|
|
|
|
| Author |
|
|
Registered
Join Date: Aug 2004
Location: The Brink
Posts: 2,834
|
964 Exhaust Port - Not Looking Good
Hi,
Found this tonight after removing headers. I was not expecting to see this. This is the worst one. What are my options? Thanks! 
|
||
02-24-2017, 06:40 PM
|
|
|
Member 911 Anonymous
|
Wow, did the guide start to walk out.
What is the history of the head work?
__________________
'85 Carrera Targa Factory Marble Grey/Black * Turbo Tail * 930 Steering Wheel* Sport Seats * 17" Fuchs (r) * 3.4 * 964 Cams * 915 * LSD * Factory SS * Turbo Tie Rods * Bilsteins * Euro Pre-Muff * SW Chip on 4K DME * NGK * Sienes GSK * Targa Body Brace PCA/POC |
||
|
02-24-2017, 08:28 PM
|
|
|
Registered
Join Date: Sep 2015
Location: Costa Rica and Pennsylvania U.S.
Posts: 3,301
|
3.6
Where was the head work done & how long ago?Head looks pretty fresh.Fred
|
||
|
02-25-2017, 03:11 AM
|
|
|
It's a 914 ...
Join Date: Jan 2008
Location: Ossining, NY
Posts: 4,699
|
What is that surrounding the guide? It doesn't look like it belongs.
|
||
|
02-25-2017, 04:10 AM
|
|
|
Registered
Join Date: Aug 2004
Location: The Brink
Posts: 2,834
|
The PO had the heads rebuilt, but a long time ago. Engine did some racing, very low mileage.
Is the head junk? I am not sure what the other "stuff" is. It is very smooth. Last edited by jamesjedi; 02-25-2017 at 05:24 AM.. |
||
|
02-25-2017, 04:52 AM
|
|
|
Registered
Join Date: Aug 2004
Location: The Brink
Posts: 2,834
|
Forgot to say - thanks for the replies.
Last edited by jamesjedi; 02-25-2017 at 05:25 AM.. |
||
|
02-25-2017, 04:53 AM
|
|
|
|
abit off center
|
The guide boss is not very large in that area and the ceramic liner looks intact you might be able to save it
 Sent from my iPhone using Tapatalk
__________________
______________________ Craig G2Performance Twinplug, head work, case savers, rockers arms, etc. |
||
|
02-25-2017, 05:32 AM
|
|
|
Registered
Join Date: Aug 2004
Location: The Brink
Posts: 2,834
|
Thanks for the replies. I am not sure what the coating is. I have a feeling that the ceramic may be damaged. I will look again today.
|
||
|
02-25-2017, 06:40 AM
|
|
|
Registered
|
It looks like the boss area around the guide has broken away, probably from when the guides were installed. Maybe the guide has walked but I don't think so, look at the back side of the guide and compare the exposed part of the guide to cgarr 's picture I don't know if this was a head that I would continue to use as is
|
||
|
02-25-2017, 06:41 AM
|
|
|
Registered
Join Date: Oct 2015
Location: Eastern Pa.
Posts: 695
|
Just experienced the same failure on number three intake. (97 3.6 L).
You said this is the worst one, are the other heads also damaged? I am not sure how my damage occurred, whether it was a weakness at the valve guide on number three, a crooked valve guide, or the result of a failed O2 sensor. Thinking this is beyond repair.
__________________
1979 SC 1986 Carrera 3.6 L+ |
||
|
02-25-2017, 08:08 AM
|
|
|
Registered
Join Date: Oct 2015
Location: Eastern Pa.
Posts: 695
|
Dropped valve guide number 3 intake
Pics of my "head"ache ... no pun intended.
I'm not liking membership in the(TPHC)Thrashed Porsche Head Club 
__________________
1979 SC 1986 Carrera 3.6 L+ |
||
|
02-25-2017, 08:16 AM
|
|
|
Member 911 Anonymous
|
OP, if anything send your heads to CGarr, he's the man
__________________
'85 Carrera Targa Factory Marble Grey/Black * Turbo Tail * 930 Steering Wheel* Sport Seats * 17" Fuchs (r) * 3.4 * 964 Cams * 915 * LSD * Factory SS * Turbo Tie Rods * Bilsteins * Euro Pre-Muff * SW Chip on 4K DME * NGK * Sienes GSK * Targa Body Brace PCA/POC |
||
|
02-25-2017, 10:08 AM
|
|
|
Registered
Join Date: May 2004
Location: Boulder, Colorado
Posts: 7,275
|
Valve guides are a press fit. Is it easy to use too much press and not enough fit? Seems like that could break the support part of the casting as shown. I've pulled some guides, but left the pressing (and the all important honing) to shops.
