Only 250whp! Motor Has Metal Shavings! LS1
09-20-2010, 11:17 PM
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Only 250whp! Motor Has Metal Shavings! LS1 So today I had a Dyno Tune today, My set-up includes:
80,000 Mile T56 LS1 from a 99 Z28 on 3.73 Gears with 180psi across the board.
TSP 228R Cam Kit with 7.400 pushrods
LS6 Intake & Injectors
Walbro 255LPH Fuel Pump
13# Spec Flywheel
The car had every parameter set and then for the Dyno Pulls.
It pulled 283rwhp first pull, power peaked at 5,000 RPM, and RIGHT after 5,000RPM it instantly dropped 50whp by 5,500rpm, and then by 6000RPM it only showed about 150whp (YES, 150whp!!!)
Something is obviously very VERY wrong here.
Completed another dyno pull, motor made 251whp and started making very very loud noises throughout the valvetrain, in which it was shut down and towed back to my house.
Tore it down, pulled the valve covers and saw shiny metal in the Oil, pulled Intake and valley cover and found HUGEEE chunks of aluminum in the valley!!!
I'm talking very large chunks, like a "pen tip".
Pulled the front timing cover and pulled the cam and the Cam journals are DESTROYED! They are scored to HELL! Some bearings are so bad the copper is showing.
Looking in to the main oil galley I see a constant stream of metal shavings. Thank god the Camshaft looks OK, as it has a little less than 100-200 miles on it. It has no score marks, and the journals have a mirror finish to them still.
Oil pressure was 18psi hot at idle, and about 20psi at around 2,000RPM, obviously very low oil pressures. I wen't ahead and pulled the motor out of the car and am taking it to the machine shop tomorrow for further inspection, and will have all bearings replaced.
One of the LS1 Lifters had the Oil seal "Popped" out of it also.
Will Install New LS7 Lifters when going back together.
Here's my question to you guys,
Can damaged cam journals and low oil press. really cause over 80-120whp LOSS on a rather compression healthy engine?
I just don't really see 80+whp coming from new journals alone, as I would imagine if a few journals were really robbing over 80-120whp they would be out-right destroyed by now? The cam looks FINE!
The tuner suggested that it is definitely a valve train issue, and it is "resonating" over 5,000RPM, as power output drops drastically, only has 150whp at 6,000RPM on a 6,500RPM limiter!
Any input on what I should do next?
The engine is out of warranty.
All Pistons look good from a top-view.
Thanks!
80,000 Mile T56 LS1 from a 99 Z28 on 3.73 Gears with 180psi across the board.
TSP 228R Cam Kit with 7.400 pushrods
LS6 Intake & Injectors
Walbro 255LPH Fuel Pump
13# Spec Flywheel
The car had every parameter set and then for the Dyno Pulls.
It pulled 283rwhp first pull, power peaked at 5,000 RPM, and RIGHT after 5,000RPM it instantly dropped 50whp by 5,500rpm, and then by 6000RPM it only showed about 150whp (YES, 150whp!!!)
Something is obviously very VERY wrong here.
Completed another dyno pull, motor made 251whp and started making very very loud noises throughout the valvetrain, in which it was shut down and towed back to my house.
Tore it down, pulled the valve covers and saw shiny metal in the Oil, pulled Intake and valley cover and found HUGEEE chunks of aluminum in the valley!!!
I'm talking very large chunks, like a "pen tip".
Pulled the front timing cover and pulled the cam and the Cam journals are DESTROYED! They are scored to HELL! Some bearings are so bad the copper is showing.
Looking in to the main oil galley I see a constant stream of metal shavings. Thank god the Camshaft looks OK, as it has a little less than 100-200 miles on it. It has no score marks, and the journals have a mirror finish to them still.
Oil pressure was 18psi hot at idle, and about 20psi at around 2,000RPM, obviously very low oil pressures. I wen't ahead and pulled the motor out of the car and am taking it to the machine shop tomorrow for further inspection, and will have all bearings replaced.
One of the LS1 Lifters had the Oil seal "Popped" out of it also.
Will Install New LS7 Lifters when going back together.
Here's my question to you guys,
Can damaged cam journals and low oil press. really cause over 80-120whp LOSS on a rather compression healthy engine?
I just don't really see 80+whp coming from new journals alone, as I would imagine if a few journals were really robbing over 80-120whp they would be out-right destroyed by now? The cam looks FINE!
The tuner suggested that it is definitely a valve train issue, and it is "resonating" over 5,000RPM, as power output drops drastically, only has 150whp at 6,000RPM on a 6,500RPM limiter!
