To learn more about the Time-Sert J-42385-500BS and other Big Sert kits read on, or select the following link Time Sert J 42385-500BS  to visit the product page for one of our most popular Big Sert kits.

©DenLorsTools.com Summary: Time Sert frequently asked questions. This article explains the difference in the Time-Sert Big Sert kits and the standard size kits. Big Sert kits have the initials BS on the end of the kit number. Like the J-42385-500BS and the J-42385-500; the two numbers are very close to being the same and are often confused with each other. Both are used for repairing threads for head bolts in the engine block of the Cadillac NorthStar.

In fact GM has instructed their factory trained auto technicians Time-Sert is their “go to” repair solution for this particular problem. In a previous Cadillac thread repair article we mentioned that GM even includes Time-Sert in their TSB (Technical Service Bulletin) regarding thread failure and repair in the NorthStar block. But what does the “BS” stand for at the end of the second tool kit number? The BS stands for Big Sert. Big Sert is the manufacturer’s branding that means the inserts are “over-sized”. Over-size inserts are required when there’s been a previous repair made that has failed. That’s why we sell the J-42385-500BS to customers that are doing second repairs on engines that have been Heli-Coiled previously. This most commonly occurs when a Heli-Coil did not hold. If the service history is not known; One way to determine if a Heli-Coil has been installed before, is to check the remnants of the threads that are clinging to a head bolt or come out with the head bolt when it’s removed. Use a magnet and see if the damaged/loose pieces of the threads are attracted to a magnet. Since aluminum is not attracted to a magnet, if there are pieces of threads that cannot be picked up with one, the threads that have failed are most likely from the aluminum block. If the small fragments can be picked up by a magnet the pieces are most likely from a steel Helicoil insert that has failed.

Question – Can I use my tap and dye set to install a Time-Sert insert?

Answer – No. The Time Sert insert uses a special size tooling. Also the kits utilize a process to install the inserts. It’s not as simple as tapping the hole and running an insert in. One of the steps with Time-Sert is using a special driver installation tool that locks the insert into place by finishing the lower threads of the insert. We provide more details on this below.

Question – Do I need to use a different size head bolt after the Big Sert is installed?

Answer – No. The Big Sert kit accepts the same size head bolts as used originally. Only the outside diameter of the insert is larger. The outside diameter of Big Sert insert that comes in the J-42385-500BS kit is 15.1mm (.594″).

Question – I have a Northstar engine with a repair already done on it that has pulled loose. Which kit do you recommend?

Answer – The Northstar engine that has the M11x1.5mm (the most common head bolt size) can use the Big Sert J-42385-500BS.

Question – Do I need to use the dowels in the 42385-500BS kit or can I just use the old ones?

Answer – In the regular size kits the original line-up dowels are used. With the oversized Big Sert kit like the J-42385-500BS, the larger outside diameter line-up dowels are needed if repairing a hole that a line-up dowel was originally in. If not repairing one of those holes with a BIG SERT then there’s no need to replace any dowels. If installing Big Sert inserts for a Northstar in every hole there will be a total of four dowels needed. Two come in the kit, two additional ones would need to be purchased. Two used per side

Question – When preparing to “seat” an insert, the driver only threads in a couple of threads. Do I have an insert that was not threaded properly? The image above shows the tiny metal pin adhered in the notch of a Big Sert insert.

Answer – No. This is the way all Time-Sert inserts and Big Sert inserts are designed. The driver always cuts the remainder, completing the threads making them ready to accept a bolt, or spark plug etc. The process also applies pressure outwards locking the insert in place from the bottom. On the Big Sert inserts there’s also a cam that is pushed outward further locking the insert into place. Time Fastener explains it like this: “The install driver seats the insert and completes the bottom internal threads locking the insert in place. This pushes the pin out to contact the threaded hole. Back out of the insert is prevented by the cam lock effect of the pin.”

Question – I see many regular size Time Sert inserts are black. Why are some Big Sert inserts copper and some silver in color?

Answer – The black Time-Sert inserts are steel and have gone through an extra Zinc Phosphate step producing a black oxide covering to help reduce the possibility of corrosion. This type of rust protection is ideal for this application because the process adds no measurable difference in the dimensions of the inserts. Basically copper plated inserts including Big Serts are steel with copper flash. They are used for washer seat spark plugs because of the properties they possess that help eliminate the possibility of seizing. Engineers have determined that it’s best for the taper seat spark plug inserts to be silver plated. There’s also some aluminum spark plug inserts for certain racing applications. Stainless steel inserts are usually recommended for medical and food service applications. In the automotive field stainless steel inserts can be used when there’s a high exposure to elements that cause oxidation (corrosion/rust) like for brake caliper threads which are exposed to metallic brake dust.

