Heads Come Off One More Time

With the heads off again, my friend checked them one more time. Quickly he noticed something strange in the oil passages in one of the heads. After some digging he got a little dirt out.

A bucketload of burned oil and other crap fell out. It seemed that some previous owner had been driving without an oil change for a few years. Or decades... Now that the engine had been running for some time with new oil, it must have loosened all this crap up.

But that was not the worse part. He also noticed something strange in two of the exhaust ports.

There were three bolts sticking out of the head inside the two middle exhaus ports. After some cleaning the other ends were found from the combustion chamber. So, someone had bored three holes through the head, made threads, added some long bolts and finally cut them and sanded the chambers clean. What, The, F***!?

Most likely we had finally found out why the engine was overheating. The bolts went straight through the water passages and this could open a way from the combustion chamber to the water. All it needed was that the head and the bolts expanded at different rates with heat.

Swapping Cooling Parts

We started to get pretty frustrated with the engine as nothing seemed to work. Water passages were now clean, the engine had a new pump and thermostat, radiator had two electric fans, ignition was fine etc. We tested pretty much every tip I got but the engine still overheated while idling on the yard. And this was already November 2010 so temperatures were below freezing.

Then it was time to switch parts. We started with the radiator as that was the easiest to change. Our own seemed to work fine but we did the test anyway to be sure. I borrowed a working radiator and drove it to my friend. We drained the cooling water and swapped the radiators although my own seemed to be in much better condition... Naturally this did not help and the engine overheated again after running about 10 minutes.

This at least confirmed that the problem was inside the engine. I was almost ready to go and buy a new engine but we decided to get the heads off one last time and take a look. Maybe the block just had been bored too much and this caused overheating. Or the block or heads were cracked. I got a tip for magnafluxing the block to see if had cracks. For now I returned the radiator and my friend started taking the engine apart yet again...

Engine Tests Continue

In August I had my summer holiday but I also bought a house that needed some restoration. I spent my whole vacation with the house so I couldn't help my friend at all. He also just had a second child so he didn't have much free time either... But I think he has more hours in hes day than I, so he did manage to put the engine back together.

He lapped all the valves in the heads and then put all the parts back together. Then it was time to fire the engine up again. Unfortunately something was wrong as it was running with only seven cylinders. This was caused by stuck lifter. Luckily it did not break the valve... By adjusting the rocker it was possible to make the engine sort of work with all cylinders but the lifter had to be changed in any case.

Now that the engine was running, the cleaning started. He ran cooling system cleaner through the engine multiple times until only clean water came out. Most likely the engine had been standing with only water in it for some time because a lot of brown sludge was found inside.

Finally it was time to test the running temperature again. Aaaaand the engine overheated even when just idling. No matter what he did, the engine just wouldn't stay cool. He added some electrical fans, changed the water pump etc but nothing helped.

While working, he also tested the compressions from the cylinders. They were about 11 bar (160 psi) so the valves seemed to be tight. We were running out of ideas. Some part was not working but we didn't know which one. We just would have to start changing parts and hope we wouldn't have to change the whole engine...

Engine Surgery

My friend started going through the engine after getting the car. One good news was that water had not actually mixed with oil but the fault list was long anyhow. Head gasget had burned, the water pump was full of sludge, exhaust gasget was blowing, little oil was leaking from the oil pan, thermostat was missing etc.

He got the first head off during the first night.

It seemed like the engine had been overhauled not so long ago. Block had been bored 0.060" over, pistons seemed new and honing marks were still clearly visible. I guess the engine had not been used much after the rebuild. As if that had been possible anyway...

In the end of July I went to see the engine. Both heads were off but no obvious reason was found for the overheating. Water passages did have some sludge, water pump needed to be replaced and thermostat was missing but we weren't sure if these would be enough to cause the engine to overheat this badly.

In the end, we desided that I would buy the missing parts and my friend would go through the heads. Then we would put the engine back together, flush the cooling system and hope it would solve our problem.

I also checked the casting numbers from the different parts. Block was 3970010 and heads were 338882. Nothing special. I also took a few pictures from the engine internals.

Engine Failure

The beginning of my trip went pretty well. Electrics seemed to work, engine ran fine and weather was wonderful! But, of course, this Corvette has a problem for every situation to sour the mood.

After a few kilometers the engine temperature rose pretty high again. After a bit more it went past the red limit. Just to be safe I stopped at a gas station to take a look. And I saw hot steam pouring from under the car. The engine had overheated quite badly and was spewing cooling liquid from the radiator to relieve pressure...

After some time I dared to open the radiator cap and saw that the radiator was almost empty. I had not given up completely yet so I fetched some water from the gas station and filled it up again. I had to add over 6 liters of water! There had not been much left in the system...

Bravely I continued slowly but after a few kilometers more, the engine overheated again. This time I stopped immediately at a bus stop but still there was steam pouring from the overflow hose. I had only driven about 30 km and was now sure I was not going to make it to my friend.

