Frequently Asked Questions

Q: What makes the NS300L™ Insert System more reliable than other types of inserts?

A: The NS300L™ is a high quality high-strength insert, with a much courser external thread, which allows the insert to have a lot more thread engagement within the aluminum block than the competitors inserts. In many cases, three times more thread engagement.

Q: Are the taps long enough to reach the bottom, or do I need to add an extension to the taps?

A:  We get this question a lot due to a YouTube video in which the customer welded an extension to the taps. Although the video is very informative, the customer had not read the instructions prior to doing the repair. In almost all cases, the standard taps are long enough. In those rare instances where a longer tap is required, an extension tap is supplied. Most times the inserts are not required to be installed to the original factory depth. The reason for this is, the head bolts usually only engage about 1" to 1¼" of threads in the block, but the head bolts usually have much more threads on them then what is being used from factory. Having more threads engaged provides a much stronger repair. As an example, the Toyota 2.4L 2AZ FE engine from 02-06 has a starting thread depth of 3", but the inserts only need to be installed 1½" due to the head bolt having almost 3" of thread. In 2007 Toyota changed the depth to the start of the threads in the same engine to around 1½", allowing more thread engagement.

Q: Why should I purchase the NS300L™ Insert System over other repair kits on the market?

A: Piece of mind! No other method has been proven to be a better, more reliable repair. Many customers have commented that they were very impressed with the quality and strength of the NS300L™ inserts, and wished they had purchased the NS300L™ Insert system in the first place rather than going through the expense and frustration of a failed repair.

Q: I noticed that the competitors kit has a stop-collar on the drill bit. What keeps your drill bit from drilling too deep?

A: The reason the competitors kit uses a stop-collar is, the depth of their hole revolves around their locking feature. They have a flange around the top of their insert to create a positive stop so that the installation tool (a tool much like a thread forming tap) also forms the last couple of threads on the bottom, inside of the insert. The flange prevents the insert from turning during this process. This locking feature expands the last couple external threads of the insert, preventing the insert from turning out in the event that the head bolts would need to be removed later. This locking feature also creates a high amount of unnecessary outward pressure in an area of the engine block that is not very thick to begin with. The NS300L™ inserts are designed without the need for a flange, eliminating the need for a stop collar and eliminating unnecessary outward pressure. The drill bit in our kit is designed to stop when it reaches the bottom of the hole. This is accomplished by removing a portion of the drill point, preventing the drill bit from drilling deeper than the original hole. The drill bit’s cutting edges are also ground in a manner that helps prevent them from grabbing and cork screwing itself into the hole.

Q: Can the NS300L™ Insert System be used if the engine has previously been repaired with coil type inserts or competitors "first repair" inserts?

A: Yes.

Q: Can I re-use the old head bolts?

A: The threads on the old head bolts are often stretched out of pitch, causing them to tighten prematurely in the new inserts. New head bolts must be used.

NOTE: IT IS HIGHLY RECOMMENDED THAT GENUINE FACTORY OEM HEAD BOLTS BE USED WITH THE NS300L™ REPAIR, AS SOME LOW PRICED AFTERMARKET HEAD BOLTS ARE NOT THE SAME QUALITY. SOME AFTERMARKET HEAD BOLTS ARE MANUFACTURED WITH POORLY FORMED THREADS WHICH CAN CAUSE THEM TO SEIZE IN THE INSERT. OCCASIONALLY THEY ARE TEMPERED IMPROPERLY ALSO, CAUSING THEM TO PREMATURELY REACH THEIR YIELD POINT.

Q: Can ARP® (www.arp-bolts.com), brand high performance head studs be used with the NS300L™ insert?

A: Absolutely. ARP® brand head studs are excellent, well engineered, high performance studs with rolled threads, that will work very well with the NS300L™ insert, in fact, we believe you will find no better combination on the market for high compression, high performance engines. Studs are typically preferred in race engines with extreme high compression, and where the engine is constantly being torn down and rebuilt. They also provide a more consistent torque load.

Q: In the future, will I be able to order the inserts alone, or do I have to purchase the complete kit every time?

A: The inserts can be purchased separately and are typically sold in sets of 11 and 21. In fact, many kits are designed that a different kit must be purchased with every different thread size. The NS300L™ Thread Repair System has been designed to be universal to work with many thread sizes. This is achieved by standardizing the outside thread of our inserts which allows you to use the same drill, taps and alignment jig for every insert size we have available.