need to fix a stripped CHT hole, I only have myself to blame |
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need to fix a stripped CHT hole, I only have myself to blame |
brant |
Jul 10 2011, 11:01 PM
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#1
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914 Wizard Group: Members Posts: 11,739 Joined: 30-December 02 From: Colorado Member No.: 47 Region Association: Rocky Mountains |
about 3 years back I tore a motor down to rebuild my rebuild.... (long story)
anyways, I only have myself to blame today I started bolting on the externals and tin found out that the CHT hole is stripped. motor is assembled and I really don't want to pull the head at this point for welding...... how do folks feel about a time sert or a heli coil in this application. I think I happen to have a heli-coil in the right size... but if I had to buy a time-sert to make it conduct the heat into the sensor I would do it. what do folk think? John, how would you tackle this repair? thanks in advance everyone. brant |
McMark |
Jul 10 2011, 11:25 PM
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#2
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914 Freak! Group: Retired Admin Posts: 20,179 Joined: 13-March 03 From: Grand Rapids, MI Member No.: 419 Region Association: None |
Helicoil would be fine. Brad Anders has found that the CHT heats up too fast in some cases and adds a spacer to keep it cooler longer. But I doubt you would notice a difference in CHT function.
Just don't drill too deep or you'll go into the combustion chamber. (IMG:style_emoticons/default/yikes.gif) Measure the depth of the OE hole, and put some tape on your drill bit to keep from going too deep. |
sean_v8_914 |
Jul 10 2011, 11:31 PM
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#3
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Chingon 601 Group: Members Posts: 4,011 Joined: 1-February 05 From: San Diego Member No.: 3,541 |
the hole is shallow. you will need a bottom tap
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brant |
Jul 11 2011, 08:12 AM
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#4
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914 Wizard Group: Members Posts: 11,739 Joined: 30-December 02 From: Colorado Member No.: 47 Region Association: Rocky Mountains |
Thanks Guys!
I think the heli-coil taps are a special pitch and unique to the tool so its not likely possible to find a bottom tap to match their unique pitch I'll check out their website and see if they make one. thanks again brant |
r_towle |
Jul 11 2011, 08:49 AM
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#5
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Custom Member Group: Members Posts: 24,624 Joined: 9-January 03 From: Taxachusetts Member No.: 124 Region Association: North East States |
buy a tap, grind off the tip until its flat and the full profile of the body of the tap....you have a flat bottom tap now.
Local hardware store tap so you wont feel so bad grinding it down. I did that one in the car once (never again) and its not to bad. Timecert worked fine, readings were fine. Rich |
brant |
Jul 11 2011, 09:11 AM
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#6
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914 Wizard Group: Members Posts: 11,739 Joined: 30-December 02 From: Colorado Member No.: 47 Region Association: Rocky Mountains |
luckily the motor is still on the stand.
I was doing final assembly on the tin work when I discovered it. I really don't want to pull the heads since I just did the full valve train measurements and cut all of the pushrods. I just checked and will have to buy that size of heilcoil after all when I pick it up, I'll play with depth and modifying it. thanks a ton! brant |
Cap'n Krusty |
Jul 11 2011, 10:10 AM
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#7
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Cap'n Krusty Group: Members Posts: 10,794 Joined: 24-June 04 From: Santa Maria, CA Member No.: 2,246 Region Association: Central California |
I just looked on the web, and I don't think Helicoil makes a 10mm x 1 insert. Timesert is gonna be the way to go. I have the kit. PM me and maybe we can work something out.
The Cap'n |
AvalonFal |
Jul 11 2011, 04:45 PM
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#8
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Member Group: Members Posts: 483 Joined: 3-July 05 From: Southern New Jersey Coast Member No.: 4,367 Region Association: MidAtlantic Region |
Used a TimeSert to do the same thing. I had to drill out the old broken CHT first. The CHT hole has a bottom so measure and use the tape trick for the drill bit, if drilling, and on the tap. TAKE YOUR TIME and keep the tap perpendicular to the hole. Here's a pic.
Paul |
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