The Ford Barn

john worden · 08-10-2024, 09:27 PM

Attempting to install Helicoil in head stud location. After drilling with the supplied drill, the supplied threading tap will not engage to start cutting threads. The block is in the car and I lubricated the drill and tap with cutting oil. We tapped lightly on the tap while turning it, but it will not engage. Any thoughts appreciated. Thanks. John

Charlie Stephens · 08-10-2024, 09:40 PM

Would it help to chamfer the hole?

Charlie Stephens

Synchro909 · 08-10-2024, 10:01 PM

I think a steady downwards pressure while you turn the tap would be better than "tapping the tap". If you chamfer the top of the hole, don't go overboard. Chamfer a little, try it and if you don't get anywhere, chamfer it a little more till you succeed. Personally though, I wouldn't chamfer it.
PS. It is important that the drill and tap are kept perpendicular tot he top of the block or the stud will not line up with its hole in the head.

johnneilson · 08-10-2024, 10:17 PM

Typically machining cast iron is done dry, no lube

J

Y-Blockhead · 08-10-2024, 11:50 PM

Quote:

Originally Posted by Synchro909

It is important that the drill and tap are kept perpendicular tot he top of the block or the stud will not line up with its hole in the head.

I agree. I use a tap guide similar to this one to ensure the tap is pertpendicular to the top of the block (or whatever you are tapping https://www.amazon.com/GATOR-TOOLS-V...3351856&sr=8-5

Bruce of MN · 08-11-2024, 01:39 AM

Sponsored Links (Register now to hide all advertisements)

This was my experience:

https://www.fordbarn.com/forum/showt...rt#post1997462

nkaminar · 08-11-2024, 06:17 AM

Synchro has a very important point. The Helicoil must be in the proper location and perpendicular to the block. I have used an old head for this, bolting it to the block and enlarging the hole where the Helicoil tap is used just enough. The head can still be used on an engine with the enlarged hole, if necessary.

I agree that a steady strong pressure is needed to start the tap. I also agree that the hole should be tapped dry. Tap a little then back out a half turn to clear the chips, then continue. Repeat to back out as you tap to continue to clear the chips.

Terry Burtz, Calif · 08-11-2024, 10:30 AM

Helicoil taps come in plug and bottoming styles.
If you are trying to start a threaded hole with a bottoming style tap, it is very difficult.

john worden · 08-11-2024, 10:42 AM

Quote:

Originally Posted by Charlie Stephens

Would it help to chamfer the hole?

Charlie Stephens

Worth considering. Thanks.

john worden · 08-11-2024, 10:46 AM

PS. It is important that the drill and tap are kept perpendicular tot he top of the block or the stud will not line up with its hole in the head.

We did make and use a guide for that purpose. Thanks.

john worden · 08-11-2024, 10:48 AM

Typically machining cast iron is done dry, no lube

We will try that. Thanks.

john worden · 08-11-2024, 10:49 AM

I agree. I use a tap guide similar to this one to ensure the tap is pertpendicular to the top of the block (or whatever you are tapping https://www.amazon.com/GATOR-TOOLS-V...3351856&sr=8-5
Thank you. John

john worden · 08-11-2024, 10:54 AM

This was my experience:

https://www.fordbarn.com/forum/showt...rt#post1997462
Thank you. This looks promising. John

john worden · 08-11-2024, 10:55 AM

This was my experience:

https://www.fordbarn.com/forum/showt...rt#post1997462
Thank you. John

Phil Brown · 08-11-2024, 12:10 PM

Agreed with Terry, trying to start a bottoming tap in a freshly drilled hole is tough to do. might also check that the drill is the correct size for your Helicoil, even if it came as a "kit" things happen in packaging

john worden · 08-11-2024, 12:23 PM

Agreed with Terry, trying to start a bottoming tap in a freshly drilled hole is tough to do. might also check that the drill is the correct size for your Helicoil, even if it came as a "kit" things happen in packaging
Will check again. I know it isn't a bottoming tap. Thanks. John

08-10-2024, 09:27 PM	#1
john worden Senior Member Join Date: Jun 2011 Location: central Iowa Posts: 500	Helicoil issue in head stud hole. Attempting to install Helicoil in head stud location. After drilling with the supplied drill, the supplied threading tap will not engage to start cutting threads. The block is in the car and I lubricated the drill and tap with cutting oil. We tapped lightly on the tap while turning it, but it will not engage. Any thoughts appreciated. Thanks. John __________________ Louvering, bias ply tire-truing, metal shaping and forming, lathe and mill work, member shop HAGERTY Ins. expert repair network. High quality paint work in Iowa.

08-10-2024, 09:40 PM	#2
Charlie Stephens Senior Member Join Date: May 2010 Location: Southern California Posts: 7,305	Re: Helicoil issue in head stud hole. Would it help to chamfer the hole? Charlie Stephens

08-10-2024, 10:01 PM	#3
Synchro909 Senior Member Join Date: Jun 2014 Location: Melbourne, Australia Posts: 8,044	Re: Helicoil issue in head stud hole. I think a steady downwards pressure while you turn the tap would be better than "tapping the tap". If you chamfer the top of the hole, don't go overboard. Chamfer a little, try it and if you don't get anywhere, chamfer it a little more till you succeed. Personally though, I wouldn't chamfer it. PS. It is important that the drill and tap are kept perpendicular tot he top of the block or the stud will not line up with its hole in the head. __________________ I sometimes wonder what happened to the people who asked me for directions. Even at my age, I still like to look at a young, attractive woman but I can't really remember why.

