Anyone broken a PRC Platinum spring?
03-21-2008, 09:57 PM
#1
7 month old engine coming back out The car started driving with a slight hesitation and I have a tapping noise in the valvetrain. No flashing SES though. Motor's still hot so I'll pull the valve covers tomorrow.
If it happens to be a broken spring, they lasted about 7K miles. Springs were setup assembled on the heads, installed height ~1.81. Heads were disassembled and re-assembled by the engine machine shop to mill the heads more.
Cam is a 227/235 .645/.650 110+2 using LSK lobes. There was valve float detected above 6800, so I lowered the rev limiter to 6600 as soon as it was diagnosed. Hopefully there's no significant damage.
If it happens to be a broken spring, they lasted about 7K miles. Springs were setup assembled on the heads, installed height ~1.81. Heads were disassembled and re-assembled by the engine machine shop to mill the heads more.
Cam is a 227/235 .645/.650 110+2 using LSK lobes. There was valve float detected above 6800, so I lowered the rev limiter to 6600 as soon as it was diagnosed. Hopefully there's no significant damage.
Last edited by JimMueller; 03-25-2008 at 03:40 PM.
03-22-2008, 04:01 PM
#3
Hmm, I can't find anything broken under the valve covers. Some of my 3/8" pushrods are a bit scuffed in a range a few inches above the bottom tip, but not all of them. Couldn't find my fuel line disconnect so I can't easily look into the intake runners.
My rocker bolt sealant didn't work and the intake ports are basically black. But the cheap fuel filter I'm using as a catch can hardly has any oil in it. The throttle body is clean inside the blade, except for a ring of brown right next to the blade.
What else can I check without pulling the heads?
Edit: Clarification
My rocker bolt sealant didn't work and the intake ports are basically black. But the cheap fuel filter I'm using as a catch can hardly has any oil in it. The throttle body is clean inside the blade, except for a ring of brown right next to the blade.
What else can I check without pulling the heads?
Edit: Clarification
Last edited by JimMueller; 03-23-2008 at 05:58 AM.
03-22-2008, 04:37 PM
#4
How did you detect valve float? I'm my 01 Z06 i broke a valve spring. Couldnt really see it when i took the valve covers off so i turned the motor over with them off and found it. It broke at about 2k miles 7300rpm with a 238/242 608/612 115lsa.
This is a picture after i spun the spring around. They were beehive springs.
This is a picture after i spun the spring around. They were beehive springs.
03-22-2008, 04:37 PM
#5
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I would like to hear if your ticking sounds like mine.
What area do you live around?I'm in east Orlando.
I was planning on spending my sunday hunting for
my tick that has shown up lately.I hope it is exhaust.
Brian
What area do you live around?I'm in east Orlando.
I was planning on spending my sunday hunting for
my tick that has shown up lately.I hope it is exhaust.
Brian
03-22-2008, 08:27 PM
#7
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How did you detect valve float? I'm my 01 Z06 i broke a valve spring. Couldnt really see it when i took the valve covers off so i turned the motor over with them off and found it. It broke at about 2k miles 7300rpm with a 238/242 608/612 115lsa.
This is a picture after i spun the spring around. They were beehive springs.
This is a picture after i spun the spring around. They were beehive springs.
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03-22-2008, 11:42 PM
#8
I dunno much about the springs as i didnt built that car myself. They were ET 2.055 LS6 heads, broke a spring in the first 2k or so and called up ET without even a question they sent me a brand new set of Patriot Golds. I described the white dots on the springs and sent them a pic and i could have sworn they said they were old style beehive springs or something because of the spring coils spiraliing opposite. This was in 05 though so it's quite possible that im not remembering right.
03-23-2008, 05:58 AM
#9
https://ls1tech.com/forums/generation-iii-internal-engine/862528-motor-falls-flat-after-6800-a.html
I didn't get the chance to shim the springs further since that discussion, although I do have the shims.
The top end is already disassembled so we won't be able to hear anything until it's back together. I live near the corner of Red Bug & 436. PM me if you still want to stop by.
I didn't get the chance to shim the springs further since that discussion, although I do have the shims.
The top end is already disassembled so we won't be able to hear anything until it's back together. I live near the corner of Red Bug & 436. PM me if you still want to stop by.
03-23-2008, 06:49 AM
#11
No broken springs so far as I can tell from looking at the front of them. I don't know if one should be able to compress a broken dual (with the inner spring still good) by hand. It it's reasonably easy, then none are broken as I couldn't depress any by hand. I don't have the tools to R&R valvesprings.
Last edited by JimMueller; 03-23-2008 at 07:07 AM.
03-23-2008, 04:01 PM
#12
My friend Robert (mrr23 here) came over and helped me put the top end back together After removing the accessory belt, he believes it's coming from the bottom of the engine, either the bellshousing or the mains, and it's just plain loud enough to make it sound like it's from the valvetrain. It's a squeaky, rattling sound. It's something which is rotating and it sounds as if the rotation is causing something else to be flung around.
Oil pressure is at almost 60psi on a cold start, and oil level was mid-hash yesterday when the engine was cold. Didn't think it was the throwout bearing as the sound didn't change with the clutch pedal position. It's a LS7 clutch & Fidanza LS2 flywheel, and FWIW I did smell the clutch for the first time since installed when I autocrossed on the 16th.
So I guess we start by pulling the tranny and inspecting the clutch. I'm hoping it's just the clutch
Oil pressure is at almost 60psi on a cold start, and oil level was mid-hash yesterday when the engine was cold. Didn't think it was the throwout bearing as the sound didn't change with the clutch pedal position. It's a LS7 clutch & Fidanza LS2 flywheel, and FWIW I did smell the clutch for the first time since installed when I autocrossed on the 16th.
So I guess we start by pulling the tranny and inspecting the clutch. I'm hoping it's just the clutch
Last edited by JimMueller; 03-23-2008 at 04:35 PM.
03-24-2008, 10:37 AM
#13
Put the car on a lift and pulled the tranny and clutch. The sound seems to be emanating from the front of the engine. Next step is to check the cam retainer bolts (which we both specifically remember using threadlocker on them). If that's not it, the motor comes out 
03-26-2008, 04:10 PM
#15
The rev kit bolts into the same location as the OEM lifter tray. The billet cracked vertically through the bolt hole between cylinders 2 and 4, and also above the #4 intake lifter. The remainder appear to be fine. There is a small triangular piece of billet missing below the screw.
I've already spoken with the rev kit vendor and sent them pictures. I was told they will call me back, as this was the first one they've known to break. I've previously discussed my valve float issues with them, and they want us to measure the valvespring pressures also.
The oilpan and filter are still on so we haven't checked for metallic particles yet. Hmm, so use the new OEM lifter trays and risk turning a lifter (done that) or replace the rev kit piece and risk a different fatality?
I've already spoken with the rev kit vendor and sent them pictures. I was told they will call me back, as this was the first one they've known to break. I've previously discussed my valve float issues with them, and they want us to measure the valvespring pressures also.
The oilpan and filter are still on so we haven't checked for metallic particles yet. Hmm, so use the new OEM lifter trays and risk turning a lifter (done that) or replace the rev kit piece and risk a different fatality?
