

M47 diesel crank by w grync


And this is why you need to cut a longer keyway and use a second key

M47 diesel crank by w grync, on Flickr

Sweet! Keyway is good for indexing the sprocket, but don't be surprised if the gear isn't a super tight fit on the crank. It rely's on the front pulley bolt to clamp it more than anything. Mine literally slipped on the crank where as the M10/S14 needed 400F oven for 20min then slipped on after expanded a few thou.


What thrust bearing part numbers to use? M50? to get a full thrust face surface. I'm sticking with factory rod bearings since near stock daily here, but interested in the mains/ thrust bearing swap.

[Retoropak]

Crank came with used original bearing ( apparently thats the thing in poland to sell used and reuse bearings). Diesel has 360 thrust bearing. But i believe the m50/m52 will fit.

I need to check king bearings catalog again. The king m42 bearings might have 360 thrust.


Little edit. M50/52 bearings have 360 oiling grove in addition to 360 thrust bearing. You would need to modify the caps in order to fit em. Metric mechanic had some info on this.
360 degree oiling grove might be a good thing if you take your engine above 7k rpm often.

Now i need to wait for the crank bolts. ( coming around 02/18). Once i have the bokts I’ll take everything to my machine shop.

I might wait for the second crank and do both at the same time.

I still think wether i should sell the spare crank or keep it. These diesel cranks are fairly easy to get in Poland i might get couple more later.


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[autox320]

Crank came with used original bearing ( apparently thats the thing in poland to sell used and reuse bearings). Diesel has 360 thrust bearing. But i believe the m50/m52 will fit.

I need to check king bearings catalog again. The king m42 bearings might have 360 thrust.


Little edit. M50/52 bearings have 360 oiling grove in addition to 360 thrust bearing. You would need to modify the caps in order to fit em. Metric mechanic had some info on this.
360 degree oiling grove might be a good thing if you take your engine above 7k rpm often.

Now i need to wait for the crank bolts. ( coming around 02/18). Once i have the bokts I’ll take everything to my machine shop.

I might wait for the second crank and do both at the same time.

I still think wether i should sell the spare crank or keep it. These diesel cranks are fairly easy to get in Poland i might get couple more later.


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Thanks for the reminder on the mains. Yeah was browsing at lunch today and saw the MM notes with the caps. Maybe something I definitely check with my daily setup. I'm hard on it of course but its still stock power. Has the M20 clutch and ltw flywheel (11 lb) setup (basically full m20 325i clutch kit and TB) using a custom lengthened clutch push rod that makes it work. I figure the way I drive at times I will check the thrust bearing wear when apart. I expect to see it having high wear due to just using all the time as a "practice" vehicle.

[autox320]

I've the m44 cover in front of me and noticed the oil filter housing port is different. I've not seen it spoke of if can adapt the M42 filter housing to the M44 cover. Appears the "drain back valve" is made into the m44 cover where as the M42 the drain back valve is part of the filter housing. Just something I'm observing closer unboxing this thing so far collecting parts.

not to hijack your thread man but you are recently doing an m42/m47

[Retoropak]

not to hijack your thread man but you are recently doing an m42/m47

Not a hijack at all. Yeah it will be a m42/44/47 hybrid. I need to find the post on the oil coolers for m42/44. I remember a nice discussion with goo quality pictures showing oil passages in the timing case etc.

I did some digging and it seems that the king bearing catalog does not have m42 specific bearings. Is m42 North American deal only? They had m40,41,43,44,47 varieties with different main bearing options that included 180 and 360 degree thrust bearings.

[autox320]

Not a hijack at all. Yeah it will be a m42/44/47 hybrid. I need to find the post on the oil coolers for m42/44. I remember a nice discussion with goo quality pictures showing oil passages in the timing case etc.

I did some digging and it seems that the king bearing catalog does not have m42 specific bearings. Is m42 North American deal only? They had m40,41,43,44,47 varieties with different main bearing options that included 180 and 360 degree thrust bearings.

Yeah think m42's were NA only from 1990-1991 just before the engine went into the first Z3. Looks like the lower thrust bearing out of the M50, but whats funny is the part number is the same stock thrust bearings for the M42. Maybe a different bearing MM is using. Still looking. Post if know the (60mm) oil groove thrust bearings part number.

Appears the oil filter housing difference is one where the filter has the aluminum cover or plastic cover. Early cars use the aluminum one so I'll remove the piece in the M44 cover and see if can fit the early m42 oil filter housing. At first glance they appear interchangeable.

early; just has o-ring



late one; talking about piece #4

[Retoropak]

From kings bearing catalog

http://www.king-catalog.com/Search/E...ke=Bmw&engine=


Fits multiple engines.

King have probably 3 or 4 different bearing that will fit m42.








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[Retoropak]

Alright i got some updates.

I started the front suspension swap.
I got the e36 subframe and bunch of steel.
I shortened the subframe by a bit more than 3” and welded it together.

Next will be frame rail mounting points and steering rack brackets.


E36 modified subframe by w grync
E36 modified subframe by w grync


A little jig i made

E36 modified subframe by w grync


And welded together

E36 modified subframe by w grync


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[autox320]

Dude, I was about to add to this thread. Just reference not hijacking. I'm building my daily driver m42 and swapping to the m44 front cover to eliminate the timing gear.My chain idle gear is failing so finally went into it again. Basically just two new guides and that's it. The chain and everything else can be reused. My other guides are new so replaced the chain. Only issue I have is the cover I bought is from a 97 Z3 so doesn't have the holder for the crank gear sensor. I'm making my own. This cover also already came with the oil pump so lucked out there also.

Figured build and refresh it. Decided boring wasn't necessary after seeing the block. Just honed and new std rings from crp filed to my preference of course. Profiled and blueprinted balanced rods pistons of what I got. Measured about 6 times, then took .010" off the block. My head was probably milled already cause cc'd at 29cc per chamber, took another .004" off to clean it up and flatten it nicely. Used a victor reinz head gasket cause slightly thinner than the elring. Spray coated with 99ma loctite.

Here's a few pics for timing chain reference and what numbers I ended. Can't wait to run it next week when can get it back in there.








https://lh3.googleusercontent.com/pw...-no?authuser=0

[Retoropak]

I test fitted the subframe today. I used e36 arm and spindle. Looks like i might go with e46 arms to macth wider rear track. Also lollipops mounting holes are lined up along the frame rail in the e46.

I will have enough space for the m42 rear sump oil pan.

ill be junkyard shopping tomorrow to get some suspension and brake bits.



E36 modified subframe by w grync
E36 subframe swap by w grync
E36 subframe swap by w grync
E36 subframe swap by w grync
E36 subframe swap by w grync

Dude, I was about to add to this thread.....


.......I bought is from a 97 Z3 so doesn't have the holder for the crank gear sensor. I'm making my own.

Please post some pictures of the crank sensor bracket once you are done. I also have the m44 timing case and will need to fabricate something.

BTW pics dont work for me

[autox320]

Mock up looks promising. I turned on link sharing to see if the photos work. I made up a crank sensor mount last night but will post a few pics of it for sure man.

Just to note again for anyone wanting to swap to a updated M44 case. Need the lower chain guide under the crank gear, the deflector guide (replaces the gear sprocket), and m44 oil pump (not sure but seems nla). The m44 pump is thicker and needed to fit the case. Last but not least metric mechanic i'm told sells the crank position sensor bracket, but one can be fabricated.

Gets rid of the fail point of a m42 timing chain deflector wheel. Also allows use of the updated m44 version metal gasket behind the case which doesn't leak