1980 M535i

Pictures and info
Late Oct, Nov 2004

    The motor went to the machine shop on Saturday, October 23rd. Thanks go my friend Gavin Gray, another E12 nut like myself, we were able to load the block in the back of his station wagon and the rest of the stuff in the back of my car. We took it to the shop on Saturday morning and I talked to the machinist about what I wanted done. I am having the bottom-end completely balanced, the rods rebuilt and peened, and the head pretty much just checked and cleaned up. The block will be acid dipped and painted.

    By Monday, when I brought the head over after I had forgotten it on Saturday (DOH!), they had already worked on the block and painted it. It looks real good but the machinist thinks due to some corrosion in the coolant passages that he'll have to deck it a bit. The exact amount hasn't been determined.

Due to the condition of the bores, which aren't bad, but aren't perfect, we think that an overbore is in the best interest of a good rebuild. I checked into oversized pistons from Mahle and the first oversize (.2mm) is $1200. The 2nd oversize, .4mm, is $1150. But I can get custom JE pistons that are forged instead of cast as the Mahles are for $800 or so. Plus another $150 for rings and I'll be $250 cheaper than the Mahles, and I think have a better, lighter weight piston. This is the direction we're probably going to take with things.

The rod rebuild hasn't begun yet, but Ted (the machinist) checked the crank and I don't need oversized bearings. So I ordered standard bearings for the mains and the gasket kits, minus the head gasket, for the motor. I will still need freeze plugs, misc dowels for the alignment of stuff on the motor like the head and oil pan, and the rod bearings.

After doing a lot of research, I've decided to go with the Frank Fahey crank hub. It isn't cheap, but my old one was scored when the machine shop got it off of the crank (I couldn't get it off no matter how hard I tried). So I was going to need a new one anyway, so I thought the Fahey hub was worth going with for the added insurance it gives against a catastrophy with the harmonic balancer. I also ordered the Sachs Sport clutch pressure plate that will be balanced along with the crankshaft and flywheel. And for the flywheel I went with an 8 1/2 pound aluminum unit from JR Racing. With that flywheel and the JE pistons, the motor should rev a bit quicker and be fun. It wasn't cost effective to remove enough material from my old flywheel to make it try to compete with the 8 1/2 pound aluminum one. And the makers of the flywheel recommended that I go with the performance clutch to go with it. The clutch pressure plate is on back order though and won't come until late Nov.

Picture are the flywheel which is now at the machine shop, the crank that has been cleaned up, the block which was cleaned and painted, and the head which was cleaned and flow tested (perfect, no cracks, no warpage, seals perfectly and the cam isn't that worn). Hopefully next week when our contact returns to JE from the SEMA show Ted and he can coordinate what kind of pistons we're going to have built for my motor!

Block cleaned and painted.

Waiting to measure for new pistons and overbore.

No freeze plugs.

I like the gunmetal paint color.

Cleaned up head.

Cam in good shape.

Crank ready to be balanced with flywheel and clutch.

Aluminum flywheel, what a work of art.

Mid-Nov 2004

    The work on the motor at the machine shop is progressing nicely. The machinist has told me that the crank is in excellent shape and I only needed standard sized bearings for the rebuild. Now I have all of the bearings, mains, rods, and also new rod hardware in the form of bolts and nuts. I considered going with ARP for them, but they had nothing off the shelf and the costs to get something custom were outrageous. I'm sure BMW OEM will be fine. Measurements and a lot of discussion has commenced and the pistons have been ordered. I ordered custom made pistons from JE which should take a few weeks. Ted, the machinist, handled the ordering process including sending an old piston to JE and making a mold of the combustion chamber of the head. We are targeting a compression bump from 9.3:1 to 9.75:1. According to the machinist's calculations though, the head has already been shaved by a previous owner and compression was already close to 9.6:1. So we're not really bumping it that much. The new pistons from JE will be 93.47mm where stock is 93.4mm. This only results in a slight overbore of 0.07mm. First oversize Mahle OEM pistons would be .2mm larger so this will actually be a smaller displacement and overbore bump than if I had gone with OEM Mahle pistons. Nice!

