Things have been quiet on the blog in recent weeks. However work is still progressing. The welders are still welding. Geoff and Martyn are still undertaking open heart – or more accurately open cylinder – surgery on the gardiner engine.
Unfortunately, it’s not the best news on the engine front…
“On stripping the rest of the engine it was clear that the rust in the
bores has affected five of the six cylinders. We considered if it was
possible to hone out the cylinders to clean them up so that they could run
on some more. Detailed measurement showed that all the cylinders are
already at maximum tolerance so a hone would certainly take them all far
too oversize. So all six liners need replacement.
The pistons are not worn out, but have been damaged by running the engine
with rusty bores.The piston rings are shot.The ring grooves in the pistons
are oversize so any new rings would have to be made higher than standard
and the pistons machined to receive them. It would cost as much to reclaim
the pistons as new ones. My advice is that they will need to be replaced.
Five out of the six big end bearings are in good order. The sixth has
brindled due to standing which is the failure of the bearing face due to
electrolytic corrosion. Not a big problem in the greater scheme of things.
We may be able to track down a new “old stock” bearing or, failing that,
get the old bearing re-metaled. Every day stuff for us.
The bottom line is that the newly discovered issues will prevent the
engine from returning to work unless a top end overhaul is undertaken.”
Unfortunately this means more parts and more man hours. In Geoff’s own words “You need to lay down for this bit”.
“Our professional advice is that your engine is a pretty good example of
its type and we doubt that sourcing another engine of similar power output and unknown provenance would come out any cheaper.”
Unfortunately extra costs but the conclusion is that the refurb is still a cost effective way of getting a good engine for the boat.
Now for the pictures:
“I have attached some pictures for your consideration. Not pretty. One
shows one of the rusty and worn liners, another the brindled big end
bearing showing the damaged face. The final picture shows one of the
ripped up pistons”
Thanks to Geoff for the excellent explanation.