rceron

iTrader: (1)

I have a 98 LS1 with a mild cam that just imploded at the track (road racing). The bearings at the crank are shot. My shop where my car is has claimed that having 30 degrees of timing at peak torque was the reason. Another shop where it was tuned says otherwise. Can anyone comment on this and please remember that this is not a daily driver but for road and track events. I of course only use 93 octane. The engine had 55k miles on it when it was put in my car. The car was only on the track for 15 minutes and I wasn't pushing hard yet so I don't think oil starvation was the issue.

thanks for any input.

R

JoeyGC5

iTrader: (24)

To much timing can cause detonation issues which could lead to undesired forces on the rotating assembly. But you would have to seriously beat the hell outta the motor for a continued time frame (while hearing knock and pinging). imo

RE AND CHERYL

iTrader: (31)

Optimum timming for an LS1 is about 27-28deg total. You could have easily had detonation with the timming at 30 deg and the engine working that hard, but you would have heard it.

I'd say your tunner whent a bit far but that most likely didn't kill the engine.

Re'

brad8266

iTrader: (23)

30 degrees at peak TQ is not good, but not enough to do that much damage to your cam only motor. Like stated you would have heard knock if it was that bad, plus knock sensors usually take care of eliminating the knock.

I suspect your damage came from something else.

LS1curious

pictures of parts ?

rceron

iTrader: (1)

Sorry I don't have pics. The shop said that the rods were purple as well. They also stated that at full WOT and full exhaust I probably would not have heard pinging/detonation, which I didn't.

So are we saying that the tune might have been the straw that broke the camel's back, so to speak?

thanks!

SladeX

I'm running 29 degrees of timing off a 91 octane tune with no issues, I switch to 94 octane for track, but on hot days I haven't heard any pinging nor has my knock sensors pulled any timing. I know they're not off either.

I would say something else took out your engine, oil pump?, oil starvation during hard turns ? Most autox people I know ensure at least 6 quarts + the long filter to make sure they have adequate oiling.

badpewter-z

iTrader: (4)

i can see to much timing taking out the upper end like pistons, valves, ect, not a crank bearing though .
being a 98 was it high mileage?

Z284U2TRY

iTrader: (5)

Oil starvation?

JoeyGC5

iTrader: (24)

You should have felt some sort of stumble or lack of power in the throttle transitions if timing was being pulled from knock at least. If the rods were purple sounds like an oil starvation problem causing heat in the rotating assembly. I bet the crank journals had the sheit burned out of them also.

gun5l1ng3r

Another 98 pump kills a 98 LS1.... I am worried

Maybe I should just get my Cali legal smog cam (Stealth II, nice and torquey) and change the pump at the same time.

Too bad I am in college and money does not grow on trees

rceron

iTrader: (1)

Thanks for the input guys. Incidentally, my engine already had an upgraded/ported oil pump. As many have pointed out, oil starvation could have been a reason given that this is a major issue with the LS1 and driving on the track. Next engine will have a 3 quart Accusump. I just want to learn more about advanced timing effects. Points about timing have been "all over the map"--definitely no clear answer.