Disaster strikes....

[SteveClem]

Oh, the joy of old cars...

[biomed32uk]

Well as has been said, things always happen for a reason, I've dealt with broken things all my working life.

I have found the reason this morning, I had the small ends done last year as they were sloppy. I have just clamped the rod on the table of my mill, with the piston off and the gudgeon pin sitting in. Put a DTI on it and its .025 and count on the run tilting the piston over.

The others are much better but I would expect them to be much better than they are. The other axis is perfect where it would rotate the piston.

Very very not happy, and now wary of sending it back there to be done, really not what I expected from them.

I now need the small ends doing again, and the block doing. Anyone reccommend anyone else in the Essex area.

At least it wasnt me, that makes me feel somewhat better as I have never had an engine that I have rebuilt do that. I feel like taking it down there and kicking up hell, but I want it doing right.

[les]

When you want something done right, you often have to do it yourself, not always possible of course but reamering a small end is possible, and if you clamp the rod to a drill stand table and stick an adjustable reamer in the chuck, things should be at 90 degrees. Turning the chuck by hand though!

[biomed32uk]

You are quite right there, and I normally do. I have a small vertical mill and could have easily set them up on that and would have a made a damn site better job than that.

Wish I had have done now, hindsight is wonderful though.

Now to find someone else to entrust the block to.

[bmcecosse]

Just pick up another set of rods....

[biomed32uk]

That thought had crossed my mind, or another bottom end to cannibalise, I shall be on the look out as I am in no great rush now.

[philthehill]

Did you turn the rod over 180 degrees and measure again to give you a plus 0.025" and a negative 0.025" as that will give a 0.050" misalignment.
Personally I would be wary of accepting the measurement taken with/from just one face of the rod on the mill table.
Phil

[biomed32uk]

No, not yet, its not the ultimate way of measuring it.

I will be doing some more controlled checking tomorrow, only a quick and dirty check, and of course the real test is for alignment with the big end. I wont be going steaming in when I go back, as I would like them to check it as well, but from my check this morning the cylinder that failed has the greatest error. I need a reason why it failed.

[philthehill]

I agree it is not the ultimate way of measuring but it still gives a good indication.

Better of course to have a really good quality surface plate, a certified/qualified dummy crankshaft big end journal to mount the rod on, two certified/qualified 'V' blocks (with clamps) on which to mount the dummy crankshaft journal and a certified/qualified height gauge to measure either side of the small end/piston pin.
With the above equipment you can also check the rod for twist if the rod (still attached to the dummy crank jounal/'V' blocks) is laid in the horizontal position and the small end/piston pin is measured either side with the height gauge.

I do hope that you do find what went wrong but some times it is not always possible to reach a qualified conclusion.
Best of luck when dealing with the engineering company.
Phil

[biomed32uk]

Well the engine components went down the engineerng shop with me, took the piston as well and their words were 'what the hell happened to that, no oil or water' ?.

They did agree the pins were a little out, however I and they would have expected the piston to show signs of being tilted, which they do not.

However they are having a better longer closer look at it and then we work out a way forwards.

Taking the opportunity do some other little jobs in the engine bay, I now have a painted battery box thats not grey stonechip primer, been wanting to do that for 18 months.