Gunslinger09

If the motor ran good when he wrecked it you will be fine to reuse that piston.

NightmareTA

iTrader: (20)

If you can feel any kind of ridge protruding from the side of the piston where that mark is, just file it down with a very fine grit file. I'd say you shouldn't have any problems running it. The pistons don't fit super tight in the bore, the rings do...so the piston doesn't have to be a "precision" fit to the bore.

Coonass350

iTrader: (19)

Thats what I was hoping. Thanks

I had thought about a file but wasnt sure. Now I will go ahead and use one. Thanks for all the help guys. Glad to finally get a definate answer. Ill go ahead and use it. Appreciate all the replies/help.

R6cowboy

iTrader: (3)

This. File any rough groove down with a very fine file til it is smooth to the touch and the piston should be ok.

chewybacca11

iTrader: (1)

Can someone elaborate why a missed gear would cause the pistons to contact the valves? Thanks. And also can you define exactly what you mean by "missed gear"

Thanks again!

R6cowboy

iTrader: (3)

Missed gear= downshifting a manual trans into the wrong gear, this will force the engine to "over-rev" which will float the valves and cause them to come in contact with the pistons. For example, I once accidentally downshifted into 2nd gear at ~85 mph when I meant to shift into 4th. The engine revved approximately 8,000 rpm and destroyed the valvetrain (bent valves and pushrods) and put knicks and notches in the pistons from all the valves hitting them.

Coonass350

iTrader: (19)

^^yup, what he said.

LilJayV10

iTrader: (39)

The engine is spinning so fast the valve springs can't control the valve. The valve starts to bounce and opens when it shouldn't hitting the piston.

DaddySS

Your pistonns should be fine with those marks on them. Don't worry about and get on with the build! ;-)

Coonass350

iTrader: (19)

Alright! thanks man!

chewybacca11

iTrader: (1)

Ahhhh... I've done that before but I feel like I pushed in the clutch before I revved that high. Are bent valves something that you will for sure notice? Or can they be only slightly damaged to the point where you will only see it if you take apart the engine? (And see the marks on your pistons haha!)

Coonass350

iTrader: (19)

I think it depends on how bad it over revved. Some guys when they miss a gear they completely destroy their valvetrain(broken pushrods, broken valves, springs, etc) Some people only bend them. Just depends.

chewybacca11

iTrader: (1)

?! Is that also why when people get a cam they can rev higher? Because their valvetrain is upgraded and there wont be valve float? ( And prob because the curve is higher)

R6cowboy

iTrader: (3)

One of the reasons why I flycut the stock pistons in my C5 was to minimize the chance of piston to valve contact during an event of valvefloat. IMO its a smart precaution, especially when installing smaller combustion chamber heads, larger cam, increased engine rpm's, etc.

Coonass350

iTrader: (19)

I have another question now guys lol I was just told by my friend that I couldnt just re-install my stock pistons into the block with new piston rings. He says it would probably need to be honed since the stock pistons/rings kinda wore a certain pattern/fit in the bore.

Is this correct? do I need to have the block honed before re-installing the stock pistons/new rings? If so that means I would then need a 347 size piston..

Coonass350

iTrader: (19)

actually I may go ahead and make a new thread. May get more views/answers that way.