You can use a helicoil but they are not rated for high torqque ratings. If it were me I would tap the threads to the next bolt size up and use the bigger bolt.
Purchase the appropriate sized easy out and drill bit from an auto parts store and drill into the center of the bolt head, you then insert the easy out and its reverse threads will back the bolt out. ( as you tighten the easy out counterclockwise the bolt will loosen )
A cracked or broken piston will cause a loss of compression, as will cracked or broken rings. The failure of a head gasket will also cause a loss of compression, as will broken, cracked or badly worn valves or valve seats. A crack in the cylinder itself (either the sleeve or the engine block), or a crack in the head itself will cause a loss of compression. A problem with the plug threads or the threads in the head (for engines that have plugs) can cause loss of compression, and injectors (for engines that have them) can leak around the threads, either because the injector threads or the threads in the head have been damaged.
A head gasket is a gasket the separates the cylinder head and the block. It separates the coolant passages, cylinders and oil passages. There are many other posts on this page that will provide more details. The head gasket provides a seal between the head and the engine block.
The Lexus cylinder head bolt torque specification is 150 pounds. The cylinder head bolts should be torqued in 50 pound intervals.
blown head gasket or cracked block blown head gasket or cracked block
the easiest way is to drill it out. drill a hole thru center of broken bolt, make sure it is smaller then the diameter of the bolt. after drilling use a easy out to remove the threads of the bolt. check that the threads in the head are ok! then put in new bolt.
The grip length of a bolt is the distance from the head of the bolt to the nut or where the threads start.
bolt strength markings. Numbers represent metric threads and slashes represent standard threads (the greater the number/slashes, the greater the strength of the bolt.
Any bolt that passes through the block/head into the cooling system should have thread sealant applied to the threads when installed.
The question itself indicates you need to do a bit of reading on the hot-rod type websites. 1st, chase the threads in the block with a thread chaser (not a tap), next be sure the head bolt threads are clean, then dip the bolt into clean motor oil, let it drip off then torque to your heart's content. remember to follow the head bolt tightening sequence (generally middle of head and then outward toward each end. run the engine to operating temperature, shut it off and re-torque the bolts. This answer assumes (factory, iron heads, no aluminum heads. Bolts for aluminum heads MUST have steel washers between the bolt and the head. Good luck. Do it right or you will be replacing a head gasket (AGAIN). I like to put Indian Head shellac compound on the head bolt threads to be sure water doesn't travel up the threads. The sealant IS NECESSARY ON A CHEVY, because the head bolts penetrate the waterjacket. Told you, that you were a rookie then left out vital information myself because I was thinking of torque readings ONLY. YOU HAVE TO PUT SEALANT ON THE THREADS. Sorry for the goof.
If you have stripped the head of a head bolt you will need to either obtain a special socket that grabs stripped bolt heads (Craftsman makes one), or you will need to drill the center out of the bolt and insert an "easy out." The second option is extremely difficult. Your third option, if you are very accurate and surgically precise would be to drill the bolt to only the inside diameter of the threads. This will cut the threads of the bolt off into the threads of the hole. Then you can use a tap to clear the threads, being very careful not to allow any metal shavings to fall into the engine.
65 foot pounds clean threads in block 1st and use sealant on the dolts that go into the water jacket...oil all other bolts
The threads in the head may be dirty. Try cleaning them out with a round wire brush. If that does not work, try a different plug. If another spark plug will not tighten, then the threads in the head are damaged and you need them professionally repaired.
bottom surface of the head to the end of the threads
Bolts are manufactured with the help of bolt making machines, a hexagonal shaped or round shaped rod is inserted into the machine, where in first stage head is formed by the block of the design of your choice, and at the scond and final stage threads are formed of the size chosen accoding to your need.
yes it will fit.
You can try to clean the head bolts using either a wire brush and solvent, a bead blaster or soda blaster. After the bolts are cleaned thread them into the block to make sure they turn freely. If there is any indication that the threads are damaged do not use the head bolts. Do not use a sandblaster to clean the head bolts since that will cause erosion of the threads, making the head bolt unusable.