Head gasket went... D'Oh!
10-16-2007, 03:48 PM
#31
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10-16-2007, 03:59 PM
#32
Sorry to hear about this Andrew. I'd also suggest doing as much of a diagnosis as you can before you start taking things apart. The more information you can get ahead of time, the better it'll help you to make decisions on things like whether to pull the engine or just the head or heads. I'd definitely do at least a leakdown test. Keep in mind that the more you take apart, the more "while you're in there" stuff will come up for you to think about. It can be a pretty slippery slope once you start down that path.
With the different manifold and in intake configuration, it's more than likely going to be a different cylinder or cylinders than the stock manifold and intake configuration.
With the different manifold and in intake configuration, it's more than likely going to be a different cylinder or cylinders than the stock manifold and intake configuration.
10-16-2007, 04:00 PM
#33
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10-16-2007, 04:02 PM
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10-16-2007, 04:03 PM
#36
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Andrew can do what most other tuners do in a case like this, inspect the plugs very carefully to find un-even cylinders.
Andrew - on that note, make sure you make what hole each plug came from - maybe even mail them over here for Todd / Luke to inspect in comparison to what Todd has seen with his motors.
Problem is, other than detonation damage to the plugs, a lot of the evidence could have been "washed away" by the coolant / water.
10-16-2007, 05:02 PM
#37
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Jim posted
Please air freight me some of what you are taking for that head cold; I need some false courage...
Marton
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I have a mild head cold must be worse than I thought.
Marton
10-16-2007, 05:06 PM
#38
10-16-2007, 05:37 PM
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you must have not read my message. " cylinder pressures are related to mass flow"
Yes, and mass flow, whether increased by boost or volumetric efficiencies, creates that "bigger bang". diesels use detonation to move things down, that is entirely different.
actually, there shouldnt be pre-ignition, and it should be ignition with a rapidly expanding flame front. when you have detonation, you have much greater forces.
the combustion chamber doesnt know how the load of air and fuel got there, it just knows its there. you put a stock head on a 6.5 liter vs a blower on a 5 liter, what is the difference if they are yeilding the same HP. the point is, if the head gaskets that mark and joe use can survive this, a mild blower on a 928 motor with less than 500rwhp should be able to survive no problem. however, the propensitiy for detonation is greater, due to compressed heated air and alternative means of metering out fuel evenly.
now, go blow your nose!
mk
Yes, and mass flow, whether increased by boost or volumetric efficiencies, creates that "bigger bang". diesels use detonation to move things down, that is entirely different.
actually, there shouldnt be pre-ignition, and it should be ignition with a rapidly expanding flame front. when you have detonation, you have much greater forces.
the combustion chamber doesnt know how the load of air and fuel got there, it just knows its there. you put a stock head on a 6.5 liter vs a blower on a 5 liter, what is the difference if they are yeilding the same HP. the point is, if the head gaskets that mark and joe use can survive this, a mild blower on a 928 motor with less than 500rwhp should be able to survive no problem. however, the propensitiy for detonation is greater, due to compressed heated air and alternative means of metering out fuel evenly.
now, go blow your nose!
mk
Kibort...nothing that you posted makes any sense at all..... Boost makes a BIGGER BANG it is as simple as that !! The bigger the bang the higher the cylinder pressures, add detonation pre-ignition and the bang goes off BEFORE the piston hits TDC and the piston rings rod bearing have to compress the bang to get to TDC before the power stroke...That is when the pressures go to the moon . Same thing as making a diesel engine from what was designed as a gasoline engine since diesels "fire" the cylinder by detonation/compression the internal pressures are so much higher it beats the motor to death. Simply stated boost increases the effective compression ratio of an engine. You stuff more air and fuel into the same space and blow it up...
10-16-2007, 05:57 PM
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Mark ...."6.5 liter vs a blower on a 5 liter" for a start figure in the mechanical advantage of the long stroke crank and if you like the difference in area of a 100 mm piston or a 104.5 mm ...
10-16-2007, 06:10 PM
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10-16-2007, 06:48 PM
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Mark sometimes some of your posts remind me of the "second harvest" practiced by ancient Indians in times of food shortages..... They would sift through the dung of their animals to find undigested seeds...a seed here a seed there grind them and make flour. But one or two seeds of truth ...
10-16-2007, 11:54 PM
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as long as it makes bread, it works for me. 
mk
mk
Mark sometimes some of your posts remind me of the "second harvest" practiced by ancient Indians in times of food shortages..... They would sift through the dung of their animals to find undigested seeds...a seed here a seed there grind them and make flour. But one or two seeds of truth ...
10-17-2007, 12:19 AM
#45
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Mark and jim... take it off line please.
Ok... who here remembers Sesame Street? Let's play, "One of these thing is not like the other..."
Can you tell? The arrow points to the front of the engine.
Did you guess #7? If you did you were right. Here's a close up.
And here's what happened when I cranked the engine (no plugs).
BTW, the coolant resevoir was at least half full when I parked it yesterday, but was empty today.
Ok... who here remembers Sesame Street? Let's play, "One of these thing is not like the other..."
Can you tell? The arrow points to the front of the engine.
Did you guess #7? If you did you were right. Here's a close up.
And here's what happened when I cranked the engine (no plugs).
BTW, the coolant resevoir was at least half full when I parked it yesterday, but was empty today.