Blew head gasket
#31
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That sucks to hear John.
I have been into the 21lb area a few times, unintentionally, on 91 RON with a two year old Widefire gasket. The ZT2 has shown John's stage II has held the A/F very nicely.
I also learned I can hit max boost at <60% throttle, I keep my foot out of the floorboard these days!
I have been into the 21lb area a few times, unintentionally, on 91 RON with a two year old Widefire gasket. The ZT2 has shown John's stage II has held the A/F very nicely.
I also learned I can hit max boost at <60% throttle, I keep my foot out of the floorboard these days!
#32
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Bill in D, how many people here have blown HG's even at 15# let alone 18#? I think you are in the extreme minority of people here successfully running over 20# without water/meth injection. If you can name more than 3 people I would be surprised. I am envious of you, but not foolish or brave enough to push my luck.
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I have ran 21-23 psi for the past year on 91 pump gas and a mix of 10% xylene for extra precaution. I am trying to tune my car for a max of 25psi with 20% xylene.
#34
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i'm curious why people are quick to suggest a widefire gasket when the only use for such is an o-ringed head. if the motor hasn't been o-ringed, there is absolutely no difference wether a widefire or non-widefire gasket is used.
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Originally Posted by nize
i'm curious why people are quick to suggest a widefire gasket when the only use for such is an o-ringed head. if the motor hasn't been o-ringed, there is absolutely no difference wether a widefire or non-widefire gasket is used.
#36
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Originally Posted by eclou
Bill in D, how many people here have blown HG's even at 15# let alone 18#? I think you are in the extreme minority of people here successfully running over 20# without water/meth injection. If you can name more than 3 people I would be surprised. I am envious of you, but not foolish or brave enough to push my luck.
You are making an assumption. That the BOOST is what caused those failures. In a way, you are making my point. Even low boost will pop a headgasket if A/F and heat are not looked at. Take care of those two and you can run 20+ without any trouble.
On a car that is as cheap as a 951 can be, there are a fair number non mechanically inclined people doing their own maintenance. Not cleaning surfaces enough on a HG change, not checking head and block for flatness, no A/F meter in their car and running more boost than their fuel delivery is set up for. That is not the boost causing failure, it is mechanical ineptitude.
Nothing wrong with that, you have to learn somewhere but if you are blowing headgaskets at 15# of boost...you need another mechanic.
#38
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Originally Posted by billindenver
You are making an assumption. That the BOOST is what caused those failures. In a way, you are making my point. Even low boost will pop a headgasket if A/F and heat are not looked at. Take care of those two and you can run 20+ without any trouble.
On a car that is as cheap as a 951 can be, there are a fair number non mechanically inclined people doing their own maintenance. Not cleaning surfaces enough on a HG change, not checking head and block for flatness, no A/F meter in their car and running more boost than their fuel delivery is set up for. That is not the boost causing failure, it is mechanical ineptitude.
Nothing wrong with that, you have to learn somewhere but if you are blowing headgaskets at 15# of boost...you need another mechanic.
On a car that is as cheap as a 951 can be, there are a fair number non mechanically inclined people doing their own maintenance. Not cleaning surfaces enough on a HG change, not checking head and block for flatness, no A/F meter in their car and running more boost than their fuel delivery is set up for. That is not the boost causing failure, it is mechanical ineptitude.
Nothing wrong with that, you have to learn somewhere but if you are blowing headgaskets at 15# of boost...you need another mechanic.
There are however a couple of factors inherent to the motor design that may make it less tolerant of boost than other cars - open deck block, steam pockets at the rear of the head. Also many cars also have already blown a HG in the stock configuration early in the lifecycle and as such it is hard to know if the plane of the head (let alone the block) has ever been checked.
Couple that with the fact that most of us run dated chips, limited fuel massagers (my 3-4 channel ARC 2), crude boost controllers, and a grocery list of used/eBay parts (almost my entire build is second-hand eBay sourced), is it surprising that most of us 3rd, 4th + hand owners avoid honing the car to the bleeding edge?
#40
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Originally Posted by lart951
I have ran 21-23 psi for the past year on 91 pump gas and a mix of 10% xylene for extra precaution. I am trying to tune my car for a max of 25psi with 20% xylene.
So the 10% mix put you about 93/94. So you were running 21-23 on "pump" for most of the US.
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Originally Posted by toddk911
So the 10% mix put you about 93/94. So you were running 21-23 on "pump" for most of the US.
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Thanks for all the replies. I am not saying that it blew because of high boost. Again I had vitesse stae 2 with smt-6. It was not fine tuned. I was told by lindsey racing running more that 18lbs is not safe on a factory set up. For what reason I do not no. I am going to get everthing checked out when the head comes off. I will keep you informed
Thanks John
Thanks John