Project Armo "330i" M-tech 1

[Skarpa]

Christmas holiday is behind. Along the family stuff I had time for some tinkering. My brother delivered me a bunch of powder coated and yellow zinc passivated parts:







Stoked on that I immediately assembled the headlights.




The faded, silver painted trim rings with wiper stoppers made way for some shiny chrome. I bought the trim rings as E30 ones but they seem to be from E34 or some other model because the didn't quite fit. They lacked the slots for the small tabs in the lights so I had to make them.








Before christmas I got a lot of stuff I was waiting for so I got to assemble the oil pump among other things.






I also received the pistons and the con rods from the machine shop. All parts were inspected and the top piston ringe grooves were widened for 1,5mm rings. The top sleeves in the con rods were replaced because the old ones were a bit worn. I assembled the piston rings and con rods to pistons so next I'll be able to check the bearing clearances and assemble the bottom end.

[Skarpa]

I must say I'm impressed with the nikasil plating and all around manufacturing precision of engine parts in general. When the cylinders in 20 year old engine look like new and the new piston rings out of package have end gaps that are within +-0,05 mm in the middle of the spec you can't complain. (And yeah, I'm aware of the problems with nikasil and fuel with high sulphur content)

[Skarpa]

The pistons are being machined (ring grooves are widened for M52 nikasil rings), the bearings and piston rings have been ordered anf there's a big shipment of OEM parts coming from Germany. While waiting for all those to arrive I've been working on smaller stuff. The throttle body heating is obviously not combatible with the itbs and also not needed in a summer car so the fluid circulation needed to be blocked.



The thin pipe is for the throttle body heating. I cut it off and silver soldered a short allen screw to block it off. I didn't want to weld because the original seams are soldered and wouldn't like too much heat right next to them.



I proof tested the joint with pressure from the public water grid which is about 5 bars around here. Should have a high enough safety margin. I didn't want to use compressed air since the setup was pretty sketchy.



I blocked the connection in the head with an M12x1.5 plug. While there I added a temp sensor for the E30 dashboard. I also installed the studs for the intake and exhaust manifolds as well as the ones in the itb adapter and ITBs themselves. There were so many M7 studs that I bought a stud socket which made the installation a lot nicer than using double nuts.





S50 intake runners are supposed to have domed chrome nuts with integrated washers that cost about 6 bucks a piece. I have the nuts but in some of them the chrome is worn. I decided that regular domed nuts will be enough for this engine. In the end I installed the itb adapter to the head. Some of the nuts are in pretty tight spots and I had to look for a slimmer wrench to finish the job. Luckily the installation is kind of a one time deal.


The studs for the ITBs have domed nuts but I think I'll swap them for ones with integrated washers. They are in pretty tight spot to be fiddling with separate washers.

I also finished this project:

We have a parts washing machine at work but it's only used very rarely because of the time and energy it takes to heat up. Today we fired it up so I decided to take apart the half shafts and wash them at the same time. The joints felt a bit notchy when turning by hand but the parts didn't really seem all that worn. Mainly the ball cages have slightly worn spots where the balls sit. I'll see what they feel like after new grease.

E30 half shafts are not that expensive so you can ask if there was any sense in this but it's done now and I'm one experience richer. As for the body of the car, lately I haven't had much time to work on it but I've managed to do some tidying up and preparing for painting. Luckily I also remembered in time that I need to drill the holes for the A/C condense water drain.

[Skarpa]

WOW ... impressive work.

Thanks!

[88M3racer]

WOW ... impressive work.

[Skarpa]

I got the crankshaft sensor position done.


"If it looks stupid but it works, it might still be you're doing it wrong." The sensor position is a bit tricky because it's on slanted face so you can't use the oil pan flange for fixing the block. I put the block on it's end but because of the limitations of the mill I had to raise to block quite a bit. Otherwise I couldn't get the spindle low enough. I used the lathe tool holders for raising the block. I positioned to block so that the spindle points directly to crankshaft centerline when located at the sensor position.



I measured the sensor for the hole diameter and came to conclusion that the diameter for the sensor hole is 18,0 mm and for the O-ring indentation it's 21,5mm. I double checked the measurement from the head. The camshaft sensor seems to have the same dimensions apart from length. I drilled the O-ring indentation to a guessed depth and then straightened the flange face using face mill.





