Update from Ian on the last two Saturdays work on D6566 engine re-assembly.  12/2/16


On Saturday 30th January, Dave L helped me with the installation of the last four cylinder heads and after
tightening them down with the ratchet the coolant rails were temporarily fitted and water was put into the
block.
Unfortunately it was found that water was seeping out from under some of the transition rubbers on Nos 6, 7
and 8 heads, the ones we have previously had problems with.
After consultation with Bob C, it was concluded that the Hylomar we had used was not up to the job due to
the level of pitting in the transition rubber seats at those positions.
He supplied me with a silicon based sealant that he said should do the trick.
So on the Sunday with the assistance of Andy P, the three errant heads were lifted again and the transition
rubber seats were cleaned and reassembled using the silicon sealant.
In each case it was obvious that the Hylomar had not adhered but the replacement sealant seemed to be the
business.
In fact it had been noted that the seatings at Nos 1 to 5 positions were in much better condition than those in
Nos 6 to 8 but had understood that Hylomar had been successfully used for sealing in this area on other
locos.
Nevertheless we also pulled No.5 head to check and here it was apparent that the Hylomar had worked,
probably as there was only minimal pitting in the seatings, but we used the silicon sealer here as well during
reassembly.
The heads removed were only lightly tightened to give the sealant a chance to set and left until the following
weekend before re-assessment


So on
Saturday 6th February, the four heads concerned were tightened down first thing and the block was
filled with water and left for 24 hours. When examined on Sunday no leakage was now evident from any of
the transition rubbers or cylinder liner seals so very encouraging!
The water was drained and the coolant rail has been removed again so as the head nuts can now be
tightened to the required 750 lb-ft torque. It is hoped that we will be able to borrow a double-balanced torque
multiplier for this purpose otherwise we will have to use our own single ended tool that was used during
dismantling which will be a lot slower. Also on Saturday, with help from Leroy and Darren, the big end bolts
were fully tightened up to the marks and the locking devices fitted.
The marks on the nuts and connecting rod having been previously applied and when aligned correspond to
the correct amount of bolt stretching. Today, once we were convinced that there were no further leaks, the
oil feed banjo fittings were successfully installed to the bottom of each head including the metric Romanian
ones so BSP must have gone far and wide!
The push rod tubes have also been bolted to all of the heads apart from the Romanian ones.
We do need metric bolts for those and they will be obtained during the week.
Leroy and Ken S were the assistants today.
The plastic injector spill pipe run has also been removed complete and kept intact for the time being to act as
a pattern for the new sections, something I wished I had done on D6575, after the event of course!
The rocker assemblies have been removed from the storage container and placed alongside the loco as
they are next to be fitted following successful completion of the head torqueing.