I posted in southern, but I wanted a few more opinions.

Here is what I installed:

• LPE GT2-3 (used from vortecHOjunkie in near perfect condition)
• 7.4" hardened pushrods
• new LS6 springs
• gaskets and crank bolt

Here is what happened:

This was my first solo cam swap, and I had helped with one other a while back. I followed the LS1 how to article step by step. Started first time after install with no issues, and after some heat cycles for the springs....truck responded to the cam well and drove great for about a week. Cruising at 75, check engine light came on and I slowed and exited the highway. No particular engine noise or misfire. As I slow the engine begins to sputter and it dies, and at this point will not run/idle. I do like having AAA.

I pulled the valve covers the next day (no I dont have pics, truck is at an engine shop). I see cyl 2 intake spring broken and this valve does not move smoothly and binds a bit when closed. Cyl 1 and 2 exhaust pushrods siezed with the valves stuck in open position and springs compressed, turns out the rods are not bent as the lifters are stuck. Rockers not loose or out of position (22 lb/ft). Report from the shop says pistons are fine (no evidence of the valves making out with the pistons), heads are being freshened up with new hardware (comp springs 918's I believe), new lifters, and a some new valves and a valve job to ensure correct spring height and pressure after the "problem".



Things I am sure of:

• springs installed correctly
• cam gear installed correctly (dot to dot)
• oil pressure never droppped, ever
• cam went in smoothly without issue

Questions I need help with:

• Are my pushrods still too long? (7.375 recommended?)
• Did I do something wrong on installation?
• Could the intake valve spring failure cause all of this?
• Or is it a chicken before the egg scenario, and something else entirely?
• Even though I am "sure" cam gear went on correctly, if off by a tooth would it have run so well for several days? Engine shop did not think so....

Any thoughts? I want to make sure this isn't from something I haven't addressed yet. I will be making a cross country drive very soon and don't relish the thought of being stranded.


Thanks fellas,

Nate

 

Where did you get the LS6 springs from?

 

http://stores.ebay.com/The-All-Chevy-Shop-586-427-69OO

This place on Ebay......

 

My first thought were they were not the yellow 02+ sl6 springs, but that site shows pictures of them as yellow

hmmm I am just about to do this exact same thing... but I was told to use 7.4" pushrods... Maybe its better to go with 918's?

 

if nothing else they were definately yellow

 

Maybe call Lingenfelter and just ask them for their opinion?

 

Mostly a mental masturbation game at this point. I got the truck back today and it runs great. I am letting all the new parts seat in after some heat cycles before I play at all. 915 springs (good to .600 lift) I don't plan to spin very high as this is my daily. New intak valve on cyl 2. New valve seals after valve job. Lifter were actually still good as well as the hardened pushrods I installed. Drive home (about 30 miles) very smooth...we'll see how it does over time.

 

what are the specs on that cam?

i got my ls6 springs from lingenfelter, same price everyone else was offering and piece of mind name.

 

Im running LS6s right now on a cam with .558 lift. They're supposed to be good to .620 from what I've heard. Maybe just luck of the draw and u caught a bad one? I wouldnt dwell on it too much or u'll go nuts

 

i thought i remember reading that their limits were .595" lift?