Pistons are fucked

"ItalianJobR53 - now with added 'MERICA and unreliability" (italianjobr53) 10/17/2020 at 19:45 • Filed to: C5Z

5

25

This is gonna be expensive...some of the valves are bent as well

sony1492 > ItalianJobR53 - now with added 'MERICA and unreliability 10/17/2020 at 19:51

0

Damn.

Do ing anything special sense its time for a rebuild?

Cash Rewards > ItalianJobR53 - now with added 'MERICA and unreliability 10/17/2020 at 19:55

1

Time to LS swap it...oh, wait. Shit.

Seriously though, this sucks. Sorry

pip bip - choose Corrour > ItalianJobR53 - now with added 'MERICA and unreliability 10/17/2020 at 19:58

2

supercharged crate motor swap

atfsgeoff > ItalianJobR53 - now with added 'MERICA and unreliability 10/17/2020 at 20:10

0

LS7 time?

Highlander-Datsuns are Forever > ItalianJobR53 - now with added 'MERICA and unreliability 10/17/2020 at 20:15

2

RacinBob > ItalianJobR53 - now with added 'MERICA and unreliability 10/17/2020 at 20:18

3

I’ve bent valves twice and had similar or worse damage to my race pistons. I bet you the piston is fine. Sand out the sharp edges and drive it.

Now note, take a careful look at the valve guides as usually they crack or break if you bend a valve. And if broken make sure the piece is not lueking in the intake manifold as if it is, it will end up in another cylinder. 

ItalianJobR53 - now with added 'MERICA and unreliability > RacinBob 10/17/2020 at 20:33

0

Ooh good to know! Would the piston with the “imprint” on it still be fine after sanding it down? I can feel the depression with my gloves on...

It’ll get aftermarket heads so I dont have to worry about the valve guides and such...

Demon-Xanth knows how to operate a street. > ItalianJobR53 - now with added 'MERICA and unreliability 10/17/2020 at 20:33

8

“High five!" --Your cylinder head.

ItalianJobR53 - now with added 'MERICA and unreliability > sony1492 10/17/2020 at 20:37

4

Im assuming the bore walls are fine, in which case I may get new pistons or sand the current ones, heads with higher compression, chop chop cam, long tubes, LS7 clutch, new slave cyl, torque tube rebuild, katech timing chain

I want 500whp NA on 91 :)

ItalianJobR53 - now with added 'MERICA and unreliability > atfsgeoff 10/17/2020 at 20:37

0

Naah...i’ll probably rebuild this motor

ItalianJobR53 - now with added 'MERICA and unreliability > Demon-Xanth knows how to operate a street. 10/17/2020 at 20:37

0

LOL!

Jordan and the Slowrunner, Boomer Intensifies > ItalianJobR53 - now with added 'MERICA and unreliability 10/17/2020 at 20:40

3

You’re gonna need more cubes. 

ItalianJobR53 - now with added 'MERICA and unreliability > Jordan and the Slowrunner, Boomer Intensifies 10/17/2020 at 20:41

1

Ya I know...500whp is optimistic, I would be happy with 450-460

RacinBob > ItalianJobR53 - now with added 'MERICA and unreliability 10/17/2020 at 20:51

3

The purpose of sanding the edges is to eliminate sha rp edges that could get hot and cause preignition. Here is a picture of my Integra type R race engine that bent valves twice. You can see where the valve tagged the piston dome as well as the “peck” marks to the left from the fragment of g uide. The mark from the valve wasn’t worth doing anything about, the peck marks on the head and piston were sanded out. That was 7 years ago, probably 20 races in all.

RacinBob > ItalianJobR53 - now with added 'MERICA and unreliability 10/17/2020 at 20:54

0

are these cast or forged pistons?

The Snowman > ItalianJobR53 - now with added 'MERICA and unreliability 10/17/2020 at 21:06

0

Does nox still count as an? If so you could get 600whp real easy

ItalianJobR53 - now with added 'MERICA and unreliability > RacinBob 10/17/2020 at 21:44

0

These are forged pistons

ItalianJobR53 - now with added 'MERICA and unreliability > RacinBob 10/17/2020 at 21:44

0

Aah, I see. Thanks for the info, thjs is definitely helpful!

ItalianJobR53 - now with added 'MERICA and unreliability > The Snowman 10/17/2020 at 21:46

0

Nope, it feels like cheating to me. Also, SCCA won't let me run nox at autocross or track days.

Longtime Lurker > ItalianJobR53 - now with added 'MERICA and unreliability 10/17/2020 at 22:28

0

Oof

ItalianJobR53 - now with added 'MERICA and unreliability > Longtime Lurker 10/17/2020 at 22:58

3

RacinBob > ItalianJobR53 - now with added 'MERICA and unreliability 10/18/2020 at 01:01

1

If they are forged, they are stout. My opinion is they are fine, but it is your call to make. 

AMGtech - now with more recalls! > ItalianJobR53 - now with added 'MERICA and unreliability 10/18/2020 at 01:02

1

Yeah, seconded, pistons are probably fine. Double check the cylinder walls for scoring if any metal particles/pieces came loose, and then also check the intake manifold and exhaust for them, like the other guy said. I’ve seen “stuff” break free from one cylinder, then migrate to the others through the exhaust and intake manifold, then cause untold damage to literally everything. Stuff can’t get past the catalyst, and exhaust pulses and fluctuates too. Usually on grenaded engines we put new intake manifold, exhaust manifold, and maybe catalyst to be safe. I've seen it happen where those weren't replaced and the new engine was destroyed. Don't make the mistake of shaking the manifolds, not hearing anything, and calling it good. Those parts can stick to carbon deposits or partially melt plastic and stick to that. Look everything over extremely well.

ItalianJobR53 - now with added 'MERICA and unreliability > RacinBob 10/19/2020 at 09:46

0

Thanks for the inputs! Haven't decided what I wanna do yet...

ItalianJobR53 - now with added 'MERICA and unreliability > AMGtech - now with more recalls! 10/19/2020 at 09:47

1

Interesting! I had not considered looking over the intake manifold, will do. Thanks a lot!