Irish44's '77 e21 320i build - with M42

[irish44j]

Engine Cleanup Time!

Now that I have the engine apart, I decided to clean it myself rather than throw away money at a machine shop. Most shops these days use a "steam cleaner" dishwasher anyhow rather than a hot bath, so I figure with some elbow grease this can be done.

Note that I plan to hone the piston bores later this week (after which I will do some more cleaning).

One of the advantages to having a little 4-cyl: the block fits nicely in a utility sink in the garage, giving me direct hot water access and drainage. Before I put it in I coated the cylinder bores with some WD-40 to keep flash rush away (and it worked), and since I have an extendable faucet (my old kitchen faucet, lol), I was able to basically keep water out of the cylinder bores for the most part anyhow.

So first I put the engine in and (both sides) sprayed it down with oven cleaner and let it soak.



Then I used a brass brush and some brillow to scrub it good and clean. Then degreased it afterwards just for good measure. Seems like it's pretty good and I need to get some engine paint and do the outsides of the block now.





Then I went to work on all the polished gasket surfaces (head gasket, oil pan gasket, timing case, etc). After I cleaned it as well as possible I block-sanded with 1000-grit wet-or-dry (slightly wet). This got the last remnants of gunk off of it and left me with a very nice and smooth surface. I can't feel any imperfections on any of the surfaces now, so should mate up nicely with the gaskets.





outer cylinder bores have some rust, but not as bad as the camera makes it look.

[irish44j]

Nice weather today, so we proceed.

First, a morning run to Harbor Freight, the greatest place on earth. Went to find a piston ring compressor, ended up buying a ton of other stuff as well, of course. And still paid $75 for all of it :)



Finished cleaning the block, and did some painting. Might as well make it pretty. The copper will look good in the Nachtblau engine bay I think...





Also finished cleaning up the block deck, and did a light hone of the cylinders.



My buddy came over to lend a hand, but unfortunately he has no hands...



Then did some leaf-blowing and raking...



my daughter wasn't impressed



and wanted to pull the pilot bearing, so fabbed up an awesome tool built of a bolt, nut, random roof rack clip, and two brake pads :)

[irish44j]

parts came in today, so my after-dinner project was assembly of the bottom end.



Yes, I know nobody seems to like VR head gaskets, but I'm not spending $200 on a HG for a $250 engine, lol. And the VR one on my other M42 has been just fine. I will note that this one appears to have a much better profile on the red gasket strip than the one for the other engine did, which is a good thing.



First test-fitted everything and Plasti-gauged. Clearance for the mains should be .023 give or take. Most of them came out about .018-.021 so that is in the neighborhood, so I'm pretty pleased with the replacement crank. Also there is minimal end-float with the new thrust bearing (360*). I don't have an end-float gauge but I cant even gap it with my thinnest feeler gauge, so it's pretty minimal for sure.



my helper assisted in assembly



and torquing the main bearing bolts



yee-haw



piston ring assembly



installed....no issues whatsoever. Went in easily with the HF piston ring compressor thingy



only one little hiccup.....ordered the wrong size of con-rod bolts. Forgot to measure them, and of course it figures that the right ones are the $8.25 each versus the $3.50 each for the ones I got. Dammit. Use the old ones to hold the caps on for the time being until I can get the right ones.

[kts]

installed....no issues whatsoever. Went in easily with the HF piston ring compressor thingy

I'm jealous, we had the same HF piston ring compressor for the tii Lemons build and that stupid thing kept expanding on us. I think it was thrown around my friend's shop a few dozen times in frustration.

Anyway I'm enjoying the progress, can't wait to see it all back together.

[irish44j]

interesting. Well, maybe it's a single-use item, lol.....luckily I don't need to use it again anytime soon hopefully. And Spencer told me that he couldn't get the HF ring pliers to work, but they worked perfectly for me. YMMV I guess....

[Dj Buttchug]

all this m42 engine building sure does bring back some lovely memories for me. looking good out there bud :up:

[StinkE30]

yep....nuts and bolts and other small stuff. An old trick learned from my grandfather. And a good use of all the empty baby food jars one gets having two little kids :)

It is weird this picture gives me a boner....?

On a more serious note, love all your builds! Keep it up!

[Nick_S]

Great progress! I've used that burnt copper color on a bunch of stuff lately.

