It’s been the far side of two-and-half months since the last post and the motor still hasn’t been completed and the body shell hasn’t really progressed. That’s not to say there hasn’t been progress, but it’s been really slow. Rob Siegel, The Hack Mechanic, counsels that in order to stay connected to a project, you need to do something – something, however small – on it regularly, even if just ordering parts or doing internet research. He says every day. Given my work schedule and life in general, I wasn’t getting the garage much more than once a week. Typically, I go out to the garage, start doing some work and find out I was missing a necessary tool or some part. So not much progress was being made, but I did have plenty of stuff to order and some research to do too! Mostly, there was lots of waiting.
Last we left off, the rotating assembly was installed into the block and it turned smoothly. That was good. To help turn the assembly, I installed the clutch and aluminum flywheel.
Shortly after doing that, I realized I made a bone-headed mistake and didn’t install the rear main seal nor its housing. A legitimate question: How could this happen? The best excuse I have is that I haven’t disassembled the original engine, bought a used block and that part wasn’t included – and then, in all the excitement of getting the rotating assembly together, I simply forgot about such things.
So, the first delay: buy a used housing on eBay and wait for it to arrive; once it does, remove clutch and flywheel, install housing and seal, reinstall clutch and flywheel.
Having never work on an M20 motor before – let alone built one – the next steps vexed me. Unsure of how to tackle it, I started taking the front covers and hubs around the timing belt.
This went smoothly until I encountered the screws securing the intermediate shaft drive. For some reason, instead of using allen screws, BMW used standard head machine screws. Given the torque on these, one simply refused to loosen. Worse, I started to strip the head as I tried. I went into the house, had a beer, and thought about how to get that thing loosened. It came to me: An impact screwdriver!
The second delay: ordering a tool I didn’t have, an impact screwdriver.
Once that arrived, it was simply a matter of a few blows with the mallet, a few more, a couple more for good measure, and the uncooperative screw was beaten into submission, first barely turning but with each blow going a bit further until I was able to remove it with a normal screwdriver. The intermediate shaft drive was off and the new one on! For good measure, new screws holding the drive were ordered and installed, too.
To get to the main pulley the main crank nut had to be removed. Simple concept but considered it’s torqued to more than 300 ft/lbs…. I puzzled on that for a while, since my electric impact wrench wasn’t strong enough. Talked to a few friends, thus further delaying progress.
One friend suggested a piece of 2x4 in the oil sump, preventing rotation and a breaker bar with an extension – in this case the handle from my floor jack. With that long of an extension, the worry is the torque is going to tip the engine stand over, not break the nut. But it worked great; first the nut slowly – very slowly – loosened. And with more movement came more pressure from me. In short order, the nut was off.
Then main pulley had to be removed and that required a puller.
The rest of the front cover removal from the old motor and re-installation on the new one went smoothly.
Next came the oil pump. Wait. Where is the new oil pump? Did I order one? How could I forget that? Couldn’t find one so I searched the invoices for the various parts I ordered. None included an oil pump, so that needed to be ordered. Another delay. While waiting I took the pressure relief valve off the old engine and put it on the new.
Once the oil pump was in hand, I mounted it on the underside of the block. First a test fit, with the drive and then locktite on the bolts. But, since I never worked on an M20 before I didn’t know how the pump (and distributor) was driven. Hence my introduction to the intermediate shaft and the drive off the belt. Some momentum was building, after all the delays, but it was still over a month since the last update here.
The distributor went in.
The head gasket on the block. The head gasket itself is unusual, a metal one that had to be custom made because of the boring out of the block.
The head on that (thanks Frank for the help).
And the head bolts holding it in place before the torquing.
But, wait, where are the washers for the head bolts? Nowhere – not ordered. Another delay. Calls to the local BMW dealers showed none in Northern California, so another parts order and another delay.
Some good progress was made, but it took a long time and had many delays.
Then I had a heart attack (I don't think it was caused by the delays in the project -- more likely genetics and my unhealthy relationship with fatty meats).
That's the bad news. And that my hope for a big push on the project seems unlikely; that's also the bad news.
The good news is that after a few days in the hospital I have the time to write up the progress. Oh, and the full recovery prognosis; that's the good news too.