Have you been involved with a major engine overhaul?
It’s not enough to just change the bearings because if the big ends have worn and are now oval, you can have some major failures.If the big ends are found to be outside the engine manufacturers’ wear limits, the first option is to replace the rod, but contrary to what a lot of people think, that isn’t always the best route for the owner.
We recently overhauled a 6-cylinder Wartsila Stork engine, and some of the connecting rods were out of tolerance, which gave the owner three options:
1. Replace the rods for new – At £6,000 per rod, that would have been an additional £36,000 to the overhaul costs
2. Put them back in and hope for the best – Thankfully, the client quickly discounted this option!
3. Machine the big ends – At £420 per rod, this included full testing, machining of serrations, reboring and honing back to a standard bore size with a 12-month warranty.
The machining is a very specialist procedure and there are very few companies we would trust to do this, but as you can see the savings can be significant.
We hope this helps show you there can be other options rather than always having to replace, but a word of caution, you won’t be able to do this for everything.
If you want some advice on other options during overhauls or intrusive work, just drop me an email.
