Ugh -Looks Like I have a Burned Exhaust valve, Just in time for Okteenerfest |
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Ugh -Looks Like I have a Burned Exhaust valve, Just in time for Okteenerfest |
Mblizzard |
Aug 1 2016, 09:59 AM
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#1
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Advanced Member Group: Members Posts: 3,033 Joined: 28-January 13 From: Knoxville Tn Member No.: 15,438 Region Association: South East States |
Well this will be fun!
I noted an odd exhaust note from my glorious CFR exhaust. Thought something had come loose inside the exhaust. Removed, checked, and all good. Checked valve adjustment. All good. Checked compression. 150 PSI plus except for #3 at 100. (IMG:style_emoticons/default/headbang.gif) Did the add some oil to cylinder with no change in compression. Going to remove the exhaust tonight again and take off the valve train on that side and pressurize the cylinder to see if I can verify the which valve is leaking. A couple of questions. Fist I bet no one has a known good 73 2.0 L head laying around that they would be willing to sell or loan? Just looking to minimize down time. Next any suggestions on a place to turn the head around quickly? Not sure if it is just the exhaust valve but considering it has less than 5K on the new top end and it is holding 100 psi I am betting it is not seriously damaged. While I am there, might as well replace the rings. so I will be needing a set of 96 mm rings. |
Eric_Shea |
Aug 1 2016, 10:21 AM
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#2
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PMB Performance Group: Admin Posts: 19,289 Joined: 3-September 03 From: Salt Lake City, UT Member No.: 1,110 Region Association: Rocky Mountains |
Replace both heads with big valve heads... best investment in fun for that motor. I might have a pair. (IMG:style_emoticons/default/wink.gif)
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Mblizzard |
Aug 1 2016, 10:24 AM
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#3
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Advanced Member Group: Members Posts: 3,033 Joined: 28-January 13 From: Knoxville Tn Member No.: 15,438 Region Association: South East States |
Replace both heads with big valve heads... best investment in fun for that motor. I might have a pair. (IMG:style_emoticons/default/wink.gif) True but not sure I can handle the "investment" in what the heads cost but what you got? |
r_towle |
Aug 1 2016, 03:55 PM
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#4
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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 |
I suggest you pull the motor out of the car...it will be faster.
Also, you need to do more diagnosis before you go buying parts. How old is the motor? Do you think there may be alot of carbon build up in the motor, enough to possibly make one of the rings get stuck, or a valve not close right? |
Bartlett 914 |
Aug 1 2016, 04:08 PM
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#5
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Advanced Member Group: Members Posts: 2,216 Joined: 30-August 05 From: South Elgin IL Member No.: 4,707 Region Association: Upper MidWest |
I suggest you pull the motor out of the car...it will be faster. (IMG:style_emoticons/default/idea.gif) |
Mblizzard |
Aug 1 2016, 04:26 PM
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#6
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Advanced Member Group: Members Posts: 3,033 Joined: 28-January 13 From: Knoxville Tn Member No.: 15,438 Region Association: South East States |
I suggest you pull the motor out of the car...it will be faster. Also, you need to do more diagnosis before you go buying parts. How old is the motor? Do you think there may be alot of carbon build up in the motor, enough to possibly make one of the rings get stuck, or a valve not close right? Less than 5k since McMark did the top end. Will do a pressurized blow through to see. |
JOEPROPER |
Aug 1 2016, 04:41 PM
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#7
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The answer is "no" unless you ask... Group: Members Posts: 1,184 Joined: 21-November 15 From: White Plains New York Member No.: 19,387 Region Association: North East States |
I'd do a leak down test and maybe pop that valve cover off to get a look at valve springs, rockers etc... How did it run before? I don't think I'd be too eager to pull the engine before doing a little more investigating. (IMG:style_emoticons/default/popcorn[1].gif)
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DaveO90s4 |
Aug 1 2016, 04:55 PM
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#8
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Member Group: Members Posts: 149 Joined: 26-April 16 From: Australia Member No.: 19,935 Region Association: None |
Worth checking valve clearances before removing rocker gear? Excessive clearance might indicate that valve not fully closed?
