Bummer
03-19-2009, 10:58 PM
#76
Drifting
Heads are not interchangeable. There is a 1-3 and 4-6 head. Intakes have to be on top and exhausxt on bottom so they can't be interchangable. Or are you talking heads between a 3.4 and a 3.6?
03-19-2009, 11:02 PM
#78
Told ya so....
Your welcome :-)
This is a common issue with the 3.4 engines that we see. This is also common on the 3.2, since they share the same root head castings and essentially a 3.4 is nothing more than a bigger bored 3.2
There is no repair for it, the crack is at a point where the port, water jacket and an oil passage all come very close to intersecting. This head is now a door stop.
The issues also occur most often on cylinders 1 and 6 and more often on the outboard exhaust valve.
This is actually a best case scenario, heads are abundant and fairly cheap compared to the cost of a crankcase, etc, etc..
These kinds of issues are my specialty... Looks like its time to go bigger, a 3.6 would be so nice and when applied to the 3.4 heads its a torque monster and I'll take that any day over HP!
Your welcome :-)
This is a common issue with the 3.4 engines that we see. This is also common on the 3.2, since they share the same root head castings and essentially a 3.4 is nothing more than a bigger bored 3.2
There is no repair for it, the crack is at a point where the port, water jacket and an oil passage all come very close to intersecting. This head is now a door stop.
The issues also occur most often on cylinders 1 and 6 and more often on the outboard exhaust valve.
This is actually a best case scenario, heads are abundant and fairly cheap compared to the cost of a crankcase, etc, etc..
These kinds of issues are my specialty... Looks like its time to go bigger, a 3.6 would be so nice and when applied to the 3.4 heads its a torque monster and I'll take that any day over HP!
Jake, what about head "reliability" on 3.6 vs 3.4/3.2?
03-19-2009, 11:24 PM
#79
Burning Brakes
No, What I am saying is he can use the 3.4 base engine coupled to our technology to create a 3.6 big bore engine that will use the 3.4 heads.
The heads have interchange IF you know what components to utilize and you apply our big bore technology.We even have our own big bore head gaskets that allow this to be a possibility.
Heads are side specific and certainly are not interchangeable...
As for reliability, the 3.2 and 3.4 heads suffer from these cracks, the two engines are essetntialy one and the same, Porsche made confusing part numbers to mask the reality that the 996 spec engine is nothing more than a glorified Boxster engine internally... The only M96 engines that don't suffer from cracks in this area are the 2.5 and 2.7, due to their smaller valves and exhaust ports keeping this portion of the head cooler..
The toughest of all M96s is the 2.5
Our interchange directives are a mile long, its all been learned by mixing and matching parts and paying attention.
The heads have interchange IF you know what components to utilize and you apply our big bore technology.We even have our own big bore head gaskets that allow this to be a possibility.
Heads are side specific and certainly are not interchangeable...
As for reliability, the 3.2 and 3.4 heads suffer from these cracks, the two engines are essetntialy one and the same, Porsche made confusing part numbers to mask the reality that the 996 spec engine is nothing more than a glorified Boxster engine internally... The only M96 engines that don't suffer from cracks in this area are the 2.5 and 2.7, due to their smaller valves and exhaust ports keeping this portion of the head cooler..
The toughest of all M96s is the 2.5
Our interchange directives are a mile long, its all been learned by mixing and matching parts and paying attention.
03-19-2009, 11:35 PM
#80
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SOOOO
his options are.. ?
stop at the heads, and build it back up using stock spec parts -or- keep tearing down and changing out what to make the big bore then add new 3.6 heads?
I dont know.....
for me, I would be very tempted to replace heads with stock (or some super engineered replacement) and get the car back on the road.
what are the cost options for both ways too (keep stock and start to build it up -vs- go with this "big bore" thing)
Thanks jake, it's a good aproach for you....much better than the early posts ( last year) which seemed a bit pushy and mr. know it all (even if it is true, this is better and we are listening)
his options are.. ?
stop at the heads, and build it back up using stock spec parts -or- keep tearing down and changing out what to make the big bore then add new 3.6 heads?
I dont know.....
for me, I would be very tempted to replace heads with stock (or some super engineered replacement) and get the car back on the road.
what are the cost options for both ways too (keep stock and start to build it up -vs- go with this "big bore" thing)
Thanks jake, it's a good aproach for you....much better than the early posts ( last year) which seemed a bit pushy and mr. know it all (even if it is true, this is better and we are listening)
03-20-2009, 12:08 AM
#82
Burning Brakes
Redridge,
This info is not on the site.. Unfortunately I have not had time to post any of this type of info, as it keeps changing constantly as we apply variables to the engine combinations... We are working at a fast pace and throwing tons of changes at the engines, but stability is just around the corner as we work to find the best combinations and standardize them.
.
He has already torn down the majority of the engine as he didn't contact me for some pointers until most of this was done.. That means he is already deep enough to have some serious decisions to make.
He can replace whats worn with new parts, or even better condition used parts along with replacing the one head, or he can apply our technology and replace the IMS, liners, etc... Its up to him and what he wants to spend.
I am with you, but what if he does this, then some of the parts that were damaged by the intermix come back to haunt him???
Honestly the cost is pretty damn close, but the application of the JE forged pistons and Nickies cylinders is not cheap whether you stay stock or go to a bigger bore.
