A second set of pistons gone...
Jan 21, 2015 | 11:39 AM
#21
You need a in person tune by someone with experience tuning turbo setups. You for sure need a bigger fuel pump. Throw a fuel pressure gauge on your truck and I am certain it will be dropping badly when you are in boost.
Blackbear isn't bad especially when tuned in person. Mail order tunes just aren't for tuning boosted setups.
Blackbear isn't bad especially when tuned in person. Mail order tunes just aren't for tuning boosted setups.
Last edited by gamble686; Jan 21, 2015 at 11:51 AM.
Jan 21, 2015 | 12:03 PM
#22
I"m running a trick kit on my 2002 5.3 and I finally had time to actually tear the engine down again. I'm running about 7 lbs with a black bear tune. Last time around, a bad batch of fuel caused a hole in #7 piston. I went through the whole thing and put a set of wisco pistons in it. About 3000 miles later she went to knocking. I assumed that I had bought cheaper bearings and spun one. Once I got it apart, the #2 piston was trashed. This time the skirt was wore about a sixteenth of an inch and the cylinder wall was scored pretty badly. Needless to say, I won't buy wisco again. I don't know if the piston clearance wasn't high enough or what the deal was but, they were supposed to be ready to go and boost capable. 
What would you guys recommend I try next? I was thinking about putting 6.0 heads on it with stock gm pistons or maybe even dropping a 6.0 in it instead. I haven't really decided what I want to do. My end goal is around 450-500 horsepower. Anyone have any ideas?
What would you guys recommend I try next? I was thinking about putting 6.0 heads on it with stock gm pistons or maybe even dropping a 6.0 in it instead. I haven't really decided what I want to do. My end goal is around 450-500 horsepower. Anyone have any ideas?
So who built the motor?
Jan 21, 2015 | 12:24 PM
#24
Thread Starter
Teching In
Joined: May 2012
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From: South Central Iowa
My dad and I built it. The pistons were supposed to be the standard size and we honed the block. I don't remember what the clearance was. My dad worked for gm for years and has built hundreds of engines so I'm sure we didn't do anything to cause the problem there.
Jan 21, 2015 | 12:26 PM
#25
Thread Starter
Teching In
Joined: May 2012
Posts: 41
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From: South Central Iowa
You need a in person tune by someone with experience tuning turbo setups. You for sure need a bigger fuel pump. Throw a fuel pressure gauge on your truck and I am certain it will be dropping badly when you are in boost.
Blackbear isn't bad especially when tuned in person. Mail order tunes just aren't for tuning boosted setups.
Blackbear isn't bad especially when tuned in person. Mail order tunes just aren't for tuning boosted setups.
Jan 21, 2015 | 02:01 PM
#28
Can you explain your setup? Do you have an intercooler? What turbo? What happened the days it went? Before I replaced and tuned anything, I would get the injectors cleaned and flowed.
Jan 21, 2015 | 02:18 PM
#29
Thread Starter
Teching In
Joined: May 2012
Posts: 41
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From: South Central Iowa
This time when the engine went, I was pulling through 3rd gear at about 4500 rpm up. As soon as I let off it was knocking. AFR gauge looked good through the pull. The first time was very similar but the whole thing went bang when I blew a hole in the piston.
Jan 21, 2015 | 02:22 PM
#30
A 2002 Silverado stock fuel pump will not provide enough fuel for your FI setup, regardless of which injectors you have, and regardless of what your wideband reads.
If we could see pictures of the damaged pistons, it would help us troubleshoot your failure. Broken/damaged parts usually tell you what went wrong.
If we could see pictures of the damaged pistons, it would help us troubleshoot your failure. Broken/damaged parts usually tell you what went wrong.