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Looking for advice on the valve spring breakage issue that some have had.

Any recommended valve springs to change to for a preventative measure? Dual spring? What would be a good brand/spec for a stock motor?

Should do upgraded/stronger pushrods as well? What length would work for stock?

Any other parts that should be upgraded while I'm in there? I know the trunion used to be a thing to change out on the LS motors, are the bronze the only alternative to stock? If I remember correctly, one non bronze aftermarket kit was having issues coming apart as well?

I'll be staying stock cam wise for another year more than likely, then something with some lope or a blower cam and lsa.

Thanks
 

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2014 PMB,Cam,Converter.Headers,CAI,
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Good question, I heard about valve maintenance as well I have an aftermarket cam but all the valve train was upgraded with that so I'd like to see what people say
 

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I have a stock cam and will be doing PAC-1218 when I do it. It'll be before I fail a spring, it has comparable spring rates to oem but a lift max of 0.600". I had them on an ls1 with an ls6 cam, no issues.
 

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I ran the PAC-1218's for 25,000 miles. Stock pushrods are 7.400". That setup was trouble free. Reused OEM pushrods, retainers and valve stem seals. I have since changed to dual coils springs, 1.8 rockers. and billet rocker pedestals. The PAC springs gave me peace of mind...
 
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The truion needle bearings are known to fall out at high rpm. Not really an issue on stock setups though. You can get replacement truion bearings or new truions that allow more angle if you have an aggressive cam.
 

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If it was me I would save your money and not do springs / trunnion kit until you do a cam. Then with the cam go with new springs that match your cam choice, titanium retainers, and CHE trunnion kit. Measure your pushrod length after installation then order correct pushrod height. I went 192k without a broken spring or trunnion needles walking out. Was I lucky or its normal. Who knows....
 

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The truion needle bearings are known to fall out at high rpm. Not really an issue on stock setups though. You can get replacement truion bearings or new truions that allow more angle if you have an aggressive cam.
As someone who suffered stock trunnion failures under 12.5k miles, I do not endorse this position.
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That's when the car was all stock. Motor failed on the test drive after the dealer dropped the pan and recovered the needles. So no, you're not immune from trunnion failures with a stock cam and low rpms.
 

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You questions depends on several factors.

If you are OEM cam, run OEM springs. If you run aftermarket cam, run aftermarket springs.

Pushrods: if the cam's base size is unchanged, then the size is 7.4". If unknown, always measure. And upgrade your pushrods over 7.4 OEM.

Valve springs: it depends on how hard you beat on it, how much lift/duration. In my uneducated opinion, 25k is the max I would go. I just changed mine for the third time.
 
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Every part if the OEM stock valve train is a compromise between manufacturing cost and quality, judged by GM to be "good enough" for a street performance engine on a statistical basis. That means that failures will occur but be relatively few spread across the entire fleet.
 

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Every part if the OEM stock valve train is a compromise between manufacturing cost and quality, judged by GM to be "good enough" for a street performance engine on a statistical basis. That means that failures will occur but be relatively few spread across the entire fleet. In the past I had a GM ZZ3 350 cu. in. small block in a Jaguar. It broke a valve spring in less than 10,000 miles. Being stranded by the side of the road in the back and beyond at a time when cell towers were limited to built-up areas is a big PITA. I now pre-emptively replace valve springs (and other valve train parts) on GM engines that I own. This may be overkill I admit.
There has been a lot of research on valve train stability in the past couple of decades. Valve train parts are all inherently flexible, and it is now understood that it is important to avoid resonance over the full rpm range. The use of beehive springs in the LS3 is not an accident, nor a money saving decision. It is to reduce reciprocating mass on the high-lift side of the valvetrain in order to move valve spring vibration out of the rpm range. It is a good idea to retain this spring design when a stock, or near-stock cam is used. High lift and/or high rpm cams need stronger springs. Dual springs are to allow friction between the two springs to dampen spring vibrations.
  • For valve springs, I use Performance Springs Inc. p/n LS 1511 ML (Max Life) beehive springs. This is the company that figured out how to make Nascar valve springs last 500 miles at 8,500 RPM.
  • The OEM rocker arms are OK for at least moderate camshaft upgrades, but the trunnions need bearing upgrade. I have used Comp Cams trunnion kits with good results, but have learned that the sharp grinding marks on the bearing trunnions need to be polished with Crocus Cloth abrasive if you want the needle rollers to last. I now prefer the CHE Precision Inc. bronze trunnion kit, as it is made to better tolerances. The rocker arms should be mounted on the Livernois precision machined saddles.
  • The CHE valve retainers p/n NSK-LS1-41-16 are the lightest steel retainers that have race proven durability. Hardly heavier than Titanium. I have had variable luck with non-steel retainers over the years. Likewise the CHE precision machined valve locks p/n NSK-LS1-4140 are quality pieces.
  • Reciprocating weight is less of an issue on the "slow" side of the valve train, and stiffer pushrods can be accommodated. Better steel, heat treating, thicker walls and larger diameter are all areas for improvement. Manton pushrods offers a 11/32" diameter x 0.120 wall pushrod that will generally fit the LS3 pushrod openings without drilling and is vastly more resistant to bending.
 

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How many miles on your engine now? I would not be concerned about changing the OEM springs until 100k personally. You can probably go safely more than 100k as long as you don't rev the snot out of it. I also agree with indebt about holding off on spending money on upgrades until you do the cam swap. I mean heck, why not swap it now?

I also would avoid the Comp trunion kit as it is poorly designed. Here is a little background with my experience.

Here is my full write and experience on the trunion side of things if you want to check it out.
 

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I also would avoid the Comp trunion kit as it is poorly designed. Here is a little background with my experience.
I second silver surfer. I had 7 out of 16 comp cam trunions fail after only 34k miles. They ended up taking out my cam and I stopped driving just in time to salvage the block. Now I'm waiting on a fully forged build (going on 10 months now :() and I'm using CHE trunions this time.
 
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If you are OEM cam, run OEM springs. If you run aftermarket cam, run aftermarket springs.
I recently had an OEM spring fail and bent that pushrod at 40k miles - Everything on the car is still factory. Was just idling in a parking space when it decided to let go.

Luckily no other damage, but wish I had done the springs and trunnions earlier. I would 100% recommend this as preventative maintenance.
 
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