Stripped plug

[peter anson]

I would recommend that you exercise caution in attempting to repairing the spark plug threads with anything other than the time-serts. This is not an area where you want to take risks. People have reported problems with helicoils and their spark plugs. Another tried some other repair and his engine spit out the spark plug in flight.

There is a time-sert tool in circulation with the members here that you can use or you can bring your heads to a machine shop to have it done.

Jake

OK, got to admit I have never used Time-serts, and they may be wonderful, but I have done plenty of thread repairs over the years using Helicoils or Recoils, which are just an Australian made equivalent, and I have never seen one fail. The only reason I can imagine is if they are not installed correctly.

Peter

[mike.smith]

OK, got to admit I have never used Time-serts, and they may be wonderful, but I have done plenty of thread repairs over the years using Helicoils or Recoils, which are just an Australian made equivalent, and I have never seen one fail. The only reason I can imagine is if they are not installed correctly.

Peter

The up-side to the Time-Serts is the ones we are using are made specifically for spark plug repairs. They create a new, flush seat, and are just about fool proof for installation.
https://www.youtube.com/watch?v=Ntiy8L97Nco
https://www.eaa.org/eaa/eaa-news-and-av ... rt-inserts

[GWMotley]

I too cracked a spark plug when using the original high torque values listed in the Aerovee assembly manual. Afterwards, I researched various spark plug manufacturers recommendations and found they suggested about half the value. I have used Heli coils and Timeserts. I believe that Peter is right and it is possible to have good results with helicoils but I think they require a higher skill set to get right. I believe Peter has the skill. That said, I know the Timeserts are much more expensive but I feel they offer a better chance for a higher first time sucesss rate and appear to be a much stronger repair in my humble opinion. I have also used Timeserts on the oil pressure NPT port at the front right side of the engine when I developed a leak and Timeserts even had a specifically marketed kit for it!