I waited a while and checked the radiator again. It was missing some water but not as much as before. Luckily I had filled a few bottles with water in the gas station so I could fill the radiator. I started driving towards home but had to stop every few kilometers to cool down.

"There is a lot to work on this car but at least the engine and driveline are working!", we had thought. Now the engine had failed big time. I was pretty pissed...

The engine overheated faster and faster and finally about 10km and three stops later I pulled over at another gas station. I checked the oil and it seemed like there was water mixed together with it. That was it, the car could not be driven any more.

Luckily my wife had been following me in another car so I left the Corvette at the gas station and we drove home.

I had a basic insurance taken for the car that protected agains theft (as if anyone wanted it), fire (much more probable) etc. I checked the papers and noted that it also covered towing if the car fails on the road. I called them the next day and they agreed to tow the car to my friends place as the engine could be fixed there. My friend said he could take the engine apart so we agreed that the car would be towed there in a couple of days.

While waiting, I bought a complete gasget set for the engine from Felpro and placed it in the Corvette when I went to meet the truck driver. He lifted the car on the truck and this time the car actually managed to get to my friends place...

Travel Preparations

As it was, we didn't have time to weld all the holes in the driver side floor when the car was at my friends garage. The plan was that I would do everything I could alone and drive the car to my friend for the rest of the welds.

There still was some work to do before I dared to drive the Corvette. I fixed some of the electrics and got all of the lights working by changing some lamp sockets and cleaning the connectors. After some fiddling the brakes worked again too. Then all that remained was to replace some hoses, change the oil and put some of the interior together.

In the beginning of July 2010 I was finally ready and took a short test drive. The car was really noisy as all the parts were not tight yet but at least it worked for about 30km. The back of the car was so low, that the exhaust hit the ground in some bumps. This also severed one of the joints so I had to reconnect it two times.

One more serious issue did appear. The engine temperature rose pretty high while driving. It went close the boiling point but I stopped to cool before that. I was not sure if this was caused just by a misreading from the new temperature sensor or if the engine was really overheating...

Couple of days later it was time to drive the 150km to my friends place. And I quickly learned that we had just started scratching the surface of the problems in this car...

Brake Caliper

While the control arm was off the car, I decided to take a look at the brake caliber. It was leaking so I got it off the car.

I dug the pistons out an quickly found the reason for the leak. One of the dust covers was loose and there was dirt under it. This had ruined the seal. I also noticed that the piston was pitted. Not badly but I decided to replace it anyway. I changed the seals and bolted the caliper back to the car. Unfortunately things didn't go so smoothly....

While I was bleeding the braked, the pedal suddenly went soft. I went to see the caliper and the same seal was leaking again. Off came the caliper and I cheked the piston holes. It seemed that someone had sand blasted the caliper and had not protected the cylinder walls. I had seen this but hoped that they would be smooth enough. They weren't. In the end I bough an used caliper and put it together with a second set of seals. Finally, after bleeding, I had working brakes on the car!

Oh, and naturally I wanted a better looking caliper. I bought some silver Hammerite paint and got a pretty good result. I would have to see how long the paint would last...

Chassis Overhaul Done

It took me some time to change the joint and bushings but finally in April the control arm was ready for install. With a fresh coat of paint, the parts looked much nicer.

And again I noticed that working alone was much more difficult than with a friend. I used the same procedure as before and after two nights of fiddling, the car was back together again. Is also painted the sway bar and changed all the bushings from it.

Now, finally, the chassis overhaul was done! Only old part still left down below was the idler arm. I didn't have plans to change it yet as it seemed to be in pretty good condition. It was great to see that I could get something done even alone :)

I Must Fight Alone

It was the end of February when we reinstalled the control arm. Again things went pretty smoothly. First we connected the arm loosely to the frame, placed the spring and connected the lower end of the shock absorber. Then the tricky part was to jack the arm up and load the spring enough so we could connect the upper end of the shock absorber. Getting the spring to stay in the correct place was a bit fiddly but together we managed to do it pretty easily. After this we didn't have to worry about the spring any more so bolting the rest of the parts together was simple. Now to do the same for the passanger side!

This is when things got a bit more difficult. My friend moved to live about 150km away from me. So from now on, I would have to work alone with the car. This would be interesting...

After helping my friend to move, I began working with the other control arm. It took me couple nights but I finally managed to get it off.

Getting the driver side was easy when there was a professional working with it but now it wasn't so simple any more. The lower ball joint was really badly stuck. No matter how much I sprayed it with WD-40, hammered it and used a pickle fork, it would not come off. I went and bought two different removal tools but neither of them worked because one was too small and the other just slipped of the joint when tightening it. I started to see red and finally got the ball joint off with the pickle fork and a larger hammer. I guess I was just afraid to use enough strength...