[irish44j]

some more evening work tonight with the wife and kids at gramma's for dinner. Cleaned up the head, valve faces, and lower timing case so I could put things back together. Then I put some things together. Still need to finish cleaning the outside of the head and paint it, but that's easier to do on the stand anyhow.

Yeah, so I took this pic and then lifted up the head to put it on, started to lower it, and thankfully stopped before I did. I think the reason is obvious :P



together again..



that last 90 degrees is a BITCH



Also took a few minutes to paint the valve cover, just for fun. I have some long-term plans for a project with it so didn't spend too much time making it perfect...

[eur04lif3]

love it

[irish44j]

Haven't gotten much done recently, spending my weekends raking leaves and finishing up the rallycross season. On that.....I won the last event, so that was 3 out of the 7 events I won in the e30 (and a 4th that my car won with a different driver who beat me), but I still came up 2 points short in the season standings and finished 2nd. That sucked.

A couple pics.





So for the e21, have done a few minor bodywork things, but mostly just trying to button up the M42. Got the updated chain rain and installed all the timing stuff, but still need to get the extended-length upper bolt for it, so can't close it all up yet.



In the meantime, I've been cleaning up other stuff that goes on the engine so I can put it all back together once the timing case is assembled. Also polished the intake manifold, but forgot to take a pic of it...



So I also took apart the TB to rebuild and thoroughly clean it (and paint the outside). No issues except the little screws that hold in the butterfly. They look to be some kind of expansion lock-screw so I need to look into whether they have to be replaced or can be re-used...hmm..

[irish44j]

Well, I've been slacking a bit in updating since not much has been going on. Been spending my weekends raking leaves.....yay.



Also made a little surprise for my 6-year old in the garage, which has a self-serving role of getting all of her sports equipment and other stuff out of my way, lol



Also in the last few weeks I've been scouring various forums for inexpensive new/used/leftover parts, trying to find some deals. I managed to round up most of the remaining parts that I needed to finish up the M42.....chain guide (updated), water pump, some other stuff. It's surprising how many new in box parts you can find if you look around enough....people always seem to have M42 stuff leftover from when they swapped to a 6cyl in their e30, which is good for me. Only thing I haven't yet found and will likely order new is the oil pressure relief valve (updated plastic one).

The last bunch of stuff came in today, just a bunch of random stuff soemone had listed. It's mostly the "mess under the intake" hosing, in very good shape. I know I can re-use much of this for the MUTI delete mod (did it in the e30), so it should cover most everything I need without having to buy any new hoses. Also a good-shape spare coolant-from-the-block thingy, which is always good to have around. And my old box of spare M42 parts has a bunch of random o-rings, seals, etc from a purchase I made a few years ago as spares for the rally car.

The latest buy, even better, came with four of the Mustang fuel injectors (which I'm using on the e30 as well), which was the best part since I paid less for all the stuff than the mustang injectors would have been by themselves I think.



Testing the old thermostat. Opened just right, one less thing to buy.



So, that said I've managed to get most of the engine back together, just gotta do the intake manifold after I clean it up and paint it, and the coolant lines, and put the oil pans back on.



Also working up a few e30 plans that I need to take care of before next rallycross season, but nothing too extreme. Lexan rear windows and some front end modification :)

Need to get my ass in gear and get going on the car bodywork now....slacking.

[Nick_S]

Awesome work as usual! If you need any parts I just pulled the M42 from my car for a swap, am parting out the whole thing.

[irish44j]

Awesome work as usual! If you need any parts I just pulled the M42 from my car for a swap, am parting out the whole thing.

I'll be in touch. I need a few things for sure!

[irish44j]

Got off my ass today and turned the car around in the garage so I could put it where it will be for the next couple months probably while I do the engine mounts, front suspension, etc.

First order of business was to remove the entire front suspension and subframe. Pretty easy stuff, honestly. Took about 15 minutes all told.





all bare



in the passenger fenderwell where all the paint and undercoat was burned away from the heat of the header. I'll have to make sure to fab up a heat shield when it's back together



Then got to the business of grinding off the stock e21 M10 engine mount on the driver's side. I'll pick up some heavy steel and make some mounts for the new engine once I have everything measured and lined up well. I have the last few parts I need for the engine on the way now, so with any luck I'll have this all set within a couple weeks.