I'm putting my heads back on soon, and I can't find thread chaser ANYWHERE. What other alternatives are there? Can I just use rubbing alcohol on a q-tip or something? I will pay someone $20 to ship me their thread chaser 7/16"-14 and I will return it. I can't find it anywhere. I want my torque specs to be right. HELP!

 

Try a bottoming hand tap. Here's a link to McMaster-Carr catalog.

http://www.mcmaster.com/

I would suggest using part number 2521A644. It's $7.80 +shipping. Search for that number. Also click on Taps in the "Machining and Clamping" section for a lot of info on taps.
A tap wrench is nice also.

Normally ground UPS will get you parts in 1-2 days.

I hope this is what you mean by "thread chaser" to clean out the threads. WD40 squirted in the hole helps while "retapping".

BTW, I wouldn't use a bottoming tap to hand tap a thread in a drilled hole. Just use it to clean out a previously tapped hole.

Good luck.

 

yes, I meant just for cleaning. I went to the site you posted and found the part #, but I want to be CLEAR that I don not want to make new threads, just clean out the thread locker out of the holes in the block so my torque readings are super accurate when putting my heads back on. If I get one more reply saying that part number you listed will do the trick, I'll order it. I heard the head bolt holes are heli-threaded or something, so I don't want to screw them up.

 

If the holes are heli-coiled, they have been tapped oversize an a stainless steel insert that loosk like a spring has been installed. It fits into the oversize tapped thread with its outside shape and has the shape of the 7/16-14 thread on it's inside diameter. It will be obvious if they are installed because the stainless steel insert is a different color from the aluminum. You can also see the top end of the Heli-coil where it stops.

Try dissolving the sealer with different solvents. Acetone might work. Alcohol probably won't touch it.

FWIW, if the holes are Heli-coiled, the H3 tap should still clean them out, Only use light wrench torque to retap, like a couple of lb-ft. Starting the tap straight BY HAND is important.

 

alright, now I'm confused. When I said I thought they were heli-coiled I meant I thought ALL LT1 heads had to go into heli-coiled threads. As in they are stock. I guess that's not true. I'm confused now. The holes don't have a different color steel insert. The heads have never been off the car before. So based on that, what do I need. It sounds difficult. I just thought I could buy the bit and the "hand" drill thing and do it all by hand. I didn't know I had to use any other tool other than the hand tool.

 

Don't use taps [bottoming or otherwise] in the holes..
Yes.. you want a THREAD CHASER not a TAP...
See thread chasers:
http://store.summitracing.com/productdetail.asp?p=1815

http://store.summitracing.com/produc...earchtype=ecat

http://www.arp-bolts.com/media/pdf_files/TO_65-66.pdf

The last one is ARP but a pdf file [need Adobe Reader to access..

Thread chasers are basically 'undersize taps' used to clean the threads.. TAPS remove material.. you don't want to remove material from the block..

LT1 blocks being cast iron, aren't helicoiled for the head bolts..

Those above sources sell a whole set for about 15 bux..

You just use a wrench on them[socket etc]

 

I also read on the 'net of a ghetto method of making your own. You merely take a new bolt and cut some flutes in it with a hacksaw and then widen them with a fine triangular file. I guess it would work in a pinch.
Note that the bolt in the link is not the same size as the SBC head bolt.

 

FWIW blocks are tapped with cut threads (as opposed to rolled or formed) and probably an H3 tap. If you start the H3 I referenced by hand the only material you will remove is any that has been damaged or deformed which is part of the idea of "retapping". You are basically putting the same tool back in that was used to make the hole in the first place. The good thing about doing by hand is that you can feel any bad or damaged threads.

If the block has been decked the chamfer on the first thread is now small/gone. Rechamfering is probably a good idea both for starting the tap the bolt. But that's a different tool.

Isn't it interesting to get different viewpoints? The beauty of the internet forums.

Good luck to you!

 

I used a tap, just a plain old tap,

I didn't go nuts I rotated in with little force, cleaned the threads with a few rounds in one way, a few back, out a few back in and so forth paying very close attention to just easing it in with little force.

I just took it easy and no problem. Treat it like you would a woman with tender care. and don't force it in.

 

Just use a tap it will be fine.feed it in gently and back it out .You will feel when it is cutting(cleaning in your case) and at that point back it off.repeat intill you reach bottom.I recomend using a plug tap if you haven't done this before.Good luck.

Rob.