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Thread: Are these pistons okay?

  1. #1
    11 sec FWD! (old name: 94atxvr2) Feedback Score 0 11secondFWD's Avatar
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    Are these pistons okay?

    I know this is from my dsm but I just wanted to know about the pistons in general.

    Here is a pic of my pistons. I traded for a stage 1 longblock. More less stock rebuild. It had treated me great this season. I pulled the head to put in L19 studs and an OEM HG. I then looked at the pistons and found them to be hit in a couple places.

    My valves did not hit 100% sure. Engine ran great til day I took it apart, and valves are fine so I am not here to debate that. They were hit previously in another car and put into this engine this way.

    I am here to ask if it is okay to reuse these pistons. Pics are below. The guy I bought the engine from, put these in when he did the rebuild. I wish he would have put new but thats what I get for trusting people. SO anyway he put in pistons that were hit by valves and were still okay in his book.

    I want to know if these are ok. I plan on 420WHP on E100 this year and dont want any unforseen things to happen. The engine ran strong as hell with the pistons like this but is it okay to run it like this? WHat are the worst possible cases? Should I get forged pistons? I really dont want too since it is new and perfect compression.


    Let me know any advice and if they are ok to run or not, Or what I should do. I dont want any spots were I could get detonation on the pistons.


    Pics
    #4


    These pistons have been ran all season. Drag raced about 40 times down the track running low 12's/ So they are not "damaged" and have perfect compression and run good. Since they have been running like this for a whole year I know they will be fine at a low power level. But I am definitely worried about detonation and hot spots. I think I have been lucky so far because I only run ethanol. However, I WILL be over 400whp and was going to push it to see if I can get some good runs.

    I would love to try and see what it does because it has performed great and has 162 psi compression across the board. But I am scared of this xmas gift I found when I took the head off.

    I dont know if this is accurate or not but the 4 piston looks the worst, the 2nd is almost the same and the 3rd and 1st are pretty much un scarred. And when I removed head bolts (stock) I notice the ones all the way toward cyl 4 (the one in the pic) loosened extremely easy and they got harder to toward cyl 1. And the ones on the far right (right of cyl 1) were hard as hell to break loose. And I did loosen according to the manual and in proper order (opposite of tightening order). I didnt go left to right or anything crazy. I just meant that the bolts going passenger to driver were progressively harder to break loose when i did them. And I thought maybe cyl 4 was detonating/knocking and stretched the bolts toward 4 a little bit. Although I was not pushing coolant or overheating.

    #1 piston (can see #2 bottom left was hit a little)

    #3

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  2. #2
    Why? Because Race Car. verified Feedback Score 0 akotten's Avatar
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    I'm no expert, but it may throw off their weight balance?
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    11 sec FWD! (old name: 94atxvr2) Feedback Score 0 11secondFWD's Avatar
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    Well they should weight the same, they are just dented. At least I think. I am guessing my only problem could be a sharp raised edge that could cause some detonation/ a hot spot to pre ignite the fuel.

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    Twin Turbo verified Feedback Score 5 (100%) GTOJOE's Avatar
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    I'm no expert but some of those marks look kinda fresh. Are you sure your valves are ok? was the timing right or the belt stretched?

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    Why? Because Race Car. verified Feedback Score 0 akotten's Avatar
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    Quote Originally Posted by 11secondFWD View Post
    Well they should weight the same, they are just dented. At least I think. I am guessing my only problem could be a sharp raised edge that could cause some detonation/ a hot spot to pre ignite the fuel.
    I think I can agree with you here. It might prevent an equal, steady burn.

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    1st ever COTM and COTY verified Feedback Score 9 (100%) green-lantern's Avatar
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    I'd be more worried about what the sides look like. I really don't think the dents would be a problem unless they have weakened the piston and now prone to breaking.

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    11 sec FWD! (old name: 94atxvr2) Feedback Score 0 11secondFWD's Avatar
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    The sides are fine. Everything is perfect compression and straight on sides. It definitely isnt from me. The pistons were just put in since the engine is a brand new rebuild. Everything was perfectly clean before put in. So for only 6 months they are quite dirty. I only run ethanol too and it keeps it pretty clean. The guy reused these pistons straight from another persons engine core, cleaned them and I have been on them all racing season.

    100% sure not from my engine thats not in question and I am not worried about that. I am worried about any problems pushing the engine this next season with these ridges/marks on the pistons.

  8. #8
    1st ever COTM and COTY verified Feedback Score 9 (100%) green-lantern's Avatar
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    Personally I wouldn't worry about it. There could be something I'm not thinking of but since you ran this a full season with no problems I'd say you a fine.

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    11 sec FWD! (old name: 94atxvr2) Feedback Score 0 11secondFWD's Avatar
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    I hope so! I know they would last if I kept it at 32 lbs/min like I had this season. But I am moving to a 47lbs/min turbo and I want to make sure these marks wont cause catastrophic problems.

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    Forum User Feedback Score 2 (100%) Maximal's Avatar
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    Could create hot spots but if you've been running fine all year I doubt they'll be a problem. Reason you don't want to just pick up another used one and throw it in?

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