Dave |
porschetub |
Aug 1 2016, 05:53 PM
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#9
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Advanced Member Group: Members Posts: 4,725 Joined: 25-July 15 From: New Zealand Member No.: 18,995 Region Association: None |
Worth checking valve clearances before removing rocker gear? Excessive clearance might indicate that valve not fully closed? Dave (IMG:style_emoticons/default/idea.gif) ,I think you mean lack of clearance and the valve may still be open. |
Mblizzard |
Aug 1 2016, 05:54 PM
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#10
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Advanced Member Group: Members Posts: 3,033 Joined: 28-January 13 From: Knoxville Tn Member No.: 15,438 Region Association: South East States |
Worth checking valve clearances before removing rocker gear? Excessive clearance might indicate that valve not fully closed? Dave Believe me I am doing all of the easy things first. But the sudden change and fact that I have checked all of the valves especially #3 it is hard to see that it could be anything else. |
r_towle |
Aug 1 2016, 05:58 PM
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#11
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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 |
That sucks.
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Mblizzard |
Aug 2 2016, 10:13 AM
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#12
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Advanced Member Group: Members Posts: 3,033 Joined: 28-January 13 From: Knoxville Tn Member No.: 15,438 Region Association: South East States |
Thanks to Eric at PMB looks like I have a couple of new big valve heads headed my way!
Of course when I tell my wife how much this will costs I might be sleeping in my 914! |
Mblizzard |
Aug 2 2016, 05:18 PM
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#13
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Advanced Member Group: Members Posts: 3,033 Joined: 28-January 13 From: Knoxville Tn Member No.: 15,438 Region Association: South East States |
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Mblizzard |
Aug 6 2016, 02:03 PM
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#14
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Advanced Member Group: Members Posts: 3,033 Joined: 28-January 13 From: Knoxville Tn Member No.: 15,438 Region Association: South East States |
Well engine out and torn down to the heads. Will start diggin in tomorrow.
Of course found more things to fix. CV joint fell apart on the passenger side. WTF? It is always something. |
stugray |
Aug 6 2016, 02:14 PM
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#15
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Advanced Member Group: Members Posts: 3,825 Joined: 17-September 09 From: Longmont, CO Member No.: 10,819 Region Association: None |
Well engine out and torn down to the heads. Will start diggin in tomorrow. Of course found more things to fix. CV joint fell apart on the passenger side. WTF? It is always something. The CVs often 'fall apart' when removing the drivetrain, but was the cage broken? |
lonewolfe |
Aug 6 2016, 03:47 PM
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#16
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Senior Member Group: Members Posts: 819 Joined: 12-September 11 From: Oakland, CA Member No.: 13,549 Region Association: Northern California |
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Mblizzard |
Aug 6 2016, 06:01 PM
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#17
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Advanced Member Group: Members Posts: 3,033 Joined: 28-January 13 From: Knoxville Tn Member No.: 15,438 Region Association: South East States |
Thanks to Eric at PMB looks like I have a couple of new big valve heads headed my way! Of course when I tell my wife how much this will costs I might be sleeping in my 914! What size valves are in the replacement heads? Are they 2.0L heads? 44 intake 38 exhaust. Original 2.0 heads. |
Mblizzard |
Aug 6 2016, 06:02 PM
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#18
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Advanced Member Group: Members Posts: 3,033 Joined: 28-January 13 From: Knoxville Tn Member No.: 15,438 Region Association: South East States |
Well engine out and torn down to the heads. Will start diggin in tomorrow. Of course found more things to fix. CV joint fell apart on the passenger side. WTF? It is always something. The CVs often 'fall apart' when removing the drivetrain, but was the cage broken? Cage looked good but the clip on end was gone! |
Bartlett 914 |
Aug 6 2016, 06:07 PM
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#19
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Advanced Member Group: Members Posts: 2,216 Joined: 30-August 05 From: South Elgin IL Member No.: 4,707 Region Association: Upper MidWest |
Well engine out and torn down to the heads. Will start diggin in tomorrow. Of course found more things to fix. CV joint fell apart on the passenger side. WTF? It is always something. The CVs often 'fall apart' when removing the drivetrain, but was the cage broken? Cage looked good but the clip on end was gone! Is the clip really necessary? I would want one installed but I believe the shaft floats laterally in the bearing once installed. |
Mblizzard |
Aug 6 2016, 07:08 PM
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#20
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Advanced Member Group: Members Posts: 3,033 Joined: 28-January 13 From: Knoxville Tn Member No.: 15,438 Region Association: South East States |
Well engine out and torn down to the heads. Will start diggin in tomorrow. Of course found more things to fix. CV joint fell apart on the passenger side. WTF? It is always something. The CVs often 'fall apart' when removing the drivetrain, but was the cage broken? Cage looked good but the clip on end was gone! Is the clip really necessary? I would want one installed but I believe the shaft floats laterally in the bearing once installed. I am pretty sure the clip is necessary. It is rare that parts are added that are not needed and the clip is present on most CV joints I have ever seen. |
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