Next step was to adjust the sensor to correct distance from the trigger ring. For that I mounted the trigger ring on the crankshaft and placed the crankshaft in the block.


The correct air gap for the sensor is 0.55 mm. I of course had a lot more because I made sure I didn't go too deep when straightening the face.


Little by little I milled off more material from the flange face and checked the sensor gap. Once I was happy with it I re-drilled the O-ring indentation to correct depth and made a small chamfer on the edge to make the installation easier. Then I drilled and tapped the hole for the retaining screw.





All in all, I'm happy with how the sensor position came out. It's a stroke of luck I had the newer style block with the sensor position included in the casting. I think this may not be the original block of the engine because casting marks in some other parts and the fact that the ECU was an older non-flashable model make me think this engine is from around '95. One of the older M52's. It's pretty easy to check, though. I have the original ecu for the engine and it has the vin number.

[Skarpa]

The ground effects are simply amazing. I've always looked back there and thought, man something to cover this up would be perfect. I want.

Thanks! I used the M3 parts and they fit the M-tech 1 okayish. Maybe facelift as well. But It wouldn't be too hard to create something similar fitting your car exactly. You could get away with pretty basic tools using thin PE plate, aluminum angle profile and pop rivets. Plus sheet metal nuts and nutserts for fixing the pieces to bumber and body.

[jeenyus]

The ground effects are simply amazing. I've always looked back there and thought, man something to cover this up would be perfect. I want.

[Skarpa]

I continued taking apart the M52. The piston rings and ring landings seemed to be ok. Not that that matters so much anymore.



When removing the crankshaft I had to stop and curse for a moment. The rear main seal cover didn't have room to come off the crankshaft and the crankshaft couldn't come off with it.




Luckily just loosening up the engine stand attachment bolts was enough to create adequate space. The crankhaft seems to be allright and will be sold to someone in need.




Then I had a good look at the M54B30 rotating assembly. I've had it for years waiting on the shelf. The crankshaft seems to be pristine. The bearing journals might be polished. I can't remember any more. With the measuring tools at hand the journals seem to be in standard size and round. The previous owner has cleaned up three pistons but three of them had a pretty thick layer of carbon deposit. I scraped it off. The pistons, wrist pins and con rods seem to be alright in my eyes. I'll send them to an engine shop for more throughout cleaning, inspection and to have the topmost ring grooves widened for M52 nikasil block piston rings.



The picture is taken with a potato I found at the bottom of the fridge. It had already started to sprout which is probably the cause for the lousy picture quality. The crankshaft was missing the trigger ring. I bought one as well as a crankshaft position sensor to take measurements for drilling and milling the sensor position in the block. My block has a placement for the sensor in casting but it hasn't been machined. M52TU/M54 crankshaft sensor is more reliable than the M52 one and allows me to use a vibration damper without the trigger ring. I'll most likely use a new M54B30 damper. Ati super damper might be cool but with the shipping to Finland the cost is astronomical. After all, dampers are wearing parts and most of the failures I've seen have happened when 10+ year old engines with original dampers have been punished hard.



Lately I've tried to come up with comprehensive shopping list with everything I still need to purchase for the car, all the way down to the seals, screws, bolts, grommets and small plastic fixings. As a part of that project I had a look at the A/C lines and drew myself a diagram of the hardlines and hoses. All the hoses will of course be replaced. I'll probably reuse the hardlines and paint (or zinc plate) them. The evaporator, drier, condenser, expansion valve and pressure switch will be new. I'll use the Nissens 94958 generic condenser since it seems to be impossible to find a car-specific parallel flow condenser for E30 in Europe. Because of the generic nature of the condenser I may need to modify the car front frame a bit to accommodate the connections.

[Skarpa]

Lots of small tinkering going on and little to show but here's something. I washed pretty much everything that comes off the engine without taking apart the rotating assembly. The parts washing machine didn't get rid of all the crusty oily sludge but the parts are still much nicer to handle after washing and the rest comes off fairly easily. I took apart the oil pump to see what was it's condition. It seemed good apart from minor polishing of the rotors. However I couldn't bring myself to putting it together with the old internals so I added the oil pump parts to my shopping list. I also took apart the vanos and replaced the piston seals. There was slight play in the vanos gear so I think I'll order the rattle kit as well.



