View Poll Results: Intake set up & #7 or #8 piston failure (public poll)
Intake reversed toward cowl & #7 failure
0
0%
Carb style intake & #7 failure
0
0%
#8 failure regardless on intake set up
0
0%
Voters: 8. You may not vote on this poll
Poll related to #7 & #8 piston failures
Poll related to #7 & #8 piston failures Please select the option closest related to how your intake was set up when #7 failed. Select #8 if it failed before #7.
It is my opinion that #7 fails first because RAM air or forced induction forces air to the rear of the intake to the #7 runner inlet. This gives #7 more air than the other pistons causing it to run leaner. Others claim it's simply a cooling issue. Regardless, of running slightly warmer @ the rear of the engine, #7 goes first for the reason stated. If it is a cooling issue, there will be an equal amount of #8 failures as the total of the #7 failures @ the end of this poll. Please also comment regarding the piston failure
It is my opinion that #7 fails first because RAM air or forced induction forces air to the rear of the intake to the #7 runner inlet. This gives #7 more air than the other pistons causing it to run leaner. Others claim it's simply a cooling issue. Regardless, of running slightly warmer @ the rear of the engine, #7 goes first for the reason stated. If it is a cooling issue, there will be an equal amount of #8 failures as the total of the #7 failures @ the end of this poll. Please also comment regarding the piston failure
TECH Addict
Joined: Mar 2013
Posts: 2,628
Likes: 30
I lost number 7 on a non ram air trans am so ram air has nothing to do with it. Number 7 runs lean and hot because its in the back of the engine and it also gets the intake air rammed into it because its in the back. GM tuned the engines on the rich side to make up for this and a stock tune will keep it cool enough. But when you load a "tune" into these cars that's when the trouble starts. The only engine I lost number 7 on had a "tune" in it. All the others (5) were bone stock and I never had any number 7 trouble. The tuned car ran much better UNTIL number 7 broke and went for a ride out the exhaust.
Last edited by RockinWs6; Sep 27, 2014 at 10:18 PM.
Most piston failures are due to over advanced spark timing and using stock heat range spark plugs. I never exceed 24* timing on LS engines, and I'm at 22* on my 11.5 CR 418 using 94 octane fuel. And I recommend a min of one heat range colder spark plugs plus a 160* F thermostat.
Russ Kemp
Russ Kemp
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I ran 27* timing on my Camaro, 145k shortblock before I did the HCI, and was at 11.7 static. Had a gigantic chrs1313 non-AC ram air as well.
I myself never had an issue, but only had the car about a year and a half after that. It WAS my daily driver though, so it's not like it day around and was drove on Saturdays.
Engine 
When tune make sure not to live engine in a diet, running lean mixture around town keeps cylinder area super heated and piston is absorbing must the heat sense is the most mayor component without cooling, when you decide to go for it the pistons are heat soaked at which time you decide to turn up the heat (way up) factoring consequences which will sure to outspend fuel savings. Ask me how I know.
Answers to mayor problems are often simple enough to pass us by.
Answers to mayor problems are often simple enough to pass us by.
When tune make sure not to live engine in a diet, running lean mixture around town keeps cylinder area super heated and piston is absorbing must the heat sense is the most mayor component without cooling, when you decide to go for it the pistons are heat soaked at which time you decide to turn up the heat (way up) factoring consequences which will sure to outspend fuel savings. Ask me how I know.
Answers to mayor problems are often simple enough to pass us by.
Answers to mayor problems are often simple enough to pass us by.
Wow, very concerning! I haven't done any big mods to the motor yet, but I have plans haha! Now the noob questions (sorry!).
So if you do mods like LT's or head + cam and you need a tune to make it run or get the most out of the mods, what do you say to the guy doing the tune?
Do you tell him to do a "conservative " tune, ie a little more rich and less timing to lessen the chances of grenading the rearmost pistons? Ask him if he's aware of this issue with the motor? Ask these questions without looking like a moron- is this possible lol?
Is it a stretch to say that a tuner wants to show you as much power as possible to highlight his skill and show you everything was money well spent? Motor longevity and well being is part of the equation I'm sure...
So if you do mods like LT's or head + cam and you need a tune to make it run or get the most out of the mods, what do you say to the guy doing the tune?
Do you tell him to do a "conservative " tune, ie a little more rich and less timing to lessen the chances of grenading the rearmost pistons? Ask him if he's aware of this issue with the motor? Ask these questions without looking like a moron- is this possible lol?
Is it a stretch to say that a tuner wants to show you as much power as possible to highlight his skill and show you everything was money well spent? Motor longevity and well being is part of the equation I'm sure...
TECH Addict
Joined: Mar 2013
Posts: 2,628
Likes: 30
I can tell you one way to see if you are too far on the lean side in any cylinders. Run the **** out of it at WOT the after it cools down pull all the plugs and look for signs of running too lean. Mine ran fantastic but was blistering the white porcelain on the plugs.
Wow, very concerning! I haven't done any big mods to the motor yet, but I have plans haha! Now the noob questions (sorry!).
So if you do mods like LT's or head + cam and you need a tune to make it run or get the most out of the mods, what do you say to the guy doing the tune?
Do you tell him to do a "conservative " tune, ie a little more rich and less timing to lessen the chances of grenading the rearmost pistons? Ask him if he's aware of this issue with the motor? Ask these questions without looking like a moron- is this possible lol?
Is it a stretch to say that a tuner wants to show you as much power as possible to highlight his skill and show you everything was money well spent? Motor longevity and well being is part of the equation I'm sure...
So if you do mods like LT's or head + cam and you need a tune to make it run or get the most out of the mods, what do you say to the guy doing the tune?
Do you tell him to do a "conservative " tune, ie a little more rich and less timing to lessen the chances of grenading the rearmost pistons? Ask him if he's aware of this issue with the motor? Ask these questions without looking like a moron- is this possible lol?
Is it a stretch to say that a tuner wants to show you as much power as possible to highlight his skill and show you everything was money well spent? Motor longevity and well being is part of the equation I'm sure...
Engine running around 14. / 14.2 air fuel ratio runs happy and cool and have very steady idle.