Engine Break In

After a long project it was finally time for the most exiting part: first start and break in. I asked a friend to join me so I could work with the throttle and he could check the timing and make sure everything seemed OK in the engine bay.

We began with the fluids. We filled the cooling system with water and poured some oil in the engine. I'll replace the water with real coolant after seeing that the engine works. Using just water is not an option in Finland and it would corrode all the parts in the engine in a couple of years anyway. We also used some Comp Cams break in oil additive to add some ZZDP. I don't trust todays oils with flat tappet camshafts so I'll be using it after every oil change.

To see that the oiling system worked we decided to pre-oil the engine before starting it. We had a power drill and made a long extension by attaching a few shorter ones together. We taped them together so none of them would drop in the engine. Then we needed a long 1/4 inch socket that would fit over the oil pump shaft.

With the contraption ready, we dropped it in the distributor hole and used the drill to turn the oil pump. But it didn't work. We tried turning it both ways but got nothing. Some nervous moments later my friend realised that I had not filled the oil filter with oil! Without it, the pump was running dry and could not start pulling oil from the pan. After quickly filling the filter, the pump started working normally. I rotated the engine by hand while my friend ran the drill so oil would get everywhere. After only a few seconds oil was flowing out of every pushrod. Phew.

It was time to fire up the engine for the first time. I stepped in the car and turned on the ignition. After some basic checks like turning on the lights so see that we had at least some electricity I turned the engine over. There was no gas in the carb so we didn't expect an immediate startup but after only a few seconds my battery started acting up. I had charged it for six hours before installing it to the car but it ran out of juice almost immediately. Damn.

Luckily I had another battery that we could use. It worked fine even thought it had been unused for the whole winter. The engine did not fire immediately but soon started banging through the exhaust. My friend fiddled with the distributor and then the engine started!

I immediately took the engine to 2000 RPM and kept it there. I made sure oil pressure rose to normal while my friend checked the timing advance. It was about 20 degrees which worked for break in purposes but I would have to measure it at idle later.

What I read from break in instructions, you should keep the engine RPM between 2000 and 2500 for 25 to 30 minutes. Unfortunately after about 7 minutes the engine temperature started to rise too high and I had to turn it off. It was getting late so I decided to let the car cool until next evening.

Before continuing the break in I did some investigation. I pulled the valve covers to make sure all rockers got oil and removed the plugs. They were a bit grey which could mean the engine was running lean. I opened the idle screws a bit and decided to continue as nothing was obviously wrong.

The engine started fine and I took the RPM to 2000. But again after 6 or 7 minutes the temperature rose too high and I had to kill the engine. I assumed that the fan and radiator just was not powerful enough to keep the engine cool without wind. I decided to continue the next day again but this time I added an electrical fan to push air through the radiator.

The fan helped a bit but still the engine ran hot. I started to get a bit worried but did the break in routine in four steps anyway. After them the engine had ran a bit under 30 minutes so it was time to investigate it. I checked the plugs again and they were the same as before. Under the valve covers everything seemed fine too. One of the valves had started ticking during the last break in run so I would have to adjust the valves again. Then it was time to drain the oil and see how it looked.

I let the oil out while still hot and luckily didn't see abnormal amounts of metal in it. I also removed the filter and drained the oil from it. It had a bit more metal flakes but I hoped everything was still OK.

It seemed that the break in succeeded but I would not know for sure before driving 500 to 1000 km. And before that I would need to get my driveshaft shortened. While I was putting the engine back together I had an epiphany. I had forgot to install the PCV valve hose previously! This meant that there was a huge vacuum leak below the carb. That could be the explanation why the engine was running lean and hot. I'd see that on my test drive.