Dad's and daughter's toys side by side




I replaced the crankshaft seal in the lower timing cover. Then I inspected the engine more closely. The piston tops had a fairly thick layer of carbon deposits on them which I scraped off with WD40 and a plastic spatula. I wasn't too happy with what was revealed:


Piston 1


Piston 2


Piston 3


Piston 4


Piston 5


Piston 6


Especially the piston four is pretty rough. With my limited experience that looks like detonation marks rather than mechanical damage. Although the detonation marks I've seen before have often been more clustered in certain areas. The head I removed didn't have corresponding damage as far as I remember but it wasn't necessarily the original head. From the signs I'd say the engine has been worked on before. I should have done a blowby test before removing the head to have a better idea of the engine's overall condition. Luckily the cylinders seem fine. You can easily see the honing marks and there's no step at the top of the cylinders you could feel. I've understood that's usually the case with nikasil blocks. Either they are pristine or, if the coating is for some reason damaged, they get pretty bad pretty quickly. I think I'll pull the internals and assemble the engine with the M54B30 rotating assembly. My original plan was to keep the B30 crank on the shelf to mock it up in a spare block and measure the setup for "evo 2" high compression engine but I can always get another crank for that purpose. Building a three-litre engine from the get go is actually what I've wanted to do anyway but until now have talked myself out of because of budget and schedule reasons. Well screw those reasons.

[econti]

Yes I knew about the gas thing, but did not know the acid part. That's cool

I was already fairly set on blasting, but it sounds like the only option for what I want.

Thanks

[Skarpa]

Undercoating as in the stuff on the underneath of the car?
How long did it take you? Probably just going to give mine to the media blaster

Yeah, that's what I mean. The original yellow pvc stuff is very good and still flexible after all these years. There wouldn't be real need to remove it but on my car on top of the original undercoating there's this black tar-like rust proofing that's been applied afterwards (a commont thing in nordic countries) I found no viable way remove the black stuff and leave the factory stuff so all must go because I want to have a nice painted finish on the underside of the car. If you plan to remove the undercoating I strongly recommend media blasting or any other non-manual method. I've been doing the whole underside of the car step by step whenever I needed to make repairs in that area. This final round included the front frame rails, the front wheel wells and the transmission tunnel around the gearbox. All the areas where you can see black rust-proofing in this pic:



That took me two to three hours so it's pretty laboursome work.


Just a quick tip, when we are on the subject: The original undercoating is pvc-based and when burning it produces hydrogen chloride. Combined with water (like humidity from air) that creates hydrochlorid acid which a strong corrodent. So whenever welding, it's improtant to remove all the original undercoating from the area as well as possible. Otherwise the spot sill rust like you've never seen. Also, don't breath the fumes from burning undercoating. Hydrochloride is not healthy either.

[econti]

Undercoating as in the stuff on the underneath of the car?
How long did it take you? Probably just going to give mine to the media blaster

[Skarpa]

Some time ago I started working on the engine. I have a refurbished head for the engine so I sold the old head to balance the budget a bit. I took the engine to my workplace and gave it a pressure wash with hot water and some solvent detergent.



After washing I took off the oil pan, the baffle plate and the oil filter housing and dried everything with compressed air and then hot air gun. Then I left a heat blower pointed at the engine for the rest of the day to make sure I left no water anywhere. After that I gave all the exposed internals a spray of oil to avoid rusting.



Oil pan, baffle, vanos, possibly oil pump and the rest of the separate pieces are going to a parts washing machine. I also cleaned and tidied up all the ancillaries.



I didn't feel the need to polish or paint anything. I just made sure the parts are not covered in grime so they are nice to handle and it's easy to spot any potential leaks. The starter seems to be an original unit from '95. I'll replace it with a new one since it's not so nice job to do once everything is assembled and in the car. EDIT: I've been informed about the poor quality of rebuilt starters so I'll service this myself.

Speaking of the car, I just finished removing pretty much all the rest of undercoating. I didn't start testing any new tricks but went with the tested and proven method of angle grinder and steel wire wheel. Creates a hell of a mess, though.


Removing the undercoating revealed one more point that needs welding: The lip on top of the engine bay side where the front fender bolts to. Should be a simple fix.

[Skarpa]

The part turned out good considering that I had no previous experience on plastic welding. It's a bit ugly here and there but seems to be strong. I'm happy. This was good practice for fixing some cracks in the bumber covers/valances where the outlook is more important.