I have been working on
the website conversionto a better framework for smart phones and single sign-on, but have been venturing down the shed on a few days. I continued dismantling the cracked block engine, checking to see what needed work as I went. The pictures for this week are in the Gallery starting
TOPIC here but you can page back and forward to see the whole story.
I took off the heads, the oil filter housing, timing cover and tappet cover. Then marked the camshaft at TDC with timing chain tight in its normal clockwise direction of rotation. Then removed the camshaft with chain and sprockets attached. Then labelled each push rod and cam follower so that they hopefully go back where they came from. One day I will build a holder to keep all this stuff neat! All the tie bolts were then released.
The unit was rolled over to remove the oil pump and oil baffle before splitting the block and removing the crank. All bearings were examined and marked. All looked good and might even be reused!!!
As expected the cylinder (4) that had practically had its head detached showed some sign of gasket blow by.
But what is remarkable is how well no 2 faired considering it had almost departed as well.
No 1 and No 3 cylinders were good considering how many hard miles the engine has done.
Here is the crack around No 4.

Here you see how it goes all the way to the water inlet beside No 4.

And here it is continuing to No 2.
I clamped the block onto the mill, drilled and then milled out a 1/8inch groove where the crack had been.
A large area around the crack was ground, sanded and wire brushed to clean up the aly. I used this technique rather than soda blasting as it does not clean well enough, and not sand blasting as I think a lot of the grit embeds itself into the aly.
Then the block was washed with washing up liquid, pressure washed and blown dry with the air gun. Careful attention was paid to oil ways as we did not want any oil contamination on the weld.
I started welding by putting 5 tack welds to bridge the crack in an attempt to reduce distortion.
Then started at the no 2 end gradually increasing current from a start of 80A. I also reduced the cleaning % from 75 that I had used previously to 60 to put more heat into the block. On the thick bits (around the cylinder head bolt holes) the amps were wound up to 150 so as to get the flow needed. But you have to be VERY careful as the weld can suddenly sag. It did this a couple of times so I turned the block over and heated again to get the sag to go back. All was going well till the foot pedal decided to die. I continued tidying up with a makeshift torch switch but not very succesfully. I have just fixed the foot pedal which required dismantling the potentiometer and straightening the very small brush inside it that had been bent. This I traced to being caused by the stop on the pedal not being set correctly and straining the pot. I am also out of Argon so ordered some more.
I am quite pleased with the result so far. I am learning fast. I have added weld to take the strain down from the bolt holes to the thicker part of the block. Pictures to follow.