[RICK LAKE]

Jerry Clayton Hey Jerry Helicoils are a cheap repair for a damaged hole. Over time they rust out, break down or just come loose.
Helicoils are best with LOW torque and LOW load carrying factors.
The top 3-5 threads hold 80% of the load, The rest is along for the ride and over time start to also hold a torque reading too. Heat cycles kill helicoils. IMO they are a quick and cheap repair at the track for making 1-2 more runs. After that, I wouldn't take a chance on them. The threads in the hole loosen and loc-tite doesn't hold them from coming loose. Helicoils strip out high torque holes over time. Been there, had this problem.
Timeserts IMO are alot better than coils. You tap into virgin metal with course threads, countersink them into the surface, they lock in the hole, and in 20+ years of using them I have not had on come out of a block or head yet. This includes alot of your LS motors. They timeserts cost double to three times the cost of a helicoil set or repair kit. I think it's great if you can get by with helicoils. The better product is still a timesert. As far Lawnmowwers and airplane motors both ran for a couple of thousand hours and got a rebuild or replaced. You race on a budget and squeeze every penny. Some motors cost 2-3 times the cost of what you are running. You are a SEMI PRO or PRO racer, Pass on the best info you have or say nothing. If you think helicoils are better than timeserts, then why are timeserts in new motors and not helicoils??? Helicoils are cheaper??? The repair kits are timeserts, not helicoils. I guess the Engineers for GM, Ford, and other companies have a different opinion about the better repair and how to do it and have it last for more than a year or a season. Rick L. Ps I have blown helicoils out of a 3.5 lawn motor engines. It came loose over time due to heat cycles and the breaking down of the material around the hole. Guess I will have to wait 20-30 years my first timesert to give out. If I was to repair airplane motors and the FAA allowed a choice, and have enough material to drill tap and install a timesert, this would be the only way I would gamble with someones life.