Author Topic: An imposter in the ranks - an M43 project (Read 14901 times)

Doctor T · « **on:** March 06, 2012, 12:51:34 PM »

Hi everyone

I'm a newbie here, typically hang around on e46zone but i'm after a bit of technical advice and fancied somewhere to hang around that's a little more roll-up-your-sleeves in approach. Anyway,on to my little project.

So i bought an early e46 318i with the M43tu 1.9l 8v lump in it a few years ago as a first car (had been a biker for the tens years before that). by the time i came to get something a bit quicker the little 318 had over 135,000 miles on it, wasn't worth much and i'd looked after it pretty well so i thought i'd keep it as a project/toy car.

So far it's been stripped out, lowered on HSD coilovers and i've had the camshaft reground to a 272 degree duration (it was 240 as standard) with an additional 0.75mm of lift. I'm not the most mechanical of people but love having something to learn on that i'd don't have to worry about breaking, a secondhand engine can be had from ebay for about �300 to �400 quid at th end of the day so the risks are low.

In additional i've recently started up a business as have now got a workshop with a CNC mill and a manual lathe which opens up a number of interesting possibilities, in researching ways to use pistons from other BMW's and boring out the cylinders I found a number of threads discussing using the M47 crank and S50/S52 pistons to increase the capacity of the M42 engine. To my understanding the bottom half of the M43 is the same as the M42, assuming that is correct is there any reason i can't do this to an M43 engine?

That way i can increase the cubic capacity of the engine, increase the compression and keep my head with reground camshaft. Does that sound doable.

So can i have an honorary membership to M42club even though i've only got half the required number of camshafts?

Nelson_40 · « **Reply #1 on:** March 06, 2012, 05:38:25 PM »

A hearty welcome to an M43 owner! After all, we have lots of M42 & M44 owners, why not get another descendant of the M40 on board?

For starters, I have never clapped eyes on an M43, nor have I torn much of the bottom end of an M42 open. As for an answer to your question, yes it does seem that everything internal that can fit an M42 can fit an M43 according to http://www.bimmerforums.co.uk/forum/f81/m43-gets-m42-head-transplant-preparation-dasc-t56813/. From everything else I have seen the blocks are the same, with the exception of oil squirters.

If you haven't already, spend some time comparing parts and part numbers.
M42 Engine. http://bmwfans.info/parts/catalog/E30/4-doors/USA/318i-M42/LHD/M/1991/browse/engine/
M43 Engine. http://bmwfans.info/parts/catalog/E46/Sedan/Europe/316i_1.9-M43/1999/browse/engine/

Sounds like an entertaining project! Post pictures if you have them, it's always interesting to see something that never came to the United States!

keflaman · « **Reply #2 on:** March 06, 2012, 07:15:26 PM »

Welcome aboard!

What's an M43?

(I could google it, but I'm trying to stimulate some conversation)

Doctor T · « **Reply #3 on:** March 07, 2012, 01:25:25 AM »

Quote from: keflaman;110819

Welcome aboard!

What's an M43?

(I could google it, but I'm trying to stimulate some conversation)

No problem, thanks for asking, I forgot how much of this board is US based, i've just got back home from dropping my girlfriend at the train station for her to get to work, was having my morning coffee and just realised there might be 'overnight' replies here since you guys are so far away.

Anyway, so the M43 engine came in three flavours, a 1.6 (M43B16), a 1.8 (M43B18) and a 1.9 (M43tuB19). Of the 1.9 there were two power levels, a 105bhp and a 118bhp. I've got the 118bhp which was available in the e46 318i and 318Ci along with the Z3 1.9.

The M43tuB19 is a four inline, single overhead camshaft with hydraulic lifters. From what i've read most of the botom end is the same as the M42, certainly the basics like the 91mm cylinder spacing.

The biggest difference i can think off is that my timing belt is in fact a timing chain.

Thanks for the Links Nelson, i'll have a look through them today, in the mean time here's some pictures of the top of the engine that I took while we were removing the camshaft for it to be sent off for reprofiling. It certainly is a fun project, just enjoying getting my hands dirty really. The new camshaft and the stripped out interior have made it much more fun, I had it weighed a while ago and with a 1/4 tank of fuel but without me in it the car it weighed 1260kg (2772 lbs), i've removed a little more since then too

Lets see if i can link to my photos of the camshaft...