08-10-2024, 10:17 PM	#4
johnneilson Senior Member Join Date: Jun 2010 Location: 34.22 N 118.36 W Posts: 1,181	Re: Helicoil issue in head stud hole. Typically machining cast iron is done dry, no lube J __________________ As Carroll Smith wrote; All Failures are Human in Origin.

08-11-2024, 01:39 AM	#6
Bruce of MN Senior Member Join Date: May 2010 Location: VA Posts: 1,808	Re: Helicoil issue in head stud hole. Sponsored Links (Register now to hide all advertisements) This was my experience: https://www.fordbarn.com/forum/showt...rt#post1997462

08-11-2024, 06:17 AM	#7
nkaminar Senior Member Join Date: Jan 2012 Location: Western North Carolina Posts: 5,874	Re: Helicoil issue in head stud hole. Synchro has a very important point. The Helicoil must be in the proper location and perpendicular to the block. I have used an old head for this, bolting it to the block and enlarging the hole where the Helicoil tap is used just enough. The head can still be used on an engine with the enlarged hole, if necessary. I agree that a steady strong pressure is needed to start the tap. I also agree that the hole should be tapped dry. Tap a little then back out a half turn to clear the chips, then continue. Repeat to back out as you tap to continue to clear the chips. __________________ A is for apple, green as the sky. Step on the gas, for tomorrow I die. Forget the brakes, they really don't work. The clutch always sticks, and starts with a jerk. My car grows red hair, and flies through the air. Driving's a blast, a blast from the past.

08-11-2024, 10:30 AM	#8
Terry Burtz, Calif Senior Member Join Date: May 2010 Location: Campbell,CA, USA Posts: 395	Re: Helicoil issue in head stud hole. Helicoil taps come in plug and bottoming styles. If you are trying to start a threaded hole with a bottoming style tap, it is very difficult.

08-11-2024, 10:46 AM	#10
john worden Senior Member Join Date: Jun 2011 Location: central Iowa Posts: 500	Re: Helicoil issue in head stud hole. PS. It is important that the drill and tap are kept perpendicular tot he top of the block or the stud will not line up with its hole in the head. We did make and use a guide for that purpose. Thanks. __________________ Louvering, bias ply tire-truing, metal shaping and forming, lathe and mill work, member shop HAGERTY Ins. expert repair network. High quality paint work in Iowa.

08-11-2024, 10:48 AM	#11
john worden Senior Member Join Date: Jun 2011 Location: central Iowa Posts: 500	Re: Helicoil issue in head stud hole. Typically machining cast iron is done dry, no lube We will try that. Thanks. __________________ Louvering, bias ply tire-truing, metal shaping and forming, lathe and mill work, member shop HAGERTY Ins. expert repair network. High quality paint work in Iowa.

08-11-2024, 10:49 AM	#12
john worden Senior Member Join Date: Jun 2011 Location: central Iowa Posts: 500	Re: Helicoil issue in head stud hole. I agree. I use a tap guide similar to this one to ensure the tap is pertpendicular to the top of the block (or whatever you are tapping https://www.amazon.com/GATOR-TOOLS-V...3351856&sr=8-5 Thank you. John __________________ Louvering, bias ply tire-truing, metal shaping and forming, lathe and mill work, member shop HAGERTY Ins. expert repair network. High quality paint work in Iowa.

08-11-2024, 10:54 AM	#13
john worden Senior Member Join Date: Jun 2011 Location: central Iowa Posts: 500	Re: Helicoil issue in head stud hole. This was my experience: https://www.fordbarn.com/forum/showt...rt#post1997462 Thank you. This looks promising. John __________________ Louvering, bias ply tire-truing, metal shaping and forming, lathe and mill work, member shop HAGERTY Ins. expert repair network. High quality paint work in Iowa.

08-11-2024, 10:55 AM	#14
john worden Senior Member Join Date: Jun 2011 Location: central Iowa Posts: 500	Re: Helicoil issue in head stud hole. This was my experience: https://www.fordbarn.com/forum/showt...rt#post1997462 Thank you. John __________________ Louvering, bias ply tire-truing, metal shaping and forming, lathe and mill work, member shop HAGERTY Ins. expert repair network. High quality paint work in Iowa.

08-11-2024, 12:10 PM	#15
Phil Brown Senior Member Join Date: May 2010 Location: Santee Calif. Posts: 638	Re: Helicoil issue in head stud hole. Agreed with Terry, trying to start a bottoming tap in a freshly drilled hole is tough to do. might also check that the drill is the correct size for your Helicoil, even if it came as a "kit" things happen in packaging

08-11-2024, 12:23 PM	#16
john worden Senior Member Join Date: Jun 2011 Location: central Iowa Posts: 500	Re: Helicoil issue in head stud hole. Agreed with Terry, trying to start a bottoming tap in a freshly drilled hole is tough to do. might also check that the drill is the correct size for your Helicoil, even if it came as a "kit" things happen in packaging Will check again. I know it isn't a bottoming tap. Thanks. John __________________ Louvering, bias ply tire-truing, metal shaping and forming, lathe and mill work, member shop HAGERTY Ins. expert repair network. High quality paint work in Iowa.