Andreas,
There was a recent thread similar to this. You can find it by searching on the title in the upper right corner of this screen.
Below is one of my posts in the thread.
Re: 0-540 Engine Rebuild Cost
Post by N3322G » 15 Feb 2013 09:19
Wrote and article about our overhaul and it might help.
http://www.comancheflyer.com/NS/tech_articles.php#1 lesson for me - choose who removes and installs carefully. We choose poorly, shop is no longer in business. Cost a LOT in future maintenance.
I've gotten private emails about choosing a shop. In our case we thought we knew enough as we'd done business with the shop for a few years. One of the red flags we missed was that they put on unapproved larger oil filters and filed a part to make them fit - didn't know until years later they had filed part off the governor. In general there was an air of arrogance - they knew more than the FAA and they knew more than the owner so they ignored both parties upon occasion. This led the shop to knowingly placing my aircraft in an unairworthy condition according to the FAA after the engines were put back on. I knew this and asked them to return the aircraft to airworthy status. The shop owner got VERY upset. The next mechanic who did an oil change found 'rampant looseness' and declined to work on the aircraft further. Either through negligence or retribution the Lord Mounts were found to be grossly under-torqued which caused damaging vibration. Over several years due to vibration the following had to be repaired or replaced, both vacuum pumps, alternators, starters, governors. Each of these items took months or years to diagnose and solve the problems. My faith in any mechanic has yet to be repaired.
I share this solely to help others avoid anything close to the above experience.