Question – Some of the Time Sert websites say you need to check the head serial number after 2001 models because there are machined (counter sinks) in the plug hole if they are not Windsor heads. Do I need to worry about the type of head on a 2003 5.4 Triton?   Image above courtesy of the Time Fastener Co.

Answer – I wouldn’t be overly concerned about which head is being worked on. Here’s why. With the exception of holes that have been previously Heli-Coiled, the counter bore is to be used on either head. I understand that some people prefer to know exactly which type of head they are working on so they know how much material they should expect to be removing. However, the 45 degree stop (on the 55518 as pictured) will prevent over-cutting. In the heads with the squared double counter-sink more material will be removed. Thanks to excellent engineering, the tool will be allowed to go down no more than 3/8″ maximum on the double countersink holes and even less on holes that are have a single counter-sink.

Question – For the 2 valve Ford Triton engine, which spark plug thread repair is best the Time-Sert 5553 or the Calvan 38900?

Answer – Time Sert and Calvan are different brands of thread repair kits, just as Hewlett-Packard and Apple are different manufacturers of computers. Each do things a little differently but each will get the job done. We sell a large volume of each brand and both have excellent feedback. The Calvan has a limited application, therefore has only one insert available. The Time-Sert brand has many inserts available and uses a different method for lining up the tooling; Time-Sert uses a self aligning tooling as opposed to Calvan that uses a separate line-up guide that only fits down the spark plug well of the 2 valve Triton. Therefore, Time-Sert can be used for more applications, not just the Triton 2 valve Triton engines.

Question – I am replacing/repairing a previously repaired spark plug thread (heli-coil blew out) and I need to know what is the difference in the (1) CalVan Tools Ford Spark Plug Insert Installer CAL38900 and the (2) TIME-SERT 5553 Ford Spark Plug Thread Repair Kit? Can I use either? Both say Ford Triton. My 1999 Expedition has the 5.4 Triton engine with deep recessed spark plug holes. The hole is now .660 inches since the blow-out and I need to repair it for the second and hopefully, the final time. Thank you for your help!

Answer – Either would work because they are both over-size, the Calvan insert is larger at .73″ on the outside of the threads compared to the Time-Sert which is .70″ on the outside of the threads. See our Ford Spark Plug Blowouts frequently asked questions article for more info on the Calvan. For other rare occasions when the hole is really enlarged an insert can be put inside an insert using the Time Sert 5553 and 5558 kits together. The Time Sert 5558 insert measures .77″ on the outside of the threads. This combination rarely needs to be used though. This is obviously the last resort when either the 38900 or the 5553 is not big enough. We sell many 5553’s and 38900’s and rarely sell a 5558 add on kit. Keep in mind the 5558 add on kit cannot be used with the Calvan.

Question – I was looking at head bolt thread repair kits but not sure if it is the right size for 95 Nissan Maxima 3.0. The bolt size I have is 11×1.25 unless I measured wrong. I do not see any kit for that size. Which kit should I purchase for my head bolt thread repair?

Answer – You may have the 10 x 1.25 mm or the 11 x 1.25 mm. Use a nut from a parts store or a thread chaser from a tap and dye set to thread onto the bolt to verify the bolt size if needed. Below are universal kits that you can adjust the depth. These are first time repair kits used when it’s the first time the threads have ever been repaired. All linked below have free next day shipping.

Time Sert 11125 11×1.25mm Head Bolt Thread Repair Kit, commonly used on Subaru

Time Sert 6250 10×1.25mm Head Bolt Thread Repair Kit, commonly used on Nissan

If the holes have had inserts installed before like Heli Coil or some other competitive brand that have failed, a Big Sert Kit which is oversize will need to be used, see below.

Time Sert Big-Sert 11125BS 11×1.25mm Head Bolt Thread Repair Kit, commonly used on Subaru – 2nd Repair uses over-size inserts.

Time Sert Big-Sert 6250BS 10×1.25mm Head Bolt Thread Repair Kit, commonly used on Nissan – 2nd Repair which uses over-size inserts.

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