RaleighSS

So while I had a great time instructing my student the second session on Monday morning proved to be the last for my LS6. This is my second motor (lost first one due to oil starvation) I had schwanke short blocks build a stock forged bottom end. I had 243 heads ported by texas speed and have a set of brian tooley valve springs installed with the 2.02 1.575 SS valves..... motor had 3 quart accusump and separate oil cooler .. Cam was similar to G5x2 but just a few deg smaller. Coming down the back at about 6400 in 4th is when the clanking started .... I shut down and coasted into the pits ... Quick compression test said #2 was down for the count .... I took it apart today and found that the valve had broken at the base and played hell on the head and the piston as well as the block wall. I never thought about valves being the weak part of the motor ... but one darn valve killed me.

kenw

Sorry about your motor. Good luck on repair

seamus2154

Wow. The LS6 is one of the most stout motors GM has had. Have heard of a few but very few. I am in fear of this and worse with the LS7. It's usually much more catastrophic
with LS7.
I hope you can salvage a lot of that motor and get back on the track. Good luck

SouthernSon

Valve spring on that valve check out okay? Keeper? Sounds like you did the right build on the motor. Stuff happens.

RaleighSS

valve spring looks great ... not sure if the springs have too much seat pressure for the valves I used, but any part can fail I guess.

StreetSpeed

Bummer. Good luck with rebuild. Mine blew up in April, picking it up next week after a total new rebuild. Wanted to just throw in a stock LS6 but decided to go crazy with a TexasSpeed 383 stroker, AFR heads, forged everything, etc. Thing better be a beast and last forever!

oh1vette

Sorry to hear....

Good luck with the repair...

truth.b

Dang sorry to hear about that Paul. Do you know what your next move will be?

miracle_whip4130

Had you ever over revved this engine? I was just thinking if you accidentally money shifted once and over revved that valve(s) could have touched piston(s) and gotten tweaked. Eventually, after many engine cycles of the tweaked valve hitting the seat the neck may have fatigued and let go. Are any of the other valves or pistons damaged? I would be interested to see if the other valves are straight.

RaleighSS

Thanks Truth ... Not sure of next plan have to see what fits the budget. Hoping I can find someone to fix the head and maybe locate a good used block that just needs a hone. I have a line on a rebuilt LS2 but not sure about that just yet.

Miracle ... Never mechanical over revved this motor as I recall. The rev limit is set at stock levels and I rarely have ran into it.

I am wondering if the seat pressure of the Brian Tooley springs is a bit much for the valves I had. I will replace all valves but will look into the specs of each to see if that is a factor ... Maybe I just had a part fail and nothing was built "wrong" or used out of tolerance.