Cam back 2 by _Dr_T, on Flickr

Cam back by _Dr_T, on Flickr

Cam out 2 by _Dr_T, on Flickr

Geoff · « **Reply #4 on:** March 08, 2012, 02:24:49 PM »

welcome, and good luck with the project. By the way, the m42 utilises a chain also. We actually do require a second camshaft to join the club, but a loophole in the by-laws does not say it has to be installed in the engine. so, throw one in the trunk and we'll call it good:D
Geoff

Doctor T · « **Reply #5 on:** March 08, 2012, 05:48:32 PM »

Quote from: Geoff;110876

welcome, and good luck with the project. By the way, the m42 utilises a chain also. We actually do require a second camshaft to join the club, but a loophole in the by-laws does not say it has to be installed in the engine. so, throw one in the trunk and we'll call it good:D
Geoff

I'll meet you half way and leave one in the garage, as i'm down to removing sound deadening with a blow torch and scraper i can't be carrying a few grams worth of camshaft :p

For some reason i though the M42 had a timing belt, no idea where i got that from, anyway the main 'work' to do will be the modifications to the M47 crank, luckily they can be had on UK ebay for �300 ish (there were two on last time i looked, one for �260 and another for �360). Would I be right in thinking that if i put the M47 crank and my crank together i should be able to see what i need to change or is there something 'hidden' i need to change?

Doctor T · « **Reply #6 on:** March 29, 2012, 05:03:59 PM »

right i think i might have hit a bit of a stumbling block with this. i'm pretty much ready to start buying the bits and bob i'll need but i've just been re-reading this thread from bimerforums http://forums.bimmerforums.com/forum/showthread.php?t=433471 which has a lot of the info i need in it and i've notice a mention about the M44 having the crank positionsensor running from a wheel on the crankshaft part way down its length whereaas the M42 doesn't have this, instead it takes the reading from the timing chain end of the crankshaft, the fix for this for the M44 seems to be to fit the M42 lower timing chain housing and crank pulley. From looking on realOEM it would seem that my crank is more closely related to that of the M44 so the question is, how/what to i ned to check to see if i can swap the crank pulley and lower timing chain housing over to fix this issue?

I'd really appreciate any help with this one. Be a shame for the project to die and swapping in an M42 will be too much work, as i'd need a new exhaust and most likely engine mounts etc, this was intended to be a bit of fun and a reasonable excuse for me to strip down and rebuild an engine :-(

DesktopDave · « **Reply #7 on:** March 29, 2012, 06:12:56 PM »

From what I've seen, the M44 and M42 cranks swap directly. You're correct about the trigger wheels. The M42 has one on the harmonic balancer, the M44 has it on the 4th crank journal IIRC. The M47 needs some machining to fit correctly. I think you'll be OK, but I have no first-hand knowledge. The correct mounts should be on the earlier case, so I'm thinking it's a straight swap.

A few more issues I've noted:
1. The later M42 case has a slightly different timing chain arrangement. Early cars use an idler wheel, later ones use an improved deflection rail. The cases have different mounts to make up for that.
2. You might also run into some problems with the crank-mounted oil pump. It was apparently made in two different thicknesses.

One more thing...the only M4x with a belt is the M40. It was updated to a chain on the M43 due to apparent heat-related failures.

Doctor T · « **Reply #8 on:** March 29, 2012, 07:12:12 PM »

ok so i think this is the potential issue

item 14 on this page shows my engines Crank Positioning Sensor (i assume thats what 'pulse sensor' means) and as you say Dave it's looks to be on the 4th journal

http://bmwfans.info/parts/catalog/E46/Sedan/Europe/318i-M43/RHD/N/1999/browse/engine/engine_block_mounting_parts/

by contrast the M42 has this sensor at the front of the crank (us this what you mean when you say harmonic balancer Dave?), item 11 on this page

http://bmwfans.info/parts/catalog/E36/Sedan/Europe/318is-M42/LHD/M/browse/engine/timing_case/

which leave me with the question, can i make the m47 crank compatible with the sensor reading from the 4th journal, if not, what needs to be done to ensure the sensor reads correctly from the front. the lower timing chain housing from the m42 looks very similar to mine so may swap over, if they do what do i need on the crank to allow the sensor to then read the crank position sucessfully?

