 need to fix a stripped CHT hole, I only have myself to blame |
|
|
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
|
  |
| brant |
 Jul 10 2011, 11:01 PM
Post
#1
|
|
914 Wizard  Group: Members Posts: 11,626 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
Post
#2
|
|
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
Post
#3
|
|
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
|
|
|
|
| brant |
Jul 11 2011, 08:12 AM
Post
#4
|
|
914 Wizard Group: Members Posts: 11,626 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
Post
#5
|
|
Custom Member Group: Members Posts: 24,584 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
Post
#6
|
|
914 Wizard Group: Members Posts: 11,626 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
Post
#7
|
|
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
Post
#8
|
|
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  |
|
|
|
|
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:
|
Lo-Fi Version | Time is now: 25th May 2024 - 07:25 PM |
Invision Power Board
v9.1.4 © 2024 IPS, Inc.