I also have purchased the Frank Fahey crank hub for safety and added assurance to my new motor when it is put together. The machine shop will be putting the lower timing chain cover on and the crank hub and pully to ensure that the proper torque (318-325 lb/ft) is applied. I dropped off the Fahey crank hub along with the Sachs Sport pressure plate so that this can be balanced with the crank and bottom end. I still need to get the pully and hardware for connecting it all to the crank hub along with the harmonic balancer. The machinist explained that he will balance some of the parts on their own to make sure they are in good shape. Then he will balance everything as a whole. The reason for that is that if I changed one thing, i.e. the harmonic balancer, that way it wouldn't disrupt the whole equation if everything else was very nearly balanced on its own.

Last weekend, Nov 6th and 7th, I disassembled the entire front end and suspension to clean up the subframe and replace some worn out parts. I replaced the front control arms, cleaned and repainted portions of the front subframe, put in the Grunts radius rod bushings that I've had sitting around forever, installed Alpina springs that I've had for a while, Bilstein Sports, and K-mac front camber plates. It was a huge amount of work, but I also crossed many things off the list of things to do. The old tie rods were rusted and non-adjustable so I will be putting new ones in including a new center link. It should drive like a new car! Unfortunately, when I removed the springs and shocks on the front I discovered that what was in there was not the original stuff. This is unfortunate because these items are specific to the M535i and I had planned to set them aside to keep. The car had KYB front shocks that someone had put in and I'm not sure what kind of springs.

Tonight, Nov 18th, as a follow-up to the front subframe removal, I noticed that the bolts holding the subframe in were not in great shape. I sourced new one, for the great price of $1 each (there are four of them) for added piece of mind. Also I put in new 17mm bolts under the strut housing where it connects to the steering hub. One was so rusted during the subframe and suspension removal weekend, that it had to be ground off. And the others weren't in great shape either. So tonight I swapped in the new hardware for the rusty hardware. And I installed new motor mounts. I couldn't believe how much of a difference there is between the old mounts and the new ones in height! See for yourself in the pictures.

Finally, the other day with all this going on, I finally finished the front airdam install. This included getting the rubber bumper strips mounted to the airdam body and my own addition, the euro license plate.

Subframe removed

The car is suspended with no subframe.

Subframe as it came out

Paint work

One of the Grunts bushings installed

Working on the spring and strut install

Spring height comparison

Subframe going back in.

Camber plate installed

Back on its wheels after subframe reinstalled and shocks/springs

Clean, painted subframe installed

Old mounts on right, new one on left

Height comparison of old to new

Rusty subframe bolt on right, getting replaced with new on left

Airdam project finished and euro plate mounted

Dec 2004

    The motor is nearly finished. I stopped at the machinist's today (Dec 7th) and all components are balanced, the rods have been peened and rebuilt, the pistons arrived from JE, the block has been bored, and the block is also painted. All that is left is reassembly.

There was a small hiccup last week when the machinist called to say that he found some small cracks in the block. They are on two of the cylinders, from the head bolt holes to the coolant passages. He said he didn't think they were that worrysome because of their size and since they didn't go to any of the bores. I spoke to several BMW "L" block owners and experts in the E12 M535i and firstfives E12 group and for the most part, everyone told me not to worry. Which is good because the block would have been very expensive to replace. And I just don't want to go without the original block on the car. I don't necessarily think it will enhance the value, but I think it is neat that the car has the original block (and head as far as I can tell, the casting date on the head is 1980 and it has "M90" cast into one side also).

I'm in no rush, but the machinist said the motor might be ready next week. If it's possible, I might try to pick it up before Christmas and get it home. It won't be that exciting though because it's just going back on the engine stand to finish the build. It's still a ways from going back into the car.

Painted block

Painted block, underside view

Closeup of pretty bores

Note magic marker around coolant passage, showing cracks (towards bottom)

Bearings ready for assembly

New JE piston and peened, rebuilt conn rod

Pretty maids, all in a row

More piston pics

Showing resurfaced conn rod bearing surface

This pic is from a few weeks ago, dropping off parts

Same, showing new conn rod hardware (BMW OEM)

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