Intermix problem, Found the crack.
04-29-2009, 03:10 PM
#31
Drifting
Thread Starter
I am not familiar with JB Weld. I have talked to a machine shop in Costa Mesa that is quite familiar with these craqcks and says they can repair them. They take out the valve guide and seld the carck, machine the area and then put in a new valve guide. Will also do a complete valve job (not new valve but grinding, etc.) as part of the process. They say then have done many of these. I know I did not even have to describe the crack to them, as soon as I told him I had a cracked head on a 3.4 996 he staid "#1 cylinder, inner exhaust valve seat, runs to the spark plug chase, see them all the time, fixed many of them."
As to the new head, the list price is $2,695, so you can get it for about $2,300. It is the head with all valves, springs, etc., the cam follower with tappet covers, and the Cam cover, but does not include the cams and gears, etc. The set has to include the cam cover as the cover serves as the top race/cap for the cam bearings and is lined bored with the head casting, so they are a matched set.
Jake Raby did say that he would measure the volume of the head being replaced against whatever head (new or used) that is replacing it as there may be variance that could cause a difference in compression and through CEL's. However, just worn valve, rings etc. can cause a variance in compression. Jake is great, and incredibly knowledgable, but is a perfectionist. As he states, he is unwilling to put anything out of his shop that could lead to bad results, warranty claims etc. He does premium work.
As to the new head, the list price is $2,695, so you can get it for about $2,300. It is the head with all valves, springs, etc., the cam follower with tappet covers, and the Cam cover, but does not include the cams and gears, etc. The set has to include the cam cover as the cover serves as the top race/cap for the cam bearings and is lined bored with the head casting, so they are a matched set.
Jake Raby did say that he would measure the volume of the head being replaced against whatever head (new or used) that is replacing it as there may be variance that could cause a difference in compression and through CEL's. However, just worn valve, rings etc. can cause a variance in compression. Jake is great, and incredibly knowledgable, but is a perfectionist. As he states, he is unwilling to put anything out of his shop that could lead to bad results, warranty claims etc. He does premium work.
04-29-2009, 03:25 PM
#32
Three Wheelin'
Yeah jb weld I wouldn't trust anyway, just threw it out there as an example because it's the most commonly known "cold weld" filler to most folks. I just figured there was some sort of suitable cold weld / filler/ sealer for aluminium that you might have uncovered in your research. Not a real fix if you can properly weld in there, which it seems from your shop's experience you can.
I'm glad you already asked yourself the compression questions. Looks like you've already really thought this through, found some smart guys with experience, and let's pray for a perfect fix. One word of caution, if it's Motormeister (IIRC they are in downey and not costa mesa, but I can't remember for the life of me) run from them, they have so many bad stories out there. If it's Euro Collectibles, Honest Engine, or Performance Developments I haven't heard anything bad, and you know the only people who speak publicly about work are those with complaints so that's a good sign. Still make sure you check everyone out seven ways to sunday.
Are you sending out the whole motor? I would if I were you assuming it wasn't too cost prohibitive, would want to bench test compression a bunch on the existing block.
2300 bucks for one head (fully dressed or not) is a big number, but not new engine big! Thanks for clarifying
I'm glad you already asked yourself the compression questions. Looks like you've already really thought this through, found some smart guys with experience, and let's pray for a perfect fix. One word of caution, if it's Motormeister (IIRC they are in downey and not costa mesa, but I can't remember for the life of me) run from them, they have so many bad stories out there. If it's Euro Collectibles, Honest Engine, or Performance Developments I haven't heard anything bad, and you know the only people who speak publicly about work are those with complaints so that's a good sign. Still make sure you check everyone out seven ways to sunday.
Are you sending out the whole motor? I would if I were you assuming it wasn't too cost prohibitive, would want to bench test compression a bunch on the existing block.
2300 bucks for one head (fully dressed or not) is a big number, but not new engine big! Thanks for clarifying
04-29-2009, 06:16 PM
#33
Drifting
Thread Starter
This is the shop that does the repair. No connection to Motormeister that I know of.
http://www.engine-machining.com/
John Edwards seemed like a pretty straight shooter when I spoke to him.
http://www.engine-machining.com/
John Edwards seemed like a pretty straight shooter when I spoke to him.
04-29-2009, 10:16 PM
#34
Three Wheelin'
I don't know him, but I did google and see a video of a cracked and weeping boxster motor posted by him on youtube. Out of prudence, I would search here, pelican, renntech, 6speed, flat6 and see if anyone's used his shop. Good luck and keep us posted!
04-30-2009, 01:38 PM
#35
Burning Brakes
Dharn,
Sorry I have not gotten back with you..
My source did not have a new head for that cylinder bank, but had plenty of the other side... They are still looking for one, though.. The used head that I have was also cracked upon closer inspection, but I may have a line on another one.
Some cracks in heads can be repaired. My cylinder head tech is the most excellent I have ever seen with welding aluminum and repairing/ straightening heads. The issue with this crack is where it is located and how difficult the area can be to weld, its risky to say the least.
I do not associate myself with any risky repairs/ fixes... Thats because if something we worked with does break it compromises the entire engine program..
I'll continue to search for a head for you, call me if you find something before I do.. (I am slammed so you'll have to leave me a voicemail)
Sorry I have not gotten back with you..
My source did not have a new head for that cylinder bank, but had plenty of the other side... They are still looking for one, though.. The used head that I have was also cracked upon closer inspection, but I may have a line on another one.
Some cracks in heads can be repaired. My cylinder head tech is the most excellent I have ever seen with welding aluminum and repairing/ straightening heads. The issue with this crack is where it is located and how difficult the area can be to weld, its risky to say the least.
I do not associate myself with any risky repairs/ fixes... Thats because if something we worked with does break it compromises the entire engine program..
I'll continue to search for a head for you, call me if you find something before I do.. (I am slammed so you'll have to leave me a voicemail)
