Damage
10-07-2007, 04:03 PM
#1
12 Second Club
Thread Starter
iTrader: (13)
Join Date: Feb 2005
Location: Gateway International Raceway
Posts: 1,575
Likes: 0
Received 1 Like
on
1 Post
Damage So if you swap heads or cams...don't drive without a tune...check the pictures to see why. I was scanning my car with HPTuners while driving and had no KR when this happened. It just started missing and this is what I found.
Well here is what the leak down test will not tell you.
Here you see the chunk out of the top of the piston
Here is another shot of the broken hyperuseless piston
And one final shot of it, looks like there is a forged 402 in my future. Suprisingly the head looks OK but there is some scarring on the exhaust valve where the piece exited the exhaust. The cylinder is still very smooth all the way around. I could probably save the block and do a 347 but why, when for just a little more you can have a 402/408.
Anybody got a line on a good sale on short blocks?
Well here is what the leak down test will not tell you.
Here you see the chunk out of the top of the piston
Here is another shot of the broken hyperuseless piston
And one final shot of it, looks like there is a forged 402 in my future. Suprisingly the head looks OK but there is some scarring on the exhaust valve where the piece exited the exhaust. The cylinder is still very smooth all the way around. I could probably save the block and do a 347 but why, when for just a little more you can have a 402/408.
Anybody got a line on a good sale on short blocks?
10-07-2007, 05:45 PM
#4
12 Second Club
Thread Starter
iTrader: (13)
Join Date: Feb 2005
Location: Gateway International Raceway
Posts: 1,575
Likes: 0
Received 1 Like
on
1 Post
Yes it sort of does. The car was tuned for H/C but I swapped to a different set of heads and had not gone for a tune yet...I wish I had found the time or taken leave or something. Now we see where I am at.
Trending Topics
10-07-2007, 10:01 PM
#8
You got problems with your knock sensors not picking up KR with HPTuners.
I say this because that piece of piston getting slammed between the piston and cylinder head should have been enough to trigger a KR reading.
Plus nothing else will ruin a piston like that unless it was total coincidence and was about to happen before the cam or it has coolant in the cylinder, or serious detonation.
I say this because that piece of piston getting slammed between the piston and cylinder head should have been enough to trigger a KR reading.
Plus nothing else will ruin a piston like that unless it was total coincidence and was about to happen before the cam or it has coolant in the cylinder, or serious detonation.
10-08-2007, 07:21 AM
#10
12 Second Club
Thread Starter
iTrader: (13)
Join Date: Feb 2005
Location: Gateway International Raceway
Posts: 1,575
Likes: 0
Received 1 Like
on
1 Post
You got problems with your knock sensors not picking up KR with HPTuners.
I say this because that piece of piston getting slammed between the piston and cylinder head should have been enough to trigger a KR reading.
Plus nothing else will ruin a piston like that unless it was total coincidence and was about to happen before the cam or it has coolant in the cylinder, or serious detonation.
I say this because that piece of piston getting slammed between the piston and cylinder head should have been enough to trigger a KR reading.
Plus nothing else will ruin a piston like that unless it was total coincidence and was about to happen before the cam or it has coolant in the cylinder, or serious detonation.
Researching a new 402 short block.
10-08-2007, 03:30 PM
#12
12 Second Club
Thread Starter
iTrader: (13)
Join Date: Feb 2005
Location: Gateway International Raceway
Posts: 1,575
Likes: 0
Received 1 Like
on
1 Post
When the problem started was when I was a mile or so away from the track (low RPM). Whether it happened in the 1/8 track (only made 2 passes) or on the way home is anybody's guess.
10-08-2007, 04:19 PM
#13
That is what the top of my piston looked like when it let go. Cracked the sleeve though and smashed the spark plug so I got multiple misfires on #2. SOMEHOW, don't ask me how... when it popped (it still ran) I pulled it apart and as I was cleaning everything in the jet wash I pulled the intake out and heard a rattling, and out came the chunk of piston... crazy. Best of luck on that 402-408.
10-08-2007, 05:04 PM
#14
12 Second Club
Thread Starter
iTrader: (13)
Join Date: Feb 2005
Location: Gateway International Raceway
Posts: 1,575
Likes: 0
Received 1 Like
on
1 Post
That is what the top of my piston looked like when it let go. Cracked the sleeve though and smashed the spark plug so I got multiple misfires on #2. SOMEHOW, don't ask me how... when it popped (it still ran) I pulled it apart and as I was cleaning everything in the jet wash I pulled the intake out and heard a rattling, and out came the chunk of piston... crazy. Best of luck on that 402-408.
10-08-2007, 05:09 PM
#15
I agree... Sometimes I wonder if these fly by night shops buy cars like ours with busted pistons, put a new plug or gasket in them, and runnem... Made it even worse being down a hole with that turbo, made the other 7 work harder and spooled the turbo up, making the situation worse. Fortunately for me, it made it 18 miles home, in the rain. Good ol LS1's. =) Fortunately you didn't grenade the sleeve, it ruined mine and I had to junk the block. If you're on a tight budget, you may get a replacement piston and run it.
10-09-2007, 12:19 PM
#18
TECH Resident
iTrader: (2)
Join Date: Sep 2004
Location: Cleveland, Oh
Posts: 810
Likes: 0
Received 0 Likes
on
0 Posts
Thats just asking for trouble.
The damage was done at the track I'm sure, you just didn't notice it until the drive home.
10-09-2007, 09:42 PM
#20
TECH Enthusiast
iTrader: (2)
Join Date: May 2006
Location: Washington
Posts: 555
Likes: 0
Received 0 Likes
on
0 Posts
hey excessive did you record your runs at the track on HP tuner?
if so take a look back and see if there was any diff between first run and second, you said your second run was slower...
i feel your pain
, but time and a new motor will heal all your wounds.
did you get my email yesterday ??
if so take a look back and see if there was any diff between first run and second, you said your second run was slower...
i feel your pain
, but time and a new motor will heal all your wounds.did you get my email yesterday ??