timecert question, helicoil uncoiling Options

[VaccaRabite]

The skinny:
Spark plug helicoil is going bad - uncoiling out of the socket. I know that I want to timesert it to fix the problem.

BUT

Since the socket has a helicoil in it (that needs to come out) what size timecert do I need to get?

ALSO

How do I get the bad helicoil out of the head without doing further damage to the head? The head is off the engine, so I am not worried about bits of coil falling into the cylinder.

This site has MANY sert options, but I don't know which one I need. HELP?!
http://www.timesert.com/html/sparkplug.html

Thanks
Zach

[HAM Inc]

Make sure you grab the tag end at the outside of the head (not the chamber side.) If you booger the first thread a little it won't be a problem since it will be removed when you do the counterbore operation.

You didn't say which engine you have, but if it is a 1.7 or 1.8, be very careful screwing the tap into the head. The 14mm pilot portion of the tap will likely make contact with the intake seat. This is worse on the 1.7's. You would think that the interference from one 1.8 (or 1.7) to another 1.8 or (1.7) would be the same, but it isn't. Some clear the seat okay, while others don't. If it is bad enough, cut off the pilot portion. A new tap will run you around $30.00. A lot cheaper than having another valve seat installed.
Once you have the head prepped for the TimeSert, make sure the shoulder on the insert fits into the counterbore before performing the swedging operation. You don't want to swedge and then find that the shoulder is sticking out of the head. If it sticks out the plug will seal against it and likely pull it out next plug change, which might mess up the threads. I have installed a blue million TimeSerts and have noticed that the QC on them is not what it used to be. I have to chuck a lot in the lathe and file down the shoulder so it fits properly.
Good luck!

[jimtab]

Make sure you grab the tag end at the outside of the head (not the chamber side.) If you booger the first thread a little it won't be a problem since it will be removed when you do the counterbore operation.

You didn't say which engine you have, but if it is a 1.7 or 1.8, be very careful screwing the tap into the head. The 14mm pilot portion of the tap will likely make contact with the intake seat. This is worse on the 1.7's. You would think that the interference from one 1.8 (or 1.7) to another 1.8 or (1.7) would be the same, but it isn't. Some clear the seat okay, while others don't. If it is bad enough, cut off the pilot portion. A new tap will run you around $30.00. A lot cheaper than having another valve seat installed.
Once you have the head prepped for the TimeSert, make sure the shoulder on the insert fits into the counterbore before performing the swedging operation. You don't want to swedge and then find that the shoulder is sticking out of the head. If it sticks out the plug will seal against it and likely pull it out next plug change, which might mess up the threads. I have installed a blue million TimeSerts and have noticed that the QC on them is not what it used to be. I have to chuck a lot in the lathe and file down the shoulder so it fits properly.
Good luck!

You don't need to cut the end off of the tap...just buy a bottom or plug tap instead of a taper tap....

[slim72914]

NO NOT YANK it out! you should be able to turn it out like you would a bolt. if you can get needle nose on it some how maybe bend the 1st thread out on the helicoil. if you just yank it out you will have to retap the threads for sure.