Bye Bye Mustang

The Mustang is gone. Gone to Tampere for rust repairs that is! I'm pretty confident that the engine works now so it was time to plan for the future. To have any hope of passing inspection this year, I would need to have the floors, rear wheel arch and a piece of the frame repaired. As I can't weld and do not have a place to do it, I talked my friend in to helping me, for a fair price.

At least I have some time to renovate my garage now while it's empty. It is full of crap that I brought in from the rented garage and I'll have to organize it. While at it, I should also upgrade the lighting so I don't have use a portable light for everything. Let's see what I get done before the Mustang returns.

Test Drive

I had some final preparations to do before driving the car. Like installing the export brace and shock retainers. Then I checked that all fluid levels were correct and measured the ignition timing. That proved somewhat difficult.

At first I could not get the engine to idle at all. It started and would stay running at high RPM but if I let the speed drop, the engine died. I tried turning the distributor but soon ran out of room to go further. I had to pull it out and rotate the rotor a few teeth. Finally after many tries I got the engine to idle at about 1300 RPM and could jump out to try and find the correct timing.

I had removed the vacuum signal from the carburetor and checked the timing with my adjustable timing light. It showed about 25 degrees! I needed to turn the distributor a lot more and jumped a few more teeth to get the initial timing to about 10 degrees. Then I could start dropping the idle speed and finally got the timing to 8 degrees at 600 RPM.

I connected all the hoses back to the engine and dropped the air cleaner on the carb. The Mustang was a complete car again.

My first drive was only about 10 km to home and back. It did not reveal any problems. Engine temperature and oil pressure were normal and there were no weird noises. Except the driver side exhaust manifold which was blowing. The exhaust pipe lower bolt is so close to the block and the clutch equalizer bar that it is really difficult to turn. I'll have to find a way to torque it later.

I've been gradually lengthening my drives with the Mustang and last weekend I drove about 350 km with it. In total I've racked about 500 km with the new engine and it has been working flawlessly. As this is still part of the break in I've kept the engine speed below 3000 RPM. After driving another 500 km I'll replace the oil and see what the engine can really do.

My test drives so far have been concentrated on larger roads and I've been avoiding stop and go traffic. After a long drive, I've noticed the temperature rising slightly when stopping. I think I'll add a fan shroud to help cure that.

The T-5 transmission has also been an excellent addition. The shifter works well and the overdrive drops engine speeds really low. At 80 km/h (50 mph) the engine turns 1300 RPM and at 120 km/h (75 mph) only 2000 RPM. The new clutch and machined flywheel also work nicely. No more jumping and slipping when moving from standstill.

All in all, my plan to build an engine with good low-end torque and attach it with an overdrive transmission seems to be a success. The Mustang is fun and easy to drive in all situations and has been trouble free thus far. It is pretty noisy though as most of the interior is missing. I'll have to replace the floors and then address that issue...

Shortening The Driveshaft

The engine was now ready for a test drive but the rest of the car not quite. As I swapped in a T-5 transmission, I was not sure if the driveshaft would fit. I had bought a new yoke for the T-5 so I pushed it in. The original yoke could not be used as it was too long.

To measure the correct length for the driveshaft, I pushed the yoke all the way in and then back out about an inch. This gave it enough room to move without bottoming in the transmission. Then it was time to drop the car on the ground and dig out the tape measure. I crawled under the car and got a measurement of 127 cm (50 inches). Originally the driveshaft was 129 cm (50.8 inches) long so I would have to take 2 cm (0.8 inches) out of it. Not much but I was expecting that from what I had read from net discussions.

The machine shops I had used previously did not have the equipment to balance a driveshaft so I searched for a new one. I managed to find Komet OY in Helsinki and after a call their prices seemed reasonable and they promised the parts back in a week so I delivered everything to them. Another problem with the transmission swap was finding out the correct U-joints. Original joint could be used in the rear but the front one was a mystery.

I bought one joint based on net discussions but after comparing it to the driveshaft, I noticed that it was not even close. To get a correct one I took the shaft and yoke to the store to be measured. We defined that I needed Precision model 505 joint that they luckily had in store. With that, the driveshaft could be assembled. It spent a week in Komet and after getting it back I cleaned it and sprayed some paint on it.

Installing the driveshaft was simple. I pushed the yoke in the transmission and then attached the two u-bolts in the rear. This was a good time to finish some loose ends around the transmission too. First I swapped the gear at the end of the speedo cable and pushed it in the transmission. The cable hole was on the driver side of the T-5 but had been on the passenger side in the old T-10. Luckily the cable was long enough to reach around the transmission.

Then I used a pump to fill the transmission with Dextron 3 fluid and it was almost ready to drive. Final detail was the shifter. I wanted to retain the original look in the cabin so I bought an original appearing shift handle and knob with a 5 speed pattern. With them bolted in, the car was finally ready for a test drive!

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.

Engine Assembly: Final Details

With the exhaust manifolds installed, all the major parts were attached to the engine. I still had a million small details left though. I started with the fuel pump. To make sure it would not leak, I spread some Hylomar on both sides of the gasket before installing it.

The original fuel pipe from the pump to the carb was in good condition so I just cleaned and used it. Then came the oil pressure sender, carburetor, fuel filter, radiator, hoses, throttle linkage, wiring and spark plugs. I bough new NGK APR6FS plugs which should have the correct heat range for my engine. I also made sure that the plug gaps were all 0,75 mm (0.03 inches).

I had bought a Pertronix Ignitor 1 module and a new coil but decided against installing them yet. I would use the original coil and points in the distributor for the engine break in. I knew they worked so I thought it would be safer that way. I turned the number one piston TDC and dropped the distributor in.

I also decided to install the clutch equalizer bar so I could disconnect the transmission from the engine during break in. It was really dirty so I cleaned and painted it. Its bushings were also really worn so I got a new mounting kit.

Final pieces were the battery and valve covers. Connecting the battery revealed a major malfunction in my new starter relay. Right when the negative lead touched the terminal sparks started flying and the engine turned over. I tested the relay and it was short circuited all the time. Luckily my original relay still worked so I installed it back. Now all that I had to do was pour in the fluids and the engine was ready for its first start!