snkchrmr

Last week at the track I missed second gear and hammered the rev limiter . Well after I got it back in second gear rolled on the throttle and the car was fluttering and spiting, had no power. Also the ses light was blinking like crazy. I coasted on down and when I got off onto the return road car was fine and has been since. Went home pulled plugs all look great, temp and everything is completly fine, no motor noise. Now the only thing I can figure is that the lifters pumped up and floated the valves maybe. If this is what happend what could I have hurt, push rods,valves,or springs maybe? Any info would be greatly appreciated.

DD966

iTrader: (3)

Had a similar experience when I miss-shifted at 6000 rpms (3--->2) OUCH. The car actually stalled out. I checked everything out as well. Everything looked good, except the SES light wouldn't go away. The dealership reset the light for me and told me when something like that happens, the PCM shuts down the fuel pump, to negate internal damage. 1000's of miles later, I swapped my cam out. Everthing looked good - valves, rods, springs, etc. were just fine. These LS1's can take quite a beating. So unless you notice something, your car is probably just fine.

SSactionLs1

I would pull the pushrods and roll them on a flat surface.

snkchrmr

Yeah my ses light hasn't came on since it flashed like 15 times when it happend so hopefully it want. I guess I may have dodged one this time. I'm going to go ahead and put a cam, springs, and push rods in it. Thanks for the info and reinsuring my confidence that nothing major is happend. I guess I'll take it back to the track this Friday and try to make a pass or two.

jyeager

When you overrev the engine the SES light flashes. I've done it when I hit 1st instead of 3rd. No damage though in my case (not to the engine anyway).

94form2000z

iTrader: (10)

I wouldn't want to have a misshift with hardened pushrods in there. Cheap insurance = stock pushrods in M6.

snkchrmr

Yeah luckly I haven't went to 1st instead of 3rd or 2nd instead of 4th. I just had it matted while it wasn't in gear,but it still scared me quite a bit. Well I'll find out tommorrow I'm going to just run the **** out of it and if it don't break then I'm no longer going to worry if it hurt anything. I'll let you know what happens.

jyeager

I've tried to debunk this myth before but it persists. The weak pushrods don't save your valves when they contact the pistons. If the pistons hit the valves the valves are toast even if your pushrods were made of pipe cleaners.

The reason the pushrods do bend when we overrev is because the float results in the lifter coming off the cam lobe and it hits the lobe on the next revolution resulting in a battle between the cam and the valve springs.
A hardened rod might survive this and nothing would be damaged.

94form2000z

iTrader: (10)

I definitely agree on the fact if the valve hits the piston no PR will help that. But the bending pushrod might just give enough to keep the valve off the piston. Might also give enough the valve just might not poke through the piston.

P Mack

iTrader: (6)

Why are you guys talking about bent pushrods and valves, he said he didn't overrev it.

94form2000z

iTrader: (10)

Gee I dunno

P Mack

iTrader: (6)

I can't tell if you're being sarcastic or not, but he said he hammered the rev limiter, not overreved. There's a big difference.

94form2000z

iTrader: (10)

Most of the time when someone hammers the Rev limiter from a mis shift that is exactly what happens. It over revs past the set rev limiter RPM. Sarcasm OFF. Big difference between missing shift, accidentally down shifting, and just not shifting quick enough.

snkchrmr

Yeah I didn't drop it in a lower gear and over rev it I just bounced the rev limiter while it wasn't in gear, but got it for a good bit. Then put it in 2nd car was sputtering wasn't going anywhere so coasted on down then it was fine once I got to the return road. I drove the car last night it seems fine I might run it to night and see what happens. The only thing is I haven't run it with the stuff I have now so I don't really have a comparison. well wish me luck.

jyeager

Actually he did overrev it even if he thinks he didn't. That's borne out by the fact that the car sputtered and the SES light blinked. It doesn't appear to have damaged anything though. Overrevving often, but not always results in bent pushrods, it just depends on how bad.
Just because you've got a rev limiter doesn't mean you can't overrev via the inertia of the flywheel.