Newb Question: Tools to clean up threads

[Mastrcruse]

I know this might be a super newbie question. Engine is coming out and I’m putting some new studs into the exhaust side of the head. I notice the suggestion of cleaning up the threads. Can someone tell me what tool(s) i need to do this? Is there a set that I should get as I go through the engine and refresh the gaskets to be ready for anything else that needs to be cleaned up?

Also, along the same line, I was removing the hard tube (#8) and the head snapped off (#10) leaving a bit of the bolt in the head. I”m guessing drill and cleanup the threads is the best way to do this? Anyone have suggestions? Wish I I could change this to a soft line but probably not a good idea.

[Mastrcruse]

If there is a set of tools or single that I can get please let me know. Total newb question but I usually freak the f* out when bolts snap but with 31 year old bolts - thinking its something that’s just gonna happen so I want to be prepared.

[e30austin]

Buy a real basic metric tap and die set. It'll have everything you'll need to get the job done. Make sure to use cutting oil or some sort of lubricant when chasing the threads, and most importantly, only go a quarter turn at a time and then back half a turn (so the chips don't jam up the tool).

As far as the broken bolt, if there is any way to put a pair of vice grips on the broken part, use some penetrating oil and localized heat and you might be able to get it out without drilling. Otherwise, a left hand drill bit will be your best bet.

[tomstin]

I think you want thread chaser versus tap to clean out head bolts and stud holes. They are designed to clean and not cut new threads. You can use a tap but be careful. A good set of both will be a worthwhile investment when working on 30+ year old cars.

Also, I find this to be the best penetrating oil http://www.kanolabs.com/penLub.html#anchor173855 Aero Kroil

[mitchlevy7]

you want something like this

https://www.amazon.com/Lang-972-Fractional-Metric-Restorer/dp/B000P6UNHE/ref=sr_1_4?keywords=thread+chaser+kit&qid=1572443255&sr=8-4

I have a slightly bigger set and I have lost track of how many times ive used it and its saved by butt. Those sticks can also be used for repairing threads that are bigger than what the set comes with (axle threads come to mind here). These should only be used for threads that are damaged or dirty, not to create new threads. If it is damaged enough, you will need a tap/die. Good luck!

[ForcedFirebird]

If you don't want to purchase a thread chaser kit, you can just put a slice in an old bolt with a grinding wheel, length-wise along the threads and thread that in/out. The slice will catch all the debris without the risk of double cutting the threads - which can happen with a tap.

[TobyB]

I've done what FF suggests numerous times. Even slitted a nut with a thin sabre saw metal blade...
If you cut the slit at an angle, it works even better.

That said, I finally broke down and ordered the metric version of the kit linked above.

Taps and dies are OK for most threads, but not so much for head bolts, main bearing cap bolts,
flywheel bolt holes, etc. The 'fit class' is usually one class looser than it should be.

t

[Mastrcruse]

I got left hand drill bits, drill and tap and extractor kit. Is it okay to put heat from a small torch on the head?

[e30austin]

A small amount of localized heat is just fine. The goal is to get the area warm enough to loosen the broken bolt, nothing more.

[whodwho]

I would definitely not use taps if chasing threads in aluminum! if you are only interested in chasing threaded holes, these worked well for me

https://www.ebay.com/itm/Jawco-MT10-...A/163682943575