To make a cost analysis for this engine I'd have to see and measure the internals.. Of course the bigger bore higher performance engine will cost more, and it should.. BUT it would have full upgrades and the cost is more justified when you get Overkill Engineering components along with added performance. No matter what he does other than a junkyard patch up, he's gonna spend 6K at minimum.
People want to learn from what we are doing.. I am sometimes too direct because I am a very intense person that only knows one way of communicating.. I never meant to be pushy.
I understand what makes this engine tick and want to share that with all of you, but it'll have to wait until lots of variables are eliminated and we have more data than anyone would ever expect from us.
This info is not on the site.. Unfortunately I have not had time to post any of this type of info, as it keeps changing constantly as we apply variables to the engine combinations... We are working at a fast pace and throwing tons of changes at the engines, but stability is just around the corner as we work to find the best combinations and standardize them.
SOOOO
his options are..
stop at the heads, and build it back up using stock spec parts -or- keep tearing down and changing out what to make the big bore then add new 3.6 heads?
?
his options are..
stop at the heads, and build it back up using stock spec parts -or- keep tearing down and changing out what to make the big bore then add new 3.6 heads?
?
He has already torn down the majority of the engine as he didn't contact me for some pointers until most of this was done.. That means he is already deep enough to have some serious decisions to make.
He can replace whats worn with new parts, or even better condition used parts along with replacing the one head, or he can apply our technology and replace the IMS, liners, etc... Its up to him and what he wants to spend.
I dont know.....
for me, I would be very tempted to replace heads with stock (or some super engineered replacement) and get the car back on the roa
for me, I would be very tempted to replace heads with stock (or some super engineered replacement) and get the car back on the roa
what are the cost options for both ways too (keep stock and start to build it up -vs- go with this "big bore" thing)
To make a cost analysis for this engine I'd have to see and measure the internals.. Of course the bigger bore higher performance engine will cost more, and it should.. BUT it would have full upgrades and the cost is more justified when you get Overkill Engineering components along with added performance. No matter what he does other than a junkyard patch up, he's gonna spend 6K at minimum.
Thanks jake, it's a good aproach for you....much better than the early posts ( last year) which seemed a bit pushy and mr. know it all (even if it is true, this is better and we are listening
I understand what makes this engine tick and want to share that with all of you, but it'll have to wait until lots of variables are eliminated and we have more data than anyone would ever expect from us.
03-20-2009, 12:24 AM
#83
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03-20-2009, 11:52 AM
#85
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2. I know you had coolant in the oil, but did you also have oil in the coolant? I was told that oil in the coolant is more common as the oil is under higher pressure when the engine is running. Although when the engine is turned off, the coolant is still hot/presurized so then it is under higher pressure. In my car I had a significant amount of coolant in the oil, and the coolant level was low (this is how the problem first became apparent as is usually the case), but there was alot of oil in the coolant, to the point that it is thicker than mayonaise.
I finally got my oil cooler off this week and am planning on pressure testing it this weekend. Maybe (but not very likely) I wll be one of the few that actually has a bad oil cooler. More likely a problem similar to yours. In draining the coolant it took hours just to let it flow out of the engine as it was not hot, and the coolant/oil mixture was so thick, almost like pudding. This mix needs to be flushed out of the entire system, engine, lines, radiators, etc. and is supposed to be very hard to do. You may want to look at PhillipJ's posts post on Renntech.org on his upgrade from a 3.4 to a 3.6 after the intermix problem on his engine. He ended up replacing the radiators with new ones.
I'm pretty familiar with cleaning cooling systems that are full of oil. It's very labor intensive and results in a lot of hazardous waste that needs to be properly disposed of, which is why most shops will simply replace instead of clean. My approach will be to flush the system before putting an engine back in, and if that requires removing parts for hot tanking or replacement, then that's what I'll do.
I guess the best news is that it is not either a cracked liner or a porous block. Liners can be replaced, but it is expensive, and porous blocks can be impossible to find or fix.
I would hope that a cracked head like this could be found on either a compression test, or more likely a leakdown test. If this is the case maybe I can do less than a complete teardown of my engine as cylinder heads can be replaced.
But seriously, if the oil is full of coolant and the engine has been run with even moderate contamination, I don't see how you'll ever have any confidence that you don't have some major damage lurking on any of the rotating parts. For that reason I think it's not prudent to simply replace the head without taking the engine apart and doing a complete inspection, bearing replacement, etc.
The above is offered with the caveat that I'm just a hobbyist mechanic, YMMV, etc.
03-20-2009, 12:01 PM
#86
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Thanks dude...your comments about the location of the root of the crack were right on the money and allowed me to quickly find the problem once I had the valve springs off on the first cylinder.
I'd like to reiterate the kudos I gave you in my post #60 in this thread and thank you again for entertaining my emailed questions. You're a generous man and the 996 DIY community is richer for your presence here.
I'd like to reiterate the kudos I gave you in my post #60 in this thread and thank you again for entertaining my emailed questions. You're a generous man and the 996 DIY community is richer for your presence here.
03-20-2009, 01:03 PM
#87
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03-20-2009, 01:06 PM
#89
03-20-2009, 02:07 PM
#90
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Doug, by my definition, I am a "hobbyist mechanic" because I know where the engine is located in the car at least 50% of the time.
Me thinks you are too modest and are very knowledgeable!