Corvette Needs New Wiring

Now that the engine was finally working, we had time to concentrate on other things. The heater box and some air conditioner ducts had cracks so I took them home and my friend went through the wiring harnesses. I fixed the ducts with some fiberglass and then painted them. Perhaps they actually stay in place and won't leak any more when I get them in the car.

Meanwhile my friend made some interesting discoveries from the wiring. He was checking the AC wires when he noticed that there were sparks flying from somewhere. Quickly he found that a loose black ground wire made them when it hit the frame! WTF? He went through the wires in more detail and found that the AC ground wire was connected to the positive terminal of the starter motor. Which in turn was connected directly to the battery! This had caused a massive short circuit inside the harnesses.

After finding this he removed the AC, ignition and headlamp harnesses from the car because we could not trust them anymore. It was a miracle that the car even ran after the damage from the short circuit or that the car had not burned completely. There must have been quite a lot of smoke after this electrical genius had connected the battery...

I had to think for a while for what to do. I could order all new harnesses but they would still be as badly designed as the original and they cost quite a lot. I had been thinking about adding relays for the headlamps at some point and I also needed an electrical fan for the radiator because the original fan clutch was not working plus the fan shroud was missing. This would be a good time to add these!

In the end I redesigned the whole headlamp harness by adding a central power junction that fed two headlamp relays and a fan relay and sensor. My friend also rebuild the AC and ignition harnesses so every wire was replaced with new ones in the engine bay. This just left the dash harness. It was way too complicated to rebuild by hand so I had to buy a new one. I did some searching and found a shop called Full Throttle Corvette from eBay that had the cheapest price and would ship to Finland. After these changes every wire would be new in the car.

I'll write another post about the redesigned headlamp harness next...

New Cylinder Heads To The Rescue!

I went to spend the new years eve with my friend and we planned to get the engine running during the weekend. At midnight on friday, we first watched the fireworks, took a few beers and entered the garage. The "new" heads were already bolted on so while he started attaching the intake manifold, I took care of the oil pan. After a few hours, the engine was almost complete but still needed coolant, oil and a few hoses. Then it was time to go to sleep before the children woke up.

We continued our project on saturday and quickly completed the engine. After adding oil, we noticed that some of it had leaked on the floor. Luckily it was only caused by loose oil plug in the pan... Perhaps I should have checked it while lying under the car :)

Then it was time to start the engine. Unfortunately the battery was dead so a charging session caused a little break. After a couple of hours we tried again. The engine turned but did not start. Eventually we had to set the no. 1 piston to TDC and check the distributor. Its gear was off by one teeth... It had been off the engine too many times because we installed it according to a wrong marking.

Another try. This time the engine fired up right away! After a little distributor turning it was running great and everything seemed to be in order. If only it hadn't overheated... In a few minutes the temperature rose to the red limit and we had to stop the engine.

A quick check later we figured that there must be air in the cooling system. We started the engine again and my friend let the air out by disconnecting the heater return hose from the water pump for a second. After this the temperature dropped immediately to normal level. After doing this couple of times, the temperature settled to normal level and we let the engine idle for a few minutes. Then it was again time to take care of the children for a while and return at night to do a proper test.

We attached an electric fan to the radiator for cooling and started running the test. We ran the engine for half an hour from idle to 2000 rpm and it worked! Temperature gauge showed pretty stable 200 degrees fahrenheit (about 93 degrees celsius) and gone was the overheating problem! As happy men, we went to sleep.

On sunday we ran the engine again and took the car for a short test drive. There was a lot of snow on the road so you couldn't really touch the gas pedal but at least the engine was working and you could drive the car. Well, actually, we were really lucky that the whole car didn't burn as we later found out but for now we were really happy to finally see some progress in the project.

Engine Dilemma

After finding bolts from the heads, we had a small break thinking about our options. I would at least need new heads but we weren't sure if they were the only problem. New Edelbrock E-Street heads could be had for about 850€ but I didn't want to buy anything that expensive before knowing that the block is fine. If it wasn't, I would have to buy a new engine. Luckily a user from Finnshark told me that he had old but functional stock heads that I could borrow. This sealed the deal. We would test the old engine one more time with borrowed heads and see what would happen.

It took me some time to get the heads and take them to my friend so he also decided to have a look in the oil pan. It was leaking a bit anyway so this was a good time to change the gasget.

There was nothing alarming in the pan. Some dirt but not much. Block was also very clean and even seemed to have four bolt mains. Crank had two stamps: 3932442 and B237. So it was a basic 350 crank made in 23. of February 1977. There was still hope for this block.

Finally in the beginning of December I got the heads to my friend. He had to clean them a bit first but we talked that we could put the engine back together after christmas. I didn't have anything useful to do at home so I took the oil pan for painting. After stripping all the old paint and cleaning the dirt, I applied some POR-15 Chevy Orange to it.

Not like new but much better than before.

Then, at new years eve, it was time to put the engine back together one more time and see if it would finally work.