my friend bought a set of je pistons from someone, the car that the piston came off from was pushing out about 500+ hp. after getting his block done from the performance shop they realized something very wrong with the piston. the rings would not go on, they would just break, upon further inspection of the piston they realized that the piston itself has been compressed. my question to you guys is, 1. has this ever happened to anyone on here? 2. what could have caused this to happen? could it be a possible case detonation? thanks
compressed piston!!
- Thread starter hks_trinidad
- Start date
i woould say he pre ignitied big time...but that just usually leaves holes....i have never heard of a compressed piston....maybe it was simply dropped or something
Dropping a piston won't do that, you are talking about forged metal here. You aren't going to compress a piston that way.
Hydrolocking a cylinder could do it however.
Hydrolocking a cylinder could do it however.
sometimes when the pistons it´s been overheated the little space where you put the ring, kind of melt thousandth of an inch and that´s enogth for the ring not to fit. I guess that´s what you ment
Adjuster
Supramania Contributor
I agree hydrolock would have enough force to crush the ring gap, but generally, there are many other weaker points that would fail first. (Like the rods for example, or the center of the piston crown, where it is thin, would deform down before the ring gap would be affected.
However, if the piston was very hot, say from the above mentioned detonation, it should show signs of pitting and material loss. (Unless it was coated, then it might not.) The hot metal would be weaker, and could cause failure of the ring lands, but generally it again blows out the center of the crown area where there is less material to support the semi molten crown surface..
However, when a piston is heated up like this, anything's possible. Squish areas could cause the detonation to start, and that could cause localized heating of the piston crown at that area v/s in the middle of the crown... Thus the reason a smooth crown surface is a good idea. It helps to prevent sharp edges and points from becomming hot spots that can cause even more detonation, and even pre-ignition. (That will end a motor's day in a hurry.)
One last question? Did your friend order the correct thickness of ring? The problem might not be the piston, but the ring thickness....
Measure twice, blame once is a good saying here I suppose.
However, if the piston was very hot, say from the above mentioned detonation, it should show signs of pitting and material loss. (Unless it was coated, then it might not.) The hot metal would be weaker, and could cause failure of the ring lands, but generally it again blows out the center of the crown area where there is less material to support the semi molten crown surface..
However, when a piston is heated up like this, anything's possible. Squish areas could cause the detonation to start, and that could cause localized heating of the piston crown at that area v/s in the middle of the crown... Thus the reason a smooth crown surface is a good idea. It helps to prevent sharp edges and points from becomming hot spots that can cause even more detonation, and even pre-ignition. (That will end a motor's day in a hurry.)
One last question? Did your friend order the correct thickness of ring? The problem might not be the piston, but the ring thickness....
Measure twice, blame once is a good saying here I suppose.
thanks alot guys for all your input on this subject. i do not have pictures up now but ill take some as soon as he gets the pistons back. it is just one piston that had the problem the rest were fine, the rings went on the other pistons fine but couldnt fit on the compressed one. he bought a set of injectors too. but i guess we will have to wait to see the flow chart to see if that was a mistake too.