Any input on what I should do next?
The engine is out of warranty.
All Pistons look good from a top-view.
Thanks!
09-21-2010, 12:31 AM
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Bad News: It sounds like it ate a lifter or two. Yes, you will lose significant power if that happens. Post a pic of your camshaft also. You need to pull the motor and check the bearings, crankshaft surface, and oil pump. My motor did the same thing. I had to replace the cam, oil pump, main and rod bearings, lifters, lifter cups, and have the crankshaft polished. You will be suprised when you take the oil pan off. It will be full of metal. I had metal shaving everywhere to include the oiling holes on the damn rods and caked under the bottom of the pistons.
Good News: Engine will be fresh.
Good News: Engine will be fresh.
Your top end disintegrated on a dyno, and you're wondering how much horsepower you lost. 
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09-21-2010, 07:02 PM
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man that sucks a buddy of mine told me about what happen (Nathan Bucanan) and i have seen ur build thats a straight bummer to get it all together and this happen
09-21-2010, 08:32 PM
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Yea it sucks.
Found out what happened though!
... The crank and entire engine has been either seriously neglected or driven very very hard. It had oil starvation issues since day one of when I bought it. The dark oil, long tubes, and skeptical at best engine shop didn't help the situation.
FIVE out of 8 rod bearings were spun in the motor, cylinder 6 being SO bad that it deep gouged the crank.
The crank is trash. The rods are trash. The block needs serious work.
This sucks.
It's all good though, my TSP cam wasn't damaged, and now I can get a new shortblock and do things correctly.
I will have a running car within 4 weeks.
Will change to high volume oil pump, ls7 lifters, arp rod and headbolts, and of course, all new gaskets and bearings/rings.
I will say this though, with only 250-280whp it was STILL a lightning fast car! (Miata)
Found out what happened though!
... The crank and entire engine has been either seriously neglected or driven very very hard. It had oil starvation issues since day one of when I bought it. The dark oil, long tubes, and skeptical at best engine shop didn't help the situation.
FIVE out of 8 rod bearings were spun in the motor, cylinder 6 being SO bad that it deep gouged the crank.
The crank is trash. The rods are trash. The block needs serious work.
This sucks.
It's all good though, my TSP cam wasn't damaged, and now I can get a new shortblock and do things correctly.
I will have a running car within 4 weeks.
Will change to high volume oil pump, ls7 lifters, arp rod and headbolts, and of course, all new gaskets and bearings/rings.
I will say this though, with only 250-280whp it was STILL a lightning fast car! (Miata)
09-22-2010, 09:03 AM
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To much clearance in the cam bearings will give massive oil pressure problems. There's a secret out here about LS' engines and cam bearings. Let me say, just stay genuine. As for your cam I'd toss it. Even though it looks ok it's probably chipped the case hardening. You will have a flat lobe/s in no time at all. If your forking out for a new short block get a new cam, twin row chain and a mellings or SLP pump. Put it together and enjoy it.
09-22-2010, 12:17 PM
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09-23-2010, 09:07 AM
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09-23-2010, 01:11 PM
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Yea it sucks.
Found out what happened though!
... The crank and entire engine has been either seriously neglected or driven very very hard. It had oil starvation issues since day one of when I bought it. The dark oil, long tubes, and skeptical at best engine shop didn't help the situation.
FIVE out of 8 rod bearings were spun in the motor, cylinder 6 being SO bad that it deep gouged the crank.
The crank is trash. The rods are trash. The block needs serious work.
This sucks.
It's all good though, my TSP cam wasn't damaged, and now I can get a new shortblock and do things correctly.
I will have a running car within 4 weeks.
Will change to high volume oil pump, ls7 lifters, arp rod and headbolts, and of course, all new gaskets and bearings/rings.
I will say this though, with only 250-280whp it was STILL a lightning fast car! (Miata)
Found out what happened though!
... The crank and entire engine has been either seriously neglected or driven very very hard. It had oil starvation issues since day one of when I bought it. The dark oil, long tubes, and skeptical at best engine shop didn't help the situation.
FIVE out of 8 rod bearings were spun in the motor, cylinder 6 being SO bad that it deep gouged the crank.
The crank is trash. The rods are trash. The block needs serious work.
This sucks.
It's all good though, my TSP cam wasn't damaged, and now I can get a new shortblock and do things correctly.
I will have a running car within 4 weeks.
Will change to high volume oil pump, ls7 lifters, arp rod and headbolts, and of course, all new gaskets and bearings/rings.
I will say this though, with only 250-280whp it was STILL a lightning fast car! (Miata)