Good job Mike. We don't see many LS valve spring failures, except some HP LS3''s. Around 2020 GM apparently ran out of valvetrain parts and outsourced them, big mistake. If you have a VS failure under 8k GM replaces all the valve springs, over 8k I hear they only replace one. I'm told only a limited number of engines are affected. The leak down trick works as long as the valve is not bent, for the most part LS production engines are non-interference. Many years ago I put an RV cam in my small block truck and broke a VS in the middle of New Mexico, no cell phones then. The Cardinal rule with valve springs is never increase the lift with a stock spring that has miles on it. Valve springs have a memory and even a few thousands more lift can lead to a failure. Short story long with my small block in the middle of nowhere - I tied the valve up with wire and drove as a 7 cylinder to a Napa store. Purchased a valve spring and a K&S VS tool. How to hold up the valve to replace the spring with no compressor or tools? I had some rope in the back of my truck, fed it through the spark plug hole when the cylinder was at BDC. Fortunately my truck was a manual with a wimpy 283. I slowly rolled the truck until the string smashed against the valve face and replaced the spring😅 Drove back to LA and put all new valvetrain in from Comp Cam. I ran that 283 until it wore out, over 300k miles, lost compression and vacuum. Ironically I put the first Gen IV LS in that truck in 2007. All the naysayers said it couldn't be done. I worked with EFI Live and we got the security system - VATS, cruise control, key off draws, tap shift and much more R&D'd on that truck. It has AFM and about 150k now on the 5.3 LH6.
Thanks Robbie. That's the reason I chose to leak test the cylinder that the spring failed on first, to determine if it was ok and I was good to go with the other seven, if not the body had to come off and go down to the heads. Then I'd do a full AFM delete but luckily all was good so the AFM delete will come down the road when I can schedule it between trips. I've built a lot of race engines in the past and never had a valve spring failure but then I was changing cams and springs quite often so they never got the miles on them that this stock L94 has now. Luckily I've never had to do the steering in the cylinder truck because I've always been fortunate too have air readily available. I'm just grateful this spring failure happened about four miles from home and not during one of our RV/Jeep gatherings and we were 30+ miles off the pavement in the back country. 😲 Thanks for taking the time you watch and comment Robbie, how to and your family had a wonderful holiday season. Mike
Very informative as usual. Always pick up some sort of new tip! Hard to believe you have approx. 65k already, doesn't seem like it was that long ago you did the conversion! Thanks for sharing.
Thanks Craig. Yeah it's hard to believe that I did the LS swap 5 years ago and already have almost 65k on it. Glad to hear to found the video informative. Thank you for your continued support and taking the time to watch. Mike
