bmw e30 m42 engine build and ballance

recently torn apart my m42 engine due to profile gasket failing and decided to take the oppertunity to re build with new rings, bearings, gaskets, seals etc. also decided to have the crank balanced and single mass flywheel lightened, which will be done this week hopefully. with pictures to follow.

so far recently just had cylinder head skimmed, valves re seated, fitted new valve stem oil seals and chemicaly cleaned.

as for the block iv checked all the oil clearances on the crank and rod bearings with plastigauge and were all within the tollerances except slightly more wear on the crank bearing nearest the timing chain.

cross hatch could still be clearly seen on the cylinder walls which tells me their has been no problems with over heating or excessive wear.

next week ill be getting the crank balanced along with rods pistons, flywheel and clutch.
having the clutch lightened.
setting piston ring end gaps and assembling bottom end and fitting pistons.

HAS ANYBODY ANY SUGGESTIONS ON HOW MUCH WEIGHT TO SHAVE OF THE FLYWHEEL?
DONT WANT IT STALLING ON GEAR CHANGES BUT WANT THE ENGINE TO REV EVEN MORE FREELY. NOT THAT IT REALLY NEEDS IT BUT WOULD REGRET NOT DOING IT WHILEST THE ENGINE IS OUT.

Has anybody had any experiance in engine balancing and what kind of gains you got in return?

crank, pistons, rods, flywheel and pressure plate has all been dropped of at machinest today for balancing and the lighting of the flywheel.

today set the end gaps on all piston rings.
painted some odd bits up.

sourced some m44 cam gears for free that had to be modified to fit m42 camshafts.
basically had to drill a 4mm blind hole in the exhaust cam and tap inn the pin for the cam sensor.

the old cams were seriously worn and needed replacing.

the hole for the sensor pin obviously has to be in the same location as it was on the m42
cam gear
I think from what i can see when the pin passes the sensor that is the tdc of cylinder 1.
so its very important its located precisley.

There wont be much of a hp or torque gain from a balance. But the engine will run smoother which less vibration smoother curves and smaller balancer. You can shave about 5-7lbs i believe without any major issues

Sent from my Garminfone using Bimmer App

thats kind off what i expected anyways, i know it will also improve on reliability also with having less stresses on internal parts.

regards the flywheel i kind of left it with them. told them i dont want it stalling between gear changes and dont want any clutch chatter. they have done a few m42 flywheels before so they know how much to take out. i hope!

i recently bought the oil pressure gauge adaptor of ebay.
i found that it doesnt realy fit the way its supposed to so had to modify it slightly.
the problem was when you screew the adaptor into the filter housing and then screew the oil pressure sensor into the adaptor it touches the engine mount and the conector plug cant be attached.
so i made a 90 deg elbow with m12 thread so i can angle the sensor away from the engine mount.

here is how it looks.

also made a start on electric fan conversion.

does anybodey know what sensor i can use for the fan switch? their is a brass plug on the drivers side of the radiator, can that be used for the sensor?

nasty!!!

still waiting for them to finish with my crank and flyweel.

pickin up monday now hopefully.

was hoping to have it built for weekend

on the flywheel you can remove 2/3s the weight and still be ok. if you also threw in lighter rods and pistons, you can shave more weight. on the electric fan, theres 2 sensors on the radiator, ones for the ac the other goes to the ecu. use the sensor for the ac and put in a lower temp sensor

cheers for that.
i just need to find a thermostat with the right size thread and switch?
you got any part numbers? would be much appreciated.

finaly picked the bits up on tuesday afternoon. my brother came along to help build the engine and drop it back inn the car, was up at the garage gone 10:00 that night and back up in the morning till 11:00 that night. had a few problems that i couldnt just leave otherwise would of had it done.

anyways this is the lightened flywheel and original flywheel.

saved around 1.5kg
i chose to have the holes drilled and shamfered for being the best way to lighten without loosing any strength.
yet to see how its affected the performance

you can probably see from the other picturs the lightend wrist pins ( shamfers drilled into the sides of pins)
also some material removed of the base of one rod to match the the weight in all rods.
this one must of been fractionaly heavyer.

some more pictures of lifting the engine into place and head being torqued up.
all went preety smoothly.

im just left with fitting the radiator, pullys, belts and bleeding the coolant system.

i have started the engine and sounds sweet as a nut! i couldnt run for too long as their was no coolant in the engine. but all seems fine. I wont even be able to realy test it till the rings have beeded inn and iv done 200 mile oil change.

next on the list of modifications will be:
ecu chip,
oil catch tank,
braking system. was looking at brembo brakes for some fiats and having some mounts made, just need to find the right size callipers.

does anybody have any suggestions on which chip to use? theirs just so many from £25 too £90 on ebay.

Originally Posted by turbo86

cheers for that.
i just need to find a thermostat with the right size thread and switch?
you got any part numbers? would be much appreciated.

bavauto.com has some sensors that just plug in for the aux fan. there should be plenty of write ups on a fan depletion on the 318. dont hear too much on them, mainly on the 325s

are you actually weighing each part you shave weight off of or just machining and grinding parts willy nilly so its all unbalanced and blows up ?

im not grinding and shaving anything! im merley showing you pictures of the work i have had done.
the crank, rods, pistons, pressure plate and flywheel has all be proffesionally balanced and lightened by quasar engineers specialist engine builders based in stockport.

Originally Posted by turbo86

im not grinding and shaving anything! im merley showing you pictures of the work i have had done.
the crank, rods, pistons, pressure plate and flywheel has all be proffesionally balanced and lightened by quasar engineers specialist engine builders based in stockport.

Originally Posted by fcsteve

are you actually weighing each part you shave weight off of or just machining and grinding parts willy nilly so its all unbalanced and blows up ?

Now who would just start hacking away at their rotating assembly for no reason. LOL

That makes ZERO sense.

BTW the engine would not blow up, something will get broken, nothing will blow up.

Originally Posted by First time

Now who would just start hacking away at their rotating assembly for no reason. LOL

That makes ZERO sense.

BTW the engine would not blow up, something will get broken, nothing will blow up.

you must have never viewed the ultimate dsm build thread. the kid was hack sawing critical parts, hand filing grooves into the head and a ton of crazy bad crap. never assume people arent completely screweing something up.

the bearings would likely go out prematurely from bad vibrations. .. no engine ever ACTUALLY blows up. but you still call a bad engine a blown engine dont you ?

dont be so sure on blownin an engine

ive seen a different vid of a tractor pull engine blowing up as well. driver was severely injured in the vid i saw tho.

Originally Posted by downhiller

dont be so sure on blownin an engine

thats some crazy video. see the size of them turbos. can imagine him thinking lets just stick two on their for a laf.

had abit of a scare when i started her up last night. i could here a knocking when the engine was running.
bearings have gone in the alternator. thank f$%k its only the alternator.

although i know i torqued everythin up to spec i still get worried. lol

Wow cant believe so idiot would just hack saw crucial pieces of his crank. That blows my mind. He must have used wikipedia as his build guide lol.

I have never had a "blown" engine. I put them together correctly. Lol. Blown headgaskets a few. But thats a different story. I havent/will not refer a engine as blown up. It just doesnt make sense, well to me anyway. I will say that it is broken because thats what it is.


Sent from me, who else?

just awaiting replacment alternator that hopefully im going to win on ebay tonight

started sanding the inlet manifold to take out the casting pours and polish up. already looks like an improvment.