Geoff · « **Reply #9 on:** March 30, 2012, 05:06:14 AM »

I am not 100% on this but I think it gets a reading from a magnet. I know thats how the cam sensor works. as to where exactly the magnet is placed...no clue.
Geoff

Doctor T · « **Reply #10 on:** March 30, 2012, 06:06:53 AM »

Quote from: Geoff;111516

I am not 100% on this but I think it gets a reading from a magnet. I know thats how the cam sensor works. as to where exactly the magnet is placed...no clue.
Geoff

thanks for this, i've just been doing a little more googling and looking on RealOEM and it looks like early M43 engines had the crank position sensor at the front, comparing images on realOEM, the lower timing chain houses look the same

Early M43

http://bmwfans.info/parts/catalog/E36/Sedan/Europe/318i-M43/LHD/M/1993/june/browse/engine/timing_case/

My M43

http://bmwfans.info/parts/catalog/E46/Sedan/Europe/318i-M43/RHD/N/1999/browse/engine/timing_case/

so my next question is, can i just get the sensor from the older engine and plug it into the car where the previous sensor went and leave the old one in place but not wired up. Or is life never that easy?

the first problem that springs to mine is is there a difference in management software, like one is OBDI and one is OBDII?

I think i really need to understand how the sensor works (i.e. what is it reading from?), seems odd that I have large diametre toothed wheel on the 4th journal and there is nothing similar to this on the nose of the rank for the earlier M43 or hte M42?

Time to google Hall effect and VR (what ever that is)

Doctor T · « **Reply #11 on:** March 30, 2012, 01:56:06 PM »

ok so a bit more digging around and it seems like the bit that is missing in my engine which is there on the M42 at the nose of the crank is items 6 and 7 here

http://bmwfans.info/parts/catalog/E36/Sedan/Europe/318is-M42/LHD/M/browse/engine/belt_drive_vibration_damper/

as youcan see, for mine (below link) they are missing, these look to line up with the location of the crank position sensor on the M42 and the earlier M43 which would suggest that the sensor 'reads' from these items.

http://bmwfans.info/parts/catalog/E46/Sedan/Europe/318i-M43/RHD/N/1999/browse/engine/belt_drive_vibration_damper/

Which does just bring me back to

1) is there room for me to add these two parts onto the end of the M47 crank (once i've modified it as needed)) without pushing the belt pulleys forward any?

2) if the above can be done, can i simply get the sensor from the older M43 or an M42 and plug it into my cars wiring as the old one was? I believe both the M42 and the M43 (older and newer) use the same type of sensor which is the VR (variable reluctance) type rather than the Hall type.

DesktopDave · « **Reply #12 on:** March 30, 2012, 03:20:23 PM »

I'd bet that the sensors are all similar enough to do that. Mounting tolerances may be different, as well as physical dimensions. I've swapped sensors between models from earlier BMWs, Bosch wouldn't jump tech halfway through a production run. As long as you have the necessary sensor clearance and # of teeth on the wheel (60-2 IIRC), I'm sure any Motronic system could be adapted.

That image isn't completely correct...the outer diameter of my crank pulley/harmonic balancer (#1) has the trigger wheel teeth on its periphery. You'd need that bit too.

Doctor T · « **Reply #13 on:** March 30, 2012, 06:17:09 PM »

Hi Dave, so are you saying that your crank pulley (#1) has teeth around the edge, which would be essentially the same as #7 from this diagram (my current engine)

http://bmwfans.info/parts/catalog/E46/Sedan/Europe/318i-M43/RHD/N/1999/browse/engine/crankshaft_with_bearing_shells/

if that is correct it would certainly may it look a lot more doable in principal.

DesktopDave · « **Reply #14 on:** March 31, 2012, 07:43:57 AM »

Yep, that's what I'm sayin'. Here's the view from the left side of the motor. I couldn't get a really good shot of the right side with it all put together. Mine has the early v-belts here. The front pulley is my deleted p/s system, then the a/c, then the alt/water pump. The alt pulley is the bright blob to the extreme lower right.

]

Yep, the crank pulley, trigger wheel and harmonic balancer are one unit in my car. It has two pieces that are fastened with a firm bit of rubber to minimize high-frequency engine vibrations.