Gary Lewis Posted January 31, 2021 Share Posted January 31, 2021 That would be handy when the need arises - hadn't heard of them either. Similar to taps and the same issue with length in your situation but a good set of thread chasers is worth it. I use mine quite often. An ounce of prevention tool. What I found here says: Here’s another example of legacy term confusion. Sometimes it is necessary to use a tap with extended length. The added length may be used to add “reach” to the tool, or to allow tapping to a depth longer than the thread length of the standard blank. Maybe it’s necessary to accomplish both! The confusion lies in what to call that style of tap. “Pulley” taps were originally designed to tap threads in a pulley assembly. Length was extended, but shank diameter was approximately the same as the thread major diameter. The shank was used as an alignment guide to reach through the pulley hub. Thread depth could not exceed the thread length of the tap. Today, the term is rarely recognized by recent generations. “Extension” taps provide additional length for reach just as pulley taps do. However, the shank diameter is reduced to allow tapping beyond the ground thread length of the tap. The shank diameter “clears” the drilled hole. So, if you can't find a pulley tap then maybe you can find an extension tap? (I'd never heard of it, either.) Link to comment Share on other sites More sharing options...
kramttocs Posted January 31, 2021 Share Posted January 31, 2021 What I found here says: Here’s another example of legacy term confusion. Sometimes it is necessary to use a tap with extended length. The added length may be used to add “reach” to the tool, or to allow tapping to a depth longer than the thread length of the standard blank. Maybe it’s necessary to accomplish both! The confusion lies in what to call that style of tap. “Pulley” taps were originally designed to tap threads in a pulley assembly. Length was extended, but shank diameter was approximately the same as the thread major diameter. The shank was used as an alignment guide to reach through the pulley hub. Thread depth could not exceed the thread length of the tap. Today, the term is rarely recognized by recent generations. “Extension” taps provide additional length for reach just as pulley taps do. However, the shank diameter is reduced to allow tapping beyond the ground thread length of the tap. The shank diameter “clears” the drilled hole. So, if you can't find a pulley tap then maybe you can find an extension tap? (I'd never heard of it, either.) Learned something new One could also take a grinder and cut flutes in a bolt that is long enough. Essentially a long chase giving the crud somewhere to go. Oil, thread, remove, clean, repeat. Link to comment Share on other sites More sharing options...
Gary Lewis Posted January 31, 2021 Share Posted January 31, 2021 One could also take a grinder and cut flutes in a bolt that is long enough. Essentially a long chase giving the crud somewhere to go. Oil, thread, remove, clean, repeat. That's a good idea, especially if you have a cutoff wheel so you can get a sharp edge on the cut. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted January 31, 2021 Share Posted January 31, 2021 What I found here says: Here’s another example of legacy term confusion. Sometimes it is necessary to use a tap with extended length. The added length may be used to add “reach” to the tool, or to allow tapping to a depth longer than the thread length of the standard blank. Maybe it’s necessary to accomplish both! The confusion lies in what to call that style of tap. “Pulley” taps were originally designed to tap threads in a pulley assembly. Length was extended, but shank diameter was approximately the same as the thread major diameter. The shank was used as an alignment guide to reach through the pulley hub. Thread depth could not exceed the thread length of the tap. Today, the term is rarely recognized by recent generations. “Extension” taps provide additional length for reach just as pulley taps do. However, the shank diameter is reduced to allow tapping beyond the ground thread length of the tap. The shank diameter “clears” the drilled hole. So, if you can't find a pulley tap then maybe you can find an extension tap? (I'd never heard of it, either.) I've never known that difference. 💡 But I've rarely encountered a situation where I needed to tap longer than the threads available on the tap. I have had situations where I needed a bottoming tap in a blind hole, but only *had* a taper tap. So I just tap as far as I can, back it out, blow it out, cut the tip off with a .045" disc and go until I bottom again. Then I back it out and cut more off, until I get threads close enough to the bottom. Scott's trick with an old bolt is pretty effective for chasing threads. Link to comment Share on other sites More sharing options...
Gary Lewis Posted January 31, 2021 Share Posted January 31, 2021 I've never known that difference. 💡 But I've rarely encountered a situation where I needed to tap longer than the threads available on the tap. I have had situations where I needed a bottoming tap in a blind hole, but only *had* a taper tap. So I just tap as far as I can, back it out, blow it out, cut the tip off with a .045" disc and go until I bottom again. Then I back it out and cut more off, until I get threads close enough to the bottom. Scott's trick with an old bolt is pretty effective for chasing threads. Until I took the course in machine work I didn't know there are different types of taps. What I learned is: Link to comment Share on other sites More sharing options...
grumpin Posted February 1, 2021 Share Posted February 1, 2021 Until I took the course in machine work I didn't know there are different types of taps. What I learned is: “Pulley tap” Never heard of them either, that I can remember. Heard of the three you showed. Cool! Interesting! Link to comment Share on other sites More sharing options...
ckuske Posted February 1, 2021 Author Share Posted February 1, 2021 Jim - I had to look up "pulley tap". I'd never heard of them. Chris - If you can't get a tap in there to clean up the threads, and Jim is suggesting that a standard tap won't reach due to the timing case, then maybe you can "push through". I can't tell from your picture for sure, but it looks like there are marks on the head of the bolt, suggesting that it might be a Grade 5. If so, it should go ahead and go in. But I'd go a ways and then back it out and clean it. Then go again. And again. The only alternative I can think of is to remove the timing cover so you can use a regular tap on it. But then you have to mess with the pan gasket. And while you are in there you might as well do the timing chain if it hasn't been replaced lately. Good luck! I started doing what you suggested - going a few more turns, backing the bolt out and cleaning it off, and repeating. It’s getting there, I had to go back to tea life later in the day but I think I’m ready to install again soon. Thanks for the advice - I try to not force things out of fear I’ll damage something that I’m not able to fix, but I’m learning they are sturdier than I give it credit for. And following Jim’s advice, I’ll use thread sealant on the ends. Link to comment Share on other sites More sharing options...
Gary Lewis Posted February 1, 2021 Share Posted February 1, 2021 I started doing what you suggested - going a few more turns, backing the bolt out and cleaning it off, and repeating. It’s getting there, I had to go back to tea life later in the day but I think I’m ready to install again soon. Thanks for the advice - I try to not force things out of fear I’ll damage something that I’m not able to fix, but I’m learning they are sturdier than I give it credit for. And following Jim’s advice, I’ll use thread sealant on the ends. Keep on keeping on, slowly, carefully, and you'll get there. Link to comment Share on other sites More sharing options...
ckuske Posted February 1, 2021 Author Share Posted February 1, 2021 :nabble_smiley_good:Keep on keeping on, slowly, carefully, and you'll get there.Will do! PS - Dang autocorrect! I meant “real life” not “tea life” :) On Sun, Jan 31, 2021 at 6:42 PM Gary Lewis [via Bullnose Enthusiasts Forum] <redacted_email_address> wrote: Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted February 1, 2021 Share Posted February 1, 2021 I think you'll be fine if you continue slowly, or find another long bolt and slot it as Scott suggested. Autocowrong, or auto-incorrect is amazingly frustrating! Link to comment Share on other sites More sharing options...
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