bent pistons

bent pistons

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    They’re VALVES, not pistons. They are usually caused when a valve spring fails or lifter fails, and the piston come into contact with the piston. Better to have a bent valve than to destroy a piston or snap/bend a connecting rod.


    I do not believe this was a contact to piston situation… there is usually more carnage… these look like they got super heated… like as in a nitro or alcohol funny car or dragster or a piss poor N2O install.


    …and I’ve done both to my bike in the past 3 years. *sigh*


    Na when I dropped a valve seat in my car this is exactly what it looked like + add in shit load of shrapnel from the old pistons.


    If these are from the same engine (which it looks like due to the geometry of the bends), a single valve spring wouldn’t have caused this. And the fact that the bends are all about the same and in the same position which would probably rule out a high temperature issue as the temperature is not even through the head. My guess would be the loss of a timing/cam belt, which would crunch up all the valves as the engine wound down.


    Interference engines. gotta love ’em. $75 belt breaks and kills the whole hunk of metal.


    I hear ya brother, I had a ’78 VW Rabbit. I removed the rev limiting rotor and floated the valves all the time trying to eke out all the power I could from it, never worried about impacting the pistons.

    fracked again

    Sheesh. Who piston your intakes?


    Looks like pistons to me. Notice the inset for a piston ring or something at the end, and notice how there is 8 large and 8 small.


    casemeth, by your comment you’ve made it clear that you’ve never worked around engines. You’ve never rebuilt one, nor have you helped rebuilding one. Don’t try to puff yourself up and talk about all your mechanic experience, because you’ve already shown it to be a lie. Just accept that you’re wrong, and talking out of your ass (as usual).


    those are valves what prob happened was the timing belt snapped and the valves got pwned by the pistons seen it happen many a times its how i pay my mortgage =)


    So this technician is working on replacing a blown head gasket and reseating the valves when he notices the owner peeking in the bay. He waves the guy over and shows the owner what is going on. The tech notices that the customer is wearing a hospital ID badge. “Are you a doctor?” “yes. A heart surgeon.” “Oh. So you repair valves, fix leaks, adjust timing, like me?” “Basically, yes.” “So, why do you as a doctor get paid more than I do as a mechanic if we both do the same kind of job?” “Well, try doing your job… Read more »


    those are valves. i’ve seen worse.


    that green blob kinda freaks me out.


    O M F G ok if u think them are pistons…. you help keep Jasper and others like them in business.

    casemods UID# 667

    Straightness tolerances are measured in microns over the length of the valve, yet these specimens are severely twisted There are many reasons why a valve might see loads that are far different in terms of magnitude and direction from those we can expect in normal service. Normal operating loads come from the valve being opened (stem compression) and closing – tension in the stem and seating loads, which may be compressive, tensile or bending depending on the location in the component. There are also some loads due to friction in the valve stem. However, none of these require a large… Read more »

    casemods UID# 667

    If the valve head then breaks off, the problems are compounded, and there is then a greater chance that the other valves will fail and that one of the pieces will subsequently puncture and pass through the piston. Where materials have little plastic deformation beyond yield before they fail, we commonly term these to be brittle, and overloading will cause them to fail by rupture. If the valves are ductile and remain in one piece – albeit twisted – the damage to the engine can be limited, and perhaps restricted to replacing the cylinder head in question and a cylinder… Read more »