What to do may come down to economics - price of a good used head versus price of welding this up, reshaping, and reboring. An oversized hole for the guide in the head is not an issue - I know of shops which just make their own guides, so they can be any OD needed. Maybe that is what most shops do? Or they buy oversized guides and turn to fit? |
||
|
02-25-2017, 11:03 AM
|
|
|
Registered
Join Date: Aug 2004
Location: The Brink
Posts: 2,834
|
Well, thanks again for the replies. I thought the smooth "stuff" was after market, however, I am guessing that it is the ceramic coating. I have pictures of all 6 of them. I am thinking that I may need to see what the intake valves look like.
    
|
||
|
02-25-2017, 11:12 AM
|
|
|
Member 911 Anonymous
|
Hmm
What is that Brown grease like Deposit on the stems? Never seen something like that
__________________
'85 Carrera Targa Factory Marble Grey/Black * Turbo Tail * 930 Steering Wheel* Sport Seats * 17" Fuchs (r) * 3.4 * 964 Cams * 915 * LSD * Factory SS * Turbo Tie Rods * Bilsteins * Euro Pre-Muff * SW Chip on 4K DME * NGK * Sienes GSK * Targa Body Brace PCA/POC |
||
|
02-25-2017, 11:37 AM
|
|
|
Registered
Join Date: Aug 2004
Location: The Brink
Posts: 2,834
|
Walte - I will need to determine what is the best in terms of quality, as well as cost. This is new territory for me.
betterair - TPHC- well, there was a time when something like this would have been VERY upsetting. This is a hobby, and this is part of that hobby. Don't get me wrong, I don't have the cash to fix this, in fact my car resembles more of a "dune buggy" then a 1977 Porsche 911S because of the cash shortage! Yes - I am now a member of the TPHC. |
||
|
02-25-2017, 11:40 AM
|
|
|
Registered
Join Date: Aug 2004
Location: The Brink
Posts: 2,834
|
Not sure what the grease is. I assume an assembly lube?
|
||
|
02-25-2017, 11:41 AM
|
|
|
Under the radar
Join Date: May 2007
Location: Fortuna, CA. On the Lost Coast near the Emerald Triangle
Posts: 7,129
|
Those guides look like they were just pressed in and the valves are clean and no carbon build up. Very strange.
Back in the day some racers would grind out the guide boss for better flow.
__________________
Gordon ___________________________________ '71 911 Coupe 3,0L outlawed #56 PCA Redwood Region, GGR, NASA, Speed SF Trackrash's Garage :: My Garage |
||
|
02-25-2017, 05:45 PM
|
|
|
|
Registered
Join Date: Jul 2001
Location: Portland Oregon
Posts: 7,007
|
Someone was not very careful when they R & I'ed the exhaust guide and thats the result. I've seen a fair amount over the years and its due to not heating the head properly when extracting & installing the guides. Proper lubricants are also necessary when installing the new guides to prevent galling and cracking.
This could be repaired by removing the guide and TIG welding, then re-machining the guide bore, followed by a new guide and honing to fit. One also needs to be sure the guide is centered correctly as well.
__________________
Steve Weiner Rennsport Systems Portland Oregon (503) 244-0990 porsche@rennsportsystems.com www.rennsportsystems.com |
||
|
02-26-2017, 09:38 AM
|
|
|
Registered
Join Date: Aug 2004
Location: The Brink
Posts: 2,834
|
Thanks for your contribution Steve...always appreciated.
It looks like all should be removed and inspected. I am not sure how important the ceramic covering is? It is not looking great in some spots. Is a repair as good as finding better heads? |
||
|
02-26-2017, 02:21 PM
|
|
Marble Grey
1969 and 1986 Porsche Targa and Coupe 1720cc and 3
My Garage
1971 Porsche 911
Baja Bug
