ITB M42

[MLM 57]

Went for a WOF today which was the first time i have driven the car in a long time. All went well, no ssues. Its louder (obviously) but quite tollerable. Sounds really good under load past about 4500 rpm where the bellow from the front almost drowns out the exhaust.

As for the warrent it failed, but only on a bulb (Doh!) but no other issues and this was a VTNZ check which i was expecting to be quite strict.

So soon to be on the road and driven daily again. Need to save for a Dyno tune now.

[MLM 57]

Warrented, reg'ed and off to the Brian Collis Memorial Bimmersport Queen Birthday Weekend Meet.

[pvl 0]

nice work with the headers and exhaust!

finally on the road, this calls for some video's doesn't it?

[MLM 57]

Monday is set as dyno day at the moment. There wont be any dyno vids as workshop rules exclude bystanders though i may see if this rule can be bent for me... If so there will be vids soon. If not im sure a few drive-by vids can be arranged...

Edited June 27, 2013 by MLM

[MLM 57]

Dynoed today thanks to Gavin at Hi Velocity. ITBs havnt made it peaky or excessivly lost bottom end power. On power it sounds freaking epic now im confident to use full rpm band at WOT. Its not making a heap of power but what i expected for a 220k km engine. 117.5hp at wheels. Will post dyno plots when i can.

[APT 194]

Awesome work, did you just get it dyno'd or remap/retune?

[MLM 57]

remaped as well.

[No name user 379]

what ignition timing was in it at 4k upwards before det?

[MLM 57]

4k was 25deg rising to 30 at 6k from the ign table. Why do you ask?

Dyno plot,

Edited July 3, 2013 by MLM

[No name user 379]

did you monitor the air intake temps?

it works out to be 100kw motor something isnt right they are around 104kw stock thus you may have and i would say you do have back pressure issues

Edited July 3, 2013 by crunchy

[MLM 57]

I wasnt present for the tune so couldnt comment on the air temps beyond the setup is not suceptable to heat soak and draws near ambient temps on the road.

By back pressure issues do you mean a restrictive exhaust? This should be more free flowing than stock given the manifold and free flowing system. The head is stock with un-modified ports which would be restricting flow however. What are your thoughts?

The motor is old and could use a birthday as well which dosnt help the numbers and I have been told this dyno "reads low". Not to make excuses but to offer a broarder picture.

Edited July 3, 2013 by MLM

[E30-323ti 66]

The cam timing isn't out of whack is it?

Don't the M42's have slotted cam gears from factory?

Oh, and where is the sound clip!! OR BAN!!!

[MLM 57]

Yeap they have adjustable cam gears from factory. The engine is internally stock never opened as far as i know so without opening it up will assume the cam timing is right. This is a 220,000km engine after all.

Vids will come, just need a camera and a person to hold it. Intake sound is epic in the car, drown out all other sounds can only guess what its like outside the car...

[No name user 379]

I wasnt present for the tune so couldnt comment on the air temps beyond the setup is not suceptable to heat soak and draws near ambient temps on the road.

By back pressure issues do you mean a restrictive exhaust? This should be more free flowing than stock given the manifold and free flowing system. The head is stock with un-modified ports which would be restricting flow however. What are your thoughts?

The motor is old and could use a birthday as well which dosnt help the numbers and I have been told this dyno "reads low". Not to make excuses but to offer a broarder picture.

yes i was meaning the cams and head, the stock cams are very mild ports need a slight tidy up to get the intake to exhaust flow better, not bagging your hard work i think theres still more in it, if it was me try and find another motor and give that a once over and drive what you have for now.

to get the best i think youll need to turn it harder to around 8k or more but itll need some serious work to support it i turn my turbo m42 to 7k and wants more but ill do bigger cams before i go any further

[MLM 57]

yes i was meaning the cams and head, the stock cams are very mild ports need a slight tidy up to get the intake to exhaust flow better, not bagging your hard work i think theres still more in it, if it was me try and find another motor and give that a once over and drive what you have for now.

to get the best i think youll need to turn it harder to around 8k or more but itll need some serious work to support it i turn my turbo m42 to 7k and wants more but ill do bigger cams before i go any further

Thanks for that. I do agree on the ports. To my inexperienced eye the exhaust looks tight and the inlet has steps and sharp edges where the factory machining meets the cast wall.

Luckily I have a spare engine to have a play with though. I think i will call what I have phase one and chip away at a phase two which hopefully adresses the head and cams etc and ideally some more rpm.

[MLM 57]

Did my first event ever this weekend. Was a heap of fun especially in the morning when the skid pan was wet.

Vids here >

Was well off the pace but stoked be finally be out there driving it.

[No name user 379]

looks great red with black wheels

[Eddie 66]

I wouldn't worry about the dyno hp reading as a gain is a gain. On the dyno I use the only m42/m44 I seen over 100hp atw have been manual ones. The US forums say a good one is around the 115hp mark but I have never seen it.

[pvl 0]

Did my first event ever this weekend. Was a heap of fun especially in the morning when the skid pan was wet.

