blue99SS

I bent my pushrods a while back, had them replaced and the motor runs smooth and feels fine. Just talked to my buddy's mechanic and he said that if I bent to pushrods then the valves are probably bent too and that you can really only tell on a leakdown test. I didn't break a spring when this happened (somehow) but I did bent one of the pushrods to about a 30 degree angle. Does this sound right? Wouldn't it run like total sh*t if the valves were bent?

stang90gt50

iTrader: (6)

Normally i dont think so... I've fixed several guys cars who bent the pushrods bad on M6 stick cars ...almost always from missing a gear REAL bad while racing. None hurt anything but the pushrods.

Ping King

iTrader: (20)

how would it bend the valves?

blue99SS

That's what I was wondering??? Yes, bending the pushrods was from a 3rd-4th down to second misshift. The car shut down almost imediatly after, so it was a BAD misshift.

Bill Bowling

iTrader: (6)

If you had a bent value it would run bad. Check the compression or do a leak down test to be safe.

Bill

Viper

iTrader: (6)

If you're running hardened pushrods, you could bend a valve on a bad misshift. If you're running stock pushrods, good chance that's all that bent. The buddy's mechanic probably doesn't realize how flimsy our stock pieces are.

LS144

iTrader: (7)

I bent my pushrods very badly and it didnt hurt the valves at all. I did a leakdown test and it checked out ok. But that wasnt good enough for me I pulled the heads and checked. Better safe than sorry.

blue99SS

Yes, they were stock pushrods. His mechanic works on LS motors all the time and says he's seen it happen to like 6 cars. Wouldn't the car run terrible if the valve's were bent or if they're slightly bent would the car run pretty good to the point where I can't tell???

blue99SS

Where would I need to go to have a leakdown test done? How exactly does it work? How much am I looking at for the test?

two step

I bent 2 p-rods and bent 2 valves and colapsed 2 lifters way back in 2000.

GuitsBoy

iTrader: (4)

When you top out a gear and accidentally shift into a lower gear instead of a higher one, you mechanically overrev the motor by quite a bit. The anemic stock valvesprings simply can not control the inertia of the valvetrain at this speed. The result is that the lifters jump off the cam lobes since the spring isnt strong enough to keep it down, with the lifter off, the valve is still further down and floating when a piston comes up and smacks the valve. This sends a sharp hit through the valvetrain, which is usually enough to collapse and bend the pushrod under the inertia of the lifter. Usually the valve is much stronger than the pushrod, so the pushrod bends to absorb the shock. I would say that of all the people who bend stock pushrods due to an overrev, 95% or more have no problems with the valves.

Ping King

iTrader: (20)

so valve float would cause bent valves, not a bent pushrod.

GuitsBoy

iTrader: (4)

No, youre missing the point. Valve float and a resulting valve to piston colission will impact both the valve and the pushrod. Since the stock pushrods are far softer, they usually bend before the valve does.... unless youre particularly unlucky or really trhrash your motor.

Wicked ls 1

I bent 15 valves and 16 pushrods,then again my timing chain broke.

blue99SS

Thanks for the post! Hopefully this week I will be having full exhaust and N20 put on it and will replace the obviously beat up stock springs with LS6 springs until I save the funds to buy some bigger/better heads.

rimalm

iTrader: (2)

I've Broken one pushrod before.. the mechanic only changed one though.. so does that mean the others might still be bent?? i dont hear a really loud ticking like before my one pushrod broke.

Boostaholic

iTrader: (4)

I've bent one pushrod before, and it sounded pretty nasty. Easy fix though in our case.

GOOSE JR.

If they were the stock rods your motor has a good chance that it is ok but if you bent a hardened rod you would have a problem.

Mark99Hawk

iTrader: (4)

When I bent pushrods, I also bent 5 valves. Most weren't bent enough to even notice with the car running but one was bent enough to cause a miss at idle (threw a code and everything).

Mark

rimalm

iTrader: (2)

is it expensive to change all the valves and pushrods?