Vids here >

Was well off the pace but stoked be finally be out there driving it.

that intake sounds awesome!

[MLM 57]

looks great red with black wheels

Cheers

that intake sounds awesome!

Thanks, You can only just hear it at the end when it starts getting some rpm on board, even then, the vid dosnt do it justice.

I wouldn't worry about the dyno hp reading as a gain is a gain. On the dyno I use the only m42/m44 I seen over 100hp atw have been manual ones. The US forums say a good one is around the 115hp mark but I have never seen it.

Thanks i did go back and check your thread as a reference, the US models atleast get the better exhaust manifold. With cams and compression 175rwhp seems possible. One day maybe.

[MLM 57]

Have started to tear down my spare engine. I bought it a few years back as an impulse buy off trade me as it was going cheap enough. Since then i have hauled it arround eveywhere and has served as a jig when building my exhaust manifold. My intentions..? Dont know yet. Having a learn and a play for hopefully not to many $$. Got some ideas but as always will be doing as much as posible myself as thats where i get the enjoyment.

Anyway some pics..

Head off, looks ok. Its the 6mm valve stem variety so should flow a bit better than the 7mm type.

CC'ed #1 chamber at 34.5 cc

Did the same for a piston as well at 7.4 cc

Used a syringe to inject water accuratly + a set of sensitive scales to verify, those bad boys can detect the air pressure created by waving your hand above them. According to my calcs this gives a 9:9ish compression ratio which is a touch down from the advertised 10:1

Block looks ok, some rust scale in the water jacket which will need cleaning out somehow. Factory crosshatching still visable

Finally cleaned and painted all the covers etc.

I have some ideas about using another maufactures pistons for a high compression overbore but need to research a bit more first.

[Allanw 1071]

Block looks ok, some rust scale in the water jacket which will need cleaning out somehow.

Go to Gilmours, or some other commercial food supplier - buy enough white vinegar to fill the block a couple of times (or submerge it). Leave to to sit for a month or so It gently removes rust with destroying anything important (take off the aluminium bits though

straight white vinegar has been used in running Model A Fords as a cooling system cleaner a number of times. I know of a guy who runs it for a month, INSTEAD of coolant/water to clean it out, then flushes and refill with coolant. A lot of model A guys run with out coolant, so the rust can be nasty sometimes.

[MLM 57]

Go to Gilmours, or some other commercial food supplier - buy enough white vinegar to fill the block a couple of times (or submerge it). Leave to to sit for a month or so It gently removes rust with destroying anything important (take off the aluminium bits though

straight white vinegar has been used in running Model A Fords as a cooling system cleaner a number of times. I know of a guy who runs it for a month, INSTEAD of coolant/water to clean it out, then flushes and refill with coolant. A lot of model A guys run with out coolant, so the rust can be nasty sometimes.

White Vinegar eh? really? Well i have some white vinegar in the cupboard and I have no idea what i bought it for so might as well give it a go...

Well after two days with a splash of vinegar in the block i must say im a convert! Allen you legend!

You can see the tide line where the vinegar was sat and the grey iron below and the scaly crud above.

Dont mind me, im off to get more vinegar...

Edited September 25, 2013 by MLM

[Allanw 1071]

Sweet

Don't use all the vinegar... It also makes great pork crackling

[MLM 57]

So thought its time for a bit of an update. Its been over a year now since the final tune and the car is still going strong at now 240000km. Its showing its 22 year old age a bit too in a few places but nothing which cant be recovered easily enough. Also in this time I have had a new Bimmer enthusiast (I hope) join the family. Born on the 17th April my first son is now my focus. However I have still found some time in the garage to have a bit of a play starting with the head DIY style as always.

So starting with the inlet port , this is how the OEM port looks as it leaves the factory, note the steps from factory machining processes.



So attack with the die grinder and some sand paper rolls for a bit and the valve guide is gone. Im not worried about valve guide life at this point as if this head ever makes it on to an engine it would never be a build for high mileage as per the factory design.



The final inlet port looks like this. It looks seriously hogged out, but in reality its only lightly shaped and smoothed. Progress is slow as I stop to measure every few minutes to make sure im not getting carried away. If your new to this like me don't under estimate the material removal power of a sand paper roll! The short side didn't get touched.



The exhaust got a bit more attention as the port closed down on itself through the short side and the roof had a hard direction change at the valve guide. Here I raised the roof a bit to open the port. Previous comments and suggestions indicated the exhaust was restricted hence the additional focus.



Only after photos for the exhaust available. I also cleaned up the chamber with where the valve is shrouded around the spark plug as there was a 1.5mm step from the seat to the chamber which would do nothing for flow.


This is only for a bit of fun and learning. I will get this port and the adjacent ones measured for flow to see if there is any difference between stock and modded. Will post results when I have them so we can all see if porting can be achieved by a novice with no experience.

Will see how the pics turn out as the posting method seems to put extra pictures at the bottom

Edited June 3, 2014 by MLM